Bond strength of adhesive systems irradiated with ER, CR: YSGG laser

• Ano de defesa: 2017
• Autor(a) principal: Zabeu, Giovanna Speranza
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Adesivos dentinários; Dentin-bonding agents; Laser; Lasers; Resistência à tração; Tensile strength

The use of high-power lasers has been studied to improve the mechanical and biological properties of the interface of enamel and dentin restorations when irradiated over adhesive systems prior to light-curing. The Er, Cr: YSGG laser has a wavelength of 2780nm, length where the water and hydroxyapatite absorption peak occurs, and it can present a favorable performance when irradiated in adhesive systems applied on dentin. To provide this evidence, this study had the objective of analyzing the adhesion on dentin of different adhesive systems irradiated with the Er, Cr: YSGG laser before light-curing. The experimental design of this study presented two variation factors: laser, divided into two levels (Er, Cr: YSGG [E] and Control - no irradiation [C]) and dentin-bonding system (DBS) divided into four levels (AdperTM Scotchbond Multipurpose [MP], AdperTM Single Bond 2 [SB], ClearfilTM SE Bond [CSE], Single BondTM Universal [SBU]). The quantitative response variable was the bond strength, obtained through the microtensile test. Eighty human molars (n=10) were obtained and they were cut to expose occlusal dentin area. The specimens were restored according to their respective groups. In the irradiated groups, irradiation of the Er, Cr: YSGG laser was performed after primer or after primer/adhesive on the simplified adhesives. After seven days, the specimens were cut to obtain sticks (0.64 mm2) and submitted to immediate microtensile test (Instron 3342) at 0.5mm/min. The fracture mode was classified according to the interface analysis in a portable digital microscope 40x. Data presented normal distribution and was analyzed by two-way ANOVA, followed by Tukey test for multiple comparisons (p<0.05). Only the adhesive factor presented statistical difference, where in the control group, the SBU adhesive was similar to SB and superior to CSE and MP and, in the laser group, the SBU was similar to SB and superior to CSE and MP which presented the lowest bond strength value. Based on these results, it was concluded that the bond strength variation was dependent on the adhesive systems and the laser irradiation did not affect the performance of dentin bonding systems in the immediate period.