Methods: A total of 23 Straumann SP 3.3mm NN, SLA® 10mm implants were placed in the mandibular premolar regions of three greyhound dogs 3 months after the teeth were removed. Five control implants with no marginal defects were placed at crestal bone level, and test implants with surgically created peri-implant defects of 1.25mm wide x 5mm depth were placed either at crestal (9 implants) or 2mm-subcrestal (9 implants) bone level. Implants on the right side were placed 1 month and on the left side 3 months prior to the dogs being sacrificed, Histological observations and histomorphometric analysis using light microscopy were undertaken.
Results: A larger portion of the implant surface was in direct contact with bone after 3 months of healing than 1 month. For all test implants defect fill was incomplete. They showed a crestal bone level closer to the implant margin. The peri-implant defect healing response at 3 months for crestal and sub-crestal implant placement was similar.
Conclusion: Peri-implant defects of 1.25mm wide healed with spontaneous bone regeneration around implants with an SLA® surface placed transmucosally at crestal or 2mm-subcrestal with a high degree of osseointegration after a 3 months healing period.