Effect ofMoistvs.DryBonding toNormalvs.Caries-affected Dentin withScotchbond Multi-Purpose Plus

Recent research indentin bonding demonstrated thesuperiority ofmoistbonding overdrybonding onnor- maldentin, butitisunclear ifthis technique isalso superior inbonding tocaries-affected dentin. Thepurpose ofthis studywastoevaluate theSEM appearance andbond strength ofScotchbond Multi-Purpose Plus(SMPP) tonor- malvs.caries-affected dentin bondedundermoistvs.dry conditions, withandwithout polyalkenoic acidinthe primer. Extracted carious humanthird molars wereground downbymeansof600-grit SiCpaper until thecarious dentin nolonger stained withcaries detector solution. Theflat sur- faces werethenprimed, bonded, andbuilt upwithresin composite. After soaking inwaterfor1day,theteeth were serially sectioned vertically into5or6slabs 0.7mm thick. Thebondedcaries-affected areas wereisolated bymeansof anultrafine diamond burtocreate anhourglass configura- tionwithacross-sectional areaof0.9mm2.Bondednormal dentin wasisolated thesameway.Eachspecimen was attached toaBencor device andtested intension tofailure. SMPPbondstodry, normal dentin wereonlyhalf asstrong (21±10MPa,x±SD)asthose madetomoist, normal dentin (42±9MPa, p<0.01). Therewasnosignificant difference between bondsmadetonormal vs.caries-affected dentin by meansofthemoist technique (42±9vs.48±4MPa,respec- tively). Removal ofthepolyalkenoic acidfromtheprimer lowered (p<0.05) thebondstrength ofSMPPtocaries- affected dentin (38±8MPa).Thebenefits ofmoist bonding extend tocaries-affected dentin. Thepolyalkenoic acidinthe SMPPprimer contributes tothehighbondstrength that can beachieved tocaries-affected dentin.