PERI-IMPLANT STRAINS WITH PALATELESS LOCATOR RETAINED MAXILLARY IMPLANT OVERDENTURES REINFORCED WITH EITHER METAL OR POLY ETHER-ETHER KETONE (PEEK) MATERIALS. AN INVITRO STUDY

ABSTRACT

Objectives: The purpose of the present report was to assess, using strain gauge analysis, the peri-implant strains with palateless locator retained maxillary implant overdentures reinforced with either cobalt chromium metal or Poly ether-ether ketone (PEEK) materials.

Material and methods: Four implants were installed in completely edentulous acrylic maxillary cast in canine and second premolar region and mucosal simulation was added. Two strain gauges were bonded at buccal and palatal surfaces of each implant. Ten experimental palateless maxillary overdentures ,5 with cobalt chromium metal reinforcement (group I) and other 5 with PEEK reinforcement (group II ) were fabricated and connected to the implants with Locator attachments (Light retention). Strain was measured at canine and premolar implants during application of axial static load of 100 N in bilateral and unilateral direction



Results: For, canine and premolar implants during bilateral and unilateral load application, the median strains of metal reinforcement were significantly higher than median strains of PEEK reinforcement. For metal reinforcement group (during bilateral and unilateral loading), and PEEK reinforcement (during unilateral loading) premolar implant showed significant higher strain than canine implants. Premolar implants for metal reinforcement showed significant higher strain during unilateral loading compared to bilateral loading.

Conclusion: Within restrictions of this invitro study, PEEK reinforcement is more recommended than metal cobalt chromium reinforcement for palateless maxillary implant overdentures from biomechanical point of view as it achieved low peri-implant strains during unilateral and bilateral loading .