title: Effects of enamel deproteinization on bracket bonding with conventional and resin-modified glass ionomer cements.
abstract: The objective of this study was to test the effects of enamel deproteinization on bracket bonding with conventional and resin-modified glass ionomer cement (RMGIC). One hundred premolars, extracted for orthodontic reasons, were divided into five groups (n = 20). Group 1 (control): enamel was etched with 35 per cent phosphoric acid, a thin layer of adhesive was applied, and the brackets were bonded with Transbond XT. Group 2: enamel was etched with 10 per cent polyacrylic acid and the brackets were bonded with conventional glass ionomer cement (GIC). Group 3: enamel was treated with 5.25 per cent NaOCl, etched with 10 per cent polyacrylic acid, and the brackets were bonded with conventional GIC. Group 4: enamel was etched with 10 per cent polyacrylic acid and the brackets were bonded with RMGIC. Group 5: enamel was treated with 5.25 per cent NaOCl, etched with 10 per cent polyacrylic acid, and the brackets were bonded with RMGIC. The teeth were stored in distilled water for 24 hours before they were submitted to shear testing. The results demonstrated that bond strength values of group 1 (17.08 ± 6.39 MPa) were significantly higher in comparison with the other groups. Groups 2 (3.43 ± 1.94 MPa) and 3 (3.92 ± 1.57 MPa) presented values below the average recommended in the literature. With regard to adhesive remnant index, the groups in which the enamel was treated with NaOCl showed a behaviour similar to that of the resin composite. It is conclude with enamel treatment with NaOCl increased bonding strength of brackets bonded with GIC and RMGIC, but increased bond strength was not statistically significant when compared to the untreated groups.
authors.affiliation: Orthodontic Graduate Program, Pontifical Catholic University of Minas Gerais, Belo Horizonte, MG, Brazil
authors.forename: Tatiana Bahia Junqueira
authors.initials: TB
authors.lastname: Pereira
authors.forename: Wellington Corrêa
authors.initials: WC
authors.lastname: Jansen
authors.forename: Matheus Melo
authors.initials: MM
authors.lastname: Pithon
authors.forename: Bernardo Quiroga
authors.initials: BQ
authors.lastname: Souki
authors.forename: Orlando Motohiro
authors.initials: OM
authors.lastname: Tanaka
authors.forename: Dauro Douglas
authors.initials: DD
authors.lastname: Oliveira
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D000180:Acrylic Resins / Q000737:chemistry; D000269:Adhesives / Q000008:administration & dosage; D000538:Aluminum Silicates / Q000737:chemistry; D001641:Bicuspid; D001840:Dental Bonding / Q000379:methods*; D003743:Dental Enamel / Q000737:chemistry*; D003799:Dental Stress Analysis; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D016910:Orthodontic Brackets; D010756:Phosphoric Acids / Q000737:chemistry; D019279:Resin Cements
chemical_list: D000180:Acrylic Resins; D000269:Adhesives; D000538:Aluminum Silicates; D005899:Glass Ionomer Cements; D010756:Phosphoric Acids; D019279:Resin Cements; C477790:Transbond XT; C006903:carbopol 940; C030242:phosphoric acid