Shear bond strength of adhesive systems to enamel and dentin. Thermocycling influence.
OBJECTIVE
The purpose of the this study was to evaluate the influence of thermocycling on shear bond strength on bovine enamel and dentin surfaces of different adhesive systems.


METHODS
Thirty sound bovine incisors were sectioned in mesiodistal and inciso-cervical direction obtaining 60 incisal surfaces (enamel) and 60 cervical surfaces (dentin). Specimens were randomly assigned to 3 groups of equal size (n=40), according to the adhesive system used: I-Single Bond; II-Prime & Bond NT/NRC; III-One Coat Bond. After 24-h storage in distilled water at 37 degrees C, each main group was divided into two subgroups: A-specimens tested after 24 h storage in distilled water at 37 degrees C; B-specimens submitted to thermocycling (500 cycles). Shear bond strength tests were performed. Data were submitted to ANOVA and Tukey test.


RESULTS
Means (MPa) of different groups were: I-AE-16.96, AD-17.46; BE-21.60, BD-12.79; II-AE-17.20, AD-11.93; BE-20.67, BD-13.94; III-AE-25.66, AD-17.53; BE-24.20, BD-19.38.


CONCLUSIONS
Thermocycling did not influence significantly the shear bond strength of the tested adhesive systems; enamel was the dental substrate that showed larger adhesive strength; One Coat Bond system showed the best adhesive strength averages regardless of substrate or thermocycling.
Dos Santos
Patrícia Aleixo
PA
Department of Operative Dentistry, Bauru School of Dentistry, University of São Paulo, Brazil.
Garcia
Patrícia Petromilli Nordi Sasso
PP
Palma-Dibb
Regina Guenka
RG
D000268:Adhesiveness; D000818:Animals; D001672:Biocompatible Materials / Q000032:analysis / Q000737:chemistry*; D002417:Cattle; D003738:Dental Cements / Q000737:chemistry*; D003743:Dental Enamel / Q000502:physiology*; D003804:Dentin / Q000502:physiology*; D007180:Incisor / Q000502:physiology* / Q000648:ultrastructure; D008422:Materials Testing; D010507:Periodicity; D033081:Shear Strength; D013696:Temperature
D001672:Biocompatible Materials; D003738:Dental Cements