Comparison of the Effectiveness of Bleaching Treatment with Activation Using Polywave LED Light, Diode Laser and Er, Cr:YSGG Laser: An in Vitro Study

Objective: This study aimed to evaluate the efficacy of non-vital bleaching treatments activated by laser systems and polywave LED light. Methods: Forty-eight extracted maxillary incisors were artificially stained using sheep blood and then the initial colour values of the stained teeth were measured and recorded with a spectrophotometer. The teeth were randomly assigned to four groups (n = 12 per group): Group 1 (control) received 30-minute non-vital bleaching treatments with 35% hydrogen peroxide (H₂O₂); Group 2 received 35% H₂O₂ with a diode laser (940 nm); Group 3 received 35% H₂O₂ with an Er,Cr YSGG laser (2780 nm); and Group 4 received 35% H₂O₂ with polywave LED light (480 nm). Spectrophotometric evaluation of color change (ΔE00) was performed on days 1, 3, and 7 post-treatment. Results: Intergroup comparisons showed significantly lower ΔE00 values in Group 1 (control) and Group 4 (H₂O₂ + polywave LED light) compared to Groups 2 (H₂O₂ + diode laser) and 3 (H₂O₂ + Er,CrYSGG laser) across all time points (P < .05). No significant difference in ΔE00 was observed between Groups 2 and 3 at any time point (P > .05). Conclusion: Both the diode laser and Er,CrYSGG laser significantly enhanced the efficacy of non-vital bleaching. Although polywave LED light achieved adequate bleaching results, its activation was less effective than that of laser systems. Keywords: Color change, laser, LED, spectrophotometric analysis, teeth bleaching, nonvital