title: Effect of desensitizing agents on the microtensile bond strength of two-step etch-and-rinse adhesives to dentin.
abstract: Desensitizers can be used to control postoperative sensitivity in adhesive restorations. The aim of this study was to evaluate the effect of desensitizing agents on the bond strength of two-step etch-and-rinse adhesive systems to dentin. Forty-two human molars were sectioned to obtain 3-mm-thick dentin discs. The discs were divided into three groups (n = 14 in each) - no-treatment control group (CT), and oxalic acid [BisBlock (BB)] and calcium phosphate [Desensibilize Nano-P (NP)] desensitizers - before the application of two adhesive systems [Adper Single Bond Plus (SB) and One-Step Plus (OSP)]. A nanoparticle composite resin was used to create a 3-mm-thick build-up. The specimens were stored in distilled water for 24 h before a microtensile bond-strength test was performed. The failure modes were determined using a stereomicroscope at 100 × magnification. Specimens were sectioned perpendicular to the interface for scanning electron microscopy analyses. The CT-SB group exhibited the highest bond strength, differing significantly from BB-SB and BB-OSP groups. Mixed failures were prevalent for all groups. Scanning electron microscopy revealed a continuous hybrid layer and resin tags in all groups. Dentin bond strength of etch-and-rinse adhesive systems was reduced by an oxalic acid desensitizer but was not affected by a calcium phosphate-containing desensitizer.
authors.affiliation: School of Health and Biosciences, Graduate Program in Dentistry, Pontifícia Universidade Católica do Paraná, Curitiba, Parana, Brazil.
authors.forename: Fernanda M
authors.initials: FM
authors.lastname: Cortiano
authors.affiliation: School of Health and Biosciences, Graduate Program in Dentistry, Pontifícia Universidade Católica do Paraná, Curitiba, Parana, Brazil.
authors.forename: Rodrigo N
authors.initials: RN
authors.lastname: Rached
authors.affiliation: School of Health and Biosciences, Graduate Program in Dentistry, Pontifícia Universidade Católica do Paraná, Curitiba, Parana, Brazil.
authors.forename: Rui F
authors.initials: RF
authors.lastname: Mazur
authors.affiliation: School of Health and Biosciences, Graduate Program in Dentistry, Pontifícia Universidade Católica do Paraná, Curitiba, Parana, Brazil.
authors.forename: Sergio
authors.initials: S
authors.lastname: Vieira
authors.affiliation: School of Health and Biosciences, Graduate Program in Dentistry, Pontifícia Universidade Católica do Paraná, Curitiba, Parana, Brazil.
authors.forename: Andrea
authors.initials: A
authors.lastname: Freire
authors.affiliation: School of Health and Biosciences, Graduate Program in Dentistry, Pontifícia Universidade Católica do Paraná, Curitiba, Parana, Brazil.
authors.forename: Evelise M
authors.initials: EM
authors.lastname: de Souza
mesh_terms: D000134:Acid Etching, Dental; D003188:Composite Resins; D001840:Dental Bonding; D003738:Dental Cements; D003804:Dentin; D017220:Dentin-Bonding Agents; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements; D013718:Tensile Strength
chemical_list: D003188:Composite Resins; D003738:Dental Cements; D017220:Dentin-Bonding Agents; D019279:Resin Cements
keywords: dental adhesives; dentin desensitizing agents; scanning electron microscopy; tensile strength