Correlation between patient satisfaction and color changes after tooth bleaching

Objective: This study aimed to investigate the relationship between patient satisfaction of outcomes and tooth color changes during and after tooth bleaching. Methods: In this clinical trial, 63 volunteers participated in an in-office bleaching procedure using a 40% hydrogen peroxide gel. The treatment consisted of two sessions, each comprising two 30-min applications of the bleaching gel. The L*, a*, and b* values of six maxillary anterior teeth were measured at baseline (T1), after the first bleaching session (T2), after the second bleaching session (T3), 1 week after the second in-office bleaching session (T4), and 3 weeks after the second in-office bleaching session (T5). The color differences (Delta E-00 ) were calculated using CIEDE2000. A satisfaction scale with a score ranging from 0 to 3 was used to record participants' level of satisfaction with their tooth color at each time point. The data were statistically analyzed using repeated measures analysis of variance and logistic regression (alpha = 0.05). Results: Significant correlations were observed between Delta L*, Delta b*, and Delta E-00 values at T3 and patient satisfaction (all p < 0.05). The regression model indicated a more pronounced impact of Delta b* on patient satisfaction compared to Delta L*. The established regression models were as follows: Logit (P-L*b* ) = -4.354 + 0.271 Delta L* - 0.585 Delta b* and Logit (P-Delta E00 ) = -2.552 + 0.521 Delta E-00 . The findings suggested a minimum Delta E-00 value of 4.90 for satisfactory results. A minimum Delta E-00 value of 3.9, 5.0, and 6.8 was necessary for central incisors, lateral incisors, and canines, respectively, to achieve a satisfactory result. Conclusions: The Delta L*, Delta b*, and Delta E-00 values were found to be significantly correlated with patient satisfaction after bleaching. Delta b* was identified as having a greater influence on patient satisfaction than Delta L* values in the regression model. Furthermore, attaining a minimum Delta E-00 value of 4.90 is necessary to achieve satisfactory outcomes. A greater Delta E-00 value is needed for canines than for incisors to achieve equivalent patient satisfaction.