A 1.5 Year Randomized Controlled Trial Comparing Standard- Sized Implants and Two Diameters Mini-Implants Retaining Mandibular Overdentures Under Functional Immediate Loading: Oral Health-Related Quality of Life and Complications

This randomized controlled trial aimed to evaluate the impact of complete mandibular overdentures retained by either two standard implants (SIs) or four mini-implants (MIs) under functional immediate loading on oral health-related quality of life (OHRQoL) and to identify any implant- and overdenture-related complications.

The study comprised 29 edentulous participants. They were randomly assigned to three groups: Group S: 11 with two SIs (3.75 mm), Group M3: 8 with four MIs (3 mm), Group M2.5: 10 with four MIs (2.5 mm), all placed under flap surgery and functionally immediately loaded. The OHIP-EDENT questionnaire was used to assess OHRQoL before treatment and at 1, 3, 6, 12, and 18 months post-loading. Any complications were also recorded. Data were analyzed using one-way ANOVA, paired t-tests, and Chi-square tests (P ≤ 0.05).

No participants dropped out, and no implant failures were observed. No statistically significant intergroup differences were found in overall OHRQoL scores or any individual domains (P>0.05). Intragroup comparisons revealed that OHRQoL scores at follow-up times (T1, T3, T6, T12, T18) were significantly lower than baseline (T0) for all groups (P<0,01), except for the social disability and handicap domain which improved in some groups (p≤0.05). No significant differences were observed between the groups regarding complications (P> 0.05).

Functional immediate loading of SIs or MIs with mandibular overdentures led to significant and sustained improvements in OHRQoL, with minimal complications across all groups. Both MI diameters (2.5 and 3.0 mm) showed no statistically significant differences in outcomes compared with SIs, supporting their use as reliable alternatives in appropriately selected edentulous patients. Clinical decision-making may therefore be guided primarily by anatomical and patient-related factors rather than by minor variations in implant diameter.