title: Effect of bleaching protocols with 38% hydrogen peroxide and post-bleaching times on dentin bond strength.
abstract: This study assessed the effect of bleaching protocols with 38% hydrogen peroxide (HP) and post-bleaching times on shear bond strength of a composite resin to dentin. One-hundred slabs of intracoronary dentin were included and randomly assigned into 2 groups according to the bleaching protocol: HP (2 applications of 10 min each) and HP activated by LED laser (2 applications of 10 min each/45 s of light activation). Groups were subdivided according to the post-bleaching time (n=10): 1 day, 3 days, 7 days, 10 days and 14 days. The control group was unbleached and restored (n=10). The specimens were restored with Single Bond adhesive system/Filtek Z250 resin using a polytetrafluorethylene matrix and were submitted to the shear bond strength testa after 24 h,. Data were analyzed by ANOVA and Tukey's test (α=0.05). Unbleached group (0.283 ± 0.134) had the highest bond strength and was statistically similar (p>0.05) to HP/10 days (0.278 ± 0.064), HP + LED laser/10 days (0.280 ± 0.078), HP/14 days (0.281 ± 0.104), HP + LED laser/14 days (0.277 ± 0.093). Lower bond strength were verified in HP/1 day (0.082 ± 0.012), HP/3 days (0.079 ± 0.013), HP + LED laser/1 day (0.073 ± 0.018) and HP + LED laser/3 days (0.080 ± 0.015), which were statistically similar (p>0.05). HP/7 days (0.184 ± 0.154) and HP + LED laser/7 days (0.169 ± 0.102) had intermediate values (p<0.05). The restorative procedure of intracoronary dentin bleached with 38% HP with or without the use of light source should be performed after at least 10 days after the bleaching treatment.
authors.affiliation: Dental School, UNAERP - University of Ribeirão Preto, Ribeirão Preto, SP, Brazil. aline.gabriel@gmail.com
authors.forename: Aline Evangelista
authors.initials: AE
authors.lastname: Souza-Gabriel
authors.forename: Lilian Oliveira Cambaúva
authors.initials: LO
authors.lastname: Vitussi
authors.forename: Camila
authors.initials: C
authors.lastname: Milani
authors.forename: Edson
authors.initials: E
authors.lastname: Alfredo
authors.forename: Danielle Cristine Furtado
authors.initials: DC
authors.lastname: Messias
authors.forename: Yara Teresinha Correa
authors.initials: YT
authors.lastname: Silva-Sousa
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry*; D054023:Lasers, Semiconductor; D008422:Materials Testing; D016877:Oxidants / Q000737:chemistry*; D010756:Phosphoric Acids / Q000737:chemistry; D033081:Shear Strength; D013314:Stress, Mechanical; D013997:Time Factors; D014073:Tooth Bleaching / Q000379:methods; D058205:Tooth Bleaching Agents / Q000737:chemistry*
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; C444701:Filtek Z250; D016877:Oxidants; D010756:Phosphoric Acids; D058205:Tooth Bleaching Agents; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate; D006861:Hydrogen Peroxide; C030242:phosphoric acid