Purpose: Mandibular implant assisted overdentures have been considered as satisfactory treatment plan of mandibular edentulism
and might be hindered by limited bone height and or width in interforaminal region which necessitate implementation of bone
grafts. However, bone graft resorption is expected after loading where the design of retention system could influence resorption
rate. So the objective of this study is to assess the effect of using retention sil versus PEEK matrix as a retention system of
overdenture on supporting bone of augmented anterior mandible.
Material and Methods: Fourteen patients were randomly assigned into two groups after being subjected to anterior mandibular
bone grafting and implant insertion., for group I patients. Implants were loaded by mandibular overdentures using the OLS
attachments system (PEEK female) and for group II implants were loaded using silicone matrix (Retention Sil 400) over the
locator abutments with its dual retention mechanism. Implant stability was assessed using (osstell). Peri-implant bone loss was
radiographically assessed after loading (at 6 months and 1 year intervals).
Results: There was no significant increase in implant stability between the two groups. However, group II presents significantly
lower bone loss one year after loading (p ≤ 0.01) than group I.
Conclusion: It could be concluded that resilient matrix (retention sil) for locator attachment induce less bone resorption than
peek matrix in anterior grafted mandibular bone.