Open Access
CC BY 4.0 · Eur J Dent 2025; 19(04): 935-947
DOI: 10.1055/s-0045-1802569
Original Article

Does the Restoration Design and Material Affect Indirect Restorations' Marginal and Internal Gap, Interfacial Volume, and Fatigue Behavior?

Authors

  • Gabriel Kalil Rocha Pereira

    1   Department of Restorative Dentistry, Faculty of Dentistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil
  • Rafaela Oliveira Pilecco

    2   Department of Conservative Dentistry, Faculty of Dentistry, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul State, Brazil
  • Lucas Saldanha da Rosa

    1   Department of Restorative Dentistry, Faculty of Dentistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil
  • Renan Vaz Machry

    3   Department of Restorative Dentistry, Faculty of Dentistry, Federal University of Minas Gerais (UFMG), Belo Horizonte, Minas Gerais State, Brazil
  • Andrea Baldi

    4   Department of Surgical Sciences, Dental School, University of Turin, Turin, Italy
  • Nicola Scotti

    4   Department of Surgical Sciences, Dental School, University of Turin, Turin, Italy
  • Luiz Felipe Valandro

    1   Department of Restorative Dentistry, Faculty of Dentistry, Universidade Federal de Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil
  • João Paulo Mendes Tribst

    5   Department of Reconstructive Oral Care, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, North Holland, the Netherlands
  • Cornelis Johannes Kleverlaan

    6   Department of Dental Materials Science, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, North Holland, the Netherlands

Funding This study was partially financed by the Brazilian National Council for Scientific and Technological Development – CNPq (G.K.R.P. research productivity scholarship Pq2, process number #304665/2022-3; R.O.P. scholarship, process number #401444/2022-8; and L.F.V. project supported at Universal call, process number#405171/2023-4), by the Brazilian Federal Agency for Coordination of Improvement of Higher Education Personnel – CAPES (Finance code 001, L.S.R. Doctorate's scholarship; and CAPES PrInt Program, Process 88881.310412/2018-01), and by the Foundation to Research Support of the Rio Grande do Sul State – FAPERGS (#24/2551-0001408-0).
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Abstract

Objectives

This article evaluates the marginal and internal gap, interfacial volume, and fatigue behavior in computer-aided design-computer-aided manufacturing (CAD-CAM) restorations with different designs (crowns or endocrowns) made from lithium disilicate-based ceramic (LD, IPS e.max CAD, Ivoclar AG) or resin composite (RC, Tetric CAD, Ivoclar AG).

Materials and Methods

Simplified LD and RC crowns (-C) and endocrowns (-E) were produced (n = 10) using CAD-CAM technology, through scanning (CEREC Primescan, Dentsply Sirona) and milling (CEREC MC XL, Dentsply Sirona), and then adhesively bonded to fiberglass-reinforced epoxy resin. Computed microtomography was used to assess the marginal and internal gap and interfacial volume. A cyclic fatigue test (20 Hz, initial load = 100 N/5,000 cycles; step-size = 50 N/10,000 cycles until 1,500 N, if specimens survived, the step-size = 100 N/10,000 cycles until failure) was performed. Topography, finite element analysis (FEA), and fractography were also executed.

Statistical analysis

Two-way analysis of variance and Tukey's post hoc tests were employed (α = 0.05) for marginal and internal gap and interfacial volume. Survival analysis based on Kaplan–Meier and Mantel–Cox tests (α = 0.05) was used for fatigue data.

Results

RC crowns demonstrated the smallest marginal gap, LD crowns the largest. Endocrowns presented intermediary marginal gap values. Internal gaps were all above the planned 120 µm space. The lowest gap was seen at the cervical-axial angle at crowns, regardless of material. At the axio-occlusal angle, LD crowns presented a lower gap than RC; meanwhile, there was no difference among endocrowns. When comparing occlusal/pulpal space, LD crowns showed the lowest values, and RC-C, LD-E, and RC-E were statistically similar. Fatigue testing revealed superior behavior for RC restorations, withstanding higher loads and more cycles before failure compared to LD. FEA indicated that the crowns required higher stress concentration to unleash their failure than endocrowns. Fractographic features confirm failure origin at surface defects located at the restoration/cement intaglio surface, where it concentrated the highest maximum principal stress.

Conclusion

RC crowns and endocrowns presented lower marginal gaps than LD ones. Differences in other internal gap outcomes exist but within a nonclinically relevant threshold. The restoration fatigue behavior was influenced by the CAD-CAM material, but not by its design.

Authors' Contribution

G.K.R.P.: Conceptualization, methodology, data curation, validation, formal analysis, investigation, writing—review and editing, and visualization. R.O.P.: Conceptualization, formal analysis, and writing—review and editing. L.S.d.R.: Methodology, formal analysis, and writing—original draft preparation. R.V.M.: Investigation and writing—original draft preparation. A.B.: Conceptualization, investigation, data curation, writing—original draft preparation, and visualization. N.S.: Validation and writing—review and editing. L.F.V.: Conceptualization, formal analysis, visualization, and project administration. J.P.M.T.: Conceptualization, methodology, software, formal analysis, investigation, resources, writing—original draft preparation, visualization, supervision, project administration, and funding acquisition. C.J.K.: Conceptualization, methodology, resources, software, validation, formal analysis, investigation, resources, writing—review and editing, visualization, 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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