Influence of Concave Versus Convex Emergence Profiles on Midfacial Mucosal Stability-A Systematic Review With Meta-Analysis.

OBJECTIVES

To systematically evaluate the influence of concave versus convex emergence profiles on midfacial mucosal stability in partially edentulous patients restored with implant-supported single restorations.

MATERIALS AND

METHODS

A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted and registered in PROSPERO (CRD420251139042). An electronic search in MEDLINE (PubMed) and Embase was performed up to May 7, 2026. Eligible studies included RCTs comparing concave (test group) and convex (control group) transmucosal prosthetic designs and reporting midfacial mucosal level changes (mm). Data extraction and risk of bias assessment (RoB 2) were performed independently. A random-effects meta-analysis was conducted using weighted mean differences (MDs) and 95% confidence intervals (CIs). Heterogeneity was assessed using the I2 statistic and sensitivity analyses were performed to evaluate the robustness of the findings.

RESULTS

Four RCTs including 144 implants with a 12-month follow-up were included. Of these, 128 implants contributed to the quantitative synthesis, with 66 implants allocated to the concave/modified emergence profile group and 62 implants allocated to the convex/non-concave emergence profile group. The pooled analysis demonstrated a mean difference of -0.31 mm (95% CI -0.63 to 0.02; p = 0.064), indicating a trend toward greater midfacial mucosal recession with convex emergence profiles compared with concave designs. Between-study heterogeneity was low to moderate (I2 = 28%), suggesting consistent findings across studies. Sensitivity analyses confirmed the direction of the effect, with pooled estimates ranging from -0.12 to -0.43 mm. Exclusion of one study resulted in a statistically significant difference favoring concave emergence profiles (-0.43 mm; 95% CI -0.70 to -0.16; p = 0.002).

CONCLUSIONS

Convex emergence profiles are associated with a tendency toward increased midfacial mucosal recession. Concave profiles are preferable to support peri-implant soft-tissue stability.

CLINICAL RELEVANCE: Emergence profile design should be considered an integral component of prosthetic and surgical planning. The use of concave transmucosal contours during provisionalization and definitive restoration may contribute to improved peri-implant soft tissue stability and enhanced esthetic outcomes.