Bond Strength of Class 1 Composite Restoration to Caries-affected Dentin

Objective: The purpose of this study was to examine the micro tensile bond strength of one-step (Clearfil Tri-S Bond (Kuraray); TB) and two-step adhesive system (Clearfil Protect Bond (Kuraray); PB) to caries-affected dentin on cavity floor of class 1 restoration. Methods: Class 1 cavity was prepared in an extracted human molar with fissure caries extending approximately halfway through dentin. Caries-infected dentin was removed using a round bur with CarieSDetector (Kuraray) to obtain caries-affected dentin (CD). For control specimen, similar to each CD cavity was prepared in a sound human extracted molar (SD). The adhesive system was applied, according to manufacturer's instruction, to the cavity and resin composite (Clearfil AP-X: Kuraray) was filled using incremental technique. After storage in a moisture box at 37°C for 24hr, the tooth was trimmed to a dumbbell shape for micro tensile bond strength test. The bond test was performed using a universal testing machine at a crosshead speed of 1.0mm/min (n=10), and the data was statistically analyzed using two-way ANOVA and Mann-Whitney's U-test. Results: Mean bond strength values (SD.) of TB and PB to CD and SD in MPa were;