الفهرس 
Table of contentsOnly 14 pages are availabe for public view
 |  | from | 167 |  |  |
| | | from | 167 | | |
Abstract
Purpose : The aim of this in-vitro study was to evaluate and compare the per -implant stresses regarding the effect of retention force of locator attachments used with different distally inclined implants assisting mandibular complete overdenture. Materials and Methods : Three duplicated epoxy resin experimental models were constructed. The models were covered by resilient silicone to simulate the oral mucosa. In the canine regions of each model, two recesses were prepared followed with inserting implants with different inclinations: group I (0 o), group II (10 o) and group III (20 o). Three identical overdentures were fabricated and connected to the implants using Locator attachments with medium retentive force (pink inserts). Utilizing the Universal Testing Machine, the crosshead speed was 51mm\min. Vertical dislodgements were performed on a metal plate attached to the model with metal chains until the attachments separated from the abutments. Results : When comparing between all groups the results of this study revealed the highest means of total stresses were significantly noted around vertical implants (group I) while there was no significant dfference between inclined implants in (group II) and (group III). The results of this study showed significant lower stresses at mesial and buccal sites in group II& III than group I. When comparing the total stress (mean of groups) between peri-implant sites, the highest stresses were significantly noted with mesial site, followed by lingual, and distal site and the lowest stress was noted with buccal site.While there was significant difference in stresses betweenbuccal and mesial sites, there was no significant difference between all other sites. When comparing stress between peri-implant sites for each group, there was no significant difference in stresses between peri-implant sites. Conclusion : from the results of this stress analysis study, it can be concluded that; the decreased retention force of locator attachments resulting from the increased distal inclination of implants used for assisting mandibular complete overdenture leading to decreased peri-implant stresses during overdenture dislodgement.