Prosthetic complications and maintenance of different attachments used to stabilize mandibular 2-implant overdentures in patients with atrophied ridges. A 5-year randomized controlled clinical trial.

Purpose: This randomized clinical trial aimed to evaluate prosthetic complications and maintenance of different attachments used to stabilize mandibular 2-implant overdentures in patients with atrophied ridges.

Methods: Ninety edentulous patients with a maladaptive capacity of wearing conventional dentures due to mandibular ridge atrophy received 2-implants in the canine regions using computer-guided surgery. The patients were randomly assigned into three groups; (1) Bar group: overdentures were connected to the implants with bar/clip attachments, (2) Telescopic group: overdentures were connected to the implants using a resilient telescopic attachment, and (3) Stud group: overdentures were connected to the implants with resilient stud (Locator) attachments. Prosthetic complications of attachments, mandibular overdentures, and maxillary dentures, and soft tissue complications of mandibular overdentures and maxillary dentures were evaluated 1 year (T1), 3 years (T3), and 5 years (T5) after denture insertion.

Results: The majority of prosthetic and soft tissue complications for all groups occurred in the first year. The most frequent prosthetic complication was wear/distortion of retentive components of locator and telescopic attachments and activation of clips of bar attachment. The bar group showed the highest incidence of overdenture relines, fractures, hyperplasia, maxillary denture mucositis, and soreness. The telescopic group showed the highest incidence of screw loosening, teeth wear/fracture, maxillary denture relines, fractures, teeth wear, teeth separation, and flappy ridges. The stud group recorded the highest incidence of wear and replacement of retentive components.

Conclusion: For 2-implant overdentures in patients with atrophied mandibles, bar attachments showed the highest incidence of complications related to mandibular overdentures, telescopic attachments showed the highest incidence of complications related to maxillary dentures, and stud attachments showed the highest incidence of complications related to the attachment components.