Clinical longevity of Deep Margin Elevation versus Crown Lengthening: A Systematic Review

Abstract

The management of deep subgingival tooth margins is a common challenge in restorative dentistry. Two widely used techniques, Deep Margin Elevation (DME) and Crown Lengthening (CL), are employed to address this issue by increasing the amount of tooth structure above the gumline to ensure proper crown placement. While both techniques are effective, a direct comparison of their clinical longevity, success rates, and complications is limited.

Objective : This systematic review aims to compare the clinical outcomes, longevity, and complications of DME and CL to assess their effectiveness in restorative dentistry.

Methods: A comprehensive search of electronic databases was conducted to identify randomized controlled trials (RCTs), prospective controlled studies, and longitudinal studies that evaluated DME and CL for deep subgingival margins. Key outcomes assessed included clinical attachment levels (CAL), probing depths (PD), bleeding on probing (BOP), gingival recession, and long-term restoration survival.

Results: A total of 8 studies were included in the review. Both DME and CL demonstrated high clinical success rates, with similar outcomes in terms of restoration survival and gingival health. However, DME was associated with higher BOP, suggesting a slightly increased risk of gingival inflammation compared to CL. CL, particularly the two-stage approach, showed benefits in terms of keratinized tissue width (KTW) and patient satisfaction. Long-term studies have demonstrated favorable results for DME in posterior restorations, with low failure rates over 12 years.

Conclusion: Both DME and CL are effective techniques for managing deep subgingival margins. While DME offers a more conservative and less invasive approach, CL is preferable in cases requiring extensive gingival recontouring or where esthetics are a priority. Further research is needed to compare these techniques directly over more extended follow-up periods to determine their long-term effectiveness and complications.