Periodontal health in teeth treated with deep-margin-elevation and CAD/CAM partial lithium disilicate restorations-a prospective controlled trial

Objectives: This prospective controlled clinical trial aimed to compare periodontal parameters of proximal deep-margin-elevation (DME) restoration margins with supragingival/equigingival restoration margins (control) on the opposite proximal surface of the same tooth.

Materials and methods: Subgingival one-sided proximal defects (mesial or distal) on (pre-)molars were restored with composite DME and CAD/CAM-manufactured lithium disilicate ceramic partial-coverage restorations. Periodontal parameters (bleeding on probing (BOP), periodontal probing depths (PPD), plaque index (PI)) were recorded after insertion of the ceramic restoration (baseline) and at 1-year recall visit and compared between DME and control on the same tooth (Fisher's exact test and Wilcoxon signed rank test, p < 0.05).

Results: Sixty-eight patients with 77 restorations were included. At baseline, periodontal parameters did not differ between DME and control. Sixty-two restorations could be examined after 1 year. BOP was significantly increased for DME (p_adj. = 0.003), but not for control (p_adj. = 0.714). Surfaces with DME showed a significantly higher proportion of BOP than control surfaces (DME: 45 restorations (73.8%), control: 27 restorations (44.3%); p_adj. = 0.005). PI increased significantly on all tooth surfaces (p_adj.<0.001), but did not differ between DME and control side (p_adj. = 0.162). Probing depths did not differ between baseline and follow-up (DME: p_adj. = 0.199, control: p_adj. = 0.116). Two restorations were replaced due to a ceramic fracture and secondary caries.

Conclusion: Proximal DME is associated with increased gingival inflammation compared to supragingival or equigingival restoration margins.

Clinical relevance: DME is a promising treatment approach for indirect restoration of teeth with deep proximal defects, but gingival inflammation should be expected.