Dietary habits influence on trace element release
from fixed orthodontic appliances in south Indian
population - In-vitro study
Dissertation submitted to
THE TAMILNADU DR. M.G.R. MEDICAL
UNIVERSITY
For Partial fulfilment of the requirements for the degree of
MASTER OF DENTAL SURGERY
BRANCH - V
ORTHODONTICS AND DENTOFACIAL ORTHOPEDICS
THE TAMILNADU DR. M.G.R. MEDICAL UNIVERSITY
CHENNAI – 600 032
2017 – 2020
ACKNOWLEDGEMENT
I seek the blessings of the ALMIGHTY GOD without whose benevolence this
study would not have been possible. I thank the almighty god in the form of my father
T JAYAPALRAJ, my mother J KALAISELVI, my sister V RAJESWARI for their
blessings, unconditional love, affection, care and prayers. I thank my sweet sister’s daughters V. ANANYA, V. ABHINAYA, and my little prince V. AADHAV
KRISHNA for their unconditional love and affection. Without them, nothing would
have been made possible.
With my heartfelt respect, immeasurable gratitude and honour, I thank my
benevolent guide, Dr. B. BALASHANMUGAM, M.D.S., Professor, Department of
Orthodontics and Dentofacial orthopedics, Tamil Nadu Government Dental College
and Hospital, Chennai – 3, for his astute guidance, support and encouragement
throughout my post graduate course and to bring this dissertation to a successful
completion.
I owe my thanks and great honour to Dr. SRIDHAR PREMKUMAR, M.D.S.,
Professor & HOD, Department of Orthodontics and Dentofacial Orthopaedics,
Tamilnadu Govt. Dental College and Hospital, Chennai - 3, for helping me with his
valuable and timely suggestions and encouragement.
My sincere and heartfelt thanks to Dr. G. VIMALA, M.D.S., our Principal,
Tamil Nadu Government Dental College and Hospital, Chennai – 3, for her continuous
and enormous support in allowing me to conduct this study and for his constant
encouragement and advice during my tough phases in curriculum.
I sincerely thank Professor Dr. G. USHA RAO, Associate Professors Dr. M.
VIJJAYKANTH, Dr. M.D. SOFITHA and Senior Assistant Professors Dr. K.
USHA, Dr. M.S. JAYANTHI, Dr. D. NAGARAJAN, Dr. MOHAMMED IQBAL,
and Dr. R. SELVARANI for their continuous support and encouragement.
I thank my junior Dr. LAKSHMI PRASANNA PALINDLA for her support in
helping and completing my thesis.
I thank my roommates Dr. G.D. RAMKUMAR, Dr. VIJAY SINGH CHAUHAN,
Dr. SENTHIL GANESH, Dr. DASARATHAN for their guidance and who were my
backbone during my entire PG life.
I thank DR. CYRIL BENEDICT for helping me in statistical analysis.
I also thank my post graduate colleagues for their help and constant support.
TRIPARTITE AGREEMENT
This agreement herein after the “Agreement” is entered into on this 27-01-2020
between the Tamil Nadu Government Dental College and Hospital represented by its
Principal having address at Tamil Nadu Government Dental College and Hospital,
Chennai-03, (hereafter referred to as, “the college”)
And
Dr. B. BALASHANMUGAM aged 48 years working as professor at the college,
having residence address at 8-B, Crescent road, Shenoy nagar, Chennai-600030, Tamil
Nadu (Herein after referred to as the ‘Principal investigator’)
And
Dr. J. HARIHARASUDAN aged 27 years currently studying as postgraduate student
in Department of Orthodontics in Tamil Nadu Government Dental College and Hospital
(Herein after referred to as the ‘PG/Research student and co- investigator’).
Whereas the ‘PG/Research student as part of his curriculum undertakes to research
“ Dietary habits influence on trace element release from fixed orthodontic appliances
in south Indian population - In-vitro study ” for which purpose the PG/Principal
investigator shall act as principal investigator and the college shall provide the
requisite infrastructure based on availability and also provide facility to the
PG/Research student as to the extent possible as a Co-investigator.
Whereas the parties, by this agreement have mutually agreed to the various
issues including in particular the copyright and confidentiality issues that arise in this
regard.
Now this agreement witnesseth as follows:
1. The parties agree that all the Research material and ownership therein shall
become the vested right of the college, including in particular all the copyright
in the literature including the study, research and all other related papers.
2. To the extent that the college has legal right to do go, shall grant to license or
assign the copyright do vested with it for medical and/or commercial usage of
interested persons/entities subject to a reasonable terms/conditions including
royalty as deemed by the college.
3. The royalty so received by the college shall be shared equally by all the parties.
4. The PG/Research student and PG/Principal Investigator shall under no
circumstances deal with the copyright, Confidential information and know –
how generated during the course of research/study in any manner whatsoever,
while shall sole vest with the manner whatsoever and for any purpose without
the express written consent of the college.
5. All expenses pertaining to the research shall be decided upon by the principal
investigator/Co-investigator or borne sole by the PG/research student (co-
investigator).
6. The college shall provide all infrastructure and access facilities within and in
other institutes to the extent possible. This includes patient interactions,
introductory letters, recommendation letters and such other acts required in this
regard.
INSTITUTIONAL REVIEW BOARD APPROVAL
PLAGIARISM REPORT
CERTIFICATE II
This is to certify that this dissertation work titled “Dietary habits influence on
trace element release from fixed orthodontic appliances in south Indian
population - In-vitro study” of the candidate Dr. HARIHARASUDAN J with
Registration Number 241719005 for the award of MASTER OF DENTAL
SURGERY in the Branch V – ORTHODONTICS AND DENTOFACIAL
ORTHOPAEDICS. I personally verified the urkund.com website for the purpose of
plagiarism check. I found that the uploaded thesis file contains from Introduction to
Conclusion pages and result shows Nine percentage (9%) of plagiarism in the
dissertation.
Guide & Supervisor sign with Seal
ABSTRACT
Background: Dietary habits may adversely affect orthodontic treatment by reduction
in the shear bond strength of brackets, increased risk of dental caries and enamel
microhardness, and change of color stability of orthodontic adhesives and elastic
ligatures. In the current literature, the number of the studies related with the impact of
acidic foods and soft drinks on the corrosion of orthodontic appliances and release of
metal ions is very limited. Metallic orthodontic devices release metals in the presence
of an electrolyte. Metal corrosion may influence both the mechanical behavior and the
appearance of the appliances. Silver-soldered joints are particularly prone to
deterioration, resulting in metal release, surface change, and loss of strength. Both
nickel and chromium can cause dermatitis, asthma, and do have mutagenic and
cytotoxic effect.
Aim: The aim of the study was to investigate the effect of dietary habits on the release
of Ni ions from orthodontic appliances in south Indian population
Objectives: The objective was to elaborate dietary recommendations for orthodontic
patients, in order to diminish the negative effects related with intensified metal ions
release by dietary factors.
Materials and methods: 100 ml of saliva substitute placed in 30 different containers
labelled with each respective dietary sample name. Fixed orthodontic appliances
comprised of brackets, bands, buccal tubes, lingual attachments, archwires were
placed in each container. Each day the fixed orthodontic components were immersed
in the respective dietary samples four times daily for two minutes and then placed
back at the respective glass containers containing artificial saliva.
This procedure is repeated daily for 90 days. The sample of artificial saliva (20ml)
from the glass container is taken into glass tubes with the help of pipette and the glass
tubes are sealed with wooden cork. The samples are tested using Inductive coupled
plasma mass spectrometer (ICP-MS) at three different time periods (1 week , 1 month
and 3 months)
Results: The results revealed that at 1st week time interval, Coca Cola, Thumbs up,
Pepsi showed the highest amount of nickel leach (0.56 mg/l, 0.55mg/l, 0.52mg/l
respectively) into the saliva substitute. After 1 month, the results revealed that Pepsi,
Lemon juice, Red bull, Vinegar showed the highest amount of nickel leached
(1.09mg/l, 0.9mg/l, 0.88mg/l, 0.88mg/l respectively) into the saliva substitute.
3 months interval results show that Pepsi, Coca cola, Red bull, Vinegar showed the
highest amount of nickel leached (2.75mg/l, 2.72mg/l, 2.68mg/l, 2.68mg/l
respectively) into the saliva substitute.
Conclusion: The results suggest that consumption of food products of low pH (such
as Pepsi, Coca cola, Red bull, Thumbs up, lemon juices and vinegar) can intensify
aggressiveness of conditions in the oral cavity and has an effect on increasing the
release of Ni from orthodontic appliances. Therefore, it would be useful to
recommend to orthodontic patients to limit consumption of foods and drinks which
are characterized by low values of pH to reduce the quantity of ions solubilized from
metal alloys.
Keywords: NiTi, SS archwires, Dietary components, Nickel leach, Inductive coupled
plasma mass spectrometer (ICP-MS)
CONTENTS
SL. NO. TITLE PAGE NO.
1. INTRODUCTION 1
2. AIMS AND OBJECTIVES 5
3. REVIEW OF LITERATURE 6
4. MATERIALS AND METHOD 38
5. RESULTS 46
6. DISCUSSION 52
7. SUMMARY AND CONCLUSION 58
8. BIBLIOGRAPHY 63
LIST OF TABLES
SL.
NO. TOPIC PAGE NO.
1 Baseline nickel content present in saliva substitute 46
2 Amount of nickel leach from fixed orthodontic components
into the Saliva substitute from different dietary components
in three different time interval
47
3
Amount of nickel leach from fixed orthodontic components
into the Saliva substitute from different dietary components
in three different time interval after deducting the baseline
nickel content from saliva substitute
48
LIST OF FIGURES
FIGURE NO.
TITLE
1 Orthodontic archwires : NiTi archwires and SS archwires (BROOKLYN
ORTHODONTICSTM)
2 Heat activated nickel titanium archwires (AMERICAN BRACESTM)
3 Brackets (“0.022”-inch slot stainless steel MBT prescription (OrthoxTM)
4 Stainless steel bands (SLR-WELCARE ORTHODONTICSTM)
5 Lingual attachments
6 Buccal tubes
7 Glass tubes with wooden cork
8 Tweezer
9 Glass container
10 Saliva substitute-SALEVATM
LIST OF CHARTS
SL.NO. TOPIC PAGE NO.
1 Nickel leach at 1week interval 50
2 Nickel leach at 1month interval 50
3 Nickel leach at 3months interval 51
LIST OF ABBREVIATIONS
Ni-Ti Nickel Titanium
SS Stainless Steel
Ni Nickel
NA Nickel allergy
ACD Allergic contact dermatitis
Cu Copper
Ag Silver
Pd Palladium
Ni-ACS Nickel-induced allergic contact
stomatitis
ICP-MS Inductive coupled plasma mass
spectrometer
Introduction
1 | P a g e
INTRODUCTION
Our diet has an impact on our well-being and on our health1. The effects of
acidic beverages on dental erosion is the result of the enamel and dentin
susceptibility to exogenous acids, originating from acidic food (fruit, yoghurt) or
beverages (fruit juice, energy drinks, cola drinks)2.
Acidic foods and drinks not only have influence on tooth enamel but also reduce
life time of dental restorations. It has been reported that soft drinks affect the
decrease of mechanical properties of restorative materials, especially surface
hardness, surface integrity, and solubility3.
Dietary habits may adversely affect orthodontic treatment by reduction in the
shear bond strength of brackets, increased risk of dental caries and enamel
microhardness, and change of color stability of orthodontic adhesives and elastic
ligatures. In the current literature, the number of the studies related with the
impact of acidic foods and soft drinks on the corrosion of orthodontic appliances
and release of metal ions is very limited4.
Soft drinks contain several acids such as phosphoric, citric, tartaric, lactic, and
maleic acid . Their pH may be close to 2.0 or 3.0, for example, Coca-Cola® 2.3,
Pepsi® 2.3, Sprite® 2.7, Red Bull® 3.1, Powerade® 3.1, orange juice 3.7, white
wine 3.0. 2
Young adults in many parts of the world consume an increasing amount of soft
drinks. The increased consumption has raised several concerns about the health
consequences such as obesity, diabetes, dental caries, dental erosion and mental
health problems5.
Introduction
2 | P a g e
Wide range of appliances routinely applied during orthodontic treatment is made
of alloys which contain cobalt, chromium, iron, nickel, titanium, among which of
the major concern are nickel and chromium. The SS brackets, wires, bands,
auxiliaries as face bow, also elements of removable appliances, contain
approximately 18% chromium, 8% nickel. NiTi wires contain around 47–50% of
NiTi. Nickel is known as strong immunologic sensitizer.4
Metallic orthodontic devices release metals in the presence of an electrolyte.
Metal corrosion may influence both the mechanical behavior and the appearance
of the appliances. Silver-soldered joints are particularly prone to deterioration,
resulting in metal release, surface change, and loss of strength. Furthermore,
brackets with metallic backing may release corrosion products that could discolor
the underlying tooth substance. 6,7
Blanco-Dalmau et al. found 31.9% of the women and 20.7% of the men in a
population of 403 showed a positive reaction to a patch test with nickel sulfate.8
Both nickel and chromium can cause dermatitis, asthma, and do have mutagenic
and cytotoxic effect.9,10,11
Having that on mind, it is important to define amount of metal (nickel and
chromium) released during orthodontic treatment and its influence on an
organism. There are two ways to achieve it: by in vitro and in vivo studies.
In the current literature, the number of the studies related with the impact of acidic
foods and soft drinks on the corrosion of orthodontic appliances and release of
metal ions is very limited.
Nickel and chromium are normally present in the foods consumed by man. Nickel
is the most common cause of metal-induced allergic contact dermatitis and
produces more allergic reactions than all other metals combined, followed by
Introduction
3 | P a g e
chromium. The average dietary intake of nickel is 200–300 μg/day. Nickel aids in
iron absorption, as well as adrenaline and glucose metabolism. It also helps in
improving bone strength and may play a role in the production of red blood cells.
The primary route of eliminating nickel is through the urine.12,13,14
Nickel is ubiquitous and is found in foods (highest in legumes, nuts, grains,
potatoes, chocolate, and fish), tap water, cosmetics, and cooking utensils.15
Barret et al proposed that the acid pH (about pH 6.5), enzymatic activity of the
saliva, organic acids and bacterial flora might provide an environment within the
oral cavity that favours corrosion. The release of metal ions from orthodontic
appliances could, therefore, hypothetically increase the quantity of these ions in
the body to above that ingested with diet and exposure to atmospheric pollution
and/or costume jewellery. 16,17
Nickel allergy (NA) is common with a prevalence of 10–15% and occurs
worldwide.18
The most common manifestation of NA is allergic contact dermatitis (ACD), a
type IV T-cell–mediated delayed-type hypersensitivity reaction. ACD occurs in
areas where skin contacts nickel-containing objects such as costume jewelry,
snaps on clothing, eyeglasses, and watches. Occupational and industrial arenas
also can be a source of nickel exposure. Allergic contact urticaria to nickel has
been reported.19
Characteristic lesions of contact stomatitis vary from barely visible, mild
erythema to a fiery red color with or without edema. Symptoms may include loss
of taste, numbness, burning sensation, and soreness of the involved area, often
accompanied by angular cheilitis. Itching is not a frequent symptom. Although it
is more difficult to provoke contact stomatitis than contact dermatitis, severe
Introduction
4 | P a g e
gingivitis associated with orthodontic therapy may be a manifestation not only of
poor oral hygiene but also of a contact hypersensitivity reaction to nickel and/or
chromium ions released during the corrosion of stainless steel.20
Aim and Objectives
5 | P a g e
AIM AND OBJECTIVES
NEED FOR THE STUDY
The goal was to elaborate dietary recommendations for orthodontic patients, in
order to diminish the negative effects related with intensified metal ions release by
dietary factors.
AIM
The aim of the study was to investigate the effect of dietary habits on the release
of Ni ions from orthodontic appliances in south Indian population
OBJECTIVES
The objective was to elaborate dietary recommendations for orthodontic patients,
in order to diminish the negative effects related with intensified metal ions release
by dietary factors.
Review of Literature
6 | P a g e
REVIEW OF LITERATURE
Dietary habits affect well-being and health.1 The increased consumption of soft drinks
has raised several concerns about the health consequences such as obesity, diabetes,
hypocalcemia, dental caries, dental erosion, and mental health problems.21,22 The use
of various combinations of metal alloys for prolonged durations in orthodontic
patients warrants special consideration regarding their biocompatibility. The oral
cavity is a complete corrosion cell, with many factors that enhance the biodegradation
of orthodontic appliances.23 Saliva acts as an electrolyte for electron and ion
conduction, and the fluctuation of pH and temperature, the enzymatic and microbial
activity, and the various chemicals introduced into the oral cavity through food and
drink are all corrosion conductors.24
The inherent heterogeneity of each metal alloy and its use with other alloys, the
microsurface discontinuity, the forces acting on the appliances, and the friction
between wires and brackets also add to the corrosion process. It has been reported that
metal ions are taken up by the adjacent oral tissues.25,26,27 An increasing demand for
biocompatibility testing of medical devices has led to the application of different
evaluation methods. In contemporary dentistry, applied materials are being introduced
to the market and frequently one material promptly replaces another, which entails
questions about long-term biocompatibility.28 Orthodontic alloys are made from
various metals, among which chromium and nickel are of major
concern.29,30,31,32,33,34,35,36 Both of these genotoxic, mutagenic, and cytotoxic metals
might induce contact allergy, asthma, hypersensitivity, birth defects, and reproductive
damage.37,38,39,40,41,42,43 Corrosion of orthodontic alloys might lead to release of
considerable amounts of nickel and chromium ions into saliva.44
Review of Literature
7 | P a g e
The systemic absorption of such metals is an extra health risk.45,46 Despite its
importance, systemic nickel changes during orthodontic treatment have been assessed
merely in a few controversial studies.17,47,48,49,50,51,52 showing systemic increases 47,51
or lack of any significant changes17,47,50,52
Usually, orthodontic treatment with fixed appliances lasts for approximately 2–3
years. Most of the patients are youngsters or adolescents. Some parts of a removable
appliance and all parts of a fixed appliance are manufactured from alloys which
contain nickel and chromium.53 Those metals are well known as sensitizing and
mutagenic agents. This shows that it is important to assess biocompatibility of
orthodontic appliances.54 As pointed out by Wataha, the corrosion of an alloy is of
fundamental importance to its biocompatibility because the release of elements from
the alloy is nearly always necessary for adverse biologic effects such as toxicity,
allergy, mutagenicity, and carcinogenicity. Alloy corrosion provides free ions that
affect the tissues around it. There is little evidence that elements released from casting
alloys contribute significantly to systemic toxicity. The cause of this might be
explained by the low release of ions over time.55 Metal tolerance and the amounts
causing toxicity are not well understood. Metals are not biodegradable, and their
sustained release might produce irreversible toxic effects from their accumulation in
the tissues. Also, the increased exposure could limit the recovery time needed for
cellular repair. Metal toxicity is governed by multiple factors, making it difficult to
truly assess the levels that produce cellular damage.56,57
Review of Literature
8 | P a g e
STUDIES RELATED TO DIET, NUTRITION CONSIDERATIONS IN
ORTHODONTICS:
Jeevan M. Khatri, Vijaymala D. Kolhe et al (2018)58 Studied the relationship
between diet and orthodontic treatment. A good diet plays an important role in
maintaining good health. With so much focus on healthier foods and more nutritional
food choices, dietary counseling and nutritional education relevant to oral health have
become an important component of dental education. In fact, 1987 guidelines for
accreditation of dental schools by the American Dental Association require that “the
graduate must be competent to provide dietary counseling and nutritional education
relevant to oral health.” Study of diet and nutrition is also a mandatory part of
curriculum in Indian dental schools. Orthodontic treatment creates physical,
physiologic, and emotional stresses that increase the nutrient mobilization and
utilization, thus raising the nutritional requirements of the person. This along with the
fact that the nutritional needs of adolescents (the age of a typical orthodontic patient)
are already stressed by growth and development as well as the emotional stress of
puberty, maintenance of a well‑balanced diet is of great importance. Fixed
orthodontic treatment (braces in common language) typically lasts for around 1½ to 3
years and, during this duration, certain dietary restrictions and modifications are
advised. Typically, the orthodontist often advises their patients to eat soft food during
treatment to avoid pressure sensitivity, but very few give clear‑cut instructions or
provide diet charts. In absence of these, patients generally switch over to convenient
easy‑to‑eat food, without any special attention to the nutrient values of the consumed
food. The literature suggests that orthodontic patients’ nutritional status can affect the
reaction of the tissues to orthodontic forces. Nutritional considerations are most
Review of Literature
9 | P a g e
critical during growth and development and environmental challenges. The literature
suggests that the nutritional status of the orthodontic patients can affect the biologic
response of the periodontal ligaments and the bone to orthodontic bands and brackets.
They concluded that to optimize patient’s physiologic response to orthodontic
treatment, it may be beneficial to provide dietary guidance to orthodontic patients in
choosing soft food diets. This includes obtaining nutrition history, evaluating the diet,
educating the patient about diet components important for oral health, motivating the
patient to improve diet, and follow‑up to support patient’s effort to change food
behaviors. Patients with braces who prefer or switchover to convenience foods such
as cakes, pastries, ice creams, and cookies, which are high in simple sugars and fats,
should be advised regarding the value of fruits, vegetables, grains, and cereals in the
irregular diet. Nutrition goals for the orthodontic patient should be to eat a variety of
foods including protein sources, dairy food, fruits, vegetables, and cereals and to limit
salt, fat, and sugar intake.
R Sharma, S Mittal, A Singla, M Virdi et al (2009)59 presented an
overview of the relationship between diet and orthodontic treatment and the
nutritional strategies which can be employed to obtain good oral and general health in
orthodontic patients.. Orthodontic treatment creates physical, physiologic and
emotional stresses that increase the nutrient mobilization and utilization thus raising
the nutritional requirements of the person. This along with the fact that the nutritional
needs of adolescents (the age of a typical orthodontic patient) is already stressed by
growth and development as well as the emotional stress of puberty, maintenance of a
well-balanced diet is of great importance. Fixed orthodontic treatment (braces in
common language) typically lasts for around 1½ to 3 yrs and during this duration
certain dietary restrictions and modifications are advised. Typically the orthodontist
Review of Literature
10 | P a g e
often advise their patients to eat soft food during treatment to avoid pressure
sensitivity but very few give clear cut instructions or provide diet charts. In absence of
these, patients generally switchover to convenient easy to eat food, without any
special attention to the nutrient values of the consumed food.
The literature suggest that orthodontic patients nutritional status can affect the
reaction of the tissues to orthodontic forces. Ascorbic acid deficiency for example is
thought to slow down orthodontic tooth movement by decreasing the body’s ability to
heal. Less than adequate levels of ascorbic acid hinder the breakdown and reformation
of collagen which is necessary for tooth movement. About 17-72% of orthodontic
patients have less than optimal levels of ascorbic acid. Retention may also be affected
by ascorbic acid levels as shown by a study in which guinea pigs with deficiency of
ascorbic acid experienced more rapid relapse of malocclusion after treatment than
non-deficient ones. The involvement of certain nutrients in orthodontics has been
looked at in the past, but the diet as a whole has not been evaluated .
They concluded that to optimize patient’s physiologic response to orthodontic
treatment, it may be beneficial to provide dietary guidance to orthodontic patients in
choosing soft food diets. This includes obtaining nutrition history, evaluating the diet,
educating the patient about diet components important for oral health, motivating the
patient to improve diet and follow up to support patient’s effort to change food
behaviors. Compliance with dietary advice is more likely if follow-up is provided.
Dietary progress should be discussed at further appointments. Nutrition care should be
an integral part of orthodontic care.
Stephen F. Litton et al(1974)60 studied the effects of an ascorbic acid deficiency
during tooth movement in guinea pigs to determine what morphologic changes could
Review of Literature
11 | P a g e
be observed during this vitamin deficiency.
Lack of normal collagen synthesis, because of the lack of ascorbic acid, resulted in an
almost complete cessation of osteogenesis and disorganization of the periodontal
ligament. It appears that ascorbic acid is necessary for the normal morphology of the
periodontal ligament and alveolar bone. This need was accentuated during the
application of light forces which placed a stress on the various tissues.
It has been documented that a relationship exists between collagen synthesis and
ascorbic acid. The lack of ascorbic acid in certain animals, including man, is believed
to prevent the normal hydroxylation of the amino acid proline to hydroxyproline.
Collagen, which contains proline and hydroxyproline, is a major constituent of the
tooth and surrounding supportive structures. During orthodontic tooth movement, the
periodontal ligament and alveolar bone are affected by the application of the
mechanical forces.
The tooth has been reported to be the first system affected in an ascorbic acid
deficiency. Changes include altered morphology of the odontoblast and its process,
hemorrhage of the pulp, osteoid-like formations in the pulp, atrophy of cells, and
cessation of dentin formation. Utilizing isotopic ascorbic acid, some authors have
found label over the odontoblasts of animals deficient in ascorbic acid. They
postulated that, even though there was an altered morphology of the cells, they had
not lost their potential to synthesize dentin.
Review of Literature
12 | P a g e
STUDIES RELATED TO SOFT DRINKS AND LOW ACIDIC FOODS ON
DENTAL EROSION.
C. Abalos, A. Paul, A. Mendoza, E. Solano, C. Palazon, and F.J. Gil
et al (2013)61 studied the the influence of soft drinks on the surface of Ni-Ti
archwires and their corrosion behavior. the corrosion resistance of Ni-Ti alloys
decreases in acid saliva and chlorine or fluoride-containing solutions. Corrosive
agents deteriorate the passive film of the titanium oxide surface, decreasing corrosion
resistance of the alloy and hence its biocompatibility. carbonated drinks, only studies
on the enamel coating that affects adherence to brackets can be found in the literature.
Such drinks are a part of the diet of young people receiving orthodontic treatment, and
can also degrade the orthodontic archwire surface. When the passive film is broken,
corrosion takes place. As a consequence, the release of metallic ions into the medium,
surface morphological changes including an increase in roughness and friction
coefficient between the archwire and the bracket, are produced. Soft drinks with low
pH values exert corrosive action on the surface of Ni-Ti orthodontic archwires,
although in different ways depending on the surface pattern. Archwires with cracked
or scratched surface patterns are the least corrosion resistant. Cracks as pre-existing
manufacturing defects show the greatest surface deterioration, due to the internal
energy stored. However, the initial roughness of archwires is not related to the
increase in roughness when they are exposed to soft drink. The cracked surface
pattern moreover shows the greatest increase in roughness; therefore, cracks should be
avoided in the archwire surface pattern. The absence of standard surface treatment
protocols for Ni-Ti results in variability in the surface finish, which in turn responds
Review of Literature
13 | P a g e
differently to corrosion. Such protocols should be helpful in securing better quality
surfaces.
T Attin, K Weiss, K Becker, W Buchalla, A Wiegand et al (2005)2
evaluated the enamel erosive potential of modified acidic soft drinks under controlled
conditions in an artificial mouth. Frequent contact of the dentition with exogenous
acids, originating from acidic food or beverages might result in dental erosion.
Evidence shows that erosion is strongly correlated with the frequency and amount of
soft drink intake. The consumption of soft drinks shows a continuing upward trend
with a distinct increase in several countries. The increasing consumption of acidic soft
drinks appears to be an increasingly important factor implicated in the etiology of
dental erosion. Erosion may be prevented by reducing the intake of acidic foods and
drinks and by modifying drinking habits. Some modifications to acidic beverages
have been suggested to reduce the potential of such drinks to demineralize and
dissolve the mineral compounds of teeth. Additions of hydrocolloids, magnesium,
calcium-citrate-malate, fluoride and calcium/phosphate to soft drinks have been
tested. Studies have shown that high amounts of calcium, phosphate or fluoride were
able to reduce the formation of erosive lesions in enamel distinctly. While
modifications of acidic solutions might lead to reduction of the erosive potential
capacity of the solutions, it is not known, whether these modifications will also reduce
erosive potential of commercial beverages with more complex compositions.
They concluded that modification of the test beverages with low concentrations of
calcium, phosphate and fluoride is able to reduce the erosive potential of the drinks.
However, with these low concentrations enamel dissolution could not be completely
prevented.
Review of Literature
14 | P a g e
Asmyhr, Grytten J, Holst D et al (2012)21 studied the occurrence of risk
factors for dental erosion for a group of young adults who are particularly susceptible
to erosion. Young adults in many parts of the world consume an increasing amount of
soft drinks. The increased consumption has raised several concerns about the health
consequences such as obesity, diabetes, dental caries, dental erosion and mental health
problems. Traditionally, caries has been regarded as the dental disease that affects
most children and young people in the Western world. This is still true, but during the
last decade, there have been several studies that have shown that erosion is also a
significant dental health problem in these young age groups. Studies show that as
many as 40–50% of 11–14-year-old children have moderate erosion.
They concluded that consumption of soft drinks and juice is high, even though the
awareness and knowledge about the causes of erosion are widespread. Young adults
with mothers with high education drink soft drinks both with and without sugar less
frequently than those who have mothers with low education. This may be a reflection
of a general healthy lifestyle among highly educated people.
STUDIES RELATED TO METAL RELEASE FROM ORTHODONTIC
APPLIANCES
H. Y. Park, T. R. Shearer et al (1983)62 measured the amounts of nickel and
chromium released from a simulated orthodontic appliance incubated in 0.05 percent
sodium chloride solution. They concluded that the average release of metals was 40
ug nickel and 36 ug chromium per day for a full-mouth appliance. This was well
Review of Literature
15 | P a g e
below the average dietary intake of nickel and chromium consumed by Americans.
However, the clinician should be aware that release of nickel and chromium from
orthodontic bands might sensitize patients to nickel and chromium and may cause
hypersensitivity reactions in patients with a prior history of hypersensitivity to these
metals.
Characteristic lesions of contact stomatitis vary from barely visible, mild erythema to
a fiery red color with or without edema. Symptoms may include loss of taste,
numbness, burning sensation, and soreness of the involved area, often accompanied
by angular cheilitis. Itching is not a frequent symptom. Although it is more difficult to
provoke contact stomatitis than contact dermatitis, severe gingivitis associated with
orthodontic therapy may be a manifestation not only of poor oral hygiene but also of a
contact hypersensitivity reaction to nickel and/or chromium ions released during the
corrosion of stainless steel.
Nils R. Gjerdet and Hakon Hero et al (1987)63 Studied the release of metals
from cobalt-chromium and stainless steel orthodontic archwires as a consequence of
short-term heating to different temperatures.
They concluded that that the corrosion resistance of stainless steel and cobalt-
chromium wires of the present composition is impaired when the wires are heated
above 400°C, stainless steel being more sensitive than cobalt-chromium. Some
clinical and technologic procedures involve heating to temperatures close to or above
the critical ranges. When heating of orthodontic wires is indicated, the temperature
should be kept as low as possible, and the heating procedure should be well controlled
to minimize corrosion of the appliances.
Review of Literature
16 | P a g e
Margret Rosa Grimsdottlr, Nils R. Gjerdet et al (1992)64 analyzed
different types of alloys used in orthodontics, and to study whether nickel and
chromium will be released from these alloys when stored in physiologic saline. Face-
bows, brackets, molar bands, and arch wires were analyzed.
They concluded that the release of nickel and chromium seemed to be related to the
composition and the manufacturing of the appliances but was not directly related to
the actual nickel and chromium content. Appliances with silver and gold solders
showed enhanced release of nickel and chromium, whereas alloys containing titanium
released little nickel when tested under static conditions.
Robert D. Barrett, Samir E. Bishara et al (1993)16 compared in vitro the
corrosion rate of a standard orthodontic appliance consisting of bands, brackets and
either stainless steel or nickel-titanium arch wires. The corrosion products analyzed
were nickel and chromium. Evaluation was conducted with the appliances immersed
for 4 weeks in a prepared artificial saliva medium at 37" C.
They concluded that :
1. Orthodontic appliances release measurable amounts of nickel and chromium when
placed in an artificial saliva medium.
2. The nickel release reaches a maximum after approximately 1 week, then the rate of
release diminishes with time.
3. The chromium release increases during the first 2 weeks and levels-off during the
subsequent 2 weeks.
4. The release rates of nickel and chromium from stainless steel or nickel-titanium
arch wires are not significantly different.
Review of Literature
17 | P a g e
5. For both arch wire types, the release rate for nickel averaged 37 times greater than
that for chromium.
6. The estimated release rates from full-mouth orthodontic appliances are less than
10% of the reported average daily dietary intake for nickel and 0.25% of those
reported for chromium.
7. How much of these corrosive products are actually absorbed by patients
undergoing orthodontic treatment still needs to be determined.
Samir E. Bishara, Robert D. Barrett et al (1993)17 studied whether
orthodontic patients accumulate measurable concentrations of nickel in their blood
during their initial course of orthodontic therapy. Blood samples were collected at
three different time periods: before the placement of orthodontic appliances, 2 months
after their placement, and 4 to 5 months after their placement.
They arrived at the following conclusions:
1. Patients with fully banded and bonded orthodontic appliances did not show a
significant increase in the nickel blood levels during the first 4 to 5 months of
orthodontic therapy.
2. Orthodontic therapy using appliances made of alloys containing nickel-titanium did
not result in a significant increase in the blood levels of nickel.
N. Staffolani, F. Damiani, C. Lilli, M. Guerra, N.J. Staffolani, S.
Belcastro, P. Locci et al (1999)65 assayed the release of metal ions from one
orthodontic appliance which included two 304 and 316 steel molar bands, ten 316
steel brackets, one nickel–titanium archwire and a brazing alloy to connect the
elements of molar bands and brackets. The authors dipped the orthodontic appliaces
Review of Literature
18 | P a g e
in both inorganic (pH 3.5–6.5) and organic acid solutions (w/v 1% each of tartaric,
citric and ascorbic acid at pH 2.2 or 1.5% each of lactic and acetic acid at pH 2.5).
The release of nickel (Ni), chromium (Cr), copper (Cu), silver (Ag) and palladium
(Pd) was determined using an atomic absorption spectrophotometer.
Their results showed that the release of Ni, Cr and Cu was markedly less at pH 6.5
than at pH 3.5 at all time points in acid solution. Daily release/single appliance after
the first day decreased. Contrary to expectations, appliances immersed in organic
acid solutions at pH 2.2 or 2.5 after 28 days generally released an amount of ions
similar to that observed in inorganic acid solution at pH 3.5, with the exception of Cu.
Release of silver and palladium, two metals present in the brazing alloy, proved to be
very low (approximately 0.2 mg after 28 days).
They concluded that daily release of Ni, Cu and Cr by an orthodontic appliance in
acid pH, particularly favourable to corrosion, was well below that ingested with a
normal daily diet. They also concluded that the quantities of metal ions released in our
experimental conditions should not be cause for concern in utilising the appliance.
Neamat Abu-bakr et al (2000)66 evaluated changes in the mechanical
properties and surface texture of compomer and other materials, used in similar
clinical circumstances, when immersed in various media. The purpose of their study
was to evaluate the effect of alcoholic and low pH soft drinks on the
compressive strength, surface microhardness, solubility, and surface texture of the
compomer.
The results showed that the average compressive strength and Vickers surface
hardness showed a significant difference between materials. Results showed an
overall increase in the solubility of specimens immersed in low pH soft drinks.
Review of Literature
19 | P a g e
They concluded that there was a difference in the mechanical properties and surface
texture of the materials tested in this study when they were immersed in various
media.
Mockers, Deroze and Camps et al (2002)67 studied the cytotoxicity of
orthodontic bands, brackets and archwires invitro.They concluded that the orthodontic
bands, brackets and archwires were considered as non-cytotoxic.
Theodore Eliades et al (2002)68 addressed the critical issues of corrosion
potential and nickel leaching from alloys by investigating the effect of intraoral
conditions on the surface reactivity of the materials. After an overview of
fundamentals of metallurgical structure of orthodontic alloys, authors provided an
analysis of corrosion processes occurring in vivo. The recent evidence suggests that
the formation of a proteinaceous biofilm on retrieved orthodontic materials that later
undergoes calcification. Authors illustrated the vastly irrelevant surface structure of in
vivo– vs in vitro–aged alloys and discussed the potential implications of this pattern
in the reactivity of the materials. However, for patients who have a history of
hypersensitivity, authors suggested the use of the Ni-free alloy substitutes or Ni
alternatives.
In general, the clinical manifestations of Ni hypersensitivity are easy to diagnose, and
extraoral or intraoral appliances containing Ni must be removed after the development
of dermal or mucosal signs in the form of rashes or swelling. Administration of
cortisone-based substances to counteract hypersensitivity has been shown to affect the
tooth movement process, reducing the movement rate, and this administration should
be avoided if the symptoms are not severe.
Review of Literature
20 | P a g e
Her-Hsiung Huang, Yu-Hui Chiu et al (2005) assayed the corrosion
resistance, in terms of ion release, of different NiTi orthodontic wires in artificial
saliva with various acidities. They concluded that the average amount of Ni ions
released per day from the tested NiTi wires in artificial saliva with various acidities,
was well below the critical concentration necessary to induce allergy and under daily
dietary intake level. According to the release amount of Ti ions, the passive film
(mainly TiO2) on NiTi wires was very protective against corrosion in the slightly
acidic artificial saliva.
Nicolas Schiff, Mickaël Boinet, Laurent Morgon, Michèle Lissac et al
(2006)69 studied the influence of fluoride in certain mouthwashes on the risk of
corrosion through galvanic coupling of orthodontic wires and brackets. Their aim was
to assess the risk of corrosion caused by galvanic coupling between wires and
brackets in different solutions: artificial saliva and fluoride mouthwashes. Two
titanium alloy wires, nickel-titanium (NiTi) and copper-nickel-titanium (CuNiTi), and
the three most commonly used brackets, titanium (Ti), iron-chromium-nickel
(FeCrNi) and cobalt-chromium (CoCr), were tested in a reference solution of
Fusayama – Meyer artificial saliva and in two commercially available fluoride (250
ppm) mouthwashes, Elmex® and Meridol®. The results indicate that NiTi wires
released the most ions in the presence of Meridol® mouthwash while Cu-NiTi wires
released the most ions in the presence of Elmex® mouthwash. Although the risks are
minimal, the clinical consequences of corrosion of orthodontic devices are quite
plausible: impaired mechanical performance can lead to unsatisfactory aesthetic
results, while Ni and Cr ions released in the organism can cause allergic reactions (
Review of Literature
21 | P a g e
Kusy, 2004 ). It is important to eliminate these risks. Fluoride mouthwashes are
advised in the prevention of dental caries during orthodontic treatment.
Their results suggested that mouthwashes should be prescribed according to the
orthodontic materials used. A new type of mouthwash for use during orthodontic
therapy could be an interesting development in this field.
F Amini, A Borzabadi Farahani, A Jafari, M Rabbani et al (2008)37
compared the concentration of nickel, chromium and cobalt in oral mucosa cells of
patients with and without fixed orthodontic appliances. The warm and moist condition
in the mouth offers an ideal environment for the biodegradation of metals,
consequently facilitating the release of metals ions that can cause adverse effects.
Biocompatibility is strongly related to ionic release and therefore the public may
express concern about possible leakage of metal ions from an orthodontic appliance.
Their findings indicated that there was no difference in the concentration of chromium
and cobalt in oral mucosa cells of patients with or without fixed appliances. However,
a significantly higher concentration of nickel can be found in buccal mucosa cells of
patients wearing fixed orthodontic appliances. Continued follow-up is needed to
determine the long-term significance of nickel release.
Maja Kuhta; Dubravko Pavlin; Martina Slaj et al (2009)70 examined the
effects of three different parameters—pH value, type of archwire, and length of
immersion—on release of metal ions from orthodontic appliances.
They concluded that all three observed parameters—chemical composition of the
archwire, pH value of the artificial saliva, and time of exposure to the solution—
influenced ion release. Statistically significant stimulation of ion release at lower pH,
Review of Literature
22 | P a g e
which is in line with the hypothesis that organic acids in dentobacterial plaque affect
the release of ions, emphasizes the major role of oral hygiene in minimizing
corrosion. The most significant release of all analyzed metal ions was measured after
the first or the second observed time period, which supports the role of oxide layers in
slowing down a corrosive process on the metal surface. Release of metal ions was
influenced by composition of the orthodontic archwire, but this was not proportional
to the content of metal in the wire. Quantities of all released ions were below toxic
levels and did not exceed the daily dietary intake. However, these levels are sufficient
to cause an allergic reaction because of the high haptenic potential of released
elements.
Marcin Mikulewicz & Katarzyna Chojnacka et al (2009)71 discussed
various approaches used to investigate biocompatibility by the analysis of metals
release by the materials of which orthodontic appliances are made. Analysis of
various biomarkers of exposure: saliva, serum, mucosa cells, or urine is used in in
vivo tests. In this work, the techniques, results, and conclusions of original papers
were compared by the implementation of the concept of a systematic review. Their
aim was to report the state-of-the-art in the research on methods used to assess
exposure to trace metals from orthodontic appliances.
They concluded that metal ions were released mostly in the initial stage of the
treatment. However, the majority of studies included 1–2 months long period and did
not reflect long-term changes nor the impact of the complete treatment, the duration
of which is several years, on the whole organism and the overall accumulation of
metals from orthodontic appliances. In studies which evaluated nickel concentrations
in blood and urine, long-term metal release was detected and significant differences
Review of Literature
23 | P a g e
were found. It leads to the conclusion that nickel ions are released from orthodontic
appliances in measurable amounts to human organism.
TP Chaturvedi, SN Upadhayay et al (2010)72 concluded that a primary
requisite of any alloy metal used in the mouth is that it must not produce corrosion
products that will be harmful to body. In spite of recent innovative metallurgical and
technological advances and remarkable progress related to orthodontic materials,
failures do occur. One of the reasons for these failures could be corrosion (material
degradation) of orthodontic appliances. It causes severe and catastrophic
disintegration of the metal body. Corrosion (material degradation) attack may be
extremely localized and causes rapid mechanical failure of a structure, even though
the actual volume loss of material is quite small. Surface roughening and deposit build
up may have adverse effects on the efficiency of relative wire/bracket function in
orthodontic treatment. Application of fluoride containing gel/toothpaste may affect
efficiency of orthodontic appliances. In future nickel free materials should be
expected in use.
Future research is needed regarding material composition influencing corrosion,
manufacturing of metallic brackets, influence of various diet pattern as well as diet
substance on corrosion, use of topical fluoride treatment during orthodontic treatment
for oral hygiene maintenance.
Antonio Jose Ortiz, Esther Fernandez, Ascension Vicente et al
(2011)73 determined the amounts of metallic ions that stainless steel, nickel free, and
titanium alloys release to a culture medium, and evaluated the cellular viability and
DNA damage of cultivated human fibroblasts with those mediums.
Review of Literature
24 | P a g e
They concluded that tubes and brackets made of the 3 alloys used, released metal ions
into a standard culture medium. Those from stainless steel had greater toxicity to
cultured human fibroblasts, measured as cell viability or as Comet olive moment, than
those from nickel-free and titanium alloys, in that order. The titanium brackets and
tubes are the most biocompatible of the 3 alloys studied.
Hend Salah Hafez, Essam Mohamed Nassef Selim et al (2011) tested the
biocompatibility (cytotoxic and genotoxic effects on human tissues) of fixed
orthodontic appliances, with 3 distinct hypotheses:
(1) Fixed orthodontic appliances do not have a toxic effect,
(2) Fixed orthodontic appliances do not have an effect on the cellular metal content in
buccal mucosa cell samples,
(3) There is no difference between the effects of the various materials of fixed
orthodontic appliances.
They concluded that Fixed orthodontic appliances decreased cellular viability,
induced DNA damage, and increased the nickel and chromium contents of the buccal
mucosa cells.
Marcin Mikulewicz & Paulina Wołowiec et al (2014)52 evaluated metal
ion accumulation in hair of patients undergoing orthodontic treatment with fixed
appliances in time.
They concluded that the kinetics of metal ions released from orthodontic appliance
and their transfer to hair tissue can be evaluated by a biomarker of chronic exposure,
which is hair mineral analysis. The outcomes of the present study revealed that the
content of Cr was statistically significantly higher during the treatment than before the
Review of Literature
25 | P a g e
beginning of therapy. However, the doses of released metal ions did not pose a
toxicological danger.
R. S. Senkutvan, Sanjay Jacob , Anila Charles et al (2014)74 analyzed
and evaluated the rate of Ni ion release from different types arch wires used in
orthodontics.
They concluded that the release of Ni was very much below with the average dietary
intake of Ni which was not capable of causing any toxic effects. The Ni release
reached a maximum after approximately 1 week, and then the rate of release
diminishes with time. The estimated release rates from full‑mouth orthodontic
appliances are less than 10% of the reported average daily dietary intake for Ni and
how much of these corrosive products are actually absorbed by patients undergoing
orthodontic treatment still needs to be determined. The ingested amount of Ni
released from orthodontic appliances cannot be quantified using the currently
available release data, but it is well below the daily dietary intake levels.
Fariborz Amini & Mobina Mollaei et al (2014)75 evaluated comparatively
the hair nickel and chromium concentrations in fixed orthodontic patients in a
prospective design.
Authors concluded that hair nickel and chromium levels might increase after 6 months
of treatment with fixed orthodontic appliances. Gender and age influence neither the
baseline nickel or chromium values nor their time-dependent alterations.
Review of Literature
26 | P a g e
Fariborz Amini, Mahsa Shariati et al (2016)76 evaluated the baseline and
during-treatment nickel and chromium levels in the GCF of fixed orthodontic patients.
As an additional finding, the gingival index was also evaluated.
They concluded that nickel and chromium concentrations in GCF might increase
considerably after 1 month and 6 months of treatment with fixed orthodontic
appliances. Gingival conditions might worsen in the initial 6 months of orthodontic
treatment.
R Vinoth Kumar, N Rajvikram et al (2016)77 evaluated the release of nickel
and chromium ions in human saliva during fixed orthodontic therapy. Their results
showed that levels of nickel and chromium were statistically significant, while nickel
showed a gradual increase in the first 10 days and a decline thereafter. Chromium
showed a gradual increase and was statistically significant on the 30th day.
They concluded that there was greatest release of ions during the first 10 days and a
gradual decline thereafter. Control group had traces of nickel and chromium. While
comparing levels of nickel in saliva, there was a significant rise from baseline to 10th
and 30th-day sample, which was statistically significant. While comparing 10th day to
that of 30th day, there was no statistical significance. The levels of chromium ion in
the saliva were more in 30th day, and when comparing 10th-day sample with 30th day,
there was statistical significance. Nickel and chromium levels were well within the
permissible levels. However, some hypersensitive individuals may be allergic to this
minimal permissible level.
Review of Literature
27 | P a g e
STUDIES RELATED TO Ni ALLERGY AND HYPERSENSITIVITY
Bertil Magnusson, Maud Bergman et al (1982)78 investigated if patients
with known nickel allergy react to dental alloys containing various amounts of nickel
after exposure to test pieces of the alloys applied on the skin. Nickel is one of the
most common metallic contact sensitizers. Of patients with eczema 6.7-11.0% were
found to have positive patch test reactions to nickel. The reactions were found three to
five times more often in women than in men.
Contact dermatitis from nickel-containing objects is usually recognized by the
patients themselves and such objects are consequently avoided. There are, however, a
great number of objects containing nickel in our environment which are not avoided
by nickel sensitive patients because the content of the alloys are decreased. Unknown
exposure to nickel is virtually inescapable. Once nickel hypersensitivity has occurred,
it will remain. The classical clinical patterns of nickel eczema with onset under
suspenders, cheap jewellery in form of necklaces, bracelets, earrings, rings,
wristwatches and other similar objects have changed to some extent with the change
in fashion. The onset of the eczema may occur in several different locations and can
be uncharacteristic (atypical) in its clinical picture.
Luis Blanco-Dalmau et al (1984)79 concluded that a standardized patch test
should be performed on every patient who is to be treated with a prosthesis that
contains nickel to detect nickel sensitivity. A patch test should also be performed on
industrial workers or employees who may be exposed to nickel.
Review of Literature
28 | P a g e
Lilian Staerkjaer and Torkil Menne et al (1990)80 investigated whether
nickel sensitive persons are at greater risk of developing discomfort in the oral cavity
during orthodontic treatment.
Allergy to nickel is a cell-mediated type IV allergy. Once hypersensitivity has been
established, all dermal and mucosal surfaces are usually involved. It is stated that oral
antigenic contacts in non-sensitized individuals may induce tolerance rather than
sensitization. In a guinea-pig model Vreeburg et al. (1984) demonstrated that a fixed
occlusal splint containing 80.5 per cent nickel and 11.4 per cent chromium could
induce a state of tolerance to these metals in non-sensitized guinea-pigs. Vander Burg
et al. (1986) examined junior hairdressers and junior nurses for nickel allergy. The
examination of the junior nurses showed that those who had a history of previous
orthodontic treatment revealed a lower prevalence of nickel sensitivity (P<0.05) than
those junior nurses who had no history of orthodontic treatment. This might indicate
that the orthodontic treatment had induced tolerance. No such effect of orthodontic
treatment was observed in the junior hairdressers, who revealed a higher prevalence
of nickel sensitivity. This may be due to heavier exposure to the allergen at an early
age, a conclusion which is supported by the lower age at which the junior hairdressers
had their ears pierced.
Authors concluded that out of 1085 girls treated by intraoral orthodontic appliances
did not reveal any instance of intraoral nickel allergic reaction. On the contrary, some
studies indicate that orthodontic appliances may induce tolerance leading to a lower
incidence of nickel sensitivity.
Review of Literature
29 | P a g e
Justin K. Bass, Howard Fine, George J. Cisneros et al (1993)81
determined the prevalence of nickel sensitivity in a sample of orthodontic patients
before treatment and determined if standard orthodontic therapy can sensitize patients
to nickel. They also assessed gingival response to nickel-containing orthodontic
appliances in patients who are nickel sensitive before treatment.
Authors concluded that :
• The prevalence of nickel allergy is higher in females than males. (28% in
females, 0% in males.)
• Nickel-containing orthodontic appliances had little or no effect on the gingiva
and oral health of the patient.
• Orthodontic treatment may induce nickel sensitivity.
J. D. Bumgardner, J. Doeller, L. C. Lucas et al (1995)82 concluded that
the metal ions released from the nickel-chromium alloys investigated impaired
cellular energy metabolism. Furthermore, larger decreases in energy metabolism were
associated with the preferential release of nickel and beryllium ions from the
beryllium containing alloys. However, alterations in cellular energy metabolism by
the alloys were not sufficient to lead to alterations in cellular morphology,
ultrastructural organization, or viability within the time constraints of these cell
culture tests. Nevertheless, the impairment of energy metabolism was associated with
decreased functional capability of the cells. Reductions in cellular function due to
metal ions released from these alloys, especially the beryllium containing alloys, raise
concerns over the maintenance of the health of the oral tissues.
Nickel-chromium alloys completely inhibited G-6-PDH activity of the cultured cells.
It was also reported that metal ions from nickel- and chromium containing alloys
Review of Literature
30 | P a g e
inhibited G-6-PDH enzyme activity of macrophages. Nickel-chromium alloys also
caused reductions in intracellular ATP levels as compared to controls. However, these
reductions, which were not <20% of controls, were not significant enough to alter
cellular morphologies or viabilities. These results correspond to previous
investigations in which metal ions released from nickel-chromium alloys did not
affect the viabilities or morphologies of cultured.
Their results indicated that the types of metal ions released from nickel-chromium
dental alloys affect the functional capability of cells at levels below those necessary to
alter cellular viability and samples. The fact that corrosion products released from
these alloys inhibited metabolic enzyme activity, and caused decreases in both cellular
ATP and proliferation were at much lower levels than levels of individual metal salt
solutions required to inhibit similar cellular processes, strongly suggests a negative
synergistic effect of released metal ions on cellular metabolism. Indeed, larger
reductions in both cellular ATP levels and proliferation were observed for beryllium-
containing alloys. These alloys have been shown to referentially release nickel and
beryllium ions.
Heidi Kerosuo, Arja Kullaa et al (1996)83 investigated the frequency of
nickel hypersensitivity in adolescents in relation to sex, onset, duration and type of
orthodontic treatment, and the age at which ears were pierced. Authors confirmed that
nickel sensitization is more common in females than in males. Also, consistent with
previous reports, the results indicated the strong positive correlation between ear
piercing and nickel sensitivity in girls.
The concern of sensitizing patients to nickel through orthodontic treatment was not
supported by this study. Orthodontic treatment as such did not seem to increase the
Review of Literature
31 | P a g e
prevalence of nickel hypersensitivity of the adolescents. Oral contacts by nickel
containing fixed orthodontic appliances, before events that may cause sensitization to
nickel (ear piercing) may have decreased the prevalence of nickel sensitization on the
adolescents.
They concluded that orthodontic treatment does not increase the risk for nickel
hypersensitivity. Rather, these results seem to suggest that orthodontic treatment with
metallic appliances before sensitization to nickel (ear piercing) may even reduce
nickel hypersensitivity. This possible clinical benefit might be of some relevance in
planning the timing of ear piercing and orthodontic treatment.
Gabriele Schuster, Ralf Reichle, Radha Ranei Bauer et al (2004)84
conducted a survey among orthodontists in the German state of Hesse, as the
orthodontic literature is largely confined to observations of single cases, meaning that
no reliable figures on the occurrence of allergic reactions in orthodontic offices are
available. The allergic potential of orthodontic appliances is overestimated in general.
Their results revealed that after extrapolation, probably less than 0.2% of patients
exhibit an allergic skin reaction in the course of their orthodontic therapy.
The clinical relevance of nickel ions released from orthodontic materials is generally
considered to be low. It is even suggested an early treatment onset might lead to a
physical reaction in terms of desensitization through the materials used. What is
important is that the intraoral stimulus (orthodontic appliance) should occur before the
extraoral stimulus (costume jewelry, wristwatch, earrings, etc.). It is often difficult to
distinguish an irritation or a toxic eczema from an allergic reaction.
Any changes to the skin should therefore be examined by a dermatologist. A
suspected contact allergy has to be confirmed by a skin patch test. Larger scale studies
Review of Literature
32 | P a g e
using skin patch tests are needed to provide more exact data on the allergic potential
of orthodontic treatment.
In order to minimize the possibility of an allergic contact reaction, corrosion-resistant
materials should be used as a matter of principle. For this reason (laser) welding is
preferable to soldering, and the recycling of brackets and bands is obsolete in all
events. Gold plating or other coatings (titanium nitride) of brackets, bands and
archwires should be avoided in general.
By paying careful attention to the case history, the orthodontist can avoid using
nickel-containing materials in patients known to have a nickel allergy and can use
ceramic, plastic or titanium brackets instead for fixed appliance therapy.
In appropriate cases, titanium molybdenum alloys or fiberglass-reinforced plastics can
be used as archwire materials. A metal/skin contact through extraoral
devices can be avoided by applying an adhesive tape, Teflon®, or synthetic (e.g. nail
polish) coating or by using polyethylene tubes.
For removable appliance therapy, nickel-reduced wires have stood the test in practice.
Alternatively flexible devices in terms of silicone elastomer positioners can be used in
appropriate cases.
Marisa Cristina Leite Santos Genelhu, Marcelo Marigo et al(2005)85
assessed the roles of age, sex, previous allergic history, and time of exposure in the
NiACS (nickel-induced allergic contact stomatitis), etiopathogeny induced by fixed
orthodontic appliances.
Some oral clinical manifestations in orthodontic patients, such as gingival
hyperplasia, labial desquamation, angular cheilitis, multiform erythema, and
Review of Literature
33 | P a g e
periodontitis might be associated with an inflammatory response induced by the
corrosion of orthodontic appliances and the subsequent release of nickel.
This inflammatory response, from an immunologic standpoint, is considered type IV
hypersensitivity. It is manifested as nickel allergic contact stomatitis (NiACS), and its
etiology and diagnosis are difficult to establish.
In its initial phase, clinical lesions have diverse features depending on the
concentration and intensity of the exposure, the presence of local barriers, and the
area affected. A burning sensation is the most frequent symptom. The aspect of the
affected mucosa is also variable, from slight erythema to shiny lesions with or without
edema. Vesicles are rarely observed, but, when they are present, they quickly rupture,
forming erosion areas.
In chronic cases, the affected mucosa is typically in contact with the causal agent and
appears erythematous or hyperkeratotic to ulcerated. Other symptoms can also be
present, such as perioral dermatitis and, rarely, orolingual paresthesia.
Authors concluded that a detailed history, with special attention to previous allergic
reactions, is the main prognostic factor to avoid NiACS manifestations during
orthodontic therapy.
Kristen K. Volkman, Michael J. Inda et al (2007)86 characterized
the relationship between Nickel allergy and many orthodontic appliances using a
survey of practicing orthodontists in Wisconsin.
The most common manifestation of nickel allergy is allergic contact dermatitis
(ACD), a type IV T-cell–mediated delayed-type hypersensitivity reaction. Allergic
contact dermatitis occurs in areas where skin contacts nickel-containing objects such
as costume jewelry, snaps on clothing, eyeglasses, and watches. Occupational and
Review of Literature
34 | P a g e
industrial arenas also can be a source of nickel exposure. Allergic contact urticaria to
nickel has been reported. Nickel allergy is more common in women by two- to six
fold, presumably because of ear piercing being the sensitizing event where intimate
contact between nickel plated earrings and injured skin occurs. Use of nickel plated
earrings in combination with other irritants such as moisture or shampoo could
potentiate sensitization. Nickel allergy is more common in younger patients and in
those who are nonatopic.
The authors concluded that adverse reactions to many orthodontic appliances in
patients with nickel allergy have been observed but are uncommon. Using suitable
alternatives, patients usually can be accommodated.
J. Noble, S. I.Ahing, N. E. Karaiskos et al (2008)87 in their paper provided
a summary of nickel allergy, its epidemiology, diagnosis and recommendations and
alternatives to treatment.
IMMUNE RESPONSE: The response by the immune system to nickel is usually a
Type IV cell mediated delayed hypersensitivity also called an allergic contact
dermatitis. It is mediated by T-cells and monocytes/macrophages rather than
antibodies and consists of two phases. The first phase, or sensitisation, occurs when
nickel initially enters the body. There is usually no response present at this time but
the immune system is primed or sensitised for an allergic response. The major
sensitisation routes are nickel-containing jewellery and foods. Foods that are high in
nickel include chocolate, soyabeans, nuts and oatmeal. A response, or the elicitation
phase, is in the form of a contact mucositis or dermatitis that occurs during re-
exposure to nickel and develops over a period of days or rarely up to three weeks. If
Review of Literature
35 | P a g e
nickel is leached from orthodontic appliances, this Type IV hypersensitivity reaction
can occur.
They concluded that, though an allergic response to nickel in the oral mucosa from
nickel containing orthodontic appliances is more infrequent than from nickel contact
on the epidermis, it can occur, particularly in females. If nickel-related intraoral
clinical signs and symptoms appear, the orthodontist should be prepared to undertake
or continue treatment without the use of Ni-Ti wires and even without stainless steel.
The frequency of orthodontic treatment and the common use of nickel containing
orthodontic materials raises the interesting question of whether orthodontic treatment
may act to increase or decrease the burden of nickel hypersensitivity in the
population. There is evidence that oral exposure to nickel may induce immunologic
tolerance to nickel and thereby reduce the incidence of nickel to nickel
hypersensitivity are distressing to patients there are many choices of materials
available to the orthodontist as alternatives.
Olga Elpis Kolokitha, Evangelia Chatzistavrou et al (2009)88 presented
a case report of an severe reaction to nickel-containing orthodontic appliances in an
adult female patient, which occurred after the surgical exposure of her impacted teeth.
The patient had no previous history of allergy and had been wearing fixed metal upper
appliances while in orthodontic treatment to assist the eruption of her impacted teeth.
The adverse hypersensitivity reactions appeared only after the surgical exposure and
included severe signs of eczematic and urticarial reactions of the face with redness,
irritation, itching, eczema, soreness, fissuring, and desquamation as well as intraoral
diffuse red zones. Diagnostic patch testing performed by the allergist revealed
Review of Literature
36 | P a g e
sensitization to nickel. The use of nickel-free brackets and archwires enabled the
authors to achieve the treatment goal and the patient’s satisfaction.
Ronny Fors, Berndt Stenberg et al (2012)89 investigated the association
between nickel sensitization and exposure to orthodontic appliances and piercings.
Authors gave the following conclusions:
• There was no increase in the risk of sensitizing adolescents to nickel by the
use of oral orthodontic appliances.
• When orthodontic appliance use preceded exposure to piercing, there was a
reduced risk of nickel sensitivity.
• There was a reduced risk with the use of full fixed appliances with an assumed
high release of nickel as compared with appliances including alloys with a
lower nickel release. The risk reduction was most prominent when the
duration of orthodontic treatment (before piercing) was 1–2.5 years.
• These results should thus reduce parental and patient concerns about
sensitization from orthodontic appliances.
The results support the concept of induction of immunological tolerance via
oral administration of nickel.
Lina Gölz, Spyridon N. Papageorgiou, Andreas Jäger et al (2015)90
assessed the existing evidence and investigated whether the prevalence of nickel
hypersensitivity, as assessed with nickel patch tests, is affected by orthodontic
treatment. As a secondary objective, the influence of orthodontic treatment was
adjusted, if possible, for other known confounding factors that might influence nickel
hypersensitivity. Unrestricted electronic and manual searches were performed until
Review of Literature
37 | P a g e
July 2013 for human clinical studies assessing orthodontic treatment and nickel
hypersensitivity.
Authors concluded that according to the existing evidence, they could not show that
orthodontic treatment influences the prevalence of nickel hypersensitivity.
However, there was evidence of confounding by various influencing factors, such as
patient sex, piercings, or allergic history, which could not be removed, owing to
incomplete data.
The existing evidence indicated that there was a significantly lower risk of nickel
hypersensitivity when orthodontic treatment preceded piercing than when orthodontic
treatment occurred after piercing. This protective role of orthodontic treatment against
nickel allergy was robust to possible confounding. This might, in part, be explained
by orally induced tolerance via nickel ions released during orthodontic treatment.
Materials and Method
38 | P a g e
MATERIALS AND METHOD
MATERIALS:
Fixed orthodontic appliance components:
• Orthodontic archwires : Nickel-titanium archwires and Stainless
steel archwires (BROOKLYN ORTHODONTICS, USA)(Figure 1)
• Heat activated nickel titanium archwires (AMERICAN
BRACESTM) (Figure-2)
• Brackets (“0.022”-inch slot stainless steel MBT prescription
(OrthoxTM) (Figure-3)
• Stainless steel bands (SLR-WELCARE ORTHODONTICS)-
(Figure-4)
• Buccal tubes (Figure-5)
• Lingual attachments (Figure-6)
Glass containers (Figure-7)
Glass tubes with wooden cork (Figure-8)
Tweezer (Figure-9)
PRODUCTS:
Saliva substitute : SALEVA-DENT AIDS (Figure-10)
Each bottle of Saleva-Dent Aids contains:
• Purified water
• Sodium Phosphate
• Sodium chloride
Materials and Method
39 | P a g e
• Potassium chloride
• Sodium Saccharine
• Sodium carboxymethyl cellulose
• Colour – Brilliant blue FCF
30 Different dietary samples
METHODOLOGY:
Type of study:
Cross sectional study (In-vitro)
Procedure Protocol
• 100 ml of saliva substitute placed in 30 different containers labelled with
each respective dietary sample name.
• Fixed orthodontic appliances comprised of brackets, bands, buccal tubes,
lingual attachments, archwires were placed in each container.
• Each day the fixed orthodontic components were immersed in the
respective dietary samples four times daily for two minutes and then
placed back at the respective glass containers containing artificial saliva.
• This procedure is repeated daily for 90 days.
• The sample of artificial saliva (20ml) from the glass container is taken into
glass tubes with the help of pipette and the glass tubes are sealed with
wooden cork.
• The samples are tested using Inductive coupled plasma mass spectrometer
(ICP-MS) at three different time periods (1 week , 1 month and 3 months)
Materials and Method
40 | P a g e
HUMAN SUBJECTS’ PROTECTION: Not applicable
RISKS: Not applicable
PATIENT PROTECTION: Not applicable
FUNDING
• Self-funding by the Principle investigator
• Monetary compensation: Nil
CONFIDENTIALITY: Not applicable
INFORMED CONSENT: Not applicable
Color plates
41 | P a g e
Figure 1: Orthodontic archwires : Ni-Ti archwires and SS archwires (BROOKLYN
ORTHODONTICS)
Figure 2: Heat activated nickel titanium archwires (AMERICAN BRACES)
Color plates
42 | P a g e
Figure 3: Brackets (“0.022”-inch slot stainless steel MBT prescription (Orthox )
Figure 4: Stainless steel bands (SLR-WELCARE ORTHODONTICS)
Color plates
43 | P a g e
Figure 5: Lingual attachments
Figure 6: Buccal tubes
Color plates
44 | P a g e
Figure 7: Glass container with wooden cork
Figure 8: Tweezer
Color plates
45 | P a g e
Figure 9: Glass container
Figure 10: Saliva substitute : SALEVA-DENT AIDS
Results
46 | P a g e
RESULTS
In the present study, 100 ml of saliva substitute placed in 30 different containers
labelled with each respective dietary sample name were taken and fixed
orthodontic appliances comprised of brackets, bands, buccal tubes, lingual
attachments, archwires were placed in each container. Each day the fixed
orthodontic components were immersed in the respective dietary samples four
times daily for two minutes and then placed back at the respective glass containers
containing artificial saliva. This procedure is repeated daily for 90 days. The
sample of saliva substitute (20ml) from the glass container is taken into glass
tubes with the help of pipette and the glass tubes are sealed with wooden cork.
The samples were tested at three different time periods (1 week, 1 month and 3
months)
The results were evaluated and tested for nickel leach from the fixed orthodontic
components into the salivary substitute at three different time intervals. (1 week, 1
month and 3 months)
STATISTICAL ANALYSIS:
Statistical analysis was done by IBM SPSS (IBM Corp. Released 2011.
IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp.)
Table 1: Baseline nickel content present in saliva substitute.
S.NO. SALIVA SUBSTITUTE BASELINE NICKEL CONTENT
A SALEVATM 0.23 mg/L
Results
47 | P a g e
Table 2: Amount of nickel leach from fixed orthodontic components into the
Saliva substitute from different dietary components in three different time
interval
S.NO. DIETARY COMPONENT
T1
(mg/L)
1 WEEK
T2
(mg/L)
1 MONTH
T3
(mg/L)
3 MONTHS
1. LEMON JUICE 0.63 1.13 2.78
2. PEPSI 0.75 1.32 2.98
3. COCA COLA 0.79 1.01 2.95
4. SPRITE 0.70 0.94 2.69
5. BOVONTO 0.68 0.88 2.70
6. 7UP 0.71 0.97 2.75
7. FANTA 0.66 0.90 2.55
8. MIRINDA 0.68 0.87 2.49
9. THUMBS UP 0.78 1.06 2.77
10. MOUNTAIN DEW 0.72 0.98 2.68
11. RED BULL 0.73 1.11 2.91
12. MONSTER 0.70 0.99 2.80
13. GATORIDE 0.67 0.88 2.45
14. VINEGAR 0.57 1.11 2.91
15. TEA 0.38 0.66 1.36
16. COFFEE 0.41 0.69 1.50
17. CURD 0.71 0.98 2.85
18. SAMBHAR 0.31 0.60 1.08
19. RASAM 0.30 0.58 0.98
20. ORANGE JUICE 0.61 0.96 2.08
21. APPLE JUICE 0.70 0.81 1.66
22. APPY FIZZ 0.69 1.01 1.78
23. POMEGRANATE JUICE 0.60 0.89 1.44
24. TROPICANA 0.58 0.78 1.32
25. MINUTE MAID 0.55 0.69 1.02
26. MAZZA 0.52 0.68 1.22
27. GRAPE JUICE 0.68 0.93 2.01
28. FROOTI 0.55 0.62 1.30
29. LEMON TEA 0.68 0.99 1.98
30. MILK 0.51 0.90 1.87
Results
48 | P a g e
Table 3: Amount of nickel leach from fixed orthodontic components into the
Saliva substitute from different dietary components in three different time
interval after deducting the baseline nickel content from saliva substitute.
S.NO. DIETARY COMPONENT
T1
(mg/L)
1 WEEK
T2
(mg/L)
1 MONTH
T3
(mg/L)
3 MONTHS
1. LEMON JUICE 0.4 0.9 2.55
2. PEPSI 0.52 1.09 2.75
3. COCA COLA 0.56 0.78 2.72
4. SPRITE 0.47 0.71 2.46
5. BOVONTO 0.45 0.65 2.47
6. 7UP 0.48 0.74 2.52
7. FANTA 0.43 0.67 2.32
8. MIRINDA 0.45 0.64 2.26
9. THUMBS UP 0.55 0.83 2.54
10. MOUNTAIN DEW 0.49 0.75 2.45
11. RED BULL 0.5 0.88 2.68
12. MONSTER 0.47 0.76 2.57
13. GATORIDE 0.44 0.65 2.22
14. VINEGAR 0.34 0.88 2.68
15. TEA 0.15 0.43 1.13
16. COFFEE 0.18 0.46 1.27
17. CURD 0.48 0.75 2.62
18. SAMBHAR 0.08 0.37 0.85
19. RASAM 0.07 0.35 0.75
20. ORANGE JUICE 0.38 0.73 1.85
21. APPLE JUICE 0.47 0.58 1.43
22. APPY FIZZ 0.46 0.78 1.55
23. POMEGRANATE JUICE 0.37 0.66 1.21
24. TROPICANA 0.35 0.55 1.09
25. MINUTE MAID 0.32 0.46 0.79
26. MAZZA 0.29 0.45 0.99
27. GRAPE JUICE 0.45 0.7 1.78
28. FROOTI 0.32 0.39 1.07
29. LEMON TEA 0.45 0.76 1.75
30. MILK 0.28 0.67 1.64
Results
49 | P a g e
Table 1 reveals the baseline nickel content already present in the saliva substitute
sample which was tested by Inductive coupled plasma mass spectrometer (ICP-
MS), which showed a presence of 0.23 mg/l amount of nickel content.
Table 2 gives the amount of nickel leached from 30 different dietary samples into
the saliva substitute, tested by Inductive coupled plasma mass spectrometer (ICP-
MS) at three different time intervals:
T1: At 1 week
T2: At 1 month
T3: At 3 months
Table 3 gives the exact amount of nickel leached from 30 different dietary
components into the saliva substitute after deducting the baseline nickel content
which was already present in the saliva substitute at three different time intervals.
The results revealed that at 1st week time interval, Coca Cola, Thumbs up, Pepsi
showed the highest amount of nickel leach (0.56 mg/l, 0.55mg/l, 0.52mg/l
respectively) into the saliva substitute.
After 1 month, the results revealed that Pepsi, Lemon juice, Red bull, Vinegar
showed the highest amount of nickel leached (1.09mg/l, 0.9mg/l, 0.88mg/l,
0.88mg/l respectively) into the saliva substitute.
3 months interval results show that Pepsi, Coca cola, Red bull, Vinegar showed
the highest amount of nickel leached (2.75mg/l, 2.72mg/l, 2.68mg/l, 2.68mg/l
respectively) into the saliva substitute.
Results
50 | P a g e
CHARTS
Chart-1
Chart-2
0.4
0.520.56
0.470.450.48
0.430.45
0.550.490.5
0.470.44
0.34
0.150.18
0.48
0.080.07
0.38
0.470.46
0.370.350.32
0.29
0.45
0.32
0.45
0.28
0
0.1
0.2
0.3
0.4
0.5
0.6
LEM
ON
JU
ICE
PE
PSI
CO
CA
CO
LA
SPR
ITE
BO
VO
NT
O
7U
P
FAN
TA
MIR
IND
A
TH
UM
BS
UP
MO
UN
TA
IN D
EW
RE
D B
ULL
MO
NST
ER
GA
TO
RID
E
VIN
EG
AR
TE
A
CO
FFE
E
CU
RD
SAM
BH
AR
RA
SAM
OR
AN
GE
JU
ICE
AP
PLE
JU
ICE
AP
PY
FIZ
Z
PO
ME
GR
AN
AT
E J
UIC
E
TR
OP
ICA
NA
MIN
UT
E M
AID
MA
ZZA
GR
AP
E J
UIC
E
FRO
OT
I
LEM
ON
TE
A
MIL
K
NICKEL CONTENT - T1
0.9
1.09
0.780.71
0.650.74
0.670.64
0.830.75
0.88
0.76
0.65
0.88
0.430.46
0.75
0.370.35
0.73
0.58
0.78
0.66
0.550.460.45
0.7
0.39
0.760.67
0
0.2
0.4
0.6
0.8
1
1.2
LE
MO
N J
UIC
E
PE
PS
I
CO
CA
CO
LA
SP
RIT
E
BO
VO
NT
O
7U
P
FA
NT
A
MIR
IND
A
TH
UM
BS U
P
MO
UN
TA
IN D
EW
RE
D B
ULL
MO
NS
TE
R
GA
TO
RID
E
VIN
EG
AR
TE
A
CO
FF
EE
CU
RD
SA
MB
HA
R
RA
SA
M
OR
AN
GE
JU
ICE
AP
PLE
JU
ICE
AP
PY
FIZ
Z
PO
ME
GR
AN
AT
E J
UIC
E
TR
OP
ICA
NA
MIN
UT
E M
AID
MA
ZZ
A
GR
AP
E J
UIC
E
FR
OO
TI
LE
MO
N T
EA
MIL
K
NICKEL CONTENT - T2
Results
51 | P a g e
Chart-3
2.5
5
2.7
5
2.7
2
2.4
6
2.4
7
2.5
2
2.3
2
2.2
6 2.5
4
2.4
5
2.6
8
2.5
7
2.2
2
2.6
8
1.1
3
1.2
7
2.6
2
0.8
5
0.7
5
1.8
5
1.4
3
1.5
5
1.2
1
1.0
9
0.7
9
0.9
9
1.7
8
1.0
7
1.7
5
1.6
4
LE
MO
N J
UIC
E
PE
PS
I
CO
CA
C
OL
A
SP
RIT
E
BO
VO
NT
O
7U
P
FA
NT
A
MIR
IN
DA
TH
UM
BS
U
P
MO
UN
TA
IN
D
EW
RE
D B
UL
L
MO
NS
TE
R
GA
TO
RID
E
VIN
EG
AR
TE
A
CO
FF
EE
CU
RD
SA
MB
HA
R
RA
SA
M
OR
AN
GE
J
UIC
E
AP
PL
E J
UIC
E
AP
PY
F
IZ
Z
PO
ME
GR
AN
AT
E …
TR
OP
IC
AN
A
MIN
UT
E M
AID
MA
ZZ
A
GR
AP
E J
UIC
E
FR
OO
TI
LE
MO
N T
EA
MIL
K
NICKEL CONTENT - T3
Discussion
52 | P a g e
DISCUSSION
Our diet has an impact on our well-being and on our health. In recent years,
people have become more aware and concerned about maintaining good health
and having a healthy lifestyle. A good diet plays an important role in maintaining
good health.58,91 Even the governments of different countries have been working
to formalize national nutrition monitoring system, and there are new labeling laws
for foods regarding fat and salt content.92
With so much focus on healthier foods and more nutritional food choices, dietary
counseling and nutritional education relevant to oral health have become an
important component of dental education. In fact, 1987 guidelines for
accreditation of dental schools by the American dental Association require that
“the graduate must be competent to provide dietary counseling and nutritional
education relevant to oral health.” Study of diet and nutrition is also a mandatory
part of curriculum in Indian dental schools.93
The warm and moist condition in the mouth offers an ideal environment for the
biodegradation of metals, consequently facilitating the release of metals ions that
can cause adverse effects.
The marked increase of orthodontic treatment has drawn attention to potential
undesired effects. Nickel (Ni)-containing alloys are present in a substantial
number and wide variety of appliances, auxiliaries, and utilities used in
orthodontics and thus become an integral part of almost every routine orthodontic
intervention.
As contemporary orthodontics relies on various bonded attachments, arch wires,
and other devices to achieve tooth movement. The demands made on them are
Discussion
53 | P a g e
complex because they are placed under many stresses in the oral environment,
which include immersion in saliva, ingested fluids, temperature fluctuations, and
masticatory force.
The oral cavity is a complete corrosion cell, with many factors that enhance the
biodegradation of orthodontic appliances. Saliva acts as an electrolyte for electron
and ion conduction, and the fluctuation of pH and temperature, the enzymatic and
microbial activity, and the various chemicals introduced into the oral cavity
through food and drink are all corrosion conductors. The inherent heterogeneity of
each metal alloy and its use with other alloys, the microsurface discontinuity, the
forces acting on the appliances, and the friction between wires and brackets also
add to the corrosion process.
Orthodontic alloys are made from various metals, among which chromium and
nickel are of major concern. Both of these genotoxic, mutagenic, and cytotoxic
metals might induce contact allergy, asthma, hypersensitivity, birth defects, and
reproductive damage. Corrosion of orthodontic alloys might lead to release of
considerable amounts of nickel and chromium ions into saliva.
The present study aims to investigate the effect of dietary habits on the
release of Ni ions from orthodontic appliances in south Indian population.
For the study, we have selected 30 different types of dietary food items which are
commonly consumed by the south Indian population. 100 ml of saliva substitute
placed in 30 different containers labelled with each respective dietary sample
name were taken and fixed orthodontic appliances comprised of brackets, bands,
buccal tubes, lingual attachments, archwires were placed in each container. Each
Discussion
54 | P a g e
day the fixed orthodontic components were immersed in the respective dietary
samples four times daily for two minutes and then placed back at the respective
glass containers containing artificial saliva. This procedure is repeated daily for 90
days. The sample of saliva substitute (20ml) from the glass container is taken into
glass tubes with the help of pipette and the glass tubes are sealed with wooden
cork.
The samples were tested at three different time periods (1 week, 1 month and 3
months) using Inductive coupled plasma mass spectrometer (ICP-MS).
The salivary substitute (Saleva-Dent aids) was tested using ICP-MS before the
immersion of fixed orthodontic components for assessing the baseline nickel
content of the saliva substitute.
The test result showed that the saliva substitute had a nickel content of 0.23mg/l,
indicating the baseline nickel content of the solution.
Each day the fixed orthodontic components were immersed in the respective
dietary samples four times daily for two minutes and then placed back at the
respective glass containers containing saliva substitute.
After 1week interval, saliva substitute from each 30 containers were taken into
numbered glass tubes from 1 to 30, and was tested for nickel content using
Inductive coupled plasma-Mass spectrometer (ICP-MS).
The results revealed that at 1st week time interval, Coca Cola, Thumbs-up, Pepsi
showed the highest amount of nickel leach (0.56 mg/l, 0.55mg/l, 0.52mg/l
respectively) into the saliva substitute.
Discussion
55 | P a g e
After 1 month, the results revealed that Pepsi, Lemon juice, Red bull, Vinegar
showed the highest amount of nickel leached (1.09mg/l, 0.9mg/l, 0.88mg/l,
0.88mg/l respectively) into the saliva substitute.
3 month interval results show that Pepsi, Coca cola, Red bull, Vinegar showed the
highest amount of nickel leached (2.75mg/l, 2.72mg/l, 2.68mg/l, 2.68mg/l
respectively) into the saliva substitute.
To maintain a healthy body it is essential to follow a balanced diet. A diet is called
balanced when it comprises of all the basic nutrients that the body requires and
also meets the calorie requirements of the individual his/her age, sex, activity level
etc in mind. A well balanced diet for a typical Indian teenager is given below.
Food Group Quantity Sources
Cereals 300g Wheat, Rice, Millets
Pulses 60g (Veg), 30g (Non-
Veg)
Sprouts/Fermented
Meat 30g Egg/Chicken/Fish
Vegetables 300g (minimum) Peas, Carrot, Pumpkin,
Beans, Green Leaf
Vegetables etc.
Fruits 100g (minimum) Orange, Apple, Papaya,
Guava, Mango etc
Milk & Milk Products 300g Cheese, Curd etc
Sugar 20g Confectionary
Fats 20g Oil/Butter/Ghee
Orthodontists often advise their patients to eat soft foods during treatment to
accommodate pressure sensitivity experienced with tooth movement however
there is little literature on how orthodontic treatment affects a patient’s diet and
even little reports on clear cut diet guidelines for orthodontic patients. A nutritious
balanced diet is the last thing on the patients mind in the initial 3-4 days of
orthodontic adjustments especially when they think that with the braces
Discussion
56 | P a g e
they have very limited food choices.
Most of them are not aware that it is possible to eat more healthily with braces
because; now one has to watch what he/she is eating.
A BRACES FRIENDLY BALANCED DIET
Cereals (Carbohydrates): - This group should provide ¼ th of our total energy
requirements. The forms in which cereals are generally consumed in a typical
Indian diet consist of chapattis, rice and bread. They are generally an easy food
groups for braces wearers because most grain products are very soft and easily
chewed. In cases of discomfort dunking/mashing chapattis in curries and dals
ensure that you don’t miss out on two most vital components of a balanced diet –
carbohydrates and proteins.
Milk and milk products: - Dairy products should comprise about ¼ th of the total
dietary requirements. Strong bones and teeth rely on a diet that is rich in calcium.
Dairy products provide us with calcium, vitamin D, potassium and even protein.
Dairy products are an excellent choice for braces wearers because most dairy
products are soft and require very little chewing. Milk, milk shakes, yogurt (curd)
and cottage cheese are commonly used milk products in Indian
diets and its consumption by patients should be encouraged.
Vegetables: - Vegetables again comprise about ¼ th of the total dietary
requirements. Vegetables provide us with vitamins and minerals that are essential
for growing bodies. Most Indian diets consume vegetables in the cooked form, so
Discussion
57 | P a g e
they don’t provide much of the problem for braces wearers. They can be meshed
up further for increased comfort. Raw vegetables or salads can be grated or cut
into bite sized pieces.
Fruits: - Fruit is an essential part of a healthy diet but eating it with braces can be
quite challenging. Hard fruits like apple, unripe pears and peaches can be very
difficult to bite into because of the brackets that are on the teeth. After a wire
change even the softest food can be a nightmare. For 3-4 days after an orthodontic
appointment, choose citrus juicy fruits such as oranges and berries. Hard fruits can
be cut bite sized pieces so they can be chewed with the back teeth. If nothing else
works fruit juice is always a healthy easy option. Frequently it is uncomfortable to
bite or chew something very cold with all that metal around the teeth. Having
eatables at room temperature helps.
Nuts and Seeds: - Carefully selecting the choices from this vegetarian group will
help keep the braces secure. Nuts and seeds are very hard and they are very small
– two challenging aspects for braces wearers. During the duration of active
orthodontic treatment select nut spreads or coarsely grind your favorite nuts and
seed.
Meat: - Meat poses a problem for braces wearers because it is fibrous, making it
hard to chew. Avoid eating meat right from the bone. Tofu or cottage cheese
provides a safe alternative to meat as a source of protein. Select, lean, tender cuts
of meat and cut them into bite size pieces before you eat it.
Summary and Conclusion
58 | P a g e
SUMMARY AND CONCLUSION
SUMMARY
The present study was done in the department of orthodontics and
Dentofacial Orthopaedics, Tamil Nadu government dental college and hospital,
Chennai in collaboration with Chennai Mettex lab, Chennai. A total of 30
different types of dietary food items which are commonly consumed by the south
Indian population was selected.
100 ml of saliva substitute placed in 30 different containers labelled with each
respective dietary sample name were taken and fixed orthodontic appliances
comprised of brackets, bands, buccal tubes, lingual attachments, archwires were
placed in each container. Each day the fixed orthodontic components were
immersed in the respective dietary samples four times daily for two minutes and
then placed back at the respective glass containers containing artificial saliva. This
procedure is repeated daily for 90 days. The sample of saliva substitute (20ml)
from the glass container is taken into glass tubes with the help of pipette and the
glass tubes are sealed with wooden cork. The samples were tested at three
different time periods (1 week, 1 month and 3 months)
The results were evaluated and tested for nickel leach from the fixed orthodontic
components into the salivary substitute at three different time intervals. (1 week, 1
month and 3 months).
Summary and Conclusion
59 | P a g e
From the findings observed in this present study it can be concluded that
1. At 1st week time interval, Coca Cola, Thumbs-up, Pepsi showed the
highest amount of nickel leach (0.56 mg/l, 0.55mg/l, 0.52mg/l
respectively) into the saliva substitute.
2. After 1 month, Pepsi, Lemon juice, Red bull, Vinegar showed the highest
amount of nickel leached (1.09mg/l, 0.9mg/l, 0.88mg/l, 0.88mg/l
respectively) into the saliva substitute.
3. At 3 months interval, Pepsi, Coca cola, Red bull, Vinegar showed the
highest amount of nickel leached (2.75mg/l, 2.72mg/l, 2.68mg/l, 2.68mg/l
respectively) into the saliva substitute.
CONCLUSION
The results suggest that consumption of food products of low pH (such as Pepsi,
Coca cola, Red bull, Thumbs up, lemon juices and vinegar) can intensify
aggressiveness of conditions in the oral cavity and has an effect on increasing the
release of Ni from orthodontic appliances. Therefore, it would be useful to
recommend to orthodontic patients to limit consumption of foods and drinks
which are characterized by low values of pH to reduce the quantity of ions
solubilized from metal alloys.
Summary and Conclusion
60 | P a g e
An orthodontic appliance friendly balanced diet
FOOD GROUP MAIN NUTRIENTS
Cereals, grain products, rice and wheat
flour, maize, rice flakes, and Maida
Energy, protein, invisible fats,
Vitamins B and B2, folic acid,
iron, and fiber
Pulses ‑ Legumes, Bengal gram, black
gram, green gram, red gram, Rajmah,
soyabean
Energy, protein, invisible fats,
Vitamins B and B2, folic acid,
calcium, iron, and fiber
Milk and meat products Protein, fat, Vitamin B2, calcium
Meat and chicken liver, fish, eggs Protein, fat, and
Vitamin B2
Fruits ‑ Apple, guava, tomato ripe,
papaya, orange, sweet lime, watermelon
Fiber, Vitamin C, carotenoids
Vegetables (green leafy) Invisible fat, carotenoids,
Vitamin B2, folic acid, iron,
calcium fiber
Other vegetables- Carrot, brinjal,
Lady’s finger, capsicum, beans, onion,
cauliflower
Carotenoids, folic acid, calcium
fiber
Fat and sugar‑butter, ghee, groundnut,
coconut oil
Energy, fats, and essential fatty
acids
Sugar and jiggery Energy
Summary and Conclusion
61 | P a g e
BRACES‑FRIENDLY EATING TIPS
When you abide by the rules of what to eat and what not to eat when wearing
braces, you are doing yourself a favor. Your orthodontist gives you dietary
guidelines for a reason. When you are wearing braces, it is important to avoid
certain foods that can damage the orthodontic appliances, brackets, and wires,
which may cause delays in treatment.
The key rule is: Nothing hard, sticky or chewy!
Here is a handy red, yellow, and green light list of do’s and don’ts when it comes
to snacking while wearing braces.
“ABSOLUTELY NO” FOOD GROUP
Gum – sugarless or otherwise
Sticky foods – toffees, candies etc
Hard food – nuts (unless grinded), popcorn, corn on the cob, pizza crusts, ice,
cookies.
Red light (never eat!):
Nuts, popcorn, chewing gum, hard pretzels, pizza crust, Gummy Bears, caramels,
jelly beans, chocolate chips, ice cubes, chapatti, paratta, nan and boiled candy, and
foods with low ph value.
Summary and Conclusion
62 | P a g e
Yellow light (use caution, cut up, and chew with back teeth) :
Nacho Chips, Bagels, Ribs, chicken wings, raw vegetables, hard fruit (i.e., apples,
unless sliced thin or cut in small pieces), fruit with pits (i.e., peaches), corn on the
cob, crusty bread, Granola Bars, and foods high in sugar (e.g., pop, candy): don’t
eat often and brush soon after.
Green light (go for it!):
Ice cream (no nuts), potato chips, steamed vegetables, pasta potatoes, French fries,
soft pretzels, yogurt, pudding, jelly, soup, subs, sandwiches, cereal in milk,
cheese, eggs, milkshakes, caramel bars, and peanut butter cups.
Bibliography
63 | P a g e
BIBLIOGRAPHY
1. Burkert NT, Muckenhuber J, Grobschsdl F, Rasky E, Freidl W (2014)
Nutrition and Health – The Association between Eating Behavior and Various
Health Parameters: A Matched Sample Study. PLoS ONE 9(2): e88278.
doi:10.1371/journal.pone.0088278
2. Attin, K Weiss, K Becker, W Buchalla, A Wiegand, Impact of modified acidic
soft drinks on enamel erosion. Oral Diseases (2005)
3. SariME, Erturk AG, Koyuturk AE, Bekdemir Y (2014) Evaluationof the effect
of food and beverages on enamel and restorative materialsby SEM and Fourier
transform infrared spectroscopy. Microsc Res Tech 77:79–90
4. Marcin Mikulewicz & Katarzyna Chojnacka, Trace Metal Release from
Orthodontic Appliances by In Vivo Studies: A Systematic Literature Review.
Biol Trace Elem Res (2010) 137:127–138 DOI 10.1007/s12011-009-8576-6
5. Occurrence of risk factors fordental erosion in the population of young adults
in Norway Asmyhr, Grytten J, Holst D. Occurrence of risk factors for dental
erosion in the population of young adults in Norway. Community Dent Oral
Epidemiol2012. © 2012 John Wiley & Sons
6. Berge M, Gjerdet NR. Corrosion of silver soldered orthodontic wires. Acta
Odontol Scand 1982;40:75-9.
7. Maijer R, Smith DC. Corrosion of orthodontic bracket bases. Am J Orthod
1982;81:43-8.
8. Blanco-Dalmau L, Carrasquillo-Alberty H, Silva-Parra J (1984) A study of
nickel allergy. J Prosthet Dent 52:116–119
9. Eliades T, Pratsinis H, Kletsas D, Eliades G, Makou M (2004)
Characterization and cytotoxicity of ions released from stainless steel and
Bibliography
64 | P a g e
nickel-titanium orthodontic alloys. Am J Orthod Dentofacial Orthop 125:24–
29
10. Genelhu M, Marigo M, Alves-Oliveira LF, Malaquias L, Gomez RS (2005)
Characterization of nickelinduced allergic contact stomatitis associated with
fixed orthodontic appliances. Am J Orthod Dentofacial Orthop 128:378–381
11. Hayes RB (1997) The carcinogenicity of metals in humans. Cancer Causes
Control 8:371–385
12. Grimsdottir MR, Hensten-Pettersen A, Kulmann A. Cytotoxic effect of
orthodontic appliances. European Journal of Orthodontics 1992;14:47–53
13. Bass JK, Fine H, Cisneros GJ. Nickel hypersensitivity in the orthodontic
patient. American Journal of Orthodontics and Dentofacial Orthopedics
1993;103:280–285
14. Kerosuo H, Kullaa A, Kerosuo E, Kanerva L, Hensten-Petterson A. Nickel
allergy in adolescents in relation to orthodontic treatment and piercing of ears.
American Journal of Orthodontics and Dentofacial Orthopedics
1996;109:148–154
15. Rietschel RL, and Fowler JF Jr (Eds). Contact dermatitis and other reactions to
metals.
16. Barret RD, Bishara SE, Quinn JK. Biodegradation of orthodontic appliance.
Part I. Biodegradation of nickel and chromium in vitro. American Journal of
Orthodontics and Dentofacial Orthopedics 1993;103:243–250
17. Bishara SE, Barret RD, Selim MI. Biodegradation of orthodontic appliances.
Part II. Changes in the blood level of nickel. American Journal of
Orthodontics and Dentofacial Orthopedics 1993;103:115– 119
Bibliography
65 | P a g e
18. Mydlarski PR, Katz AM, Mamelak AJ, et al. Contact dermatitis. In
Middleton’s Allergy Principles & Practice. Adkinson N F Jr, Yunginger JW,
Busse WW, Bochner BS, Holgate ST, and Simons E R (Eds). Philadelphia:
Mosby, 1581–1597, 2003.
19. Contact urticaria. In Fisher’s Contact Dermatitis. Rietschel RL, and Fowler JF
Jr (Eds). Philadelphia: Lippincott Williams & Wilkins, 581–604, 2001.
20. In vitro yelease of nickel and chromium from simulated orthodontic
appliances H. Y. Park, D.M.D., and T. R. Shearer, Ph.D.
21. Asmyhr Q, Grytten J, Holsr D (2012) Occurrence of risk factors for dental
erosion in the population of young adults in Norway. Community Dent Oral
Epidemiol 40:425–431
22. Aghili HA, Hoseini SM, Yassaei S, Fatahi Meybodi SA, Zaeim MH,
Moghaadam MG (2014) Effects of carbonated soft drink consumption on
orthodontic tooth movements in rats. J Dent (Teheran) 11:123–130
23. Anusavice K. Phillips’ science of dental materials. 11th ed. Philadelphia: W.
B. Saunders; 2003: p. 57-64.
24. Eliades T, Bourauel C. Intraoral aging of orthodontic materials: the picture we
miss and its clinical relevance. Am J Orthod Dentofacial Orthop
2005;127:403-12.
25. Amini F, Farahani A, Jafari A, Rabbani M. In vivo study of metal content of
oral mucosa cells in patients with and without fixed orthodontic appliances.
Orthod Craniofac Res 2008;11:51-6.
26. Faccioni F, Franceschetti P, Cerpelloni M, Fracasso M. In vivo study on
metal release from fixed orthodontic appliances and DNA damage in oral
mucosa cells. Am J Orthod Dentofacial Orthop 2003; 124:687-94.
Bibliography
66 | P a g e
27. Garhammer P, Schmalz G, Hiller KA, Reitinger T. Metal content of biopsies
adjacent to dental cast alloys. Clin Oral Invest 2003;7:92-7.
28. Brantley WA, Eliades T (2001) Orthodontic materials: scientific and clinical
aspects. Georg Thieme, Stuttgart, pp 271–286
29. House K, Sernetz F, Dymock D, Sandy JR, Ireland AJ (2008)Corrosion of
orthodontic appliances—should we care? Am J Orthod Dentofac Orthop
133:584–592
30. Faccioni F, Franceschetti P, Cerpelloni M, Fracasso ME (2003) In vivo study
on metal release from fixed orthodontic appliances and DNA damage in oral
mucosa cells. Am J Orthod Dentofac Orthop 124:687–693
31. Mikulewicz M, Chojnacka K (2010) Trace metal release from orthodontic
appliances by in vivo studies: a systematic literature review. Biol Trace Elem
Res 137:127–138
32. Hafez HS, Selim EM, Kamel Eid FH, Tawfik WA, Al-Ashkar EA, Mostafa
YA (2011) Cytotoxicity, genotoxicity, and metal release in patients with fixed
orthodontic appliances: a longitudinal in-vivo study. Am J Orthod Dentofac
Orthop 140:298–308
33. Amini F, Rakhshan V, Mesgarzadeh N (2012) Effects of long-term fixed
orthodontic treatment on salivary nickel and chromiumlevels: a 1-year
prospective cohort study. Biol Trace Elem Res 150:15–20
34. Amini F, Rakhshan V, Sadeghi P (2012) Effect of fixed orthodontic therapy
on urinary nickel levels: a long-term retrospective cohort study. Biol Trace
Elem Res 150:31–36
35. Amini F, Harandi S, Mollaei M, Rakhshan V (2015) Effects of fixed
orthodontic treatment using conventional versus metal injection molding
Bibliography
67 | P a g e
(MIM) brackets on salivary nickel and chromium levels: a double-blind
randomized clinical trial. Eur J Orthod. doi:10.1093/ ejo/cju079
36. Amini F, Rahimi H, Morad G, Mollaei M (2013) The effect of stress on
salivary metal ion content in orthodontic patients. Biol Trace Elem Res
155:339–343
37. Amini F, Borzabadi Farahani A, Jafari A, Rabbani M (2008) In vivo study
ofmetal content of oralmucosa cells in patients with and without fixed
orthodontic appliances. Orthod Craniofacial Res 11:51–56
38. Matos de Souza R, Macedo de Menezes L (2008) Nickel, chromium and iron
levels in the saliva of patients with simulated fixed orthodontic appliances.
Angle Orthod 78:345–350
39. Amini F, Jafari A, Amini P, Sepasi S (2012) Metal ion release from fixed
orthodontic appliances—an in vivo study. Eur J Orthod 34: 126–130
40. Eliades T, Athanasiou AE (2002) In vivo aging of orthodontic alloys:
implications for corrosion potential, nickel release, and biocompatibility.
Angle Orthod 72:222–237
41. Hwang CJ, Shin JS, Cha JY (2001) Metal release from simulated fixed
orthodontic appliances. Am J Orthod Dentofac Orthop 120: 383–391
42. Kocadereli L, Atac PA, Kale PS, Ozer D (2000) Salivary nickel and chromium
in patients with fixed orthodontic appliances. Angle Orthod 70:431–434
43. Agaoglu G, Arun T, Izgi B, Yarat A (2001) Nickel and chromium levels in the
saliva and serum of patients with fixed orthodontic appliances. Angle Orthod
71:375–379
44. Natarajan M, Padmanabhan S, Chitharanjan A, Narasimhan M (2011)
Evaluation of the genotoxic effects of fixed appliances on oral mucosal cells
Bibliography
68 | P a g e
and the relationship to nickel and chromium concentrations: an in-vivo study.
Am J Orthod Dentofac Orthop 140:383–388
45. Kusy RP (2004) Clinical response to allergies in patients. Am J Orthod
Dentofac Orthop 125:544–547
46. Li Z, Gu JY, Wang XW, Fan QH, Geng YX, Jiao ZX, Hou YP, Wu WS
(2010) Effects of cadmium on absorption, excretion, and distribution of nickel
in rats. Biol Trace Elem Res 135:211–219
47. Abtahi M, Jahanbin A, Yaghoubi M, Esmaily H, Zare H (2013) Are more
nickel ions accumulated in the hair of fixed orthodontic patients? Indian J
Dent Res 24:298–301
48. Martin-Camean A, Molina-Villalba I, Jos A, Iglesias-Linares A, Solano E,
Camean AM, Gil F (2014) Biomonitorization of chromium, copper, iron,
manganese and nickel in scalp hair from orthodontic patients by atomic
absorption spectrometry. Environ Toxicol Pharmacol 37:759–771
49. Menezes LM, Quintao CA, Bolognese AM(2007) Urinary excretion levels of
nickel in orthodontic patients. Am J Orthod Dentofac Orthop 131:635–638
50. Levrini L, Lusvardi G, Gentile D (2006) Nickel ions release in patients with
fixed orthodontic appliances. Minerva Stomatol 55: 115–121
51. Mikulewicz M, Wolowiec P, Loster B, Chojnacka K (2014) Metal ions
released from fixed orthodontic appliance affect hair mineral content. Biol
Trace Elem Res
52. Kusy RP (2002) Orthodontic biomaterials: from the past to the present. Angle
Orthod 72:501–512.
53. Hafez HS, Selim EMN, Eid FHK, Tawfik WA, Al-Ashkar EA, Mostafa YA
(2011) Cytotoxicity, genotoxicity, and metal release in patients with fixed
Bibliography
69 | P a g e
orthodontic appliances: a longitudinal in-vivo study. Am J Orthod Dentofacial
Orthop 140:298–308
54. Wataha J. Biocompatibility of dental casting alloys: a review. J Prosthet Dent
2000;83:223-34.
55. Rojas E, Herrera L, Poirier L, Ostrosky-Wegman P. Are metals dietary
carcinogens? Mutat Res 1999;443:157-81.
56. Schmalz G, Garhammer P. Biological interactions of dental cast alloys with
oral tissues. Dent Mater 2002;18:396-406.
57. Khatri JM, Kolhe VD. Nutrition and orthodontics.Int J Orthod Rehabil
2018;9:163-7.
58. R Sharma, S Mittal, A Singla, M Virdi. Nutritional Guidelines for Orthodontic
Patients. The Internet Journal of Nutrition and Wellness. 2009 Volume 10
Number 2.
59. Stephen F. Litton, Orthodontic tooth movement during an ascorbic acid
deficiency. Am J Orthod March 1974.
60. C. Abalos, A. Paul, A. Mendoza, E. Solano, C. Palazon, and F.J. Gil. Influence
of Soft Drinks with Low pH on Different Ni-Ti Orthodontic Archwire Surface
Patterns. Journal of Materials Engineering and Performance Volume 22(3)
March 2013—759
61. H. Y. Park, and T. R. Shearer, In vitro yelease of nickel and chromium from
simulated orthodontic appliances. Am J Orthod August 1983.
62. Gjerdet NR, Here H. Metal release from heat-treated orthodontic archwires.
Acta Odontol Scand 1987;45:409-414. Oslo. ISSN 0001-6357.
Bibliography
70 | P a g e
63. Margret Rosa Grimsdottlr, Nils R. Gjerdet, Arne Hensten-Pettersen
Composition and corrosion of in vitro orthodontic appliances.AM J
ORTHOD DENTOFAC ORTHOP 1992;101:525-32.
64. N. Staffolani, F. Damiani, C. Lilli, M. Guerra, N.J. Staffolani, S. Belcastro, P.
Locci. Ion release from orthodontic appliances. Journal of Dentistry 27 (1999)
449–454
65. Neamat Abu-bakr, Linlin Han, Akira Okamoto, and Masaaki Iwaku, Changes
in the mechanical properties and surface texture of compomer immersed in
various media. The journal of prosthetic dentistry volume 84 number 4
66. O Mockers, D Deroze, J Camps. Cyotoxicity of orthodontic bands, brackets
and archwires in vitro. Dental materials 18(2002) 311-317
67. Theodore Eliades, Athanasios E. Athanasiou, In Vivo Aging of Orthodontic
Alloys: Implications for Corrosion Potential, Nickel Release, and
Biocompatibility. Angle Orthodontist, Vol 72, No 3, 2002
68. Nicolas Schiff, Mickaël Boinet, Laurent Morgon, Michèle Lissac, Francis
Dalard and Brigitte Grosgogeat. Galvanic corrosion between orthodontic wires
and brackets in fluoride mouthwashes. European Journal of Orthodontics 28
(2006) 298–304 doi:10.1093/ejo/cji102.Advance Access publication 20
January 2006
69. Maja Kuhta; Dubravko Pavlin; Martina Slaj; Suzana Varga; Marina Lapter-
Varga, Mladen Slaj.Type of Archwire and Level of Acidity:Effects on the
Release of Metal Ions from Orthodontic Appliances. The EH Angle Education
and Research Foundation DOI: 10.2319/083007-401.1.
Bibliography
71 | P a g e
70. Marcin Mikulewicz & Katarzyna Chojnacka. Trace Metal Release from
Orthodontic Appliances by In Vivo Studies: A Systematic Literature Review.
Biol Trace Elem Res (2010) 137:127–138 DOI 10.1007/s12011-009-8576-6
71. TP Chaturvedi, SN Upadhayay. An overview of orthodontic material
degradation in oral cavity. Indian J Dent Res, 21(2), 2010
72. Antonio Jos_e Ortiz,a Esther Fern_andez,b Ascensi_on Vicente,a Jos_e L.
Calvo,c and Clara Ortiz Metallic ions released from stainless steel,nickel-free,
and titanium orthodontic alloys: Toxicity and DNA damage. Am J Orthod
Dentofacial Orthop 2011;140:e115-e122
73. Hend Salah Hafez, Essam Mohamed Nassef Selim, Faten Hussein Kamel Eid,
Wael Attia Tawfik, Emad A. Al-Ashkar, and Yehya Ahmed Mostafa.
Cytotoxicity, genotoxicity, and metal release in patients with fixed orthodontic
appliances: A longitudinal in-vivo study. Am J Orthod Dentofacial Orthop
2011;140:298-308
74. R. S. Senkutvan, Sanjay Jacob, Anila Charles, Vaishali Vadgaonkar, Suruchi
Jatol-Tekade, Parag Gangurde. Evaluation of nickel ion release from various
orthodontic arch wires: An in vitro study. Journal of International Society of
Preventive and Community Dentistry January-April 2014, Vol. 4, No. 1
75. Fariborz Amini & Mobina Mollaei & Saghar Harandi & Vahid Rakhshan,
Effects of Fixed Orthodontic Treatment on Hair Nickel and Chromium Levels:
A 6-Month Prospective Preliminary Study. Biol Trace Elem Res,17 November
2014 DOI 10.1007/s12011-014-0188-0.
76. Fariborz Amini, Mahsa Shariati, Farhad Sobouti, and Vahid Rakhshan, Effects
of fixed orthodontic treatment on nickel and chromium levels in gingival
Bibliography
72 | P a g e
crevicular fluid as a novel systemic biomarker of trace elements: A
longitudinal study. Am J Orthod Dentofacial Orthop 2016;149:666-72.
77. Kumar RV, Rajvikram N, Rajakumar P, Saravanan R, Deepak VA,
Vijaykumar V. An Accurate Methodology to detect Leaching of Nickel and
Chromium Ions in the Initial Phase of Orthodontic Treatment: An in vivo
Study. J Contemp Dent Pract 2016;17(3):205-210.
78. Magnusson, B., Bergman, M., Bergman, B. & Soremark, R.: Nickel allerg)-
and nickel-containing dental alloys. Scand. J. Dent. Res. 1982: 90: 163-167.
79. Luis Blanco-Dalmau, Harold Carrasquillo-Albert and Juan Silva-Parra, A
study of nickel allergy. The journal of prosthetic dentistry july 1984 volume 52
number 1.
80. Lilian Staerkjaer and Torkil Menne. Nickel allergy and orthodontic treatment.
European Journal of Orthodontics 12 (1990) 284-289.
81. Justin K Bass, Howard Fine, George J Cisneros. Nickel hypersensitivity in
orthodontic patients. Am J Orthod dentofac orthop 1993;103:280-5.
82. J. D. Bumgardner, J. Doeller, and L. C. Lucas. Effect of nickel-based dental
casting alloys on fibroblast metabolism and ultrastructural organization.
Journal of Biomedical Materials Research, Vol. 29, 611-617 (1995).
83. Heidi Kerosuo, Arja Kullaa, Eero Kerosuo, Lasse Kanerva, and Arne Hensten-
Pettersen, Nickel allergy in adolescents in relation to orthodontic treatment
and piercing of ears. AM J ORTHOD DENTOFAC ORTHOP 1996;109:148-
54.
84. Gabriele Schuster, Ralf Reichle, Radha Ranei Bauer, Peter M. Schopf.
Allergies Induced by Orthodontic Alloys: Incidence and Impact on Treatment.
J Orofac Orthop 2004;65:48–59. DOI 10.1007/s00056-004-0312-4.
Bibliography
73 | P a g e
85. Marisa Cristina Leite Santos Genelhu, Marcelo Marigo, Lúcia Fraga Alves-
Oliveira, Luiz Cosme Cotta Malaquias, and Ricardo Santiago Gomez.
Characterization of nickel-induced allergic contact stomatitis associated with
fixed orthodontic appliances. Am J Orthod Dentofacial Orthop 2005;128:378-
81.
86. Kristen K. Volkman, Michael J. Inda, Peter G. Reichl, and Michael C.
Zacharisen. Adverse reactions to orthodontic appliances in nickel-allergic
patients. Allergy Asthma Proc 28:480 –484, 2007; doi:
10.2500/aap.2007.28.3018.
87. J. Noble, S. I. Ahing,
N. E. Karaiskos,
W. A. Wiltshire. Nickel allergy and
orthodontics, a review and report of two cases. BRITISH DENTAL JOURNAL
VOLUME 204 NO. 6 MAR 22 2008.
88. Olga Elpis Kolokitha; Evangelia Chatzistavrou. A Severe Reaction to Ni-
Containing Orthodontic Appliances. Angle Orthod. 2009;79:186–192.
89. Ronny Fors, Berndt Stenberg, Hans Stenlund and Maurits Persson. Nickel
allergy in relation to piercing and orthodontic appliances – a population study.
Contact Dermatitis 3 March 2012. doi:10.1111/j.1600-0536.2012.02097.x.
90. Lina Gölz, Spyridon N. Papageorgiou and Andreas Jäger. Nickel
hypersensitivity and orthodontic treatment: a systematic review and meta-
analysis. Contact Dermatitis 24 February 2015. doi:10.1111/cod.12392
91. Romito LM. Introduction to nutrition and oral health. Dent Clin North Am
2003;47:187‑207.
92. Yetley EA, Beloian AM, Lewis CJ. Dietary methodologies for food and
nutrition monitoring. Vital Health Stat 4 1992;27:58-67.
Bibliography
74 | P a g e
93. Ministry of Health and Family Welfare, Government of India. MDS Course
Regulation 2007. Dental Council of India, Ministry of Health & Family
Welfare, Government of India; 2007.