(17) Periodontal and Biological Aspects of Deep Margin Elevation, a New Treatment Approach For Subgingival Restorations

Introduction: Cervical margin relocation (CMR) was introduced in 1998 and renamed deep margin elevation (DME) in 2012. In this technique, teeth with deep subgingival carious lesions or fractures are treated with a subgingival resin composite restoration followed by a supragingival crown restoration. This procedure has been suggested as an alternative to crown-lengthening surgery and has gained substantial attention in recent years. The present study evaluated the available data in regards to the periodontal and biological aspects of this approach.

Methods: A detailed literature search was conducted searching Medline, Embase, DOSS, and Google Scholar in October 2021 using "deep margin elevation", "margin relocation" or "proximal box elevation" terms to evaluate the current scientific evidence for the effects of DME on periodontal health. Identified clinical trials with a minimum follow-up of three months were included in the study.

Results: A total of 30 articles reporting DME procedure were identified. Only five articles reported on the periodontal health of teeth treated with DME. Two of five articles were excluded due to being case reports/series; leaving three clinical trials for inclusion. None of the studies were randomized controlled clinical trials. The most prevalent variable to assess the periodontal health was bleeding on probing (BOP) followed by plaque index (PI), probing depth (PD) and radiographic bone loss (RBL). The follow up periods in the three clinical studies were 12, 57.7, and 3 months, respectively (average of 24.23 months). The rate of BOP was reported as 53%, 50%, and 7.5%, respectively. The changes in PD and RBL were not consistent among the studies; while two studies showed an increase in these values, one study reported a significant reduction. One of the studies evaluated the histologic response of supracrestal periodontal tissues to DME after 3 months. The authors reported that, when the restoration margin was at least 3 mm away from the alveolar bone, the inflammation level of gingival tissue was similar around the teeth treated with DME and natural teeth.

Conclusions: There are minimal long-term clinical studies evaluating the periodontal health of restored teeth utilizing the DME technique. Given the high prevalence of BOP in two of the three studies, and the lack of consistency in PD and RBL changes among the available studies, application of this technique in routine dental practice should be considered with caution. The scientific evidence of DME as an alternative to surgical crown lengthening for restoring deep subgingival lesions requires considerably more clinical and histologic investigation in the form of randomized controlled clinical trials with larger sample sizes, and longer follow-ups.

Lead Author's Contributions to the Research Project. : The Lead Author was responsible for the study design, data collection, performing the data analysis and the composition of the abstract.