Gingival Recession and Marginal Adaptation of Zirconia Crowns with Two Subgingival Margin Designs - A Randomized Clinical Trial

Sep 27, 2026

Uploaded by Theodore

Aim to evaluate feather-edge versus deep chamfer subgingival finish-line designs on gingival position and marginal adaptation of zirconia crowns. Thirty patients needing posterior tooth restorations received CAD/CAM milled zirconia crowns and were randomized into two groups: 15 with featheredge and 15 with deep chamfer preparations. Crown margin position and marginal adaptation were assessed at baseline, 6 months, and 1 year after resin cementation. No significant differences were found between designs across all follow-up points. Conclusion: both designs produced clinically acceptable outcomes after 1 year.

LanguageEnglish

CategoryHealthcare

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Pages9

Reading Time23 min

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ORIGINAL RESEARCH Gingival Recession and Marginal Adaptation of Zirconia Crowns with Two Subgingival Margin Designs: A Randomized Clinical Trial Heba El-Khayat1, Eman M Anwar2, Omnia Nabil3, Mostafa Aboushahba4 Received on: 07 August 2025; Accepted on: 06 September 2025; Published on: 10 October 2025 AbstrAct Aim: The aim of the study was to evaluate the effect of feather-edge finish line and deep chamfer finish line on gingival position and marginal adaptation. Methods: Thirty patients requiring restoration of a posterior tooth received zirconia crowns (BruxZir shaded 200) . Fifteen patients received subgingival featheredge finish line preparations (intervention group), and the other 15 patients received subgingival deep chamfer finish line preparations (comparator group) . CAD/CAM milled zirconia crowns were cemented with resin cement. Position of crown margin (gingival recession) and marginal adaptation measurements were taken at baseline, 6 months, and 1 year. Results were tabulated, and statistical analysis was performed. Results: The results of gingival recession and marginal adaptation showed no significant difference between featheredge and deep chamfer designs at baseline, 6 months, and 1 year. Conclusions: Monolithic zirconia crowns with subgingival restorative margin designs can be used with deep chamfer and featheredge margin designs, as both designs showed clinically acceptable results regarding gingival recession and marginal adaptation. Both margin designs behaved similarly after 1 year of clinical service, so special attention should be given to the position of the finish line and conservation in the choice of design. Clinical significance: Both margin designs behave comparatively regarding gingival recession and marginal adaptation with zirconia crowns. To favor the more conservative approach that would preserve tooth structure, the featheredge margin design would be preferred, if not otherwise needed. Keywords: Finish line design, Gingival recession, Marginal adaptation, Randomized clinical trial, Zirconia. The clinical trial was registered with the Clinical Trial [Registry of clinicaltrials.gov](Registry of clinicaltrials.gov) (NCT04729569). The Journal of Contemporary Dental Practice (2025): 10.5005/jp-journals-10024-3932 IntroductIon Full coverage ceramic crowns were traditionally known to be non-conservative. Chamfer finish lines are conventionally used to facilitate laboratory procedures and to provide optimum marginal fit.1 However, one of the common problems reported in the literature after crown placement is migration of the gingival margin levels relative to crowns with horizontal finish line designs.2 Recently, vertical finish line designs are becoming popular, especially in cases like short teeth where improved retention is needed, or where conservation is generally required, such as in mandibular incisors.3 Eventhough vertical finish lines are not novel, research is required to evaluate their clinical performance over longtime periods when used with new materials.4 Some authors claim that vertical preparations can increase gingival health eventhough they could be difficult to detect.3 Studies that compare responses to horizontal and vertical finish line designs are scarce.2 Vertical preparations are either “shoulderless” or “edgeless.”Shoulderless vertical preparations are only related to margin design, such as featheredge finish lines. Whereas, edgeless preparations are ones that involve the creation of a new prosthetic cementoenamel junction and essentially involve a gingittage [referred to as a biologically oriented preparation technique (BOPT)] .5 Biologically oriented preparation technique requires more time during temporization for healing.2 1Department of Fixed Prosthodontics, Faculty of Dentistry, Cairo University, Cairo; Department of Fixed Prosthodontics, Faculty of Oral and Dental Medicine, Future University in Egypt, Cairo, Egypt 2Department of Fixed Pro

FAQs

What was the aim of this randomized clinical trial?

To evaluate the effect of feather-edge finish line versus deep chamfer finish line on gingival position and marginal adaptation of zirconia crowns.

How were patients and crown designs assigned in the study?

Thirty patients requiring posterior tooth restoration received CAD/CAM zirconia crowns; 15 were prepared with subgingival featheredge finish lines and 15 with subgingival deep chamfer finish lines.

What were the main findings regarding gingival recession and marginal adaptation?

Gingival recession and marginal adaptation showed no significant differences between the two designs at baseline, 6 months, and 1 year. Both designs demonstrated clinically acceptable, similar performance after 1 year.

Sep 27, 2026

Uploaded by Theodore