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Updated: Jun 28, 2025
Quasistatic Mechanical Testing for Computer-Aided Design and Manufacturing Occlusal Veneers Cemented to Milled Dentin Analog Material
Published on: December 20, 2024
Influence of thermal aging on the marginal integrity of computer aided design/computer aided manufacturing fabricated
Diana Lopez1, Hassan Ziada2, Neamat Hassan Abubakr3
1Department of Restorative Dentistry, Harvard School of Dental Medicine, Boston, MA, USA.
Background/Purpose:
The adaptation and marginal integrity of computer-aided designed and computer-aided manufactured (CAD/CAM) crowns after exposure to thermal aging need to be investigated. The present in-vitro study was designed to investigate the marginal integrity of CAD/CAM fabricated crowns cemented on extracted teeth after thermocycling aging.
Materials And Methods:
Twenty-six newly extracted human premolars were prepared for full-coverage CAD/CAM crowns and were divided into two groups (leucite-reinforced glass-ceramics and lithium disilicate glass-ceramics). Both crowns' groups were cemented using dual curing resin cement. All specimen margins were measured for marginal integrity using an imaging system 24 h post cementation; then after 1, 3, and 5 estimated clinical years (10,000, 30,000, and 50,000 thermocycles). Two-way ANOVA analysis were used to determine whether the mean value difference is significantly different (ɑ = 0.05).
Results:
The average margin gaps recorded for leucite-reinforced glass-ceramic crowns were: 82.61 μm initial, and 91.02 μm after 5 estimated clinical year). For the lithium disilicate glass-ceramic crowns, the average margin gaps recorded were: 100.01 μm initial, and 120.21 μm after 5 estimated clinical year. During all measuring intervals, the leucite-reinforced glass-ceramic crown group had a lower marginal discrepancy. No statistically significant difference between the two groups was recorded.
Conclusion:
After being subjected to thermocycling, both CAD/CAM ceramic crowns, exhibited an increase in their marginal discrepancy; the difference was within the accepted clinical range.
