title: Microtensile bond strength of composite resin to glass-infiltrated alumina composite conditioned with Er,Cr:YSGG laser.
abstract: Tribochemical silica-coating is the recommended conditioning method for improving glass-infiltrated alumina composite adhesion to resin cement. High-intensity lasers have been considered as an alternative for this purpose. This study evaluated the morphological effects of Er,Cr:YSGG laser irradiation on aluminous ceramic, and verified the microtensile bond strength of composite resin to ceramic following silica coating or laser irradiation. In-Ceram Alumina ceramic blocks were polished, submitted to airborne particle abrasion (110 μm Al(2)O(3)), and conditioned with: (CG) tribochemical silica coating (110 μm SiO(2)) + silanization (control group); (L1-L10) Er,Cr:YSGG laser (2.78 μm, 20 Hz, 0.5 to 5.0 W) + silanization. Composite resin blocks were cemented to the ceramic blocks with resin cement. These sets were stored in 37°C distilled water (24 h), embedded in acrylic resin, and sectioned to produce bar specimens that were submitted to microtensile testing. Bond strength values (MPa) were statistically analyzed (α ≤0.05), and failure modes were determined. Additional ceramic blocks were conditioned for qualitative analysis of the topography under SEM. There were no significant differences among silicatization and laser treatments (p > 0.05). Microtensile bond strength ranged from 19.2 to 27.9 MPa, and coefficients of variation ranged from 30 to 55%. Mixed failure of adhesive interface was predominant in all groups (75-96%). No chromatic alteration, cracks or melting were observed after laser irradiation with all parameters tested. Surface conditioning of glass-infiltrated alumina composite with Er,Cr:YSGG laser should be considered an innovative alternative for promoting adhesion of ceramics to resin cement, since it resulted in similar bond strength values compared to the tribochemical treatment.
authors.affiliation: Special Laboratory of Lasers in Dentistry (LELO), Department of Restorative Dentistry, School of Dentistry of the University of São Paulo, São Paulo, SP, Brazil. cpeduard@usp.br
authors.forename: Carlos de Paula
authors.initials: Cde P
authors.lastname: Eduardo
authors.forename: Marina Stella
authors.initials: MS
authors.lastname: Bello-Silva
authors.forename: Simone Gonçalves
authors.initials: SG
authors.lastname: Moretto
authors.forename: Paulo Francisco
authors.initials: PF
authors.lastname: Cesar
authors.forename: Patricia Moreira
authors.initials: PM
authors.lastname: de Freitas
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D002516:Ceramics / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D001840:Dental Bonding; D003776:Dental Porcelain / Q000737:chemistry; D005898:Glass / Q000737:chemistry; D053844:Lasers, Solid-State; D019279:Resin Cements / Q000737:chemistry* / Q000528:radiation effects; D012822:Silicon Dioxide / Q000737:chemistry; D013718:Tensile Strength
chemical_list: D003188:Composite Resins; C483026:In-Ceram Alumina; D019279:Resin Cements; D003776:Dental Porcelain; D012822:Silicon Dioxide; D000537:Aluminum Oxide