Open Access
CC BY 4.0 · Eur J Dent 2025; 19(03): 638-649
DOI: 10.1055/s-0044-1791705
Original Article

Comparative Analysis of CAD-CAM Workflow Variations on the Marginal and Internal Gaps and Fatigue Behavior of Ceramic and Resin Composite Dental Crowns

1   Department of Conservative Dentistry, Faculty of Dentistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil
,
2   Post-Graduate Program in Oral Sciences (Prosthodontics Units), Faculty of Dentistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil
,
3   Department of Surgical Sciences, Dental School, Turin, Piedmont, Italy
,
4   Department of Restorative Dentistry, Faculty of Dentistry, Federal University of Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil
,
5   Department of Reconstructive Oral Care, Academic Centre for Dentistry in Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, North Holland, The Netherlands
,
2   Post-Graduate Program in Oral Sciences (Prosthodontics Units), Faculty of Dentistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil
,
6   Department of Dental Material Sciences, Academic Centre for Dentistry in Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, North Holland, The Netherlands
,
3   Department of Surgical Sciences, Dental School, Turin, Piedmont, Italy
,
2   Post-Graduate Program in Oral Sciences (Prosthodontics Units), Faculty of Dentistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil
› Institutsangaben

Funding This work is part of the fulfillment of the requirements of the PhD degree (R.O.P.) in the Post-Graduate Program in Oral Sciences at the Faculty of Dentistry, Universidade Federal de Santa Maria (Rio Grande do Sul State, Brazil). Besides, this study was partially financed by the Brazilian National Council for Scientific and Technological Development—CNPq (R.O.P. doctorate scholarship, project #140118/2022-5; R.V.M. postdoctoral scholarship; project no. 151004/2022-6; G.K.R.P. research productivity scholarship Pq2, process number #304665/2022-3), by the Brazilian Federal Agency for Coordination of Improvement of Higher Education Personnel—CAPES (finance code 001, L.S.R. doctorate's scholarship), and by the Foundation to Research Support of the Rio Grande do Sul State—FAPERGS (project #21/2551-0001961-1).
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Abstract

Objectives To analyze the marginal/internal gap and the fatigue behavior of crowns made of two different materials, using four combinations of a digital workflow—two intraoral scanners (IOSs) and two milling machines.

Materials and Methods Crowns were made considering three factors: IOS (a confocal microscopy-based scanner: TRIOS 3—TR; or a combination of active triangulation and dynamic confocal microscopy: Primescan—PS), milling machines (four-axis: CEREC MC XL—CR or five-axis: PrograMill PM7—PM), and restorative material (lithium disilicate—LD or resin composite—RC) (n = 10). The bonding surface of each crown was treated and bonded to each respective glass fiber-reinforced epoxy resin die using a dual-cure resin cement. A computed microtomography analysis was performed to access marginal/internal gap. The specimens were subjected to a cyclic fatigue test (20 Hz, initial load = 100 N/5,000 cycles; step size= 50 N/10,000 cycles until 1,500 N, then if specimens survived, the step size was increased to 100 N/10,000 cycles).

Statistical Analysis For data analysis, three-way analysis of variance and Kaplan–Meier with log-rank (Mantel–Cox) test were performed (α = 0.05).

Results TR resulted in a smaller axial-occlusal angle and occlusal gap, and five-axis milling resulted in a smaller marginal gap, axial-occlusal angle, and occlusal gap. Angled points and occlusal surface showed a tendency for overmilling. RC crowns displayed higher survival rates and a more pronounced topography compared with LD independently of the scanning and milling method. LD crowns produced with a five-axis milling machine resulted in higher fatigue performance and rougher topography compared with a four-axis machine.

Conclusion RC crowns displayed better fatigue behavior compared with LD, while LD benefited from a five-axis machine for improved survival probability.

Authors' Contributions

R.O.P. contributed to conceptualization, data curation, methodology, formal analysis, investigation, visualization, and writing—original draft. L.S.d.R. and R.V.M. to methodology, formal analysis, investigation, and writing—review and editing. A.B. to methodology, software, formal analysis, investigation, and writing—review and editing. J.P.M.T. to methodology, investigation, and writing—review and editing. L.F.V. to conceptualization, methodology, investigation, writing—review and Editing, and funding acquisition. C.J.K. to methodology, investigation, writing—review and editing. N.S. to conceptualization, methodology, software, investigation, writing—review and editing, and supervision. G.K.R.P. to conceptualization, methodology, investigation, writing—review and editing, supervision, project administration, and funding acquisition.




Publikationsverlauf

Artikel online veröffentlicht:
12. März 2025

© 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

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