Comparison of tooth surface roughness after bleaching with conventional and different light-activated methods

Purpose the increasing demand for aesthetic dental treatments has made in-office tooth bleaching a popular and minimally invasive procedure. However, bleaching may alter enamel surface roughness, potentially increasing plaque retention and discoloration. Laser activation has been proposed as a safer alternative. This study compared the effects of conventional bleaching, LED activation, and different laser systems (Diode, KTP, Nd-YAG, and CO₂) on enamel surface roughness. Methods sixty freshly extracted human anterior teeth were selected. Samples were randomly assigned to conventional bleaching (without light activation), LED bleaching, and laser bleaching groups, including KTP, Diode, Nd-YAG, and CO2 lasers (n = 10). Pre-treatment surface roughness evaluation was done for all samples. Samples were treated with Opalescence Xtra Boost (Ultradent, USA) for the control group and JW Power Bleaching Gel (Heydent GmbH, Germany) for other groups. Surface roughness was evaluated after bleaching in all groups. Kruskal-Wallis test and Two-Way ANOVA were done to statistically analyze study data, using GraphPad Prism v9, and P-values lower than 0.05 were considered significant. Results LED caused significantly greater surface roughness change compared to bleaching without light (P = 0.0236). Laser-activated groups did not differ significantly from the conventional group or from each other. In the middle third, LED activation resulted in significantly higher roughness compared with the KTP laser (P = 0.029). Conclusion LED activation resulted in greater roughness changes, particularly in the middle third of enamel, while laser activation generally preserved enamel surface integrity, compared to the conventional group.