Purpose: Sites that will receive dental implants need to be quantitatively and qualitatively suitable for this therapy. The treatment of postextraction areas with biomaterials associated with platelet-rich plasma (PRP) might make the repair process more efficient, resulting in desirable bone characteristics. The present study sought to evaluate the effectiveness of PRP in the process of new bone formation when associated with biomaterials. Materials and Methods: Four female dogs were used for this study. Mandibular postextraction sites received implants, along with bone substitutes (Bio-Oss [BO] or Biogran [BG]), on the right side of the mandible and these biomaterials plus PRP on the left side of the mandible. Thirty days later, the tissues were prepared and histologic analyses were carried out to compare the repair processes. Results: PRP accelerated the repair process for both BO and BG; however, the action of PRP associated with BO did not surpass that of BG alone. Conclusions: The addition of PRP appears to accelerate the repair process. Keywords: biomaterials, platelet-rich plasma, repair