Document Type : Original Article
Instructor, Restorative Dentistry Department, Faculty of Dentistry, Tanta University
Instructor, Restorative Dentistry, Pharos University, Alexandria, Egypt
Objective: In vitro evaluation of the effect of bleachorexia on mineral content of tooth structure. Materials and methods: All labial surfaces of 30 sound human premolars were protected with nail varnish except a window of labial enamel. Group I: Deluxe home whitening kit was applied 1 hour once daily for 14 days, rinsed by distilled water and stored in artificial saliva. Minerals were measured using EDX, remineralization with NovaMin® for 10 minutes. Group II: As in gp I but abuse of bleaching 2 hours daily for 7 successive days (14 cycles). Group III: Bleaching for an hour twice daily for 3 days and 1 hour in the fourth day (seven cycles), remineralization and all procedures were repeated for 7 more cycles. Results: All data was collected and statistically analyzed. Crest was used to compare the mineral content in the 3 tested gps at 95% level of significance. Fluoride content was affected significantly by the bleaching in the 3 tested gps. After remineralization Gp I&II were affected (p values 0.043 &0.00) while Gp III didn’t gain any benefit (p value of 0.160). Comparing the bleaching cycles vs remineralization for 10 min all gps recorded a significant difference with p values of 0.011, 0.059 & 0.033 for gps I, II&III respectively. Phosphate content in all gps were significantly affected by bleaching & remineralization (p values of 0.001). Using Tukey test, the time of application of bleaching has an oblivious effect on the phosphate and Ca content which couldn’t regain it by remineralization.