title: Effect of Metalloproteinase Inhibitors on the Microtensile Bond Strength of Composite Resin to Er:YAG Laser-Irradiated Dentin.
abstract: This study evaluated the effect of matrix metalloproteinase (MMP) inhibitors - 2% (CHX) and sodium fluoride (NaF) (5000 ppm) - on microtensile bond strength (μTBS) of composite resin to Er:YAG laser-irradiated dentin after chemical degradation of the bond interface. The occlusal surface of forty sound human molars was removed exposing the dentin surface (n=10), which was polished, irradiated with Er:YAG laser, acid etched and dried. Twenty specimens were rewetted with 2% CHX (control group) and 20 were rewetted with NaF (5000 ppm). The adhesive system was applied and a 4-mm-high plateau of light-cured composite resin was built up. Resin-dentin sticks were obtained with a rectangular cross-sectional area (0.8-1 mm2) and were either stored in water at 37 ?#61616;C for 24 h or submitted to chemical degradation. For chemical degradation, they were immersed in 10% NaOCl aqueous solution for 5 h and rinsed in water for 1 h. The sticks were submitted to microtensile test in a mechanical testing machine at 0.5 mm/min until failure. Fracture pattern was analyzed using SEM. μTBS values were calculated in MPa and submitted to analysis of variance ANOVA (α=0.05). The variance analysis showed that the 'MMP inhibitor' and 'degradation' factors (p=0.214 and p=0.093, respectively) and interaction between the factors were not statistically significant (p=0.143). Mixed failure predominated in all groups. In conclusion, the 2% CHX and NaF 5000 ppm presented similar μTBS of composite resin to laser-irradiated dentin before and after chemical degradation.
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, USP - Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Beatriz Carlos
authors.initials: BC
authors.lastname: Correa
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, USP - Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Galo
authors.affiliation: Department of Pediatric Dentistry, FSG - Faculdade da Serra Gaúcha, Caxias do Sul, RS, Brazil.
authors.forename: Camila
authors.initials: C
authors.lastname: Scatena
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, USP - Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Borsatto
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, IMED - Faculdade Meridional, Passo Fundo, RS, Brazil.
authors.forename: Aloísio Oro
authors.initials: AO
authors.lastname: Spazzin
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, USP - Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Silmara Aparecida Milori
authors.initials: SA
authors.lastname: Corona
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, IMED - Faculdade Meridional, Passo Fundo, RS, Brazil.
authors.forename: Daniel
authors.initials: D
authors.lastname: Galafassi
mesh_terms: D003188:Composite Resins; D053844:Lasers, Solid-State; D045726:Metalloproteases / Q000187:drug effects* / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology*; D013718:Tensile Strength
chemical_list: D003188:Composite Resins; D011480:Protease Inhibitors; D045726:Metalloproteases