Fatigue damage of monolithic posterior computer aided designed/computer aided manufactured crowns.

Abstract

PURPOSE:

To analyse fatigue damage of monolithic computer-aided-designed/computer-aided-manufactured (CAD/CAM)-materials after loading with high masticatory forces in standardized posterior crowns in a mouth-motion-simulator.

METHODS:

For manufacturing of test specimens (5 groups, 16 specimens each), two corresponding Standard-Tessellation-Language-(STL)-data-sets (one for the teeth and one for the crowns) were designed. The teeth were CAD/CAM-milled of human third molars and the crowns of three different CAD/CAM composite blocks (Lava Ultimate,'LU'; Brilliant Crios'BC'; Cerasmart,'CS'), one polymer-infiltrated-ceramic network (Vita Enamic,'VE') and a control group of lithium disilicate ceramics (IPS e.max CAD,'EM'). Crowns were adhesively cemented with their corresponding luting system on the human teeth. Half of the specimens were light-cured ('LC') and the others were chemical-cured ('CC'). A mouth-motion-simulator (WL-tec, 2 Hz, 37 °C) applied dynamic cyclic loading between 50-500 N for a period of 1 million cycles. Afterwards, a dye penetration test (aqueous basic-fuchsine) revealed damage of test specimens. Each specimen was sectioned into four equidistant slices and the area without damage was measured with a digital microscope (Zeiss) and radial cracks at the cementation surface were assessed. Data were subjected to Tukey's test.

RESULTS:

All specimens showed fatigue damage in the occlusal contact area. LU, BC and CS exhibited a significant greater area without damage compared to VE and EM (p < .05). EM and VE showed additional radial cracks at the cementation interface in both curing modes, whereas LU, BC and CS showed only radial cracks with chemical-cured luting cement.

CONCLUSIONS:

Monolithic CAD/CAM composite crowns showed significantly lower fatigue damage, particularly if the luting system was light-cured.

• Authors: Maximiliane Amelie Schlenz, Alexander Schmidt, Peter Rehmann, Bernd Wöstmann
• Journal: Journal of prosthodontic research (J Prosthodont Res) Vol. 63 Issue 3 Pg. 368-373 (Jul 2019) ISSN: 2212-4632 [Electronic] Japan
• PMID: 30878521 (Publication Type: Journal Article)
• Copyright: Copyright © 2019 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Chemical References

• Dental Porcelain

Topics

• Ceramics
• Computer-Aided Design
• Crowns
• Dental Porcelain
• Dental Restoration Failure
• Dental Stress Analysis
• Fatigue
• Humans
• Materials Testing