Long‐Term Outcomes of 6‐mm Short Implants Supporting Splinted Crowns in Posterior Regions: A 12‐Year Prospective Multi‐Centre Single‐Cohort Study

AIM: To assess the clinical, radiographic and patient-reported outcomes (PROs) of 6-mm short implants supporting splinted crowns in posterior regions at 12 years following early prosthetic loading. MATERIALS AND METHODS: This prospective study enrolled 45 patients (95 implants; Ø4 × 6 mm) across three centres. Participants received 2-3 implants in posterior regions, with all prosthetically rehabilitated via screw-retained splinted crowns following a 6-week healing period. Clinical and radiographic parameters were assessed at implant placement, prosthetic loading and post-loading intervals (6/12/24/36/60/96/144 months). Biological and mechanical complications were documented at each revisit. PROs were collected at the 12-year follow-up. RESULTS: Thirty-nine patients completed the 12-year follow-up, including three evaluated remotely. Mean marginal bone level change was -0.09 ± 0.26 mm. Seven implants failed, with four occurring before early loading and the other three after 5 years post loading. The cumulative survival rate was 92.6%. Prevalences of peri-implant mucositis and peri-implantitis were 37.8% and 2.7% at the implant level, corresponding to 50.0% and 5.6% at the patient level, respectively, while mechanical complication prevalence was 31.1%. Patients were highly satisfied with implant treatment at the final follow-up. CONCLUSIONS: Six-mm short implants supporting early loaded splinted crowns in posterior regions could achieve stable clinical outcomes and marginal bone levels with high satisfaction over a 12-year follow-up period. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01346696.