2026-01-132026-01-132025LELES, Cláudio Rodrigues et al. Factors associated with the risk of fracture of mandibular overdentures on one or two implants: findings from a 5-year follow-up. Journal of Prosthodontic Research, Tokyo, 2025. DOI: 10.2186/jpr.JPR_D_24_00205. Disponível em: https://www.jstage.jst.go.jp/article/jpr/advpub/0/advpub_JPR_D_24_00205/_article. Acesso em: 8 jan. 2026.1883-1958e- 2212-4632https://repositorio.bc.ufg.br//handle/ri/29398Purpose: This was a prospective study conducted alongside a randomized controlled trial (RCT) that evaluated the incidence of fractures and associated risk factors in single-implant overdentures (1-IOD) compared with two-implant overdentures (2-IOD). Methods: The participants received either a mandibular 1-IOD or 2-IOD (attachments: Straumann® retentive anchor and elliptical titanium matrix with gold insert; implants: 4.1 mm diameter, Straumann® Standard Plus SLActive® Regular Neck), within the context of a randomized clinical trial. The primary outcome of interest was the incidence of IOD fractures at 5-year follow-up. Prosthetic factors, such as area and cervico-incisal height in the attachment region, and volume at the inter-canine region, were measured. Patient-related factors including age, sex, handgrip strength, manual dexterity, bite force, and chewing performance were assessed. Data analysis included descriptive statistics, bivariate tests, Kaplan-Meier plots, and linear discriminant analysis with log10 transformation for variable normalization. Results: A total of 47 patients were recruited, and 34 (n = 34, 1-IOD = 16, 2-IOD = 18; mean-age: 63.9 ± 8.6 years; 79.4% women) completed the 5-year follow-up. There were no differences in the incidence of fractures between the 1-IOD and 2-IOD groups (P < 0.05). Fractures were more frequent in younger patients, and reduced cervico-incisal IOD height was significantly associated with fractures (P = 0.040). Linear discriminant analysis predicted fractures with 84.4% accuracy and identified cervico-incisal height and age as key predictors. Conclusions: There were no significant differences in the incidence of overdenture fractures between groups. Reduced cervico-incisal denture height in the attachment region of ball-retained IODs was associated with mandibular IOD fractures. Further studies with larger cohorts are recommended to identify additional risk factors for mandibular IODs.engAcesso Abertohttp://creativecommons.org/licenses/by-nc-nd/4.0/Implant overdenturesSingle-implant mandibular overdentureTwo-implant mandibular overdentureEdentulous jawRemovable prosthodonticsArtigo10.2186/jpr.JPR_D_24_00205