Introduction: The use of more than two implants for mandibular overdentures will improve the retention and stability. The aim of this randomized clinical trial was to compare bone height changes around three implant retained mandibular overdentures using ball, locator and telescopic attachment
Materials and Methods: Twenty-four completely edentulous patients were seeking to install three implants in the edentulous mandible to improve retention of their complete dentures. Three implants were installed in the canine-premolar areas bilaterally and one in the midline. Three month healing period was allowed, and then patients were randomized using sealed envelopes into three groups; patients receiving ball attachments, patients receiving locator attachments and patients receiving telescopic attachments. Bone height changes were recorded using standardized peri-apical x-rays at the day of pick up, at 3, 6 and 12 months follow up. One Way ANOVA test was used followed by Tukey`s Post Hoc test for multiple comparisons. Two sided p values less than 0.05 was considered statistically significant.

Results: At 6 and 12 month follow up the middle implant showed greater significant bone height changes than the right and left implants in all of the three groups. Ball attachment group showed a greater significant bone height changes when compared to the locator and telescopic attachment group at 6 and 12 month follow up.

Conclusion: The implant installed in the mid line showed the greatest significant bone height changes and the ball attachment have experienced the greatest significant bone height changes after 12 month follow up period.