Effects of attrition, prior acid-etching, and cyclic loading on the bond strength of a self-etching adhesive system to dentin

Abstract

The purpose of this study was to evaluate the effects of dentin attrition, phosphoric acid etching, and cyclic loading on the microtensile bond strength (μTBS) of a self-etching adhesive system to dentin. Flat dentin surfaces of human molars were assigned to eight experimental groups based on those with or without attrition, prior acid-etching, and cyclic loading. Resin composite paste was placed and polymerized after the bonding procedure according to manufacturer's instructions. The specimens were subjected to μTBS testing at a crosshead speed of 0.5 mm/min. Results showed that the minimum mean value of μTBS was 14.9 MPa in the group without attrition and acid-etching but with loading, while the maximum mean value of μTBS was 40.0 MPa in the group without attrition and loading but with acid etching. Therefore, the value of μTBS to dentin without attrition was significantly decreased by cyclic loading but that to dentin with attrition was not affected.

Dentin bond strength of a new adhesive system containing calcium phosphate experimentally developed for direct pulp capping

“…Based on the result obtained in this study, this pretreatment of the dentin surface did not adversely affect the dentin bond strength. The µTBS value of Clearfil SE Bond to dentin with this pretreatment was 52.7 MPa in this study, which was significantly higher than the 29.2 MPa obtained for the same adhesive without pretreatment in a previous study 28) . This significant difference in µTBS value hence suggested that pretreating the dentin surface with 10% NaClO gel followed by alternate irrigation with 3% H2O2 and 6% NaClO might be effective in increasing the dentin bond strength of self-etching primer systems.…”

Ensaio de resistência adesiva por microtração: revisão de literatura

“…As técnicas estudadas para seu armazenamento até o uso vão desde o congelamento 69 , refrigeração 49 até o armazenamento em temperatura ambiente. Para tanto, pode-se utilizar substâncias tais como água destilada 18,29,49,56,58,59 solução fisiológica 34 , timol 29,33,50,62,67 , e cloramina t 6,9,12,15,16,17,18,20,24,27,30,[37][38][39]41,[44][45][46]55,61,64,71,72 . Os protocolos com timol e cloramina T são indicados para evitar crescimento bacteriano, sem alterar a morfologia do substrato 33, 50,62 .…”

“…O protocolo de armazenamento mais atual para os dentes humanos é a utiliza-ção da cloramina T a 0,5%, sob refrigeração (4°C) 6,9,12,15,16,17,18,20,24,27,30,[37][38][39]41,[44][45][46]55,61,64,71,72 , mas também é comum o armazenamento em água destilada 18,29,49,56,58,59 . No entanto, um estudo recente de Mobarak et al 29 (2010) concluiu que o tempo e a forma de armazenamento não afetam os resultados obtidos no teste de microtração, ao comparar dentes recém-extraídos, dentes armazenados por 2 anos em cloramina-T a 0,5% sob refrigeração e dentes secos posteriormente reidratados no momento da execução do experimento.…”

“…A velocidade de 1mm/min é a mais utilizada ultimamente 9,18,22,33,34,[40][41][42][45][46][47]50,58,59,61 , pois resultados demonstraram um padrão de distribuição de estresse mais uniforme 75 . Há estudos que também utilizam a velocidade de 0,5mm/min para execução do teste 14,16,19,20,30,38,43,49,62 obtendo também resultados positivos. Dessa forma, consideramos que ambas as velocidades são válidas e devem ser escolhidas pelo pesquisador.…”