Predictive factors on the efficacy and risk/intensity of tooth sensitivity of dental bleaching: A multi regression and logistic analysis

Objectives: The aim of this study was to identify predictor factors associated with the whitening outcome and risk and intensity of bleaching-induced tooth sensitivity from pooled data of 11 clinical trials of dental bleaching performed by the same research group. Methods: The individual patient data of several published and ongoing studies about dental bleaching was collected and retrospectively analyzed. At the patient-level, independent variables (bleaching techniques [at-home and in-office protocols], sex, age and baseline tooth color in shade guide unit [SGU]) as well as dependent variables (color change in shade guide units (Delta SGU), color change in the CIEL*a*b* system (Delta E), risk and intensity of TS in a visual analog scale) were collected. Multivariable linear regression and multivariable logistic regression models were carried out using backward elimination whenever the p-values were higher than 0.05. Results: A significant relationship between baseline color and age on color change estimates was detected (p < 0.001). Every increase of one SGU in the baseline color resulted in an increase of approximate 0.66 in the final Delta SGU and 2.48 for the Delta E. For every increase of one year in the participant's age we observed a decrease of the whitening degree of 0.07 for the final Delta SGU and 0.69 for the Delta E. The bleaching technique was shown to be a significant predictor of Delta SGU (p < 0.001) but not of Delta E. In regard to TS, baseline color and bleaching technique are significant predictors (p < 0.001). The risk of TS for at-home bleaching was 51% (95% CI 41.4-60.6) and for the in-office 62.9% (95% CI 56.9-67.3). Conclusions: Younger patients with darker teeth reach a higher degree of whitening. Patient with darker teeth and submitted to at-home bleaching presents lower risk and intensity of TS. Clinical significance: The baseline color of the teeth and the patient's age is directly related to the effectiveness of dental bleaching and TS. (C) 2015 Elsevier Ltd. All rights reserved.