Effect of Four Remineralizing Agents on Microhardness of Initial Caries

Objective: To evaluate the effects of 4 remineralizing agents on microhardness of enamel and cervical dentin initial caries under dynamic pH-cycling conditions. Method: Fifty extracted sound premolar teeth were cut into halves of 2 sections (enamel and cervical dentin) and embedded in clear resin blocks. Initial caries lesions were prepared with demineralizing solution for 16 hours (37°C). Then the specimens were divided into the following 5 groups: control group, calcium sodium phosphosilicate group, casein phosphopeptide-amorphous calcium phosphate group, fluoride gel group and tricalcium phosphate plus fluoride group. The specimens were submitted to a pH-cycling model with a high cariogenic challenge for 10 days. Surface microhardness (SMH) measurements were performed before and after demineralization and after 10 days of treatment. Then, the result of surface microhardness (SMH) was assessed to calculate the percentage change of surface microhardness loss (% SML) and surface microhardness recovery (% SMR). Result: All the treatment groups showed significantly increased surface microhardness  than the control group (p<0.05). Within the treatment groups, fluoride gel and tricalcium phosphate plus fluoride significantly increased the enamel microhardness more than casein phosphopeptide-amorphous calcium phosphate and calcium sodium phosphosilicate (p<0.05). However, in cervical dentin, casein phosphopeptide-amorphous calcium phosphate and tricalcium phosphate plus fluoride showed the better results (p< 0.05). Conclusion: Four remineralizing agents  (casein phosphopeptide-amorphous calcium phosphate, calcium sodium phosphosilicate, fluoride gel and tricalcium phosphate plus fluoride) were effective to remineralize enamel and cervical dentin initial caries.