Clinical Periodontal Outcomes Following Deep Margin Elevation in Posterior Teeth: A Systematic Review and Meta-Analysis

Deep margin elevation (DME), also termed cervical margin relocation (CMR) or proximal box elevation (PBE), is a conservative alternative to surgical crown lengthening for managing deep proximal subgingival defects.However, its periodontal consequences are uncertain, particularly when restorative margins approach the supracrestal tissue attachment (STA).This systematic review and meta-analysis aimed to evaluate the periodontal effects of DME/CMR/PBE in posterior teeth compared with non-elevated margins or surgical crown lengthening, with emphasis on bleeding on probing (BoP), probing pocket depth (PPD), plaque index (PI), gingival inflammation, clinical attachment level (CAL), and radiographic bone level.The review was conducted in accordance with PRISMA 2020.Electronic searches of MEDLINE/PubMed, Embase, CENTRAL, Scopus, and Google Scholar were conducted to identify clinical studies evaluating periodontal outcomes of DME-type procedures with at least 12 months of follow-up.Randomized trials were appraised using RoB 2 and non-randomized studies using ROBINS-I, while random-effects meta-analyses were performed where sufficient methodological homogeneity existed.The qualitative synthesis included 13 clinical studies, and four studies contributed to at least one meta-analysis.From the findings, DME/CMR/PBE was associated with significantly higher odds of BoP than control margins (OR 2.14; 95% CI 1.27 to 3.61), with negligible heterogeneity.In contrast, no statistically or clinically meaningful difference was observed for PPD, and sensitivity analysis confirmed the robustness of this finding after excluding analytically non-standard data.Pooled PI data likewise showed no significant difference between elevated and control margins.Even though CAL and radiographic bone outcomes were reported too infrequently and heterogeneously to permit quantitative pooling, the available studies did not suggest progressive periodontal breakdown when case selection, margin finishing, and plaque control were adequate.Inter-material comparisons revealed no clinically meaningful superiority when resin composite, resin-modified glass ionomer (RMGI), high-viscosity glass ionomer, or bioactive ionic resin were used as DME base materials.Overall, DME appears periodontally acceptable in appropriately selected posterior teeth when STA is respected and meticulous plaque control is maintained, although confidence in this conclusion is limited by the small and methodologically weak evidence base.