Effects of several tea components on acid resistance of human tooth enamel

Objectives: The effects of tea components on the acid resistance of human tooth enamel were investigated by an in vitro experiment. A further study focused on the action of tannin, the main component of tea, in combination with fluoride. Results: Some components such as tannin, catechin, caffeine and tocopherol were demonstrated to be effective for increasing acid resistance, and their effects increased dramatically when they were used in combination with fluoride. A mixed solution of tannic acid and fluoride showed the highest inhibitory effect (98%) on calcium release to an acid solution. Tannin in combination with fluoride showed obvious inhibition of the formation of artificial enamel lesions in comparison with APF as determined by electron probe microanalysis, polarized-light microscopy and Vickers microhardness measurement. Conclusions: These results demonstrate that besides the fluoride, the organic components of tea also possess the property of increasing the acid resistance of tooth enamel. They also suggest that the organic components appear to play a primary role in their actions rather than fluoride.