EFFECT OF NOVALOC AND EQUATOR ATTACHMENTS RETAINING 3D-PRINTED MANDIBULAR SINGLE-IMPLANT OVERDENTURES ON PERI-IMPLANT BONE HEIGHT AND BONE DENSITY: A RANDOMIZED CLINICAL TRIAL

Abstract Background: Mandibular implant overdentures have become a well-established treatment modality for the rehabilitation of completely edentulous patients by improving prosthesis retention, stability, masticatory efficiency, and patient satisfaction compared with conventional complete dentures. Although two-implant overdentures are considered the standard of care, a single midline implant has emerged as a cost-effective and less invasive alternative while maintaining favorable clinical outcomes. Recent advances in digital dentistry and additive manufacturing have further improved prosthetic fabrication by enabling the production of highly accurate three-dimensional (3D)-printed overdentures with reduced manufacturing time and enhanced reproducibility. Despite these developments, the influence of different stud attachment systems on peri-implant bone preservation in 3D-printed single-implant mandibular overdentures remains insufficiently documented. Materials and Methods: Twenty completely edentulous patients were enrolled in this prospective randomized clinical study and received a single implant placed in the mandibular symphyseal region. After the osseointegration period, all participants were rehabilitated with 3D printed mandibular single implant overdenture. Patients were randomly allocated into two equal groups (n = 10): Group I received the OT Equator attachment system, whereas Group II received the Novaloc attachment system. Peri-implant crestal bone height and peri-implant bone density were assessed using cone-beam computed tomography (CBCT) at overdenture insertion (T0), six months (T1), and twelve months (T2). Statistical analysis was performed to evaluate both intergroup and intragroup differences, with the level of significance set at P < 0.05. Results: Both attachment systems demonstrated successful clinical performance throughout the one-year follow-up period. A reduction in peri-implant bone height and bone density were observed in both groups over time. No statistically significant differences were detected between the groups at baseline or after six months. However, after twelve months, the Novaloc group exhibited significantly greater preservation of peri-implant bone height and bone density compared with the Equator group (P < 0.05). The percentage of crestal bone loss and reduction in bone density were consistently lower in the Novaloc group throughout the study period.: Conclusions: Both OT Equator and Novaloc attachment systems provided effective retention for 3D-printed mandibular single-implant overdentures and demonstrated favorable clinical outcomes during the first year of function. Nevertheless, the Novaloc attachment exhibited superior preservation of peri-implant bone height and bone density, suggesting a more favorable biomechanical distribution of occlusal stresses. Long-term clinical studies with larger sample sizes are recommended to confirm these findings.