TY  - JOUR
A1  - Weigl, Paul
A1  - Sander, Anna
A1  - Wu, Yanyun
A1  - Felber, Roland
A1  - Lauer, Hans-Christoph
A1  - Rosentritt, Martin
T1  - In-vitro performance and fracture strength of thin monolithic zirconia crowns
T2  - The journal of advanced prosthodontics
N2  - 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℃ and 55℃, 2×3,000 cycles, 2 min/cycle; ML: 50 N, 1.2×106 cycles), while the other samples were stored in water (37℃/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; α=.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.
KW  - Zirconia
KW  - Minimal invasive
KW  - Monolithic crown
KW  - Cementation
KW  - Ceramic
Y1  - 2018
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/46598
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-465988
SN  - 2005-7814
SN  - 2005-7806
N1  - This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
VL  - 10
IS  - 2
SP  - 79
EP  - 84
PB  - Korean Acad. of Prosthodontics
CY  - Seoul
ER  -