Comparative analysis of implant survival, peri-implant health, and patient satisfaction among three treatment modalities in atrophic posterior mandibles: a randomized clinical study.

Background: This study assessed the clinical outcomes of fixed and removable implant-assisted prostheses for the rehabilitation of atrophied distal extension mandibular ridges.

Methods: Thirty partially edentulous patients with atrophied distal extension mandibular ridges were randomized to three groups (n = 10/group). Group ALF received long implants following alveolar ridge augmentation to support fixed restorations. Group SF received short implants to support fixed restorations. Group OVD received two long implants to support a removable partial denture. The plaque index (MPI), gingival index (MGI), Pocket depth (PD), implant stability (IS), and crestal bone loss (CBL) were assessed: immediately after the prosthesis insertion (T0), six months (T6), and twelve months (T12) later. All groups were assessed for patient satisfaction after 12 months using a visual analogue scale (VAS) survey.

Results: Implant survival rates were 89.7%, 91.7%, and 85% in the ALF, SF, and OVD groups (Chi-square = 0.972, log-rank test, p =.673). The ALF and SF groups had significantly greater plaque and gingival scores (P <.05) than the OVD group At T6 and T12. The ALF group exhibited significantly higher PD and IS values (P ˂ 0.05) compared to the OVD group At T6 and T12. The OVD group had the greatest significant CBL values (P <.05) at T6 and T12, whereas the SF group presented the lowest significant values. The ALF and SF groups showed the highest significant satisfaction levels (P <.05) regarding appearance, esthetics, retention, stability, chewing, bolus quality, and occlusion. On the other hand, the OVD group expressed the highest significant satisfaction (P <.05) with surgery, healing, and cleaning.

Conclusions: Fixed restorations supported by either short implants or long implants inserted in augmented bone are equally successful in the rehabilitation of the atrophic posterior mandible, with improved patient satisfaction than implant-assisted partial dentures. Nevertheless, the SF group had favorable peri-implant soft tissue health and decreased marginal bone loss compared to the ALF group. Conversely, implant-assisted partial overdentures demonstrated favorable peri-implant soft tissue health and increased patient satisfaction regarding surgery and healing compared to fixed restoration.

Trial registration: Current Trial NCT05978115 (28/07/2023) "Retrospectively registered".