OBJECTIVE: To synthesize umbrella-level evidence on laser or light activation and photobiomodulation in in-office dental bleaching, including whitening efficacy, tooth sensitivity, and biological safety. Systematic reviews were searched in PubMed, Embase, Scopus, Web of Science, and the Cochrane Library using terms related to dental bleaching, hydrogen peroxide, laser activation, light activation, and photobiomodulation. MATERIALS AND METHODS: Systematic reviews and meta-analyses evaluating in-office bleaching with optical activation or photobiomodulation were included. Outcomes were color change, tooth sensitivity, pulpal safety, and adverse effects. Methodological quality was assessed using A Measurement Tool to Assess Systematic Reviews 2, and certainty was judged through an umbrella-level certainty framework. RESULTS: Ten systematic reviews published from 2007 to 2024 were included. Laser or light activation showed no consistent improvement in final whitening efficacy compared with nonactivated protocols. Sensitivity was not reduced and was less favorable in some high-energy protocols. Photobiomodulation reduced post-bleaching sensitivity across placebo-controlled randomized trials without impairing color change. Safety findings were mainly parameter-dependent, especially regarding intrapulpal temperature during high-energy activation. CONCLUSIONS: Laser or light activation did not improve final whitening efficacy. Photobiomodulation reduced post-bleaching sensitivity without reducing whitening efficacy. High-energy activation showed parameter-dependent thermal concerns. CLINICAL SIGNIFICANCE: Current evidence does not support the routine use of laser activation to improve bleaching outcomes, whereas photobiomodulation represents a sensitivity-reducing adjunct for susceptible patients.
Allende et al. (2026) studied this question.