The impact of implant diameter on strain around implant retaining mandibular overdentures with bar attachments (An in vitro study)

Objectives: This vitro study's objective was to assess the impact of implant diameter on strain around implants retaining mandibular overdentures with bar attachments Purpose :The aim of this in vitro study was to evulate , by means of strain gauge analysis , the effect of different implant diameters on strain around two-implants retaining a mandibular over denture with bar attachments.Material and Methods: Three epoxy models with silicon mucosal simulation was fabricated and two laboratory implants were inserted in canine areas.according to implant diameter ,the experimental casts were randomly divided into 3 groups, groupI(4.3mm), groupII(3.8mm),groupIII(3mm)and all implants had a length of 10mm.three denture were fabricated and connected to implants with bar attachments. Four linear strain gauges were bonded to the epoxy resin at mesial, distal, buccal ,lingual surfaces of each implant. 100N static load was applied unilaterally over frist molar positions. Starins were measured at mesial,distal,buccal,lingual peri-implant sites. Loading side and non loading side Results: the results showed that for loading and non loading side ,for majority of surfaces and for molar positions small diameter implants recorded the highest strain, followed by medium diameter implants and the smallest strain was recorded with large diameter implants Conclusion: it is recommended to use the largest implant diameter as possible to minimize peri-implant strain when bar attachments are used to retained mandibular overdentures to implants Randomized controlled clinical trials are needed to evulate the effect of different implant diameters on peri-implant crestal alveolar bone loss Key words : implant ,overdenture, bar ,strain