Effect of Calcium Phosphate on Enamel Demineralization by Fruit Juices

Most fruit juices are naturally acidic and may cause enamel demineralization. Objectives: to study the preventive effect of calcium phosphate on enamel demineralization caused by fruit juices. Methods: human premolar was longitudinal cut into 2 pieces. The first piece was immersed in natural fruit juices (control group) and the second, in 300 mg/dl calcium phosphate added fruit juice (test group) for 60 minutes. The hardness of enamel was measured by Vicker's microhardness tester before and after immersion. There were 5 kinds of juice; orange, apple, grape, guava and pineapple, and 10 teeth were used for each juice. The averaged hardness of each group were calculated and the differences between control and test group were analyzed by paired t-test at 95% confidence limit. Results: the percentage of hardness decrease after immersion in orange, apple, grape, guava and pineapple of control were 16.38, 24.45, 15.25, 3.10, 4.78, and test group were 19.57, 14.29, 1.94, 0.44, 1.59 respectively. In control group, orange, apple and grape juices showed the erosive potential by decreasing hardness of enamel significantly (p>0.05). In test group, orange juice was the only one that significantly decreased hardness of enamel (p>0.05). Conclusions: calcium and phosphate added to some erosive fruit juices was capable to prevent enamel demineralization.