Comparative evaluation of the effect of black and green tea on artificially demineralized permanent enamel: in vitro study

Abstract

ABSTRACT Purpose: To evaluate and compare the effect of black and green tea on initial enamel caries like lesions of extracted human permanent teeth through microhardness analysis and polarized light microscopic evaluation. Materials and methods: Fifty extracted young premolars with a standardized window on enamel were immersed in a demineralizing solution for 48 hours to produce subsurface enamel lesions. They were divided into two groups according to the type of treatment (n= 25), group I: teeth were treated by black tea infusion; group II: teeth were treated by green tea infusion. The enamel surface microhardness was measured at baseline, after the incipient enamel lesion, and after treatment. Additional twenty young premolars were selected and prepared for evaluation of the changes in enamel birefringence using the polarized light microscope. Results: Both groups showed a statistically significant increase in enamel surface microhardness after treatment as compared to the demineralization phase. By comparing the two groups, there was a statistically significant difference in the percentage of surface microhardness recovery after treatment in favor of the black tea group (P <0.0001). The polarized light microscope showed an increase in the negative enamel birefringence in both groups with less degree in the green tea group. Conclusion: Both black and green tea have a remineralizing effect on the initial enamel caries lesions with better effect of the black tea. Keywords: Initial enamel lesions, Black tea, Green tea, Microhardness, Polarized light microscope.