Objective: This study compares the color change of non-vital anterior teeth after laser-activated bleaching and conventional walking bleaching technique.
Materials and methods: Sixty extracted teeth were endodontically treated, stained in a black tea solution, and the baseline shade was measured using a spectrophotometer (Easyshade, VITA). Bleaching was done using either: internal bleaching with 35% H2O2 (Opalescence Endo) and then tooth sealed for 5 days (Gr1), 35% H2O2 (JW Next) for 7 minutes (Gr2), internal and external bleaching for 7 minutes (Gr3), diode laser-activated internal bleaching for 30 seconds (940 nm, continuous wave, 2 W, noncontact mode, 300 um, non-initiated tip), wait for 7 minutes, second laser application for 30 seconds, tooth sealed for 5 days (Gr4), diode laser-activated internal bleaching for 24 hours (Gr5), or diode laser-activated internal and external bleaching for 24 hours (Gr6) (n = 10). The color change (ΔE00) was measured and data were analyzed using one-way analysis of variance followed by Tukey post hoc test (a = 0.05). The inner dentin of the samples was inspected using scanning electron microscopy.
Results: All the tested bleaching techniques were able to change the color. All the laser-activated bleaching protocols, namely, Gr4, Gr5, and Gr6, showed higher mean ΔE00 values than the non-laser-activated bleaching Gr2 and Gr3 (p < 0.05) and were statistically similar (p > 0.05) to the control group Gr1. Laser-activated bleaching caused surface modification and dentinal tubule opening.
Conclusion: All the tested laser-activated bleaching protocols showed faster and more efficient color change, comparable to the conventional 5-day walking bleaching protocol.
The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/).