Survival rate of immediate functionally loaded ball-attachment mini-implants retaining mandibular overdentures: A systematic review

AIM: Immediate loading protocols are frequently applied when placing mini-implants (MIs), although many of these may not be functional loading. Data on immediately functionally loaded MIs are limited. Therefore, this systematic review aimed to answer the question: What is the survival rate (SR) of immediately functionally loaded MIs placed in the edentulous mandible to retain a complete mandibular overdenture? SETTINGS AND DESIGN: Studies published in peer-reviewed journals up to April 2025 were considered. MATERIAL AND METHODS: An electronic search was conducted using MeSH terms and free-text search in April 2025 across Web of Science, PubMed, Cochrane Central, EBSCOhost, and ScienceDirect. Eligible criteria included case-control studies, retrospective and prospective case series, cohort studies, clinical trials, and randomized controlled trials. STATISTICAL ANALYSIS USED: Not applicable. RESULTS: Out of 1854 identified references, seven studies met the inclusion criteria, three randomized controlled and four prospective case series. A total of 496 immediately functionally loaded MIs were placed in 124 patients. The diameters of MIs were 1.8, 2.0, 2.1, 2.2, and 2.4 mm. Within the 1st year, 16 out of 495 MIs failed, resulting in a 1-year SR of 96.77%. A 24-month SR of 94.4% was reported by three studies, and a 36-month rate of 94.77% was reported by two studies. CONCLUSIONS: Current evidence indicates that immediately functionally loaded MIs are a promising option for retaining mandibular overdentures, with a high 1-year SR of 96.77%. However, the limited number of included studies and relatively short follow-up periods highlight the need for further well-designed, long-term research to validate these findings.