Effect of the Chemo-Mechanical Caries Removal on Mechanical-Properties of Dentin

Objectives: The aim of this study was to evaluate the effectiveness of caries removal using chemo-mechanical agent (Papacarie Duo) and conventional excavation methods in permanent dentin as well as the remineralization of the affected dentin after one month of restoration with three different dental materials: glass ionomer, Biodentine, and adhesive/composite resin. We postulate that there is no difference in hardness and elastic modulus values of the adjacent dentin among the caries removal techniques and among the remineralization techniques.
Methods: 3 experimental groups: (GI - Glass Ionomer, R - adhesive/composite resin, and B - Biodentine) and each group was incubated for 1 month prior to testing. Two cavities were made into each tooth using a bur, 1. One of the preparations was then treated with Papacarie Duo (C) to simulate chemomechanical caries removal and the other remained untouched (M – mechanical). Finally the restorative material according to the group was placed into both preparations. Samples were stored at room temperature until prepare to testing. The samples were sectioned into halves, encased in acrylic, and systematically polished. Nanoindentation test was used onthe adjacent dentin with a load of 1000µm at two different distances from the restorative material (immediately below the restorative material (0) and 200µm below this point (1)).
Results: The elastic modulus and hardness both resulted with the material and dentin depth showing a statistical difference but the treatment with or without Papacarie Duo presented no difference. The elastic modulus ranged from 21.20 to 30.77MPa. The highest mean was observed with the group of Biodentine under mechanical carie removal technique immediately below the restorative material (BM0). The hardness means were from 0.74 (BC0) to 1.25MPa (BMO). The highest mean for both properties was observed at the BM0 Group. The lowest average for elastic modulus was to GiC0 group and for hardness to BC0.
Conclusions: With the limitations of this study, we can conclude that the caries removal techniques can influence the mechanical properties of the dentin but it depends on the restorative material and depth of the dentin.