Weigl, Paul and Sander, Anna and Wu, Yanyun and Felber, Roland and Lauer, Hans-Christoph and Rosentritt, Martin (2018) In-vitro performance and fracture strength of thin monolithic zirconia crowns. JOURNAL OF ADVANCED PROSTHODONTICS, 10 (2). pp. 79-84. ISSN 2005-7806, 2005-7814
Full text not available from this repository. (Request a copy)Abstract
PURPOSE. All-ceramic restorations required extensive tooth preparation. The purpose of this in vitro study was to investigate a minimally invasive preparation and thickness of monolithic zirconia crowns, which would provide sufficient mechanical endurance and strength. MATERIALS AND METHODS. Crowns with thickness of 0.2 mm (group 0.2, n=32) or of 0.5 mm (group 0.5, n=32) were milled from zirconia and fixed with resin-based adhesives (groups 0.2A, 0.5A) or zinc phosphate cements (groups 0.2C, 0.5C). Half of the samples in each subgroup (n=8) underwent thermal cycling and mechanical loading (TCML)(TC: 5 degrees C and 55 degrees C, 2x3,000 cycles, 2 min/cycle; ML: 50 N, 1.2x10(6) cycles), while the other samples were stored in water (37 degrees C/24 h). Survival rates were compared (Kaplan-Maier). The specimens surviving TCML were loaded to fracture and the maximal fracture force was determined (ANOVA; Bonferroni; alpha=.05). The fracture mode was analyzed. RESULTS. In both 0.5 groups, all crowns survived TCML, and the comparison of fracture strength among crowns with and without TCML showed no significant difference (P=.628). Four crowns in group 0.2A and all of the crowns in group 0.2C failed during TCML. The fracture strength after 24 hours of the cemented 0.2 mm-thick crowns was significantly lower than that of adhesive bonded crowns. All cemented crowns provided fracture in the crown, while about 80% of the adhesively bonded crowns fractured through crown and die. CONCLUSION. 0.5 mm thick monolithic crowns possessed sufficient strength to endure physiologic performance, regardless of the type of cementation. Fracture strength of the 0.2 mm cemented crowns was too low for clinical application.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | LITHIUM-DISILICATE CROWNS; FIXED-PARTIAL DENTURES; LOAD-BEARING CAPACITY; ALL-CERAMIC CROWNS; LABORATORY SIMULATION; FINITE-ELEMENT; SINGLE CROWNS; MOLAR CROWNS; CEMENT TYPE; BITE FORCE; Zirconia; Minimal invasive; Monolithic crown; Cementation; Ceramic |
| Subjects: | 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Medicine > Lehrstuhl für Zahnärztliche Prothetik |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 04 Mar 2020 14:40 |
| Last Modified: | 04 Mar 2020 14:40 |
| URI: | https://pred.uni-regensburg.de/id/eprint/14820 |
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