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. 2024 Apr;19(2):971-977.
doi: 10.1016/j.jds.2023.07.009. Epub 2023 Jul 19.

Influence of thermal aging on the marginal integrity of computer aided design/computer aided manufacturing fabricated crowns

Diana Lopez  1 , Hassan Ziada  2 , Neamat Hassan Abubakr  3
Affiliations

Influence of thermal aging on the marginal integrity of computer aided design/computer aided manufacturing fabricated crowns

Diana Lopez et al. J Dent Sci. 2024 Apr.

Abstract

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.

Keywords: CAD/CAM crowns; Lithium discilicate glass-ceramics; Lithium-reinforced glass-ceramics; Marginal integrity.

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Conflict of interest statement

The authors declare no conflicts of interest with respective to the research and publication of this article.

Figures

Fig. 1
Figure 1
Tooth VPS model for the standardization of the preparation.
Fig. 2
Figure 2
Scanning and digital processing of the crowns.
Fig. 3
Figure 3
Average marginal gap for the examined crowns up to five simulated clinical years.
Fig. 4
Figure 4
Leucite reinforced sample at initial (A); 10,000 cycles (B); 30,000 cycles (C); and 50,000 cycles (D).
Fig. 5
Figure 5
Lithium disilicate sample at initial (A); 10,000 cycles (B); 30,000 cycles (C); and 50,000 cycles (D).
See this image and copyright information in PMC

References

    1. Reiss B. Long-term clinical performance of CEREC restorations and the variables affecting treatment success. Comp Cont Educ Dent. 2001;22:14–18. - PubMed
    1. Chiang H., Staffen A., Abdulmajeed A.A., Janus C., Bencharit S. Effectiveness of cad/cam technology: a self-assessment tool for preclinical waxing exercise. Eur J Dent Educ. 2021;25:50–55. - PubMed
    1. Shi H.Y., Pang R., Yang J., et al. Overview of several typical ceramic materials for restorative dentistry. BioMed Res Int. 2022;2022 - PMC - PubMed
    1. Sulaiman T.A. Materials in digital dentistry—a review. J Esthetic Restor Dent. 2020;3:171–181. - PubMed
    1. Wendler M., Belli R., Petschelt A., et al. Chairside CAD/CAM materials. Part 2: flexural strength testing. Dent Mater. 2017;33:99–109. - PubMed

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