Two-year evaluation of periodontal parameters following deep-margin-elevation and CAD/CAM partial lithium disilicate restorations - a prospective controlled clinical trial.

Objectives: This prospective clinical trial evaluated periodontal parameters at proximal deep-margin-elevation (DME) restoration margins 2 years after placement and compared them with baseline values and with supragingival/equigingival margins (control) on the opposite proximal surface of the same tooth.

Methods: One-sided subgingival proximal defects in (pre-)molars were restored using composite DME and CAD/CAM-manufactured lithium disilicate partial restorations. Periodontal parameters (bleeding on probing (BOP), probing depths (PD), plaque index (PI)) were recorded after ceramic insertion (baseline) and at 2-year follow-up, and compared between DME and control (Fisher's exact test and Wilcoxon signed rank test, p < 0.05).

Results: Sixty-eight patients with 77 restorations were included; 51 patients with 57 restorations were re-evaluated at 2 years. Two restorations were replaced (ceramic fracture, secondary caries), and one tooth developed apical periodontitis. Periodontal parameters were not significantly different at baseline. After 2 years, BOP increased significantly at the DME (p = 0.010), but not at controls (p = 0.517); but BOP was not significantly different between DME and control (p = 0.110). PD was significantly higher in DME vs. control (p = 0.015), but remained stable in both groups over the 2-year period (DME: p = 0.171, control: p = 0.517). PI increased significantly in both groups (p < 0.001), but did not differ between both sides (p = 0.341).

Conclusion: Proximal DME was associated with increased gingival inflammation at 2-year recall compared to baseline.

Clinical Significance: DME is a promising approach for restoring teeth with deep proximal defects, but proximal DME is associated with increased gingival inflammation. The periodontal situation remains stable after the first year of placement.