A influência do corte com diferentes discos e velocidades na integridade dos espécimes e na resistência adesiva de uma cerâmica a um cimento resinoso dual em ensaio de microtração

• Ano de defesa: 2010
• Autor(a) principal: Castro, Martha Chiabai Cupertino de
• Orientador(a): Miranda, Mauro Sayão de
• Banca de defesa: Cunha, Alfredo Gonçalves , Sadek, Fernanda Tranchesi , Souza, Hilda Maria Montes Ribeiro de , Dias, Katia Regina Hostilio Cervantes , Masioli, Marco Antônio
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade do Estado do Rio de Janeiro
• Programa de Pós-Graduação: Programa de Pós-Graduação em Odontologia
• Departamento: Centro Biomédico::Faculdade de Odontologia
• País: BR
• Palavras-chave em Português: Cerâmica; Microtração; Microscopia eletrônica de varredura; Resistência adesiva; Cerâmica odontológica; Resistência à tração; Adesivos dentinários
• Palavras-chave em Inglês: Ceramics; Microtensile strength; Scanning electron microscopy; Bond strength
• Área do conhecimento CNPq: CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA
• Link de acesso: http://www.bdtd.uerj.br/handle/1/13970

The aim of this research was to verify the influence of different cutting speeds and brand of diamond saws during microtensile specimen preparation on the bonding strength values and on the samples microscopy integrity (SEM). Twenty lithium disilicate glass-ceramic blocks (IPS e.max Press ) were bonded with dual-cure resin cement (Rely X ARCTM) to composite (Z100TM) blocks, built incrementally. The manufacturers recommendations were followed for ceramic treatment surface and placement on the resin cement, as well. After storage for 24 hours in distillated water at 37°C, the specimens were divided in two groups of diamond saws, Buehler® and Extec® brands, which were further subdivided using 200rpm and 400rpm speeds (B2; E2; B4 and E4 respectively), and they were sectioned into two perpendicular axes obtaining sticks shaped specimens with cross-sectional area of 1.0mm². For each experimental situation the sticks were randomly separated; 15 for the analysis to the SEM and 30 to be submitted to tensile strength. Mean bond strength values (MPa) were: E4 = 20.3 ± 12; B4 = 24.2 ± 11.3; B2 = 25.2 ± 9.0; and E2 = 28.6 ± 10.4. The statistical analysis of data showed that the values of bond strength at 200 rpm speed were significantly higher as compared to 400 rpm speed, regardless of saw employed. In SEM, it was noted better integrity of sticks at 200 rpm speed with presence of less extensive cracks in external edges. It was also found that the Extec® saw at 400 rpm showed eccentric movement to cutting and achieved higher number of premature losses, a significant decreased mean total area of bond (p<0.05), in addition to significant difference in strength values compared with 200 rpm speed. It was concluded that using different speeds and their interaction with the used saw interfere with the integrity of specimens and the bond strength values, being more pronounced when using the Extec® saw.