Ridge alterations following flapless immediate implant placement with or without immediate loading. Part II: a histometric study in the Beagle dog

Objective: To assess the effect of immediate loading on ridge alterations following implants placed into fresh extraction sockets in a dog model. Material and Methods: Six Beagle dogs were used. Four implants were placed into post-extraction sockets in the lower jaw immediately after the removal of premolars 3 and 4. In the control side, two implants remained without occlusal loading, and in the test side, they received an immediate prosthesis with occlusal contacts (involving implant sites). Extraction sockets without implants were used as a test in non-involved implant sites. Three months later, the dogs were sacrificed. Results: Vertical distance from implant shoulder to bone crest (BC) was similar for both groups. BC at the buccal aspect was located 3.66 mm apical to the shoulder in the test group and 4.11 mm in the control group. This difference was not statistically significant. Buccal bone resorption was more pronounced in the premolar 3 area than in the premolar 4 area. In edentulous sites, the buccal bone crest was located 0.97 mm apical to the lingual counterpart. Conclusion: Immediate implant placement with or without immediate loading does not prevent the amount of bone resorption that occurs following tooth extraction without immediate implant placement.