Objectives: The aim of this study was to radiographically compare bone height change around implants immediately inserted and loaded with two different loading protocols (immediately loaded and delayed loaded) in implants retained mandibular overdenture .
Materials and methods: Fourteen completely edentulous male patients with remaining mandibular two canines were randomly assigned into two equal groups: Group A: Seven patients had rehabilitated by immediately placed implant retained mandibular overdenture with immediate loading of the implants opposed by conventional maxillary complete dentures. Group B: Seven patients had been rehabilitated by immediately placed implant retained mandibular overdenture with delayed loading of the implants (after 3 months) opposed by conventional maxillary complete dentures. Marginal bone loss was evaluated at time of implant loading (baseline), 3 months, 6 months and 12 months after loading.
Results: The results of this study had revealed that the marginal bone height gradually decreased throughout the study period in the two studied groups. On comparing marginal bone loss at both groups after one year follow-up group (A) had a significantly higher value (1.27±0.21), (1.27±0.11) (at mesial and distal surfaces respectively) than group (B) (1.03±0.09) (0.98±0.14) (p < 0.001) (at mesial and distal surfaces respectively).
Conclusion: Within the limitation of this study, it could be concluded that delayed loading induces less marginal bone loss than immediate loading in immediately loaded mandibular implant overdentures.