. 1 RESEARCH METHODOLOGY AND BIOSTATISTICS Dr. Vidhur Chouhan Department Of Conservative Dentistry And Endodontics SNO. TOPIC 1. Introduction 2. Categories Of Research 3. Problem Formulation 4. Hypothesis 5. Data Collection 6. Analysis and Interpretation 7. Writing a Report 8. Conclusion 9. References CONTENTS INTRODUCTION Word Research derived from “Recherche” “To go about seeking” Earliest use of term dates back to late 16 th century Research in India has been dated to pre Vedic era, where the word “Jignyasa”- desire to know was used. Initially gurukulas were the centers of learning and research. “Continual search for truth using scientific method” Soben Peter. Definitions “Research is the endeavor to discover new or collate old facts by critical study” - Oxford English Dictionary “Research is a fundamental state of mind involving continual examination of doctrines and axioms upon which current thought and action are based” - Theobald Smith Refers to laboratory , clinical and field investigations that lead to improvement in control of oral diseases and health care delivery.”
Transcript
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RESEARCH METHODOLOGY AND BIOSTATISTICS
Dr. Vidhur ChouhanDepartment Of Conservative Dentistry And Endodontics
SNO. TOPIC
1. Introduction
2. Categories Of Research
3. Problem Formulation
4. Hypothesis
5. Data Collection
6. Analysis and Interpretation
7. Writing a Report
8. Conclusion
9. References
CONTENTS
INTRODUCTION
Word Research derived from “Recherche”
“To go about seeking”
Earliest use of term dates back to late 16th century
Research in India has been dated to pre
Vedic era, where the word “Jignyasa”-
desire to know was used.
Initially gurukulas were the centers of learning and research.
“Continual search for truth using scientific method”Soben Peter.
Definitions
“Research is the endeavor to discover new or collate old
facts by critical study”
- Oxford English Dictionary
“Research is a fundamental state of mind involving
continual examination of doctrines and axioms upon
which current thought and action are based”
- Theobald Smith
Refers to laboratory ,
clinical and field investigations that lead to
improvement in control of oral diseases and
health care delivery.”
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To contribute new knowledge or re-evaluate current knowledge to improve all phases of oral health care.
Purpose?
To improve techniques and practices of identifying and treating oral diseases in individuals
Purpose?
To develop and test theories related to oral health care and oral disease processes.
To identify and solve problems indigenous to advancement , decision making and change in oral health care delivery.
To promote the oral health of the public by improving education, service, practice and delivery.
Categories of Research
Basic and Applied
Empirical and Theoretical
Quantitative and Qualitative
Conceptual and Empirical
Scientific Method
“It refers to a series of standarized procedures used in research to increase the likelihood that information
gathered will be relevant ,reliable and unbiased”
Steps In Scientific Methods
Problem Formulation
Hypothesis Formulation
Data Collection
Analysis and Interpretation
Writing a Report
“A Comparative Evaluation of Duraphat and Fluorprotector”
Problem Formulation
“A researchable problem is a statement or question that
poses an unknown relationship between variables and
serves to focus the entire investigation”.
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Ideal Requirements Of Research Problem
Problem must be of interest to researcher.
Should contribute to oral health leading new knowledge, improving current practices or developing new theories
Problem must be observable and capable of measurement through known methods of quantification
Must be significant to some aspects of oral health care.
A hypothesis is defined as
“tentative prediction or
explanation of relationship
between two or more
variables”.
Hypothesis Formulation
It is an assumption made before investigation regarding the outcome under study.
(H1 )Alternate Hypothesis- It is the
hypothesis ,which assumes that there is
significant difference between 2 values
(H0 )Null Hypothesis-Hypothesis which assumes that there is no significant difference between 2 values.
In general hypothesis are stated in null form.
It is the procedure used to decide whether a hypothesis is to reject or not is called testing of hypothesis
Testing Of Hypothesis
Steps in testing the hypothesis
Draw the conclusion
Obtain table Value
Compute the value of Test Statistic
Choose level of significance
Set the Hypothesis
Compare critical value with table value
Sampling is “process or technique of selecting a
sample of appropriate characteristics and
adequate size”.
SAMPLNG AND SAMPLE DESIGNS
A sample is a part of population called ‘Universe’ or
‘Parent population’.
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ADVANTAGES OF SAMPLING
ThoroughInvestigation
Reduces no. of Personnel
IDEAL REQUIREMENTS OF A SAMPLE
Representativeness
Size
Sample Selection
Purposive Selection
Random Selection
Individuals are purposively selected to represent
population under study
Sample of units are randomly selected to represent all
characterstics of population.
NON-PROBABILITY SAMPLING
Not true representative of population
Used in cases where researcher not
able to obtain a random sample.
Less desirable than probability sampling.
QUOTA SAMPLING
General composition of sample decided
in advance as quota.
Done to insure inclusion of particular
segment of population.
Limitation- Do not generalize population
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PURPOSIVE SAMPLING
Used to serve a very specific need/purpose.
This type of sampling is used for hard to track
population.It is a chain referral sampling(snowball sample)
CONVINENCE SAMPLING
This sampling based on “taking what you can get”
Accidental sample
Volunteers contribute to this type of sampling
PROBABILITY SAMPLING
True representative of population
Each individual unit in population has
known probability of being selected.
Recommended method of sampling.
SIMPLE RANDOM SAMPLING
Each and every unit of population has the same
chance of being included in the sample.
Each unit is determined by chance only
SYSTEMATIC SAMPLING
Select one unit at random and then select additional
units at evenly spaced interval till sample of required
size attained.
STRATIFIED SAMPLING
Population is divided into strata according to
certain common characterstics.
Random /Systematic sampling than performed
independent of strata.
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CLUSTER SAMPLING
Sampling unit are clusters eg: Villages
First sample of clusters are selected and then all
units of selected clusters are surveyed.
DATA COLLECTION
Data can be collected from surveys, experiments,
hospital records and other public service reports.
Collected Data are important determinants for
oral health care programs.
SOURCE OF DATA
Data obtained by investigator himself.
Data already recorded is utilized to serve purpose of study.Eg: OPD Records.
Direct Personnel Interviews.Oral Health ExaminationQuestionnaire Method
DATA CLASSIFICATION
When data is collected on basis of
attributes or qualities.Like- sex, malocclusion,
cavity etc
When data is collected through measurement
using calipers.Like- arch width, length, fluoride concentration .
Data are distinct and separate and also takes only fixed values like whole numbersEg: DMF Teeth.
Variable take any value in a given range, decimal or fractionalEg:arch length,mesiodistal width
PRESENTATION OF DATA
After collection of data next step is to sort and classify them in characterstic group or classes.
The objective is to make data simple ,concise,meaningful, and helpful in further analysis.
2 Methods of Presenting Data
Tabulation Charts and Diagrams
TABULATION
Simple devices used for presentation of data.
Standard principles for table construction:
i. Data must be presented according to size, chronologically or alphabetically.
ii. Should be self explanatory.
iii. Specific units of measure for data should be given.
iv. Should contain a title, which should be clear , concise and to the point.
v. If data not original, their source should be mentioned.
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TYPES OF TABLES
MASTER TABLES SIMPLE TABLES FREQUENCYDISTRIBUTION
TABLEThey are the tables which contain all data obtainedfrom survey
One way table which supplies answers to questions
Simplest table with 2 columns:
- First column lists classes into
which data are grouped
- - Second column lists frequencies
for each classification
Charts and Diagrams
Considered as most convincing and appealing ways of depicting statistical results. Useful as:
Attractive to eyes.
Facilitate comparision of data ,thereby facilitating conclusion directly or indirectly
Simplify complexity in understanding.
Give bird’s eye view Of entire data
Charts and Diagrams
DISCRETE
Histogram Line chart
Frequency chart
Bar chartsPie chartsPictogram
CONTINOUS
Charts and Diagrams
Bar Charts A way of presenting set of numbers by length of bar with
width remaining same.
It can be :-Simple bar chartMultiple bar chartProportional bar chart
Pie Diagrams
Divided into different sectors corresponding to frequencyof variables in distribution
Line Diagrams
Simplest type of diagram useful to study changes of values in variable over time.
Histogram
Pictorial diagram of frequency distribution.No space between cells of a histogram.
Charts and Diagrams
Frequency polygon Pictorial diagram of frequency distributionPoint is marked over mid point of blocks which are connected by straight lines
Cartogram
Maps are used to show Geographical distribution of frequencies of characterstic.
Pictogram
Small pictures or symbols used for presenting data
Scatter Diagram
Show relationship betweentwo variables.
If dot clusters around straight line,It shows linear relationship.
Analysis and Intrpretation
Analysis and interpretation is done using “biostatistics”
The word “statistics” comes from italian
word ‘statista’ meaning “statesman”
John Graunt considered as the father of health statistics.
Statistics is science of compiling, classifying and
tabulating numerical data and expressing results in
a mathematical or graphical form
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BIOSTATISTICS
Biostatistics is branch of statistics concerned with
mathematical facts and data related to biological events.
Measure mortality and morbidity
Evaluate achievements of public
health care programs
Evaluate efficacy of vaccines etc.
Fix priorities in public health care
programs
BASIS FOR STATISTICAL ANALYSIS
POPULATION
(U)
VARIABLES(V)PROBABILITY
DISTRIBUTION(P)
Collection of units of observation that are of interest and target of investigation
It is a condition , concept or event whose value is free to vary within a population.
VARIABLE
“A Variable is a state , condition, concept or eventwhose value is free to vary within a population”
CLASSIFICATION
Independent Variable- Variables that can be manipulated in study to see what effect they will have on dependent variable.
Dependent Variable- Variables in which changes are result of amount of independent variable.
Confounding Variable- Variables which may influence effect of independent variable on dependent variable.
It is central value around which the other values are distributed.
OBJECTIVE: to condense the entire mass of data & facilitate comparison
MEASURES OF CENTRAL TENDENCY/STATISTICAL ANALYSIS
PROPERTIES
It should be easy to understand and compute.
It should be based on each and every item on series.
It should not be affected by extreme observations.
ARTHIMETIC MEAN
◆ Simplest Measure.
◆ Obtained by summing up the values of all observations ,divided by total number of observation.
Here; Xi = value of each observation in data; n=no. of observations
ADVANTAGES:Easy to calculate and understandIt is most useful of all averagesDISADVANTAGES:May be unduly influenced by abnormal values
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MEDIAN
◆ It is the middle value in a distribution such that one
half of the units in the distribution have a value
smaller than or equal to the median and one half have
a value greater than or equal to the median.
◆ All the observations are arranged in ascending or
descending order of their magnitude and middle value
is selected as the median.
Even number of observations: mean of the middle two values is taken as the mean.
Odd number of observations: middle value is taken as median.
Advantage: Not affected by abnormal values
MODE
◆ The mode or the modal value is that value in a series
of observations that occurs with the greatest
frequency
◆ There can be more than 1 mode for a given series
When mode ill defined it canbe calculated using following
relation:
Mode = 3 median – 2 mean
IMPORTANT POINTS
◆ Depending on nature of data and objective of study,
appropriate measure of central tendency used:
◆ Most commonly used: ARITHMETIC MEAN
◆ Extreme values in the series: MEDIAN
◆ To know the value that has high influence in the series:
MODE
MEASURES OF DISPERSION
It helps to know how widely the observation are spread on
either side of average.
Dispersion is the “degree of spread or variation of the
variable about a central value”
Measures Of
Dispersion
Range
Median Deviation
Standard Deviation
RANGE
◆ Though simplest method, but gives no information
about the values that lie between the extremes
values.
◆ Subject to fluctuations from sample to sample
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MEAN DEVIATION
It is the average of the deviations from the arithmetic
mean. Given By:
M.D = Ʃ (X – Xi)
n
Where, Ʃ ( sigma ) is the sum of,X is the arithmetic
mean, Xi is the value of each observation in the data,
n is the number of observation in the data.
STANDARD DEVIATION
Most important and widely used measure of studying dispersion.
Also known as ‘root mean square deviation’, because it is the square root of the mean of the squared deviations from the arithmetic mean.
◆ Greater the SD, greater will be themagnitude of dispersion from the mean◆ Smaller SD means a higher degree of
uniformity of the observations
NORMAL DISTRIBUTION CURVE
◆ Also known as “Gaussian curve, Normal curve”
◆ When data is collected from a very large number of people and a frequency distribution is made with narrow class intervals, resulting curve is smooth and symmetrical , is called a ‘Normal Curve’.
Area between one SD on either side of mean
Area between three SD on either side of mean
Area between two SD on either side of mean
The limits on either side of mean are called confidence limits
There might be many normal curves but only one standard normal curve.
STANDARD NORMAL CURVE
Bell Shaped
Total area of curve is one , mean is zero,
SD is one.Mean, Median, Mode coincide
Perfectly Symmetrical Curve
TESTS OF SIGNIFICANCE
◆ When different samples drawn from the same
population, estimates differ known as Sampling
Variability
◆ Tests of Significance deals with techniques to know
how far differences differences between estimates is
due to sampling variation.
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TYPE OF TESTS◆ Uses Parameter like SD OR MEAN for comparision.◆ Uses data from normallydistributed population
◆ Can deal with nominal and ordinal data
Developed by Karl PearsonNon parametric test used for measuring sampling
variation of qualitative dataIt is used when data is measured in terms of attributes
/qualities .Advantage : Can be used when more than two groups are
to be compared
Parametric Tests◆ Used to test significance of difference between large
samples>30◆ Pre Requisites for Z test:
1. Sample must be randomly selected2. Data must be quantitative3. Variable assumed to follow a normal distribution in the
population
Z test◆ It was designed by W.S Gosset◆ It is used when sample size is small◆ Also called “Student t-Test”◆ t = ratio of observed difference between
two means of small samples to the standarderror of difference in the same.
t test
Criteria for applying ‘t’ test:
a. Sample must be randomly selected
b. Data must be quantitative
c. Sample should be less than 30
It is applied to find significance of difference between two proportions:
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PAIRED t TEST UNPAIRED t TEST
• Applied to data of independent observation from one sample only
• Applied to data of independent observation from two different samples
• Data is collected before and after intervention.
• Data is collected between intervention.
• Size of two groups should be same
• Size of two groups need not be same
◆ Also known as Analysis Of Variance.◆ Tests equality of 3 or more means of more
than two groups
ANOVA TEST
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◆ After analysis and interpretation, next step is writing
report.
◆ Basic purpose of this is to communicate research
process and observed findings to professional
community and colleagues so that findings may be
evaluated and implemented for benefit of a larger
population.
◆ All text on title page should be centered vertically and
horizontally.
◆ Should not contain page number
TABLE OF CONTENTS
INTRODUCTION
BACKGROUND
METHODOLOGY
RESULTS
CONCLUSION
• Should contain few short introductory paragraph.
• Should catch the attention of reader.• Contain statements about need of study.• Include dramatic illustrations or quotes• Should contain:A. Statement of problemB. PurposeC. Significance of studyD. Research question/hypothesis
Contain review of literatureShow what previous researchers have discovered.
Also include special terms that are unique to study
Operational definitions should also be included
• Describe basic research plan.• Includes :A. Defining populationB. Drawing representative sample
from populationC. Research on sampleD. When research began and completed.E. Describes Validity and Reliability assessment.
• Collected demographic information is reported in a simple way in results.• Contain:A. Type of statistical testB. Statistics and conclusion, followed by appropriate
table.C. Restate research question
◆ Should contain summarizing paragraphlike what was done and found
◆ Should also contain reasons why the results might have turned out the way they did.◆ Discuss findings
It appears at end of a piece of work.
IMPORTANCE
Indicates thorough investigation
CITATION- A way to tell readers that certain part of your work has been derived from another source at thesame time acknowledging that source.
BIBLIOGRAPHY- “there may be many articles which we have referred but not referenced in text, would be headed BIBLIOGRAPHY.
SECONDARY REFERENCING-Refer to document which you you have not seen but have been used and cited by some other book. Cite book which refer to document.
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◆ Author-date style.
◆ Also referred as “Parenthetical system” because name
and date are placed in brackets
◆ The citation within text are given using
author’s name and date in brackets
while reference list is given at end of document
being arranged alphabetically.
HARVARD STYLE
Also known as citation –sequence approach
The style was developed by US National Library of Medicine and adopted as part of their ‘Uniform Requirements For manuscripts submitted to Biomedical Journals’.
The medical journals generally require Vancouver Style.
Uses a number series within text to indicate references.
The reference list at end is ordered numerically as they
appear in text.
Each citation is given a unique number in order in which it
appears in text, either in brackets or superscripted
Details of source are either given at footnotes or endnotes.
Main text reads more easily and is less obtrusive.
Two or more references to same author have been cited: arrange in chronological order by date of publication.Eg: Brown 1991,1994
Two or more references to same author have been cited from same year: differentiate them with a,b,c annotation.Eg: Smith 1996a,Smith 1996b
Two authors sharing same surname: add their initials in citation.Eg: Smith TH 1992’Smith W 1992
Two author included use ‘and’ If three or more authors use ‘et al’.
Two or more consecutive citations from same source are cited, word ibid is used
Research is quest
for knowledge
through diligent
search aimed at
discovery and
experimentation
of new
knowledge.
Scientific
method is a
systemic body of
procedures and
techniques
applied in
carrying out
investigation
targeting
obtaining new
knowledge.
Research and
scientific methods
may be considered
a critical inquiry
leading to
discovery of new
fact or
information,which
increases our
understanding of
human health and
disease.
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REFERENCES THANK YOU
“Difficulties in life do not come to destroy you, but to help you realize your hidden potential and power, Let difficulties know that you too are difficult..”
APJ Abdul Kalam
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Root Canal Sealers
1
Dr. Vidhur ChouhanDepartment Of Conservative Dentistry And Endodontics
Contents• Introduction
• Definition
• Ideal Requirements
• Functions
• Classifications
• Direction of use, Advantage, Disadvantages
• Recent advancements
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Introduction
Purpose of sealing the root canal is to prevent priapicalexudates from diffusing into unfilled part of the canal,
to avoid reentry and colonization of bacteria from reaching the periapical tissues, therefore to
accomplish fluid tight seal.
RC Sealer is used only as adjunctive materials in the obturation of RC system and improve the outcome of
treatmnet
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The adequate combination of sealing ability and biocompatibility is important to improve prognosis of
root canal treatment
Studies have shown most commercially available sealers can irritate the periapical tissues .
So, for the RC sealers toxicity should be minimal and at later time period material should become as inert as
possible.
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Definition
SEALER, root canal (cement)-A radiopaquedental cement used, usually in combination
with a solid or semisolid core material, to fill voids and to seal root canals during obturation.
❑Glossary of Endodontic Terms
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Ideal RequiremnetsShould provide an excellent seal apically and laterally.
Should produce adequate adhesion when it sets.
Should be radiopaque
Should be dimensionally stable.
Should be easily mixed and introduced in the root canal
Should be non staining
Should be easily removed if necessary.
Be insoluble in tissue fluids
Should be bactericidal and non irritating
should be slow setting to ensure sufficient working
•Should not provoke an immune response onperiapical tissues
•Should not be mutagenic.- Cantatore.
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Functions Of Sealers
• Binding agent to cement the well fitted primary cone into a canal
• Filler for the discrepancies between the cone and the canal walls
• Lubricant to facilitate the seating of the primary cone into the canal
• Certain techniques dictate the use of particular sealer
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Classification
Cements
Pastes
Plastics
INGLE
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Type-I: Filling Material intended to be use with core materialClass-1 Powder and liquid sets by non-polymerization processCass-2 Two pastes sets by non-polymerization processClass-3 Polymer and resin system, sets by polymerization process
Type-II: Filling Material intended to be use with or without core materialClass-1 powder and liquid sets by non polymerizing processClass-2 Paste and paste sets by non polymerization processClass-3 Material include metal AmalgamClass-4 Material include polymers and resin sets by polymerizationCOHEN 9
Non absorbableeg.: Diaket, ketacendo,AH 26/AH plus
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Classification
Eugenol Non Eugenol Medicated
Based on Composition
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Silver Containing
Kerr sealer (Ricket1931)
Procosol radio opaque silver cement
(Grossman, 1936)
Silver Free
Procosol non staining cement (Grossman,
1958)
Grossman’s sealer (Grossman, 1974)
Tubliseal (Kerr, 1961)
Wach’s paste (Wach)
EugenolBased
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Non-EugenolDiaket
AH2
Chlorpercha
NogenolHydron
Endofil
Glass Ionomer Cement
Polycarboxylate
Calcium phosphate
cement
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Diaket A
N2
Endomethasone
SPAD
IodoformPaste
Riebler’sPaste
Mynol paste
Ca(OH)2 Paste
Medicated
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Based on principal
ingredient
Zinc Oxide Based
EugenolContaining
Non-Eugenol
Containing
IodoformBased
Idodoformbased
Vitapex16
PolyacrylicBased
PolyacrylateCement
Glass Ionomer Based- Ketac Endo
Calcium Hydroxide Based
Sealapex
CRCS(Calcibiotic Root Canal Sealer)
Apexit
Apexit plus
Vitapex
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Resin Based
Polyvinyl resin based
Diket DiketA
Epoxy resin
AH26 AH Plus
Methacrylatebased resin
Fiber fill Hydron Epiphany
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Lee
Endofill
Roeko Seal
Gutta Flow
Silicon Based
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Mono Block Concept
• It means to creation of a solid, bonded continuous material from one dentin wall of the canal to other.
• This phenomenon strengthen the root.
MonoblockConcept
Primary
Secondary
Tertary
Franklin R. Tay J endo 200720
• Primary- Obturation is done completely with core material. Eg: MTA
• Secondary- Bond is there between etched dentin of canal wall and impregnated with resin tags which are attached to resin cements which are bonded to core layer. Eg: Resilon based cement
Calcium and hydroxyl ions of MTA + phosphate-containingsynthetic body fluid apatite like interfacial deposits
(BIOLOGIC APATITE) –Benham Bolhari et al JOE 2014
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• Tertiary- Conventional GP is coated with resinwhich bond with sealer, which further bond to canal wall– Anatomic post system
– EndoRez system
– Activ GP
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Methods of sealer placement• Coating the sealer with master gutta
• It is sticky due to the presence of Canada balsam
• Increasing thickness of the sealer lessens its lubricating effect so it is indicated where there is possibility of over extension.
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ADVANTAGES
• It is a good germicidal, relatively low tissue irritant .
• The sealer is biocompatible to the periapicaltissue.
DISADVANTAGES
• Wach’s paste has medium working time and has less lubricating quality.
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Manipulation• The sealer is supplied as powder and liquid
separately. One drop of liquid is used with an appropriate amount of powder.
• Mixed to a creamy smooth consistency and should string out atleast one inch when spatula is raised from the glass slab.
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Zinc Oxide Based Sealers
TUBLISEAL
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Zinc Oxide Based Sealers
MANIPULATION
• Tubliseal sealer is contained in two collapsible tubes containing a
• base and accelerator which when mixed together to about half an
• inch (which is sufficient in most cases) forms a creamy mix.
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ADVANTAGES• The sealer does not stain the tooth structures.
• It is extremely lubricating has a high rate of flow giving a thinner film.
• Expands after setting
DISADVANTAGES• Very low viscosity -makes extrusion through the
apical foramen
• Irritating to the periapical tissue• Short working time
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Zinc Oxide Based Sealers
INDICATIONS
• When apical surgery is to be performed immediately after filling
• Because of good lubricating property, it is used in cases where it is difficult for a master cone to reach the apical third of the root canal.
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Systemic Toxicity and Allergies of ZOE sealers
• Formaldehyde, which is released from ZOE sealers containing paraformaldehyde, is a known allergen (hapten) as well.
• Local Toxicity and Tissue Compatibility
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• A number of case reports document that paraformaldehydecontaining ZOE sealers may cause an aspergillosis of the maxillary sinus when the root canals of upper posterior teeth are overfilled and the sealers are pressed into the maxillary sinus.
Advantages•Not affected by moisture•ST= 24-36 hours•5-7 days at room temperature•Greater adhesion to dentin•Low solubility•Tissue compatibility•Slight shrinkage
PASTE- B•Adamantianeamine•N,N- di benzyl-5 Oxanonane-diamine-1,9,TCD-diamine•Zirconium oxide•Silica•Silicone oil 66
Properties
Working time- 4hrsSetting time- 8 hrsFilm thickness- 26μ
Shrinkage- 1.76%Solubility- 0.31%
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AH26 V/S AH Plus
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•Powder and liquid•Releases small amount offormaldehyde on mixing.•Causes tooth staining.•Film thickness: 39μ.•Setting time :24- 36 hours.•Good radio opacity•Less soluble
•Less toxic so biocompatible•Does not cause staining •It is 20μ
•Setting time: 8 hours•Better radio opacity•Half solubility when compared to AH 26
Methacrylate Resin Based
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HYDRON
• Rapid setting hydrophilic, plastic material used as root canal sealer without the use of a core.•Wichterle and lim in 1960• It is available as an injectable root canal filling material• Polymer of hydroxy ethyl methacrylate
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Advantages
•A biocompatible material•Conform the shape of the root canal because of its plasticity
Disadvantages
•Short working time•Very low radiopacity•Irritant to the periapical tissues•Difficult to remove from the canals
Endo REZ• UDMA based
• Bio compatible, Hydrophilic sealer
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• Radiopacity similar to GP• Good Adaptation• Good Flow• Remain Soft and Plastic for
longer time
Advantages
• Shelf life(18 months)• Poor sealing in apical third• Shrinkage (hammad et al 2008)Diasadvantages
EPIPHANY
• Self etched primer and sealer
• Core material (RESILON points)❖Claimed to achieve excellent seal by creating a
MONOBLOCK
• Prior to the application of primer,
• 17% EDTA – smear layer removal
• Rinsing with saline or 2% CHX
• Primer with paper points
• Sealer mixed (dual syringe mixed with auto mixing tip)
• Applied into the canal using lentulo spiral or Master Cone
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• Highly Radiopaque• Easy to remove
• Dual curing and Hydrophilic
• Biocompatible, nonmutagenic, and noncytotoxic
• Less irritating
• Improves the fracture resistance of the roots
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Properties
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RESILON
• Initial studies on resilon favorable
• Resilon polycaprolactone polymer core contains a blend of dimethacrylates that bonds with the methacrylate-based sealer, which in turn bonds with the root dentin, forming a monoblock.
• Final irrigation with CHX or EDTA
• Biocompatible
• Low cytotoxicity
73Resilon: a methacrylate resin-based obturation System2010 Association for Dental Sciences of the Republic of China
Properties•Excellent flow• Insolubility•Dimensional stability – expands slightly (0.2%)•Extremely biocompatible, does not containEugenol•Highly radiopaque
ENDOFILL
COMPOSITION• The base-
– Bismuth sub nitrate- Radio opacifier. – Active Hydroxyl terminated dimethyl polysiloxane,– Benzyl alcohol – Hydrophobic amorphous silica (10 to 30 milli microns particle size).
• Catalysts-– Ethyl ortho silicate,
– Poly dimethyl siloxane– Catalyst intermediate.
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• When set has a rubbery consistency.
• Initially the manufacturer recommended that it be injected into the canal as the sole sealer.
• It is virtually nontoxic the least irritating sealer on the market.
• When used properly as a sealer with gutta perchait is quite similar to other sealers.
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ADVANTAGES• It is easy to prepare.• It has a adjustable working time, low viscosity and
rubbery in consistency.• It is easy to remove as Gutta Percha.
DISADVANTAGES• The endofill cannot be used in the presence of
hydrogen peroxide and the canal must be absolutely dry.
• It also shrinks upon setting, but has an affinity for flowing into tubules.
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GUTTA FLOW
• Syringe delivery system.
• Self mixing followed by dispensing tube
• Cold-flowable filling system
• Combines gutta percha with sealer
• WT: 15min.
• ST: 25-30min
78
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79
ADVANTAGES DISADVANTAGES
• Flowable , thixotropic• Dimensionally stable
• Expands slightly
Larger armamentarium needed
MEDICATED ROOT CANAL SEALERS
80
N2•Sargenti and Ritcher•Formaldehyde – prolonged fixation and antiseptic action
Composition
Powder
Bismuth Carbonate9.93%Zinc Oxide
64.50%
4.67%Bismuth nitrate14.90%
Paraformaldehyde5.71% Ferric Oxide
0.04%
Zinc stearate0.074%
• Liquid contents:
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TOXICITY** Degree of irritation is severe with over filling , persistingparesthesia
Disadvantage– Difficult to remove in the event of retreatment
– Toronto/Osract group – chloroform and ultrasonic no.25 file
84
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85 86
Recent Advances
CERAMICS-BASED SEALERS
‘Endodontic grafting’
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Filling of the root canal with ceramic sealer, which due to itsosseoconductivity action promotes the physiological closure ofthe canal by cementoid hard tissue, can be called “endodontic
grafting.” Such endodontic grafting can ensure the lasting root’s
health while it constantly remains in contact with body fluids.
CPM Sealer• Presented as a white modified portland cement-
based material.
• Significant difference is the presence of calcium carbonate, which intends to increase the release of Calcium ions offering good sealing properties, adhesion to dentinal walls, adequate flow rate, and biocompatibilty
• 4-META promotes monomer diffusion into the acid-conditioned and underlying intact dentinand produces functional hybridized dentin with polymerization.
• The formation of the hybrid dentin is the major mechanism of bonding
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Conclusion
• In endodontic practice, the success of root canal therapy mainly depend on achieving a compact fluid tight seal of the apical end of the root canal, so as to prevent the ingress and accumulation of irritants causing biological breakdown of attachment apparatus leading to failure.
• Root canal sealers along with solid core material play a major role in achieving a good seal.
102
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References
• John I Ingle, Endodontics. Fifth ed. 2002 • 2. Grossman LI. Endodontic practice. 10th ed. 1982 • J Biomed Mater Res B Appl Biomater. 2008 Feb;84(2):430-5• Oper Dent. 2005 Jul-Aug;30(4):533-9• Monoblocks in endodontics – Franklin R.Tay et al JOE 2007• K.mamootil & H.H.Messer IEJ 2007• INSIDE DENTISTRY—JANUARY/FEBRUARY 2006• Richard S. Schwartz JOE—Volume 32, Number 12, December 2006• Darrag/Fayyad Adhesives in endodontics. Part II ENDO (Lond
