Platelet rich plasma and autologous bone graft in healing of experimental bone defects in the rabbits cranium. Microscopic study

Abstract

Abstract

This study was undertaken to evaluate a protocol to obtain platelet rich plasma (PRP) and to describe the microscopic aspects of bone defects repair after the local application of (PRP) associated or not to autogenous bone graft (EOE). The fronto-parietal portion of 18 rabbit´s skull was exposed, allowing the perforation of four defects (5.0 mm diameter each), numbered I to IV, being two of them in the right antimere and two in the left one, until the meninges could be seen at the bottom. Defect I received PRP only; defect II received 3.0 mg of EOE only; defect III received EOE associated to PRP; defect IV was left to heal naturally, serving as control. Three experimental groups (G1, G2 and G3) consisting of six rabbits were sedated, anesthetized and euthanize (sodic thiopental super-dose) on the 30^th, 60^th and 90^th days, respectively for groups. The laboratorial protocol proposed to make PRP showed to be easily performed, low cost and made possible the concentration of platelets between 1.600.000 and 2.000.000 / mL in all the animals. Histology evidenced that PRP participated negatively in the initial phase of repair, increasing the inflammatory process and negatively influencing the precocity of bone formation. In relation to the amount of new bone, bone filling exhibited by the treatments autogenous bone graft alone and PRP associated to the autogenous bone graft came in a similar form, however, the autogenous bone graft used alone determined the precocity of bone repair.