title: Adhesion to Er:YAG laser-prepared dentin after long-term water storage and thermocycling.
abstract: This in vitro study evaluated the microtensile bond strength of a resin composite to Er:YAG-prepared dentin after long-term storage and thermocycling. Eighty bovine incisors were selected and their roots removed. The crowns were ground to expose superficial dentin. The samples were randomly divided according to cavity preparation method (I-Er:YAG laser and II-carbide bur). Subsequently, an etch & rinse adhesive system was applied and the samples were restored with a resin composite. The samples were subdivided according to time of water storage (WS)/number of thermocycles (TC) performed: A) 24 hours WS/no TC; B) 7 days WS/500 TC; C) 1 month WS/2,000 TC; D) 6 months WS/12,000 TC. The teeth were sectioned in sticks with a cross-sectional area of 1.0-mm2, which were loaded in tension in a universal testing machine. The data were subjected to two-way ANOVA, Scheffé and Fisher's tests at a 5% level. In general, the bur-prepared group displayed higher microtensile bond strength values than the laser-treated group. Based on one-month water stbrage and 2,000 thermocycles, the performance of the tested adhesive system to Er:YAG-laser irradiated dentin was negatively affected (Group IC), while adhesion of the bur-prepared group decreased only within six months of water storage combined with 12,000 thermocycles (Group IID). It may be concluded that adhesion to the Er:YAG laser cavity preparation was more affected by the methods used for simulating degradation of the adhesive interface.
authors.affiliation: University of São Paulo, School of Dentistry of Ribeirão, Preto, Department of Operative Dentistry, São Paulo, Brazil. flbamaral@gmail.com
authors.forename: Flávia Lucisano Botelho
authors.initials: FL
authors.lastname: do Amaral
authors.forename: Vivian
authors.initials: V
authors.lastname: Colucci
authors.forename: Aline Evangelista
authors.initials: AE
authors.lastname: de Souza-Gabriel
authors.forename: Michelle Alexandra
authors.initials: MA
authors.lastname: Chinelatti
authors.forename: Regina Guenka
authors.initials: RG
authors.lastname: Palma-Dibb
authors.forename: Silmara Aparecida Milori
authors.initials: SA
authors.lastname: Corona
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate; D002417:Cattle; D003188:Composite Resins; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000295:instrumentation*; D003762:Dental Instruments; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000379:methods; D003799:Dental Stress Analysis; D003804:Dentin; D017220:Dentin-Bonding Agents; D004356:Drug Storage; D053844:Lasers, Solid-State; D008855:Microscopy, Electron, Scanning; D011897:Random Allocation; D019279:Resin Cements; D013718:Tensile Strength; D014867:Water
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; C444701:Filtek Z250; D019279:Resin Cements; C115612:single bond; D014867:Water; D017438:Bisphenol A-Glycidyl Methacrylate