Synergistic Effect of Proanthocyanidin And Tri-calcium Phosphate On Dentine Remineralization

Objectives: Proanthocyanidin has been shown to enhance dentine collagen stability and remineralization of artificial root caries. To evaluate the effect of proanthocyanidin (PA) in combination with tri-calcium phosphate (TCP) on dentine remineralization. Methods: Demineralized root fragments (n=75) were randomly divided into five groups based on treatments: (i) 6.5% PA, (ii) TCP, (iii) TCP+6.5% PA, (iv) 1000 ppm fluoride and (v) deionized water (control). Each specimen was immersed in the demineralizing solution for 14 hours, testing solutions/pastes for 2 hours and remineralizing solution for 8 hours. Highly purified collagenase type VII from Clostridium was further added to obtain a remineralization solution that contains 7.5 U/mL collagenase. The pH cycling was performed at 37 ^oC for 8 days. The total remineralizing solution was collected after the pH cycling. Collagen degradation depth and lesion depth were evaluated using transverse microradiography. Resistance to collagen degradation was determined by estimating hydroxyproline release. Sixty micro-liters of the solution (from stock solution collected each day) were subjected to chemical analysis of degraded collagen using the simplified chloramine-T method. Data was analyzed using one-way ANOVA and Tukey multiple comparison tests. Results: Results of one-way ANOVA showed that the testing solutions had a significant effect on the collagen degradation depth (p<0.001), lesion depth (p<0.001) and hydroxyproline release (p<0.001). The addition of PA to TCP significantly reduced collagen degradation depth, when compared to TCP group only (p<0.001). Lesion depth was the lowest in the TCP-PA group (p<0.001). The addition of PA to TCP also decreased hydroxyproline release, when compared to TCP group only (p<0.001). Conclusion: The addition of PA to TCP enhanced remineralization in root caries lesions by reducing collagen degradation and inhibiting demineralization.