Development of a new preclinical model to study early implant loss: a validation study in the beagle dog

Abstract

ObjectivesTo develop a new preclinical model to study early implant loss, where local infection conditions would impair the implant osseointegration.Materials and methodsForty-eight smooth, 2.9-mm diameter experimental implants were placed in the mandible of 8 beagle dogs (3 in each side). In half of the animals (test group, n = 24 implants), the implants received ligatures around the implant-abutment connection. In the other half, no ligatures were placed (control group, n = 24 implants). Four weeks later, implants were extracted in a flapless approach and standard 3.3-mm diameter SLActive implants were placed into the same osteotomy site without any further drilling. Eight weeks after the second implantation, animals were sacrificed and analyzed in terms of implant survival.ResultsAfter 8 weeks of healing, 4 implants were lost in the control group and 14 in the test group. This corresponded to a 17.4% of early implant loss in the control group and 58.3% in the test. Most of the early failures occurred within the first 5 weeks of healing.ConclusionsImplants placed in a pre-contaminated site present higher early loss than those placed in a non-contaminated site. This study represents a valid and robust preclinical model to study mechanisms and reduction of early implant loss as new technologies become available.Clinical relevanceScientific rationale for the study: There is lack of animal models to study early implant loss. Thus, a proposal of a new model is presented. With the validation of this model, new technologies can be implemented to prevent early implant loss.