Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) ; Objective: This study histologically analyzed the healing of fresh frozen bone allograft (FFBA) with or without platelet-rich plasma (PRP) in bony defects surgically created in the mandible of dogs.Material and methodsBilateral resection defects were surgically created on the inferior border of the mandible in 10 dogs. The defects were randomly divided into three groups: C (the defect was filled by blood clot only), FFBA (the defect was filled with particulate FFBA), and FFBA/PRP (the defect was filled with particulate FFBA combined with PRP). The animals were euthanized at 12weeks post-surgery. Histomorphometric and histological analyses were performed. Data were statistically analyzed using Friedman test and Dunn test (P