Aim: This in vitro study was performed to evaluate the effect of different implant numbers and lMaterials and methods: Five implants were inserted in the interforaminal area of mandibular edentulous acrylic model in the following locations; 1) one in midline areas, 2 in canine areas and 2 in premolar areas. Locator attachments were used to connect mandibular experimental overdentures (n=5) to the implants. Two linear strain gauges were bonded at buccal and lingual surface of each implant. According to the implant number and location of the implants, the strain was measured (during unilateral and bilateral loading) locations on strains around implants retaining mandibular overdentures with locator attachments.
Results: For midline implants during bilateral and unilateral loading, the highest strains were noted with group 1 and group 5, and the lowest strain was noted with group 4.
Conclusion: within the limitations of this in vitro study, three implants used to retain mandibular overdentures with locator attachments were associated with reduced peri-implant strains than one or 2-implants regardless of placement of posterior implants in canine or premolar areas. However, the midline implants is at increased risk of implant overloading than distal implants. This risk decreased when distal implants are positioned in canine areas.