Evaluation of microhardness of residual dentin in primary molars following caries removal with conventional and chemomechanical techniques: An In vitro Study

Background: Many patients consider removal of caries to be a very unpleasant experience. Removal of caries with conventional drill is considered traumatic mainly due to fear and anxiety of children and their parents. Minimally invasive dentistry adopts a philosophy that integrates prevention, remineralization, and minimal intervention for the placement and replacement of restorations, thus reaching the treatment objective using the least invasive surgical approach, with the removal of the minimal amount of healthy tissues. Chemomechanical caries removal (CMCR) is a method for minimally invasive, gentle dentin caries removal based on biological principles which is an effective alternative to the traditional method. The present study was done to compare the microhardness of sound dentin before and after carious removal using a chemomechanical method and a conventional method. Materials and Methods: The present in vitro study was done on 28 proximal surfaces of fourteen extracted primary molars (with active caries on one proximal surface and sound side as control). The study was done to assess the Knoop microhardness of remaining dentinal surface after caries removal using a slow speed conventional bur and a chemomechanical method (Carie-Care™). Results and Conclusion: The rotary instrument group showed a consistent microhardness value with not much difference according to depth. The chemomechanical group showed a lesser microhardness value closer to the cavity floor than away from it. The microhardness values at all depths were significantly different for each treatment group with an increased value seen in the rotary group. The mean microhardness values of residual dentin in treated side were found to be insignificant when compared among each interval in each group. The microhardness of sound dentin had high significant difference from that of residual dentin in both the rotary group and the chemomechanical group.