Background This randomized clinical trial was designed to evaluate osteogenic potential of Cissus quadrangularis in alveolar distraction to facilitate implant installation. Material and methods Twenty patients with atrophic ridge were treated by alveolar distraction. After completing distractor activation, patients were randomly divided into two equal groups according to administered drug (placebo and Cissus quadrangularis group). After a consolidation period, distractors were removed and implants were inserted. Clinical evaluation was done to assess wound healing, and distractor and implant stability. Histological evaluation was performed at time of implant insertion. Radiographic evaluation was performed to assess bone volume and density after distraction, as well as, density and bone loss around implant. Results Radiographic and histological results showed that bone formation and maturation of study group were faster than that of control group. There was a significant increased bone density in distracted area and around implant in study group than control group. A significant bone loss at end of consolidation period, and around implant at end of the study was reported in control group than study group. Conclusion Cissus quadrangularis administration during the consolidation period is associated with increased osteogenic potential of distracted bone. The histological and radiographic findings of current study proved that Cissus quadrangularis not only enhances rate of new bone formation, but also bone density to withstand the biomechanical requirements of implant placement in a shorter time. Trial registration This study was retrospectively registered on www.ClinicalTrial.gov: NCT04669795-17\12\2020.

Aim:The purpose of this study was to evaluate clinical and radiographic results of implant supported fixed prosthesis with and without cantilever extensions for "All on four" implant rehabilitation of atrophied mandible. Materials and methods:Ten completely edentulous individuals with atrophied mandibular ridges were classified into 2 groups: 1) Group I: included 5 patients with posteriorly placed mental foramen, 2) Group II: included 5 patients with anteriorly placed mental foramen. All participants were managed by 4 implants according to the "All on four" protocol using a Nobel Biocare metal guide and open flap surgery. Implants were immediately loaded by existing mandibular dentures. Group I restored with fixed prosthesis without cantilevers, and group II restored with fixed prosthesis with distal short cantilevers. Plaque and gingival index, probing depth, implant mobility and bone loss (using cone beam CT) were evaluated after prosthesis delivery (T0), six months (T6) and 12 months (T12) after delivery Results: For posterior implants, group II showed significant higher plaque index, and gingival index than group I after 6 and 12 months. No differences in probing depth, implant mobility and bone resorption between groups was noted for anterior and posterior implants. Posterior implant showed significant higher plaque scores (for both groups) and gingival scores (for group II) than anterior implants after 6 and 12 months. Posterior implant showed significant higher pocket depth for both groups. Conclusion:Within the limitation of this study, fixed prosthesis with short cantilever can be used successfully to rehabilitate patients with atrophied mandibular ridges and anteriorly placed mental foramen with "All on four" concept as it was associated with favourable clinical and radiographic outcomes similar to prosthesis without cantilevers