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

14/10/ :23 © Author / Presentation ReferenceSlide 2 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.

14/10/ :23 © Author / Presentation ReferenceSlide 3 Definition “a short, sharp transient pain, arising from exposed dentine in response to thermal, chemical or osmotic stimuli”

14/10/ :23 © Author / Presentation ReferenceSlide 4 Dentine exposed by either Loss of enamel covering crown (attrition, erosion) Gingival recession with exposure of root surface and loss of cementum

14/10/ :23 © Author / Presentation ReferenceSlide 5 Causes:Attrition - excessive tooth contact Erosion - acidic drinks Loss of tooth enamel with exposure of underlying dentine

14/10/ :23 © Author / Presentation ReferenceSlide 6 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

14/10/ :23 © Author / Presentation ReferenceSlide 7 LocalisedGeneralised Gingival recession with exposure of root surface and loss of cementum

14/10/ :23 © Author / Presentation ReferenceSlide 8 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

14/10/ :23 © Author / Presentation ReferenceSlide 9 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)

14/10/ :23 © Author / Presentation ReferenceSlide 10 Enamel Dentine Pulp Root cementum Healthy tooth

14/10/ :23 © Author / Presentation ReferenceSlide 11 Gingival recession

14/10/ :23 © Author / Presentation ReferenceSlide 12 Teeth most commonly affected by recession and hypersensitivity Incisors 26% Canines 25% Premolars 38% Molars 12%

14/10/ :23 © Author / Presentation ReferenceSlide 13 Patients report sensitivity to: Thermal stimulus (cold) 75% Tactile stimulus 25% Osmotic stimulus (sweet) 16%

14/10/ :23 © Author / Presentation ReferenceSlide 14 cold Heat Movement of fluid in the tubules Odontoblasts Exposed root dentine Hydrodynamic theory Tubules exposed at dentine surface

14/10/ :23 © Author / Presentation ReferenceSlide 15 Brain Fluid movement Nerve receptors Hydrodynamic theory

14/10/ :23 © Author / Presentation ReferenceSlide 16 Non-sensitiveSensitive No of open tubulesx8 x Diameter of tubules Fluid Flow (Poisseuille’s law)y16 y *Absi et al, J Clin Periodont 1987; pictures from Sept 2006http:// Structural differences between sensitive and non-sensitive dentin*

14/10/ :23 © Author / Presentation ReferenceSlide 17 Exposure of root surface and root dentine can occur as a result of: Abrasion - toothbrushing Periodontal disease Periodontal treatment

14/10/ :23 © Author / Presentation ReferenceSlide 18 Abrasion

14/10/ :23 © Author / Presentation ReferenceSlide 19 Abrasion

14/10/ :23 © Author / Presentation ReferenceSlide 20 Abrasion and acid erosion

14/10/ :23 © Author / Presentation ReferenceSlide 21 Exposure of root surface and root dentine can occur as a result of: Abrasion - toothbrushing Periodontal disease Periodontal treatment

14/10/ :23 © Author / Presentation ReferenceSlide 22 Peridontal disease

14/10/ :23 © Author / Presentation ReferenceSlide 23 Exposure of root surface and root dentine can occur as a result of: Abrasion - toothbrushing Periodontal disease Periodontal treatment

14/10/ :23 © Author / Presentation ReferenceSlide 24 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

14/10/ :23 © Author / Presentation ReferenceSlide 25 Periodontal treatment

14/10/ :23 © Author / Presentation ReferenceSlide 26 Treatment Principles: Two Mechanisms Tubule occlusion Inhibition of sensory nerve activity

14/10/ :23 © Author / Presentation ReferenceSlide 27 Treatment principles: two mechanisms Tubule occlusion Inhibition of sensory nerve activity

14/10/ :23 © Author / Presentation ReferenceSlide 28 Stimulation of nerve endings PAIN Stimulus Fluid movement Dentinal tubule Hydrodynamic theory Odontoblast

14/10/ :23 © Author / Presentation ReferenceSlide 29 Occlusion Tubule OcclusionOpen Tubule

14/10/ :23 © Author / Presentation ReferenceSlide 30 Tubule occlusion

14/10/ :23 © Author / Presentation ReferenceSlide 31 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;

14/10/ :23 © Author / Presentation ReferenceSlide 32 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;

14/10/ :23 © Author / Presentation ReferenceSlide 33 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

14/10/ :23 © Author / Presentation ReferenceSlide 34 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 ppm MFP Gel 1 month of treatment needed for some relief Papas AS et al. J Dent Res 71 (Special Issue); 28, 1992

14/10/ :23 © Author / Presentation ReferenceSlide 35 Duraphat varnish

14/10/ :23 © Author / Presentation ReferenceSlide 36 Treatment Tubule occlusion Inhibition of sensory nerve activity

14/10/ :23 © Author / Presentation ReferenceSlide 37 Inhibition of sensory nerve activity Potassium salts

14/10/ :23 © Author / Presentation ReferenceSlide 38 Typical structure of a neuron nucleus Myelin sheath Ranvier‘s node Schwann‘s cell Desensitizing of nerves

14/10/ :23 © Author / Presentation ReferenceSlide 39 Resting potential at neuronal membranes K + gradient from inside to outside K + diffuses from inside to outside along the gradient

14/10/ :23 © Author / Presentation ReferenceSlide 40 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 Depolarisation Influx of Na + ions

14/10/ :23 © Author / Presentation ReferenceSlide 41 Desensitization through buffering the membrane potential with K + K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ Potassium ions Pain receptor Reduced nerve stimulation Increased K + concentration at the outside of membranes decrease the diffusion of K +, thus stabilizing the membrane potential

14/10/ :23 © Author / Presentation ReferenceSlide 42 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

14/10/ :23 © Author / Presentation ReferenceSlide 43 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

14/10/ :23 © Author / Presentation ReferenceSlide 44 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

14/10/ :23 © Author / Presentation ReferenceSlide 45 Desensitising efficacy of dentifrices containing potassium salts Double-blind design, 80 participants Results: Tactile stimulus Hu et al Groups BL4W8W Sensodyne F *35.13* Colgate Sensitive *34.88*

14/10/ :23 © Author / Presentation ReferenceSlide 46 Desensitising Efficacy of Dentifrices containing potassium salts Double-blind design, 80 participants Results: Air Blast Hu et al Groups BL4W8W Sensodyne F Colgate Sensitive

14/10/ :23 © Author / Presentation ReferenceSlide 47 Desensitising therapies – treatment options At Home TreatmentsIn Office TreatmentsPreventive Measures

14/10/ :23 © Author / Presentation ReferenceSlide 48 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

14/10/ :23 © Author / Presentation ReferenceSlide 49 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

14/10/ :23 © Author / Presentation ReferenceSlide 50 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

14/10/ :23 © Author / Presentation ReferenceSlide 51 Back-up

14/10/ :23 © Author / Presentation ReferenceSlide 52 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