Comparison of the bleaching efficacy of different agents used for internal bleaching – a systematic review and meta-analysis

 

Journal of Endodontics 

Published:November 08, 2021DOI:https://doi.org/10.1016/j.joen.2021.10.011

Abstract

Introduction

Aim was to analyze and compare the efficacy of different bleaching agents typically used for internal bleaching of endodontically-treated discolored teeth.

Methods

Electronic databases (PubMed, Web of Science, Cochrane Library) were searched by two reviewers for clinical trials in which the color of endodontically-treated discolored teeth, before and after internal bleaching, was examined using shade guide units (ΔSGU) or a spectrophotometer/colorimeter (ΔE). The efficacies of the bleaching agents were compared using subgroup analyses. Statistical heterogeneity was assessed with Cochran’s Q and I2-statistic. Publication bias was evaluated using funnel-plots.

Results

Eight studies were included in the systematic review, out of which six could be included in the meta-analyses. Internal bleaching led to a significant change in tooth shade (ΔSGU: 6.27 [95%-CI: 5.36–7.17], ΔE: 12.83 [95%-CI: 9.46–16.20]). With regard to ΔSGU, the use of carbamide peroxide (35% or 37%), hydrogen peroxide (35%), and the combination of sodium perborate and hydrogen peroxide (3% or 30%) led to better bleaching effect than did sodium perborate (padj.≤0.026). Regarding ΔE, there were no significant differences between carbamide peroxide (37%), hydrogen peroxide (35%) and sodium perborate mixed with hydrogen peroxide (p=0.051). Risk of bias of included studies was classified as moderate to high.

Conclusions

Carbamide peroxide, hydrogen peroxide, and sodium perborate have a significant bleaching effect on discolored, root-canal-treated teeth. For a valid assessment of shade stability and comparison of bleaching agents resp. their concentrations, further studies with long term recalls are necessary.