Composite resin bond strength with different dentin-bonding agents in two storage times

Abstract

Water degradation of dentin bonding agents may influence bond strength in composite resin restorations after some periods of time. The aim of this study was to evaluate the influence of storage time with thermociclyng and type of dentin bonding agents used on the composite resin restorations microshear bond strength. Twenty molars were used and divided into two evaluation periods (24 hours and 6 months, plus thermocycling). Each tooth had its occlusal surface dentin exposed, and received three units of test made of Flow composite resin, with the following adhesive systems: Scotchbond multipurpose (3M/ESPE – group 1), Clearfi l SE Bond (Kuraray – group 2) and Adper Single Bond (3M/ESPE – group 3). Subsequently to the microshear bond strength testing, data were analyzed by ANOVA, Tukey and Student t tests (α = 0,05). The results showed that there were no differences between Scotchbond multipurpose, ClearFil SE Bond and Adper Single Bond on microshear bond strength after 24 hours of storage. After 6 months, ClearFil SE Bond demonstrated higher resistance than Scotchbond multipurpose. Scothtchbond multipurpose presented a reduction in its performance when 6 months passed. ClearFil SE Bond and Adper Single Bond suffered no influence resultant from the storage period.