Evaluation of the efficacy of diode laser in bleaching of the tooth at different time intervals using spectrophotometer: An in vitro study

AIM: This study aimed at comparative evaluation of the efficacy of tooth bleaching using different concentrations of carbamide peroxide (CP) with and without diode laser at 980 nm for 2.5 and 5 min time duration. MATERIALS AND METHODS: Hundred intact human incisors were selected. Teeth were artificially stained using black tea solution. Samples were randomly allocated into four groups: Group I: distilled water, Group II: 15%, 20%, and 35% CP without laser, Group III: 15%, 20%, and 35% CP using diode laser for 2.5 min, and Group IV: 15%, 20%, and 35% CP using diode laser for 5 min. Color measurements were made using spectrophotometer. Data were statistically analyzed by ANOVA, repeated measures of ANOVA, and Tukey post hoc test. RESULTS: 35% concentration of CP gave similar mean shade (ΔE) value at T2, as 15% CP at T3. At T3, 15% concentration of CP using diode laser for 2.5 min gave similar mean shade (ΔE) value, as 35% concentration of CP using diode laser for 2.5 min. CONCLUSION: 35% CP causes change in chroma and whitens the tooth at a faster rate with a significantly more lightening effect. Bleaching twice weekly produces a similar effect when using high or low concentrations of CP. Laser-assisted bleaching decreases the time of whitening process.