Abstract:

Background and Aim: One of the adverse effects of acidic whitening materials is salivary pH changes of the oral cavity and the resultant damage to tooth structure. The concern for potential side effects is greater when OTC bleaching products are used without consultation of a dental professional. The purpose of this in vivo study was to evaluate the effect of bleaching strips on salivary pH of dental students (in vivo).

Materials and Methods: This experimental in vivo research was done on 20 dental students aged 20-24 years old. All subjects signed a consent form before participating in the study. Students' unstimulated salivary pH was measured by saliva- check kit (GC, USA). Bleaching strips (crest advanced vivid white strip, USA) containing 9.5% hydrogen peroxide were applied to the surface of six anterior maxillary teeth for 14 days (30 minutes daily) according to the manufacturer's instructions. Salivary pH was measured on first, seventh and fourteenth day of the treatment. Measurements were taken 10 minutes, 20 minutes, and 30 minutes into the treatment as well as 30 minutes following treatment completion. Statistical analysis was done by Friedman and Kruskal-Wallis tests.

Results:  A statistically insignificant decline in salivary pH level was seen 10 minutes into the procedure on first, seventh and 14th day of the treatment (p<0.2). Salivary pH value returned to baseline 30-60 min after initiation of treatment. The difference in baseline and final pH value (upon completion of treatment) was not statistically significant (P>0.05). 

Conclusion: Based on the results of this study, bleaching strips containing 9.5% hydrogen peroxide have no effect on salivary pH.