الفهرس | Only 14 pages are availabe for public view |
Abstract 1. Purpose: The aim of this in vitro study was to evaluate the stresses transmitted to peri-implant areas around the four implants, from different palateless overdentures bases materials (Thermoplastic nylon material & acrylic resin material lined with soft liner). 2. Materials and Methods: One acrylic model with silicon mucosal simulation was fabricated with four dummy in both canines and second premolars. According to material the denture bases were divided into two groups (group I) palateless overdenture with acrylic denture base relined with soft liner (group II) palateless overdenture with thermoplastic nylon material denture base. Twenty overdentures were fabricated and connected to implants with ball attachments. Four strain gauges were bonded to the acrylic resin model at mesial, distal, buccal, lingual surfaces of each implant. 60 N static loads were applied bilaterally over mesial cusp of the first molar and unilaterally over central occlusal fossa of the first molar, stresses were measured at mesial, distal, buccal and, lingual peri-implant sites. 3. Result: The highest strain recorded with thermoplastic nylon denture base, followed by Acrylic denture base lined with soft liner. The highest strain recorded at distal surface followed by mesial, palatal buccal surface. Anterior implants recorded higher strain than posterior implants. 4. Conclusion and recommendation: using of acrylic palateless overdenture lined with soft liner retained with four implants possible to minimize stress transmitted to implants than the thermoplastic nylon material. |