title: Effect of changing enamel conditioner concentration on the shear bond strength of a resin-modified glass ionomer adhesive.
abstract: The purpose of this study was to determine the effects on shear bond strength of changing the concentration of the enamel conditioner used with resin-reinforced glass ionomer. Shear bond strength was measured within 30 minutes after bonding. Forty-six freshly extracted human molars were collected and stored in a solution of 0. 1% (weight/volume) thymol. The teeth were cleaned and polished, then randomly separated into 2 groups. In group I, enamel was conditioned with a 10% polyacrylic acid solution before bonding. In group II, the enamel was conditioned with a 20% polyacrylic acid solution. The results of t test comparisons of the 2 experimental groups (t = 4.9) indicate significant differences (P =.001). Shear bond strength was significantly greater in the group conditioned with the 20% polyacrylic acid concentration (X = 3.3 +/- 2.6 MPa) than in the group conditioned with the 10% concentration (X = 0.4 +/- 1.0 MPa). The present findings indicated that the lower initial shear bond strength of resin-reinforced glass ionomer adhesive can be improved more than 8-fold when the concentration of the polyacrylic acid enamel conditioner is increased from 10% to 20%. The clinician needs to take these properties into consideration when ligating the initial archwires.
authors.affiliation: College of Dentistry, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Bishara
authors.forename: L
authors.initials: L
authors.lastname: VonWald
authors.forename: J F
authors.initials: JF
authors.lastname: Laffoon
authors.forename: J R
authors.initials: JR
authors.lastname: Jakobsen
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D000180:Acrylic Resins / Q000737:chemistry*; D000538:Aluminum Silicates; D016009:Chi-Square Distribution; D003743:Dental Enamel / Q000737:chemistry; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; D006801:Humans; D011897:Random Allocation; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D000180:Acrylic Resins; D000538:Aluminum Silicates; D017220:Dentin-Bonding Agents; C095451:Fuji Ortho LC; D005899:Glass Ionomer Cements; C006903:carbopol 940