The Effect of Diode Laser Irradiation on Surface Roughness of Bleached Enamel: An in Vitro Study

Aims: To evaluate the influence of post bleaching diode laser irradiation on the surface roughness of bleached enamel. Materials and methods: Forty bovine teeth were prepared and then randomly divided into two equal groups (n=20) according to the inoffice bleaching technique as follows: CB: Conventional inoffice bleaching technique LB: Laserassisted inoffice bleaching technique. Each group was then subdivided into two subgroups (n=10) according to laser irradiation setting as follows: C2: Conventionally bleached followed by 2-Watt laser irradiation, C4: Conventionally bleached followed by 4-Watt laser irradiation, L2: Laserassisted bleached followed by 2Watt laser irradiation and L4: Laserassisted bleached followed by 4Watt laser irradiation. Surface roughness was assessed three times for all the specimens: before bleaching, 24 hours after bleaching and finally 24 hours after post bleaching diode laser irradiation by utilizing profilometer. Paired samples ttest and independent samples t test was utilized for statistical analysis at p0.05. Results: Both bleached groups exhibited a significant increase in the surface roughness of enamel with no statistically significant difference between them. Post bleaching diode laser irradiation at 4Watt resulted in a significant increase in surface roughness of enamel, while 2Watt diode laser irradiation resulted in nonsignificant increase in surface roughness of enamel. Conclusions: Inoffice bleaching techniques had a negative impact on enamel in terms of surface roughness. Post bleaching diode laser irradiation at 2Watt power parameter is more preferred than 4Watt power parameter.