Bond Strength of an All-in-one Adhesive System to Caries-affected Dentin

Objective: The purpose of this study was to examine the micro-tensile bond strength of an all-in-one adhesive system (Clearfil Tri-S Bond (Kuraray);TSB) to caries-affected dentin on cavity floor of class 1 restoration, and to examine the relationship between the bond strength and DIAGNOdent(KAVO) value. Methods: Class 1 cavity was prepared in a extracted human molar with fissure caries extending approximately halfway through dentin. Caries-infected dentin was removed using a round bur with Caries Detector (Kuraray) to obtain caries-affected dentin (CD). For control specimen, similar to each CD cavity was prepared in a sound human molar (SD). The tooth was restored with TSB and Clearfil AP-X (Kuraray) according to manufacturer's direction. 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. Prior to the test, DIAGNOdent value of dentin, adjacent to resin-dentine interface, was examined. The bond strength test was performed using a universal testing machine at a crosshead speed of 1.0mm/min (n=10), and then the data were statistically analyzed using Student's t-test and simple regression analysis. Results: Mean values (s.d.) of the bond strength in MPa were ; CD; 5.86(1.96) / SD; 14.77(3.30), and there was statistical difference between the two groups (p<0.01). DIAGNOdent values were, CD; 12.90(3.36) / SD; 8.05(1.08), and CD was statistically higher than SD (p<0.01). There were no significant correlation between TBS and DIAGNOdent value in both CD (r=0.0659) and SD (r=0.2080). Conclusion: Severe factors (i.e. caries affected dentin and c-factor) presumably affected the bond strength. It seemed to be difficult to anticipate bond strength from a DIAGNOdent value.