الفهرس 
AbstractOnly 14 pages are availabe for public view
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Abstract
Mandibular implant assisted overdenture is an especially attractive treatment because of its relative simplicity, minimal invasiveness and economy. Splinting of implants by bar, prevent micromovement and hence improve secondary ossointegration in addition to improvement of overdenture retention.Aim of work: The purpose of this in-vitro study was to evaluate and compare stresses were transmitted to two implants assisting mandibular complete overdenture by using two types of bar attachment: a) prefabricated instant adjusting bar b) infibra ribbon bar.Materials and Methods: This in vitro study was carried out on a six standard educational edentulous mandibular models. According to the type of bar attachment used, models were classified into two main groups as follow: group I had instant adjusting bar attachment and group II had infibra ribbon bar attachment, they connected to installed implants at canine region. The models were covered by polyvinyl siloxane impression material to simulate the oral mucosa covering the ridge. Acrylic resin complete mandibular overdentures were constructed. Strain gauges were bonded at labial, lingual, mesial, and distal surfaces of each implant abutment. LLOYD Digital loading device was used to apply vertical load of 50 N on the overdentures at right first molar. The stresses were measured. Data was collected and statistically analysis.Result: This study revealed thatthe highest stress was observed at the labial surface and the lowest one at the distal surface of loaded and unloaded side of implant abutment, implant abutment surfaces that assisted mandibular complete overdenture with bar attachment was subjected to a more stresses applied on loading side compared to unloading side, and implant abutment surfaces subjected to a more stresses when it connected to instant adjusting bar joint attachment compared to infibra ribbon bar attachment mandibular complete overdenture.Conclusion: Infibra ribbon bar is the attachment of choice for assisting the mandibular complete overdenture because it reduce the induce stresses applied on the implant abutment. Instant adjusting bar joint isn’t advocated as attachment for mandibular complete overdenture because of inducing high stresses on implant abutment.