BACKGROUND: The use of laser irradiation for dental surface treatment may increase tooth-composite bond strength. Its use on bleached teeth may decrease the waiting time between bleaching and restorative procedures. OBJECTIVE: This study aimed to evaluate the bond strength between a composite resin and bovine enamel bleached with 35% hydrogen peroxide and etched with Er:YAG laser. MATERIALS AND METHODS: Thirty bovine teeth were randomly divided into six groups (n = 5): G1, unbleached and restored 24 h after storage in artificial saliva, etching with 35% phosphoric acid (PA) (control); G2, unbleached and restored 24 h after storage in artificial saliva, etching with Er:YAG laser and 35% PA; G3, bleached and restored immediately afterward, etching with 35% PA; G4, bleached and restored 24 h after bleaching, etching with 35% PA; G5, bleached and restored immediately afterward, etching with Er:YAG and 35% PA laser; G6, bleached and restored 24 h after bleaching, etching with Er:YAG laser and 35% PA. Bond strength was quantitatively evaluated by microtensile test (1.0 mm/min). Data were submitted to statistical analysis using ANOVA and Tukey tests (α = 0.05). RESULTS: Bond strength values (MPa) were G1, 26.17 ± 4.44; G2, 28.87 ± 3.94; G3, 17.25 ± 4.58; G4, 21.93 ± 5.02; G5, 16.69 ± 2.31; and G6, 29.06 ± 8.31. There was no statistically significant difference among groups G1, G2, and G6 (p = 0.119), which presented higher bond strength than group G4, followed by groups G3 and G5. CONCLUSION: Er:YAG irradiation of bleached surfaces may favor bonding procedures when performed 24 h after bleaching.
BACKGROUND: The use of laser irradiation for dental surface treatment may increase tooth-composite bond strength. Its use on bleached teeth may decrease the waiting time between bleaching and restorative procedures. OBJECTIVE: This study aimed to evaluate the bond strength between a composite resin and bovine enamel bleached with 35% hydrogen peroxide and etched with Er:YAG laser. MATERIALS AND METHODS: Thirty bovine teeth were randomly divided into six groups (n = 5): G1, unbleached and restored 24 h after storage in artificial saliva, etching with 35% phosphoric acid (PA) (control); G2, unbleached and restored 24 h after storage in artificial saliva, etching with Er:YAG laser and 35% PA; G3, bleached and restored immediately afterward, etching with 35% PA; G4, bleached and restored 24 h after bleaching, etching with 35% PA; G5, bleached and restored immediately afterward, etching with Er:YAG and 35% PA laser; G6, bleached and restored 24 h after bleaching, etching with Er:YAG laser and 35% PA. Bond strength was quantitatively evaluated by microtensile test (1.0 mm/min). Data were submitted to statistical analysis using ANOVA and Tukey tests (α = 0.05). RESULTS: Bond strength values (MPa) were G1, 26.17 ± 4.44; G2, 28.87 ± 3.94; G3, 17.25 ± 4.58; G4, 21.93 ± 5.02; G5, 16.69 ± 2.31; and G6, 29.06 ± 8.31. There was no statistically significant difference among groups G1, G2, and G6 (p = 0.119), which presented higher bond strength than group G4, followed by groups G3 and G5. CONCLUSION: Er:YAG irradiation of bleached surfaces may favor bonding procedures when performed 24 h after bleaching.
Authors: Andréa Dias Neves Lago; Patrícia Moreira de Freitas; Erika Michele Dos Santos Araújo; Adriana Bona Matos; Narciso Garone-Netto Journal: Int J Dent Date: 2017-02-09