Efeito do preaquecimento de cimentos resinosos na resistência de união de cerâmica à dentina

• Autor(a) principal: Castro, Fernanda Maria de
• Data de Publicação: 2014
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/3874
• topic: Polimerização; Aquecimento; Cimentos de resina; Porcelana dentária; Adesivos dentários; Polymerization; Heating; Resin cements; Dental porcelain; Dental cements; CIENCIAS DA SAUDE::ODONTOLOGIA

Evaluate bond strength (BS) between leucite glass ceramic and dentin when luted with conventional and self-adhesive resin cements, preheated or not, through a microtensile bond strength test (μTBS) and examine the fracture mode. Materials and Methods: Twenty-four extracted human third molars were sectioned for the removal of the occlusal enamel and root portion, and ramdomly divided into four groups, with four teeth for each group. Twenty-four leucite glass ceramic discs (IPS Empress Esthetic, Ivoclar Vivadent, Schaan, Liechtenstein) were obtained and luted to the teeth, following manufacturers instructions, divided in four (4) groups: GI – RelyX ARC (3M ESPE) + Scotchbond Multi-Purpose Plus (3M ESPE); GII – RelyX ARC preheated 60°C + Scotchbond Multi-Purpose Plus; GIII – RelyX U200; GIV – RelyX U200 preheated 60°C. They were cut into 1 mm2 specimens, stored in destilled water for 24hs at 25±2°C and submitted to the μTBS in a universal testing machine. Each fragment of the specimen was analysed in stereoscopic microscope (45X) to classify the failure mode. SEM images of a representative pair of each failure mode were obtained. Data were statisticaly analysed with Variance Analysis (ANOVA) and Tukey (α=0.05). Results: There were statistical significant differences on BS between the cements RelyX ARC and U200 (p<0.05) in both groups with and without heating. There were no significant differences on BS between groups GI (12.98 MPa) and GII (12.87 MPa) and between GIII (6.81 MPa) and GIV (8.58 MPa) for both cements tested (p>0,05). The most common failure mode observed in all groups was adhesive, followed by mixed and ceramic cohesive failure; no group presented dentin cohesive failure. Conclusion: Preheating of resin cements to 60ºC did not enhance BS for both cements. BS for conventional resin cement was greater than self-adhesive resin cement. Adhesive failure was the most common failure mode.