Survival rate and prosthetic complications of short dental implants supporting implant overdentures: A systematic review and meta-analysis

Abstract

Objectives: To evaluate the survival, marginal bone level changes (MBL), prosthetic complications, and patient-reported outcome measures (PROMs) of short dental implants (<8 mm) supporting implant overdentures. Data: Eight studies (3 RCTs, 5 prospective cohorts; 181 patients; 189 short implants) were synthesized. Primary quantitative findings at 1 year: Implant survival: 97.2% (95% CI, 93.1-98.9%; I-2 = 0%). MBL: pooled mean 0.53 mm (95% CI, -0.20 to 1.27; I-2 = 95.8%). Prosthetic complications: predominantly minor; 45.7% of patients experienced >= 1 maintenance event-most commonly matrix/insert replacement (24.7%) and relining (14.0%); overdenture fractures were uncommon (3.1%). PROMs: consistently high satisfaction, but reporting was heterogeneous. Certainty (GRADE): moderate for survival; low to very low for MBL, complications, and PROMs due to heterogeneity and imprecision. Sources: Systematic review and meta-analysis conducted per PRISMA 2020 (PROSPERO CRD420251042692). Databases searched to May 2025: MEDLINE, Embase, and Scopus. Risk of bias assessed with RoB 2 (RCTs) and ROBINS-I V2 (cohorts). Quantitative synthesis used logit transformation with a Hartung-Knapp random-effects model for survival; inverse-variance random-effects model for MBL; and random-effects generalized linear mixed models (RE-GLMM) for complications. PROMs were narratively synthesized. Study selection: Eligibility included randomized controlled trials and prospective clinical studies evaluating short dental implants (<8 mm) supporting overdentures and reporting >= 1 target outcome (survival, MBL, prosthetic complications, PROMs). After screening and full-text assessment, 8 studies met the inclusion criteria and were included in the quantitative and/or qualitative synthesis. Conclusions: Short implants supporting overdentures show high short-term survival, limited bone remodeling, and manageable maintenance demands, supporting their use where vertical bone height is limited. Long-term, adequately powered trials with standardized outcome reporting are needed to establish predictability over time.