All on Six Versus Parallel Implant Distribution for Maxillary Denture Opposing Mandibular All on Four

Thirty maxillary edentulous patients with previous mandibular All-on-4 screw retained prosthesis and their age ranged from 55 to 65 years were selected from the outpatient clinic, of prosthodontics Department, Faculty of Dentistry, Mansoura University from March 2022 to July2022 and 80% power was used to calculate patients sample according to the results of a previous study 1 which showed no significant difference was reported when comparing occlusal stability ,implant stability and periimplant soft tissue changes between different implants angulation of both groups. (Effect size=.70mm and α=.05). The power analysis was performed using the G\*Power program (version 3.1.5, Kiel, Germany)