Clinical Effects of Prolonged Application Time of an In-office Bleaching Gel

Abstract

By refreshing the in-office bleaching gel at each clinical appointment, clinicians can improve the bleaching speed and reduce tooth sensitivity rates. SUMMARYObjective: The aim of this study was to evaluate whether the use of a gel applied for 1 3 45 minutes would have the same bleaching rate and tooth sensitivity levels when compared with 3 3 15-minute applications.Methods: In-office bleaching was performed in 30 participants with 35% hydrogen peroxide gel. In one group (n=15; 3315 minutes), the bleaching agent was refreshed every 15 minutes, three times at each bleaching appointment. In the other group (n=15; 1345 minutes) the gel was left undisturbed on the buccal surfaces of all teeth for 45 minutes at each bleaching appointment. This protocol was repeated after one week. The bleaching evaluation was completed by two blinded, calibrated evaluators who compared the baseline color of the maxillary anterior teeth with a valueoriented shade guide after each period. The patients recorded the tooth sensitivity on a 0-4 scale. The color changes were evaluated by appropriate tests (a=0.05). The percentage of patients with tooth sensitivity and its intensity were also statistically analyzed (a=0.05), respectively.Results: The use of gel for a single 45-minute period (1345 minutes) decreased the bleaching efficacy (p,0.05) 86.7%, and 100% of patients from the 3 3 15-minute and 1 3 45-minute groups, respectively, experienced tooth sensi-

Effectiveness of nano-calcium phosphate paste on sensitivity during and after bleaching: a randomized clinical trial

“…An equivalent and significant tooth color enhancement was observed in both study groups. The degree of whitening obtained in this study is similar to that reported in other clinical trials 9,17,19 and also in the literature review. 1 Finally, it should be mentioned that only a value-oriented shade g uide was used for identification of color changes throughout the study period.…”

“…9,12,17,20 Tooth sensitivity was not reduced by previous application of a nano-calcium phosphate paste; thus, preventing us from rejecting the first null hypothesis.…”

“…This was done because it is an easy, fast, and satisfactory method used in several investigations. 9,17,19 Additionally, a recent study showed that visual assessment of tooth color with a value-oriented shade guide is a valid method, with good reliability in differentiating between dark and light colors. 30 …”

“…Thirty-eight patients (nineteen in each group) were required to have an 80% chance of detecting a decrease in the primary outcome measure from 83% (mean absolute risk of tooth sensitivity 9,12,17 ) in the control group to 43% in the experimental group (a = 0.05). The sample size was calculated on the website www.sealedenvelope.com.…”

The Relationship of Hydrogen Peroxide Exposure Protocol to Bleaching Efficacy

“…However, Reis and others 12 reported contradictory results in their recent clinical trial. In-office bleaching was performed in 30 participants with 35% hydrogen peroxide.…”