Comparative evaluation of microshear bond strength of the caries-affected dentinal surface treated with conventional method and chemomechanical method (papain)

BACKGROUND: There is a growing interest in chemomechanical excavation (papain) in permanent molar teeth. There are several studies dealing with primary molar teeth. AIM: The aim of this study was to evaluate the influence of conventional method and Carie-care (chemomechanical method) on the microshear bond strength (μSBS) and the type of failure of an adhesive system to caries-affected dentin of permanent molar teeth. MATERIALS AND METHODS: Twenty permanent molar teeth with carious lesions extending into the dentin were selected. Through the center of the carious lesion, teeth were sectioned mesiodistally and divided into two groups based on the method of caries excavation (conventional and chemomechanical method). The time required for the completion of excavation procedure was noted. Samples were again divided into two subgroups in each according to the method of restoration (Ketac N100 and Filtek Z350 composite). The bonded interface was subjected to μSBS testing in a universal testing machine. Fractured surfaces were examined under a stereomicroscope, and representative specimens were examined under scanning electron microscope for the type of failure. STATISTICAL ANALYSIS: It was achieved with unpaired t-test and Kruskal-Wallis H-test at 5% level of significance. RESULTS: The μSBS values of Carie-care groups were similar to that of the conventional method. The μSBSs of resin composite were significantly (P < 0.001) more than that of resin glass ionomer bonded irrespective of the method of caries excavation. CONCLUSION: A papain-based chemomechanical agent can be used safely as a method for caries removal when employing conventional adhesive systems.