Comparative Evaluation of the Effect of CPP-ACP and Resin Infiltration on Brown Spot Color Parameters after Using 20% Carbamide Peroxide

Tooth colored restorations are the commonly used current approach for aesthetic problems associated with brown spots. Considering the importance of conservative dentistry, the aim of this in vitro study was to evaluate the efficacy of color correction using casein phosphopeptide amorphous calcium phosphate (CPP-ACP) and resin infiltration after using 20% carbamide peroxide for brown spots in esthetic areas. In this experimental study, 70 human teeth samples with brown spots were collected. In the first step, 20% carbamide peroxide was applied and then samples were divided into two groups to be treated with CPP-ACP or resin infiltration. Color parameters of the samples were evaluated at baseline, after bleaching, after using infiltration resin and CPP-ACP. Any color shift was measured using spectrophotometer. The results were analyzed by SPSS version 20. For statistical analysis, paired t test, independent t-test and repeated measures ANOVA were used. P value<0.05 was considered significant. After using 20% carbamide peroxide, L* and b* increased and a* decreased significantly (p<0.001). By using CPP-ACP, decreases in a* and b* were not significant (p>0.05) but L* increased significantly (p<0.001). Application of infiltration resin caused a significant decrease in a* (p<0.001); however, the decrease in L* and the increase in b* were not statistically significant (p>0.05). Comparison of the two groups showed that the degree of color shift (ΔE) in brown spots was significantly different only after bleaching (p<0.001). Repeated measures ANOVA showed that ΔE between brown spots and adjacent sound enamel did not change significantly in the two subgroups (p>0.05). The results show that for esthetically unfavorable brown spots, using 20% carbamide peroxide with CPP-ACP or resin infiltration can improve the appearance. In general, application of resin infiltration with carbamide peroxide is preferably recommended for improving translucency.