Evaluation of patient satisfaction and maximum biting force of three differently constructed bars on two implants retaining mandibular overdenture - one year follow-up (a randomized controlled clinical trial).

Background: Different bar construction techniques will affect the bar passive fitness, which may induce stresses or strain on the implant and/or tightening screw and sequentially may affect the biting force and patient satisfaction.

Aim of the study: This clinical investigation assessed patient satisfaction and maximum biting force (MBF) using three differently constructed (conventional casting, milling, and 3D printing CAD/CAM techniques) cobalt-chromium (Co-Cr) bar-retained implants mandibular overdentures over a one-year period of follow-up.

Materials and methods: Thirty edentulous patients seeking for two implants bar-retained mandibular overdentures were randomly assigned into three groups as the following: Group I: 10 patients received a Co-Cr conventional casting bar, Group II: 10 patients received a Co-Cr CAD/CAM milled bar, and Group III: 10 patients received a Co-Cr CAD/CAM 3D-printed bar. All the bar groups were connected to two implants in the canine area bilaterally. Within the first two weeks following implant placement, patients received the definitive prosthesis. Patient satisfaction was evaluated by using the (OHIP-EDENT-19) questionnaire form after 6, and 12 months. Additionally, the maximum biting force was tested at after delivery, 3, 6, and 12 months for each group. The results were collected, tabulated, and statistically analyzed.

Trial registration: This study was recorded on ClinicalTrials.gov retrospectively registered (ID: NCT06401187) on 30/04/2024.

Results: After one year follow up, regrading patient satisfaction the three groups showed no statistically significant difference. Although, the functional limitation domain was in favor of the milled bar. Regarding the maximum biting force, no statistically significant difference was found among three groups. However, at 12 mouths follow-up the milled bar showed statistically value.

Conclusion: Within the limitations of this study, the conventional, milled and 3D printed bar overdentures groups can be used as a satisfactory treatment modality for edentulous mandible in terms of patient satisfaction and maximum biting force.