cosmetic dentistry - beauty & science

I 25 research _ hypersensitivity I cosmeticdentistry 2_2012 ThePro-Arginformulacontainsarginine,anamino acid found in saliva. The positively charged arginine binds to the negatively charged dentine surface. This attracts a calcium-rich layer from the saliva to infil- trateandblockthedentinaltubules(Fig.6).16 Thistechnologyisavailableforin-officeapplication, through a paste that is delivered by prophylaxis cup. Thereisalsoatoothpasteforat-homeuse.Thein-office pastehasbeenfoundtoprovideimmediateandlasting relief of hypersensitivity for four weeks when it is ap- pliedasthefinalpolishingstepofaprofessionalclean- ing.25 Ithasalsobeenfoundtodecreasedentalprophy- laxisdiscomfortwhenusedpriortotheprocedure.26 _Depolarisation of the nerve The second major group of desensitisation prod- uctsworksbydepolarisingthenervethattransmitsthe painresponse.Afterthenervehasbeendepolarised,it cannot re-polarise and this diminishes its excitability. The ingredient that produces this effect is potassium nitrate.27 AccordingtotheFDA,forapotassiumnitrate toothpastetoclaimtobedesensitisingitmustcontain 5%oftheingredient.Potassiumnitratepenetratesthe enamel and dentine to travel to the pulp and exerts a calmingeffectonthenerve.Thiseffectcanbethought ofasanesthetic-like.28 Potassiumnitrateproductsareidealforwhitening sensitivity. Whitening sensitivity occurs due to the easypassageofperoxidethroughtheenamel(asemi- permeable membrane) and dentine to the pulp. De- sensitisation products that work by occluding the dentinaltubulesareineffectiveinpreventingthepas- sageofthetinyperoxidemolecule,whichcantravelin theinterstitialspacesbetweenthetubules.28 Potassiumnitratecanbedeliveredinseveraleffec- tivewaystocounteractwhiteningsensitivity: 1.Pre-brushing with a 5 % potassium nitrate tooth- paste for two weeks pre-whitening and during whitening: It takes approximately two weeks for the potassium nitrate to be at peak desensitisation efficacy.29 2.Whitening tray delivery of a potassium nitrate toothpaste for ten to 30 minutes during whitening treatment:Thisappearstobeveryeffectiveformore acutesensitivity.28 Itispreferabletouseatoothpaste without sodium lauryl sulphate, which is the pri- mary ingredient in most toothpastes, and creates the effect of foaming. Sodium lauryl sulphate has been associated with increased gingival irritation, especiallyonprolongedcontact. 3.Syringe delivery of potassium nitrate and fluoride: The material is applied as needed for specific areas ofsensitivity. 4.Potassium nitrate incorporation into the whitening gel itself: Bleaching efficacy does not appear to be affectedbythisaddition.30 _Conclusion Treatment of dentine hypersensitivity is a simple, clearprocess.Itstartswithadifferentialdiagnosis,rul- ing out other possible aetiologies like caries, pulpitis, cracks,marginalleakage,etc.Next,anattemptismade to eliminate predisposing factors such as periodontal disease,para-function,acidicdietandxerostomia. At the same time, the patient is evaluated with respect to the potpourri of potential desensitisation ingredients and the products that contain them. It is essential for the dental practitioner to be familiar with theseingredients,theirmechanismsofaction,benefits andindications.Somepatientsmayrequiremorethan onetypeoftreatment.Thetreatmentisfine-tuneduntil asuccessfulsolutionisfound.Thereisnolongerarea- son for any patient to endure dentine hypersensitivity. Simple answers have been found to this long-time problem,andthedentisthasgainedapatientforlife._ Editorial note: A complete list of references is available fromthepublisher. Fig. 5a & b_ACP forms a mineral barrier of hydroxyapatite, which occludes the exposed dentinal tubules. (Courtesy of GC) Fig. 6_The Pro-Argin formulation attracts a calcium-rich layer from the saliva to infiltrate and block the dentinal tubules. (Courtesy of Colgate) DrFayGoldstephasbeen afeaturedspeakerintheADA SeminarSeries,andhaslectured attheAmericanDentalAssociation, Yankee,AmericanAcademy ofCosmeticDentistry,Academy ofGeneralDentistry,andthe BigAppledentalconferences. Shehaslecturednationallyandinternationallyon Conservativedentistry,innovationsinhygiene,dentist healthissues,magnificationandofficedesign.Shehas servedontheteachingfacultiesofthepostgraduate programmesinAestheticDentistryatSUNYBuffalo, UniversityofFlorida,UniversityofMinnesotaandUniversity ofMissouri-KansasCity.Shehasbeenacontributing authortothreetextbooksandhaspublishedmorethan 20articles.SheisaFellowoftheAmericanCollege ofDentists,InternationalAcademyforDental-Facial EstheticsandAcademyofDentistryInternational. ShesitsontheeditorialboardsoftheOralHealthJournal (healing/preventivedentistry)andDentalTribune USEdition.Shehasbeenlistedasoneoftheleaders incontinuingeducationbyDentistryTodaysince2002. DrGoldstepisaconsultanttoanumberofdentalcompanies andmaintainsaprivatepracticeinToronto,Canada. _about the author cosmeticdentistry Fig. 6 Fig. 5b Fig. 5a