Additively Manufactured Implants for Mandibular Overdentures: RCT Part 1 - Clinical and Peri-Implant Outcomes

Abstract

Abstract This study reported preliminary clinical outcomes of a randomized clinical trial comparing immediate and conventional loading protocols for mandibular overdentures supported by two narrow-diameter implants with a regular platform manufactured by additive technology. The focus was on primary implant stability, assessed using insertion torque and the implant stability quotient (ISQ). Sixteen completely edentulous participants (11 men, 5 women; mean age: 67.7 ± 7.6 years) received new complete dentures prior to surgery and were followed for up to 180 days, depending on the outcome assessed. Insertion torque was recorded at implant placement (motor and manual wrench), implant stability was measured at baseline and 90 days, and peri-implant healing and health parameters were evaluated at 7, 14, 30, 60, 90, and 180 days. A significance level of 5% was adopted for all statistical analyses. Immediate loading was performed on the day of implant placement, while conventional loading occurred after a 12-week healing period. The immediate loading group showed higher insertion torque (motor: 58.13 ± 5.18 Ncm, p=0.001; wrench: 58.44 ± 4.37 Ncm, p=0.004). ISQ increased significantly from baseline to 90 days in both groups (Immediate: 68.05 ± 6.08 to 72.44 ± 3.38; Conventional: 65.58 ± 5.47 to 70.72 ± 4.63; p<0.001), with no significant between-group differences (p=0.117). Peri-implant healing was more stable in the conventional group, with 100% of bone beds healed at 30 days (p=0.01). Significant between-group differences were observed at selected time points for peri-implant outcomes (p<0.05). Within the limitations of this preliminary short-term evaluation, both protocols appeared clinically feasible.