One-year prospective study on single short (7-mm) implant overdentures in patients with severely resorbed mandibles

Objective This prospective study aimed to assess the effectiveness of using a single short implant to retain a single-implant mandibular overdenture (SIMO) in participants with severely atrophic edentulous mandibles. Material and Methods The study sample included 18 edentulous participants with severely resorbed mandibular ridges and limited bone height in the symphyseal region sufficient for the insertion of a 7.0-mm-height implant. First, patients received new conventional dentures or had their dentures relined, followed by the insertion of a 3.75 x 7 mm morse-taper implant, and the incorporation of a stud-type attachment and a nylon retentive insert after a 3-month healing period. Implant stability quotient (ISQ) was measured at baseline and after 3 and 12 months. Patient-reported outcomes (satisfaction with the dentures and oral health-related quality of life) were assessed before implant placement and at the 3-, 6-, and 12-month follow-ups. Clinical-radiographic outcomes and the incidence of prosthodontic events were assessed throughout the follow-up period. Results The implant survival rate was 100%. ISQ increased from baseline (72.7 +/- 6.6) to the 3-month (82.0 +/- 3.3) and 1-year (85.4 +/- 2.9) follow-ups (p < .001). After 1 year, satisfaction with the mandibular prosthesis increased significantly, and the overall OHIP-Edent score decreased by 79.2%. No effects were found for the maxillary denture (p = .420). Due to dissatisfaction with treatment, two participants (11.1%) required additional implants after the 1-year follow-up and were considered as prosthodontic failures. Conclusion Single-implant mandibular overdenture retained by a short implant showed favorable outcomes after 1 year. Further studies with larger samples and longer follow-up periods are needed to confirm the findings of this single-group prospective study. The present study was registered at the Brazilian Clinical Trials Registry (REBEC), identifier RBR-7p2xmg. The trial registry occurred during the study execution, and its final approval was delayed because of several formatting adequacies required by the platform REBEC.