RESUMO
The aim of this study was to evaluate the fracture resistance of endodontically maxillary premolars restored with mesio-occlusal-distal (MOD) inlays made with ceramic (IPS-Empress 2) and ceromer (Targis) and luted with three different dual-cured resin cements (Enforce, Variolink II, Panavia F). Sixty maxillary premolars were randomly distributed into six groups, according to their mesio-distal and facio-lingual dimensions. The teeth were endodontically treated and MOD cavities prepared. After the restorations were cemented, the samples were thermocycled and submitted to an axial compressive load by the action of a rounded end steel cylinder contacting the incline planes of occlusal surfaces of the teeth. The mode of fracture was analysed with a microscope. The best results were found with the combinations (cement/restorative material) Enforce/Targis (107.57 kgf) and Enforce/Empress (90.21 kgf) followed by Variolink II/Targis (86.44 kgf)-Variolink II/Empress (84.07 kgf) and Panavia F/Targis (82.43 kgf)-Panavia F/Empress (76.73 kgf). Analysis of variance (P < 0.05) showed a significant difference between Enforce and Panavia cements regardless of the restorative material. Considering the same luting agent there was no statistically significant difference between the restorative materials. Fracture of lingual cusps occurred in 55 of the 60 teeth and most of them were of the cohesive type.
Assuntos
Dente Pré-Molar , Materiais Dentários , Silicatos de Alumínio , Preparo da Cavidade Dentária/métodos , Porcelana Dentária , Restauração Dentária Permanente/métodos , Análise do Estresse Dentário/métodos , Cimentos de Ionômeros de Vidro , Restaurações Intracoronárias , Teste de Materiais/métodos , Maxila , Cimentos de Resina , Cimento de SilicatoRESUMO
This study evaluated the influence of three cleaning agents on the bond strength of complete crowns cemented with zinc phosphate and polycarboxylate cements. For the polycarboxylate cement group, three cleaning agents were used: Tergentol; Tergentol + polyacrylic acid; Tergentol + citric acid. Zinc phosphate cement was used as a control group with Tergentol. There were no statistically significant differences of mean retentive force for either cement regardless of the test conditions. The marginal fit after cementation was also evaluated and the results of zinc polycarboxylate were lower than zinc phosphate cement and were statistically significant.
Assuntos
Coroas , Colagem Dentária/métodos , Resinas Acrílicas , Cimentação , Ácido Cítrico , Adaptação Marginal Dentária , Detergentes , Humanos , Teste de Materiais , Cimento de Policarboxilato , Irrigantes do Canal Radicular , Tensoativos , Cimento de Fosfato de ZincoRESUMO
The purpose of this research was to test the traction resistance of cast posts and cores with and without roughness cemented with zinc phosphate cement in cuspids roots, with smooth and roughness canals walls. From the results of the tests and statistical analysis there was significant difference between roughness posts cemented in root canals with roughness walls and smooth posts cemented in smooth root canals. It was also analyzed, the retention of cast crows cemented on roughness posts and canals and it was concluded that posts are responsible for crows retention, when the cores were done at the correct way.
Assuntos
Técnica para Retentor Intrarradicular , Cimento de Fosfato de Zinco , Cimentação , Dente Canino , Análise do Estresse Dentário , Humanos , Propriedades de Superfície , Resistência à TraçãoRESUMO
The objective of the negative carving technique is to develop properly the occlusal principles during fabrication of occlusal surfaces of temporary crowns or metalhi restorations.