Title: 1415 - Fracture Resistance of Posterior Monolithic Three-Unit FPDs: Ceramics vs. Composite
Michael Koziel (Presenter)
Thomas Niem, Justus-Liebig-University Giessen
Antje Hübner, Justus-Liebig-University Giessen
Bernd Wöstmann, Justus-Liebig-University Giessen
Objectives: Nowadays due to the patient’s higher aesthetic standards, the request for monolithic materials for Fixed Partial Dentures (FPD) restorations in the molar region has increased. Nevertheless information about the fracture load of posterior monolithic three-unit FPDs is still scarce. The purpose of this in vitro study was to evaluate the fracture resistance of posterior three-unit FPDs made of different dental materials before and after thermomechanical loading in a chewing simulator.
Methods: A maxillary second premolar and a first molar were digitally designed and milled out of titanium. In total sixteen FDPs were fabricated from each material in a standardized anatomical shape: group ZLS zirconia-reinforced lithium silicate (Celtra Press), LD lithium disilicate (IPS e.max Press), group FZ fluorescent zirconia (LAVA Esthetic) and group HC hybrid composite (LuxaCam Composite). Thereafter, one half of the specimens from each group (n=8) were placed in a chewing simulator (SD-Mechatronics-Cs-4.8; 1.2million chewing cycles with 108N, 1.4Hz, 0.5mm slide). During the chewing simulation thermocycling (5°C/55°C) was performed (105 seconds per cycle). To determine the fracture strength all specimens (aged and non-aged) were loaded until they fractured (0.5mm/min feed, Zwick 1454, Zwick GmbH). Besides descriptive statistics parametric methods were used for statistical analysis (One-way Anova, Post-hoc-test Bonferroni).
Results: All specimens survived the thermodynamic loading. HC showed the highest fracture strength before/after cyclic load (mean 1642.8N/1598.4N), followed by FZ (mean 1600.6N/1571N). Both materials showed significantly higher fracture strength than ZLS (mean 1267.7N/1087.1N) and LD (mean 1125.3N/1175.1N). However, no significant effect could be identified for the thermodynamic loading for each material.
Conclusions: Other than anticipated the hybrid composite showed a fracture strength comparable to zirconia after artificial ageing.
This abstract is based on research that was funded entirely or partially by an outside source:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE