Objective: The objective of this in vivo study was to radiographically evaluate the marginal bone loss around implants supporting mandibular overdenture retained by PEEK clips on PEEK bars in comparison to the conventional Poly-Oxy-Methylene (POM) clips on metallic Cobalt Chromium (Co-Cr) bars.
Subjects and Methods: Thirty completely edentulous patients (16 males and 14 females) were selected free from any systemic or local diseases that contraindicate implant placement, or preclude the final results of the study. All patients firstly received conventional upper and lower complete dentures, and two conventional implants in the interforaminal region then, divided in to two equal groups; in group I (control group), patients received mandibular implant overdentures retained by two POM clips on Co-Cr bar, and in group II (study group), patients received mandibular implant overdentures retained by two PEEK clips on PEEK bar. Assessment of marginal bone loss around the implants was performed radiographically at time of loading (Base line), 6, 12, and 18 months after loading.
Results: The results represented statistically significant decrease in bone height from each follow-up time to the next for both groups. Group I showed statistically significant greater bone loss when compared to group II.
Conclusion: Using modified PEEK for construction of bar and clip attachments can decrease bone loss around implants supporting mandibular overdenture when compared to Co-Cr bars with POM clips due to the stress breaking effect of the PEEK material.