CAD/CAM Polymer vs Direct Composite Resin Core Buildups for Endodontically Treated Molars Without Ferrule

Güth, J.-F.; Edelhoff, D.; Goldberg, J. und Magne, P. (2016): CAD/CAM Polymer vs Direct Composite Resin Core Buildups for Endodontically Treated Molars Without Ferrule. In: Operative Dentistry, Bd. 41, Nr. 1: S. 53-63

Abstract

Objectives: The aim of this study was to investigate the restoration of broken-down endodontically treated molars without ferrule effect using glass ceramic crowns on different composite resin core buildups. Methods and Materials: Forty-five decoronated endodontically treated teeth (no ferrule) were restored with a semidirect buildup using an experimental computer-aided design/computer-aided manufacturing (CAD/CAM) high-performance polymer (HPP group) or with light-curing composite core buildups of Tetric Evo-Ceram with (TECP group) or without (TEC group) a glass-fiber-reinforced post. All teeth were prepared to receive bonded glass ceramic crowns (Empress CAD luted with Variolink II) and were subjected to accelerated fatigue testing. Cyclic isometric loading was applied to the palatal cusp at an angle of 30 degrees and a frequency of 5 Hz, beginning with a load of 200 N (x5000 cycles) and followed by stages of 400, 600, 800, 1000, 1200, and 1400 N at a maximum of 30,000 cycles each. Specimens were loaded until failure or to a maximum of 185,000 cycles. Groups were compared using the life-table survival analysis (log rank test at p=0.05). Average fracture loads and number of survived cycles were compared with one-way analysis of variance (Scheffe post hoc at p=0.05). Results: None of the tested specimen withstood all 185,000 load cycles. There was a significant difference in mean fracture load, survived cycles, and survival;the HPP group (fracture load 975.27N +/- 182.74) was significantly higher than the TEC (716.87N +/- 133.43;p=0.001) and TECP (745.67 +/- 156.34;p=0.001) groups, and the TEC and TECP groups showed no difference (p=0.884). Specimens in the TECP group were affected by an initial failure phenomenon (wide gap at the margin between the buildup/crown assembly and the root). Conclusions: Semidirect core buildup made from high-performance polymer enhanced the performance of all-ceramic leucite-reinforced glass ceramic crowns compared with direct light-curing composite resin buildups. The use of a fiber-reinforced post system did not influence the fatigue strength of all-ceramic crowns.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Medizin
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• ISSN: 0361-7734
• Sprache: Englisch