Platelet-rich plasma does not improve bone regeneration around peri-implant bone defects--a pilot study in dogs

The purpose of the present study was to evaluate the influence of platelet-rich plasma (PRP) on bone regeneration in dehiscence-type bone defects around dental implants. Ten male adult mongrel dogs were used. Three months after teeth extractions, an osteotomie for implantation and a buccal dehiscence defect were prepared on both sides of the jaws. Two dental implants with machined surfaces were placed on each implant site of the mandible. Dehiscences were randomly assigned to the following groups: (1) test (PRP) and (2) control. After 3 months animals were sacrificed; implants and adjacent hard tissues were processed for undecalcified sections. Bone-to-implant contact (BIC), bone density (BD) within the limits of implant threads, bone density (BO) and new bone area (NB) in a zone lateral to the implant, corresponding to bone defects, were obtained and measured. Inter group analysis (paired Student's t-test, alpha = 5%) demonstrated no statistically significant differences for any of the parameters when PRP was used (P > 0.05). Within the limits of the present study, it was concluded that platelet-rich plasma alone did not enhance bone regeneration for peri-implant defects.