Waldecker M, Rues S, Rammelsberg P, Bömicke W. Validation of in-vitro tests of zirconia-ceramic inlay-retained fixed partial dentures: A finite element analysis.
Dent Mater 2019;
35:e53-e62. [PMID:
30686709 DOI:
10.1016/j.dental.2019.01.017]
[Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 12/13/2018] [Accepted: 01/13/2019] [Indexed: 10/27/2022]
Abstract
OBJECTIVE
In the past, discrepancies between laboratory results and clinical behavior have been observed for all-ceramic restorations. This analysis of fracture resistance of zirconia-based inlay-retained fixed partial dentures (IRFPDs) aimed at identifying correlations between an in-vitro test setup and the clinical situation. The effects of tooth material, tooth mobility, restoration design, load direction, and different cements were taken into account.
METHODS
The in-vitro test model and IRFPD were reverse engineered (Geomagic DesignX) and meshed predominantly with hexahedral elements (approx. 230,000 elements). Homogenous, linear-elastic behavior was assumed for all materials. On the basis of the calculated stresses (ANSYS 18.2) and already known strength distributions for the restorative materials fracture resistance of the complete restoration and force at initial damage (fracture within the veneer) was estimated on the basis of the principal stress hypothesis. Differences depending on the assumed clinical situation and effects of different variables on fracture resistance were evaluated.
RESULTS
All variables tested in the finite element analysis affected the calculated fracture resistance of the IRFPD. Use of resin teeth led to an underestimation of fracture resistance by up to -57%, whereas fracture resistance of IRFPDs on metal abutment teeth was close to the clinical reference (-6% to +15%). Good correlation between the clinical scenario and that using metal teeth could only be achieved when the natural resilience of the abutment teeth was simulated.
SIGNIFICANCE
When testing fracture resistance of zirconia-based IRFPDs, metal abutment teeth in combination with simulated tooth resilience can reflect the clinical situation accurately.
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