Title: 1414 - Microleakage of CAD/CAM-crowns After bruxism: Zircon Versus Hybrid Ceramics


Carsten Fiege (Presenter)
Justus-Liebig-University Giessen

Maximiliane Schlenz, Justus-Liebig-University Giessen
Alexander Schmidt, Justus-Liebig-University Giessen
Bernd Wöstmann, Justus-Liebig-University Giessen


Objectives: Studies regarding the impact of bruxism on microleakage in zirconia restorations are rare. Thus it was the objective of this study to analyze the impact of extended loading on microleakage CAD/CAM fabricated crowns in a chewing simulation test.

Methods: Fifty extracted human-third-molars were CNC-milled into identical die and restored with CAD/CAM- produced full crowns (Brilliant-Crios, Coltene (BC); Vita-Enamic, Vita-Zahnfabrik (VE), high-translucent-zircon-3-Y (Z I), ultra-high-translucent-zircon-6-Y (Z II). All crowns (n=4*10) were luted according to manufacturer’s specifications using light-curing. Half of the specimens per group were loaded in a chewing-simulator (CS4.8, SDMechatronik, Germany) simulating normal masticatory function (NF) (1.2Mio. cycles, 100N, 0.7mm Sideshift, 37°C) the other half bruxism (B) (1.2Mio. cycles, 90N, 1.5mm Sideshift, 37°C). A dye penetration test was performed to detect microleakage. For inspection a digital microscope (Zeiss) was used. Furthermore the abrasion of stainless-steel antagonists was investigated at baseline and follow-up using a 3D- Scan (GOM, Germany) and matched after chewing-simulation.
For statistical analysis median test was used.

Results: Only ZI showed significantly lower microlekage in the B-group compared to the NF-group (p< 0.05). For the other materials there was no significant difference between NF and B. Highest microlekage was found in ZII (in NF) (Mean, Interquartil Range: 3.9%, 0.0- 8.0%) followed by VE (in B) (3.3%, 2.8-3.7%). Lowest leakage was found in ZI (B). Both zircon types (ZI and ZII) showed a higher abrasion of the antagonist compared to the hybrid-ceramics (BC and VE).

Conclusions: Within the limitations of this in vitro study, both ZrO2 types, as well as hybrid-ceramics, can be recommended for patients with bruxism. However zircon showed higher abrasion of the antagonist compared to hybrid-ceramics.

Student Presenter

This abstract is based on research that was funded entirely or partially by an outside source:

Disclosure Statement:
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