Salivary pH changes during 10% carbamide peroxide bleaching

The purpose of this study was to evaluate the effect on salivary pH of a 10% carbamide peroxide solution when used with a custom-fitted guard for bieaching teeth. Baseline pH values were established for tmstinmkited saliva and on saliva produced while wearing an empty guard. After insertion of o guard hiliffilied with Proxigel, salivary pH measurements were made at5-mintite intervals tintil the values returned lo baseline levels. Mean salivarypH values were 6.81 ± 0.11 for unstimulated samples and 6.91 ± 0.18 after insertion ofthe empty guard. After insertion ofthe filled guard, there was a statistically insignificant decrease in salivary pH during the first 5 mintites. followed by an increase above baseline at 10 minutes, to a mean peak value of 7.32 ± 0.27 at 15 minutes. The difference between the baseline values and rhe mean peak value at 15 minutes was statisticaily significant. The results of the study indicated that the pH ofsaliva increased significanlly during the first 15 minutes of nightguard vital bleaching and did not significantly drop below baseline in the first 2 hours after insertion with a moderately low-pHsoltition.