Débora Lopes Salles Scheffel1, Hérica Adad Ricci1, Carlos Alberto de Souza Costa2, David Henry Pashley3, Josimeri Hebling4. 1. Department of Orthodontics and Pediatric Dentistry, at the Araraquara School of Dentistry, UNESP - Univ Estadual Paulista, Araraquara, São Paulo, São Paulo, Brazil. 2. Department of Physiology and Pathology, at the Araraquara School of Dentistry, UNESP - Univ Estadual Paulista, Araraquara, São Paulo, São Paulo, Brazil. 3. Oral Biology, Department of Oral Biology, College of Dental Medicine, Georgia Health Sciences University, Augusta, Ga., USA. 4. Department of Orthodontics and Pediatric Dentistry, at the Araraquara School of Dentistry, UNESP - Univ Estadual Paulista, Araraquara, São Paulo, São Paulo, Brazil. jhebling@foar.unesp.br.
Abstract
PURPOSE: The purpose was to evaluate the effect of acid etching time on the bond strength of a simplified etch-and-rinse adhesive system to noncarious and caries-affected dentin of primary and permanent teeth. METHODS: Twenty-four extracted primary and permanent teeth were divided into three groups, according to the acid etching time. Four teeth from each group were exposed to a microbiological caries-inducing protocol. After caries removal, noncarious and caries-affected dentin surfaces were etched with 37 percent phosphoric acid for five, 10, or 15 seconds prior to the application of Prime & Bond NT adhesive. Crowns were restored with resin composite and prepared for microtensile testing. Data were submitted to Kruskal-Wallis and Mann-Whitney tests (α=0.05). RESULTS: Higher bond strengths were obtained for noncarious dentin vs. caries-affected dentin for both primary and permanent teeth. Reducing the acid etching time from 15 to five seconds did not affect the bond strength to caries-affected or noncarious dentin in primary teeth. For permanent teeth, lower bond strength values were observed when the noncarious dentin was etched for five seconds, while no difference was seen between 10 and 15 seconds. CONCLUSIONS: For Prime & Bond NT, the etching of dentin for five seconds could be recommended for primary teeth, while 10 seconds would be the minimum time for permanent teeth.
PURPOSE: The purpose was to evaluate the effect of acid etching time on the bond strength of a simplified etch-and-rinse adhesive system to noncarious and caries-affected dentin of primary and permanent teeth. METHODS: Twenty-four extracted primary and permanent teeth were divided into three groups, according to the acid etching time. Four teeth from each group were exposed to a microbiological caries-inducing protocol. After caries removal, noncarious and caries-affected dentin surfaces were etched with 37 percent phosphoric acid for five, 10, or 15 seconds prior to the application of Prime & Bond NT adhesive. Crowns were restored with resin composite and prepared for microtensile testing. Data were submitted to Kruskal-Wallis and Mann-Whitney tests (α=0.05). RESULTS: Higher bond strengths were obtained for noncarious dentin vs. caries-affected dentin for both primary and permanent teeth. Reducing the acid etching time from 15 to five seconds did not affect the bond strength to caries-affected or noncarious dentin in primary teeth. For permanent teeth, lower bond strength values were observed when the noncarious dentin was etched for five seconds, while no difference was seen between 10 and 15 seconds. CONCLUSIONS: For Prime & Bond NT, the etching of dentin for five seconds could be recommended for primary teeth, while 10 seconds would be the minimum time for permanent teeth.