Maintenance and risk factors for fractures of overdentures using immediately loaded conventional diameter or mini implants with Locator abutments: A cohort study

Abstract

Background: Fractures in mandibular implant-retained overdentures are a common complication. However, little is known on the related risk factors and outcome differences when using two conventional diameter or two mini implants. Purpose: The purpose of this study was first, to evaluate the required maintenance and complications with the overdentures and second, to analyze risk factors for overdenture fractures. Materials and Methods: This cohort study was conducted in edentulous patients with complete dentures. Patients received either two conventional (4.1 mm in diameter) and two mini (2.9 mm or less in diameter) implants, based on available buccal-lingual ridge width. All implants were immediately loaded with mandibular overdentures retained by Locator abutments. The number of prosthodontic after care visits (scheduled and unscheduled) were recorded and compared between the two implant diameter groups. Fracture occurrence was the primary outcome variable. Risk estimates were presented as odds ratios (ORs) with 95% confidence intervals (CIs). The ORs were adjusted for potential clinical confounders (ie, necessity of relining, matrix recapture, abutment loosening, implant diameter, height of the Locator, and retention force). Results: A total of 50 edentulous patients were analyzed. One conventional diameter and three mini implants failed within a 1-year follow-up period. Prosthetic maintenance requirements for overdentures on both implant diameter groups were comparable. A total of 12 overdenture fractures (four in the mini implant group and eight in the conventional diameter group) occurred. Adjusted OR (AOR) analysis showed a significant association between abutment loosening and overdenture fracture (AOR = 12.00, 95% CI = 1.11-129.45; P = .041). Conclusion: Within the limitations of this study, the present findings suggest that implant diameter does not affect number of prosthetic maintenance and complications, and that abutment loosening is a risk factor for overdenture fractures, regardless of the implant diameter used.

Application of Immediate Loaded Mini Dental Implants for Retaining Mandibular Overdenture Prosthesis in Edentulous Patients: A Systematic Review

“…In the qualitative analysis, quality assessment exhibited a wide variety across the included articles (Table 3). Four studies demonstrated a low risk of bias [8,41,42,44], two studies showed medium risk of bias [39,43], and five studies exhibited high risk of bias [17,[36][37][38]40]. Therefore, a high risk of bias was observed for the included studies.…”

“…Of the 11 included articles, 9 were prospective studies [8,17,36,[37][38][39][40][41][42], while 2 were randomized clinical trials [43,44]. For the placement of MDIs, the majority of the articles…”

“…Of the 11 included articles, 9 were prospective studies [8,17,[36][37][38][39][40][41][42], while 2 were randomized clinical trials [43,44]. For the placement of MDIs, the majority of the articles used full-thickness flaps (n = 5) [8,39,40,43,44], followed by flapless technique (n = 4) [17,36,41,42] and minimal thickness flap procedure (n = 2) [37,38]. In the included studies, the length and the diameter of MDIs used ranged between 8-18 mm and 1.8-3 mm, respectively.…”

“…In the included studies, the length and the diameter of MDIs used ranged between 8-18 mm and 1.8-3 mm, respectively. Five studies utilized 1-piece implants [17,36,39,40,44], one study used 2-piece implants [43], while 5 studies did not mention the design of implants used (Table 1) [8,37,38,41,42].…”

“…The patients expressed a high level of satisfaction and OHrQoL with this treatment modality. The groups of investigated participants varied as per the study type; seven studies were conducted using MDIs only [8,17,36,39,40,42,44]; three studies compared the utilization of MDIs with SDDIs [37,38,43]; and one study compared the outcomes of immediate with early loaded MDIs to retain mandibular overdentures [41].…”