14/10/2015 22:23 © Author / Presentation ReferenceSlide 1 Dentine Hypersensitivity.

21/04/23 06:09 © Author / Presentation ReferenceSlide 1

Dentine Hypersensitivity


Introduction

Besides being an extremely uncomfortable disturbance for the patient, dentine hypersensitivity is difficult for the dentist to diagnose and solve as it is a physiological phenomenon of high complexity.


Definition

“a short, sharp transient pain, arising from exposed dentine in response to thermal, chemical or osmotic stimuli”


Dentine exposed by either

• Loss of enamel covering crown (attrition, erosion)

• Gingival recession with exposure of root surface and loss of cementum


Causes: Attrition - excessive tooth contact

Erosion - acidic drinks

Loss of tooth enamel with exposure of underlying dentine


Etiology – Loss of enamel with exposure of underlying dentin

• Abrasion

• Attrition

• Abfraction

• Erosion

• Fracture

• Enamel is resistant to tooth-brushing, but acid softened enamel is highly susceptible to brushing abrasion*

• “Abrasive” toothpastes may produce a smear layer, thereby reducing sensitivity**

*Davis and Winter, Br. Dent J, 1980, **Adams et al, Oxford U. Press, 1992


Localised Generalised

Gingival recession with exposure of root surface and loss of cementum


Etiology – Gingival recession with exposure of root surface and loss of cementum

• Incorrect tooth-brushing or flossing• Secondary to specific diseases – periodontitis, necrotising-ulcerative gingivitis (NUG)• Periodontal procedures• Age• Gingival trauma (picking, hard foods)• Crown preparation

Localised

Generalised


In 93% of instances pain involves root surfaces exposed as result of gingival recession

The focus of this presentation will be dentine hypersensitivity associated with gingival recession (exposure of the neck of

tooth)


Enamel

Dentine

Pulp

Root cementum

Healthy tooth


Gingival recession


Teeth most commonly affected by recession and hypersensitivity

• Incisors 26%

• Canines 25%

• Premolars 38%

• Molars 12%


Patients report sensitivity to:

• Thermal stimulus (cold) 75%

• Tactile stimulus 25%

• Osmotic stimulus (sweet) 16%


cold

Heat

Movement of fluid in the

tubules

Movement of fluid in the

tubules

Odontoblasts

Exposed root dentine

Hydrodynamic theory

Tubules exposed at

dentine surface


Brain

Fluid movement

Nerve receptors

Hydrodynamic theory


Non-sensitive SensitiveNo of open tubules x 8 xDiameter of tubules 0.43 0.83Fluid Flow (Poisseuille’s law) y 16 y

*Absi et al, J Clin Periodont 1987; pictures from http://www.thejcdp.com, Sept 2006

Structural differences between sensitive and non-sensitive dentin*

http://www.thejcdp.com/


Exposure of root surface and root dentine can occur as a result of:

• Abrasion - toothbrushing

• Periodontal disease

• Periodontal treatment


Abrasion


Abrasion


Abrasion and acid erosion







Peridontal disease







Root sensitivity following periodontal therapy

Fischer et al. (1991)

9% patients sensitive before treatment

55% patients sensitive 1 week after

Tammaro et al. (2000)

23% sensitive before treatment

54% sensitive 1 week after treatment


Periodontal treatment


Treatment Principles:Two Mechanisms

• Tubule occlusion

• Inhibition of sensory nerve activity


Treatment principles:two mechanisms




Stimulation ofnerve endingsPAIN

Stimulus

Fluid movement

Dentinal tubule

Hydrodynamic theory

Odontoblast


Occlusion

Tubule OcclusionOpen Tubule


Tubule occlusion

Measures type of productStannous Fluoride Toothpaste, Gel

RinseHigh fluoride Varnish, Gels

Precipitating salts Calcium phosphateSilicatesHydroxyapatite

Restorative materials AdhesivesResins

Laser Softlaser


Home care treatment: SnF2 Gel (Gel-Kam)

Abstract:

• 18 subjects

• Eight weeks, double blind, placebo controlled clinical study

• Treatment of dentinal hypersensitivity

• Thermal stimulus

Blong MA et al. Dental Hygiene, November 1985; 489-92


Home care treatment: SnF2 Gel (Gel-Kam)

Results:

• After 4 and 8 weeks treatment subjects in the Gel-Kam group experience a significant higher resistance against low temperatures than the placebo group.

Blong MA et al. Dental Hygiene, November 1985; 489-92

Thermal Threshold Measures

60

65

70

75

80

Baseline 2 weeks 4 weeks 8 weeks

Assessment intervals

Deg

rees

Fah

ren

hei

tGel-Kam Control


In office treatment: High fluoride varnish (Duraphat)

Abstract:

• 59 subjects

• Two / four weeks, examiner blind, positive controlled clinical study

• Treatment of dentinal hypersensitivity

• Heat, cold, touch and air-blast stimuli

Papas AS et al. J Dent Res 71 (Special Issue); 28, 1992


In office treatment: High fluoride varnish (Duraphat)

Results:

• Pain relief after a single varnish treatment

• Almost no pain felt (air-blast stimulus) after 3 treatments

• For positive control 1.500 ppm MFP Gel 1 month of treatment needed for some relief

Papas AS et al. J Dent Res 71 (Special Issue); 28, 1992


Duraphat varnish


Treatment




Inhibition of sensory nerve activity

• Potassium salts


Typical structure of a neuron

nucleusMyelin sheath

Ranvier‘s node

Schwann‘s cell

Desensitizing of nerves


Resting potential at neuronal membranes

• K+ gradient from inside to outside

• K+ diffuses from inside to outside along the gradient


Action potential

• Changes in the membrane lead to an influx of Na+ and an increased efflux of K+ which leads to a depolarisation of the membrane realized as pain

++

++

++

Number of open Na+ channels

Number of open Na+ channels

DepolarisationDepolarisation

Influx of Na+ ionsInflux of Na+ ions


Desensitization through buffering the membrane potential with K+

K+

K+

K+ K+

K+ K+

K+K+

K+

Potassium ions

Pain receptor

Pain receptor

Reduced nerve stimulation

Reduced nerve stimulation

• Increased K+ concentration at the outside of membranes decrease the diffusion of K+, thus stabilizing the membrane potential


Desensitising efficacy of dentifrices containing potassium nitrate

Abstract:

• 68 subjects

• 12-week, double-blind, three-way parallel comparative study

• Treatment of dental hypersensitivity

• Cold air and tactile stimuli

Silverman G et al. 1985


Desensitising efficacy of dentifrices containing potassium nitrate

Results:

• Dentifrices containing potassium nitrate were significantly more effective in reducing discomfort caused by tactile and thermal stimuli than placebo

Silverman G et al. 1985

0

0.5

1

1.5

2

2.5

Baseline 4 weeks 12weeks

Mea

n c

old

air

sco

res

Potassium Nitrate Control


Desensitising efficacy of dentifrices containing potassium salts

Abstract:

• 80 subjects

• Examinations at 4 and 8 weeks

• Tactile and air-blast stimuli

Hu et al. 2004


Desensitising efficacy of dentifrices containing potassium salts

Double-blind design, 80 participants

Results: Tactile stimulus

Hu et al. 2004

Groups BL 4W 8W

Sensodyne F 19.75 29.92* 35.13*

Colgate Sensitive 19.19 29.29* 34.88*


Desensitising Efficacy of Dentifrices containing potassium salts

Double-blind design, 80 participants

Results: Air Blast

Hu et al. 2004

Groups BL 4W 8W

Sensodyne F 2.50 1.74 1.31

Colgate Sensitive 2.53 1.80 1.33


Desensitising therapies – treatment options

At Home Treatments In Office TreatmentsPreventive Measures


Treatment options

1. Eliminate aetiological and predisposing factors, such as acid foods and traumatic toothbrushing

2. Advise the use of a toothpaste that either occludes the tubules or reduces the responsiveness of the nerves together with a soft toothbrush

3. In severe cases: additional professional application of fluoride varnish and / or at home application of stannous fluoride or high fluoride gels


Preventive Measures

• Often underestimated by dental professionals*:

• Use proper brushing and flossing technique

• Avoid brushing of acid eroded enamel (brush no earlier than 2-3 hours after consuming acidic foods or drinks)

• Diet hygiene, avoiding exogenous acids (fruits, fruit juice, soft drinks, wine)

• Treatment of diseases that associate regurgitation, or severe vomiting (gastric acid reflux, nervous bulimia)

*Rees et al, J Dent 2003


CONCLUSIONS

• Dentinal hypersensitivity is a common condition.

• Professional diagnosis is essential to eliminate other possible causes of pain

• Treatment possibilities are based on – Tubule occlusion

– Desensitizing of nerves

• Treatment options should be based on the severity – Mild and medium : Home maintenance

(Sensitive toothpaste plus soft toothbrush) Home treatment (Fluoride Gels)

– Medium to severe: Acute in-office treatment (Varnish) plus additional at home treatment (fluoride gels) and

maintenance


Back-up


Acknowledgements

This lecture has been prepared by Prof. Robin Davies (DHU Manchester, UK) Irina Tarba (Professional Relations Manager, Colgate Romania) and Michael Warncke, (Professional Relations Manager, Colgate Germany)

© Scientific Affairs, Colgate Europe / South Pacific, Geneva, Switzerland

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14/10/2015 22:23 © Author / Presentation ReferenceSlide 1 Dentine Hypersensitivity.

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