Correlation between patient satisfaction and color changes after tooth bleaching

Abstract

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 (ΔE₀₀ ) 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 (α = 0.05).

Results: Significant correlations were observed between ΔL*, Δb*, and ΔE₀₀ values at T3 and patient satisfaction (all p < 0.05). The regression model indicated a more pronounced impact of Δb* on patient satisfaction compared to ΔL*. The established regression models were as follows: Logit (P_L*b* ) = -4.354 + 0.271ΔL* - 0.585Δb* and Logit (P_ΔE00 ) = -2.552 + 0.521ΔE₀₀ . The findings suggested a minimum ΔE₀₀ value of 4.90 for satisfactory results. A minimum ΔE₀₀ 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 ΔL*, Δb*, and ΔE₀₀ values were found to be significantly correlated with patient satisfaction after bleaching. Δb* was identified as having a greater influence on patient satisfaction than ΔL* values in the regression model. Furthermore, attaining a minimum ΔE₀₀ value of 4.90 is necessary to achieve satisfactory outcomes. A greater ΔE₀₀ value is needed for canines than for incisors to achieve equivalent patient satisfaction.

Clinical significance: This study emphasizes the importance of considering the extent of color change needed to achieve patient satisfaction after tooth bleaching procedures.

Keywords: clinical trial; color differences; in-office bleaching; logistic regression analysis; patient satisfaction.