title: Effect of acid and laser etching on shear bond strength of conventional and resin-modified glass-ionomer cements to composite resin.
abstract: Success in sandwich technique procedures can be achieved through an acceptable bond between the materials. The aim of this study was to compare the effect of 35% phosphoric acid and Er,Cr:YSGG laser on shear bond strength of conventional glass-ionomer cement (GIC) and resin-modified glass-ionomer cement (RMGIC) to composite resin in sandwich technique. Sixty-six specimens were prepared from each type of glass-ionomer cements and divided into three treatment groups as follows: without pretreatment, acid etching by 35% phosphoric acid for 15 s, and 1-W Er,Cr:YSGG laser treatment for 15 s with a 600-μm-diameter tip aligned perpendicular to the target area at a distance of 1 mm from the surface. Energy density of laser irradiation was 17.7 J/cm(2). Two specimens in each group were prepared for evaluation under a scanning electron microscope (SEM) after surface treatment and the remainder underwent bonding procedure with a bonding agent and composite resin. Then the shear bond strength was measured at a crosshead speed of 0.5 mm/min. Two-factor analysis of variance and post-hoc Tukey test showed that the cement type, surface treatment method, and the interaction of these two factors significantly affect the shear bond strength between glass-ionomer cements and composite resin (p < 0.05). Surface treatment with phosphoric acid or Er,Cr:YSGG laser increased the shear bond strength of GIC to composite resin; however, in RMGIC only laser etching resulted in significantly higher bond strength. These findings were supported by SEM results. The fracture mode was evaluated under a stereomicroscope at ×20.
authors.affiliation: Department of Operative Dentistry, School of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Elmira Jafari
authors.initials: EJ
authors.lastname: Navimipour
authors.forename: Siavash Savadi
authors.initials: SS
authors.lastname: Oskoee
authors.forename: Parnian Alizadeh
authors.initials: PA
authors.lastname: Oskoee
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Bahari
authors.forename: Sahand
authors.initials: S
authors.lastname: Rikhtegaran
authors.forename: Morteza
authors.initials: M
authors.lastname: Ghojazadeh
mesh_terms: D000134:Acid Etching, Dental; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry*; D053844:Lasers, Solid-State; D010756:Phosphoric Acids / Q000737:chemistry*; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D005899:Glass Ionomer Cements; D010756:Phosphoric Acids; D019279:Resin Cements; C030242:phosphoric acid