Bone healing in critical-size defects treated with platelet-rich plasma: a histologic and histometric study in rat calvaria

Background and Objective: The purpose of this study was to analyze histologically the influence of autologous platelet‐rich plasma on bone healing in surgically created critical‐size defects in rat calvaria. Material and Methods: Thirty‐two rats were divided into two groups: the control group (group C) and the platelet‐rich plasma group. An 8‐mm‐diameter critical‐size defect was created in the calvarium of each animal. In group C the defect was filled by a blood clot only. In the platelet‐rich plasma group, 0.35 mL of platelet‐rich plasma was placed in the defect and covered by 0.35 mL of platelet‐poor plasma. Both groups were divided into subgroups (n = 8) and killed at either 4 or 12 wk postoperatively. Histometric (using image‐analysis software) and histologic analyses were performed. The amount of new bone formed was calculated as a percentage of the total area of the original defect. Percentage data were transformed into arccosine for statistical analysis (analysis of variance, Tukey, p