Retentores customizados em CAD/CAM utilizando diferentes materiais estéticos: avaliação da resistência à fratura e de união

• Ano de defesa: 2017
• Autor(a) principal: Spina, Denis Roberto Falcão
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Positivo; Brasil; Pós-Graduação; Programa de Pós-Graduação em Odontologia Clínica; UP
• Palavras-chave em Português: CAD-CAM; Pino intrarradicular; Materiais dentários; CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA
• Link de acesso: https://repositorio.cruzeirodosul.edu.br/handle/123456789/2146

Endodontically treated teeth with extensive coronary involvement and that will be restored with prosthesis usually require the use of post-and-cores. The materials used to make the posts must have physical and mechanical characteristics similar to those of the remaining dentin. The objectives of this thesis were: 1. to evaluate fracture resistance (FR) after fatigue and push-out bond strength (BS) with and without fatigue, in customized post-and-cores manufactured with different aesthetic materials in CAD/CAM; 2. describe the technique of fabrication and installation of an intraradicular aesthetic post-and-core made by the CAD/CAM system. In the first manuscript, ninety single-rooted extracted teeth were selected, endodontically treated and prepared to receive the posts. The specimens were randomly divided into 3 equal groups according to the material: hybrid ceramic Vita Enamic (HC); nano-ceramic resin composite Lava Ultimate (RC); and experimental epoxy-resin reinforced by glass-fiber (FG). The postand-cores were manufactured using CAD/CAM and cemented using a self-adhesive resin cement (Rely X Unicem2). A subgroup of 30 specimens (n=10) was subjected to fatigue (1,000,000 cycles at 5 Hz) and then to the FR test. Another subgroup with 60 specimens was submitted to the BS test, with and without fatigue. Data were submitted to analysis of variance (FR – one-way ANOVA; BS – two-way-ANOVA) and Tukey 's test (α = 0.05). The FR values (mean±SD, in Newtons) were 414.5±83.9 (HC), 621.3±100.3 (RC), and 407.6±109.0 (FG), with RC showing significantly higher FR values (p<0.05). For BS, there was no statistically significant difference among the materials, with and without fatigue (p>0.05). In the second manuscript, the customization of post-and-cores was described using CAD/CAM technology from the poly-vinyl siloxane molding. The machining was performed in a block of Lava Ultimate nano ceramic resin composite. The direct scanning on the molding allowed efficiency and speed when compared to the manufacture of the sealant by the technique of the acrylic resin post, besides allowing the use of a resin with properties similar to those of the dentinal remnant, in a case performed in the second upper premolar with follow-up of 6 months. It can be concluded that the type of material used for confection of the customized post-and-core had a significant influence on the FR, but not on the BS of the specimens. Fatigue performance did not influence the BS for different materials. The clinical technique of manufacturing customized post-and-cores by the scanning of the molding was efficient and fast. The material used was adequate after 6 months of clinical use.