Purpose: The aim of the present clinical trial was to evaluate the 12-month success rate of titanium dental implants placed in the posterior mandible and immediately loaded with 3-unit fixed partial dentures. Materials and Methods: Patients with missing mandibular premolars and molars were enrolled in this study. To be included in the study, the implants had to show good primary stability. Implant stability was measured with resonance frequency analysis using the Osstell device (Integration Diagnostics). Implants were included in the study when the stability quotient (ISQ) exceeded 62. Clinical measurements, such as width of keratinized tissue, ISQ, and radiographic assessment of peri-implant bone crest levels, were performed at baseline and at the 12-month follow-up. The comparison between the baseline and the 12-month visits was performed with the Student t test for paired data (statistically significant at a level of a = 0.05). Results: Forty implants with a sandblasted, large grit, acid-etched (SLA) surface (Straumann) were placed in 20 patients. At 12 months, only 1 implant had been lost because of an acute infection. The remaining 39 implants were successful, resulting in a 1-year success rate of 97.5%. Neither peri-implant bone levels, measured radiographically, nor implant stability changed significantly from baseline to the 12-month follow-up (P > .05). Discussion: The immediate functional loading of implants placed in this case series study resulted in a satisfactory success rate. Conclusion: The findings from this clinical study showed that the placement of SLA transmucosal implants in the mandibular area and their immediate loading with 3-unit fixed partial dentures may be a safe and successful procedure. (Case Series) Parole chiave: alveolar process, dental esthetics, dental implants, facial growth, jawbone, orthodontics, puberty