This study aims to know the effect of PRP on bone healing and regeneration after cystoectomy within studying clinical and radiological bone density changes. The research sample comprised 18 patients (14 males, 4 females) (20 cystic lesions in the upper jaw,1-3 cm diameter). This sample was divided into 2 similar groups : The experimental group: Platelets-rich Plasma with Tri-Calcium Phosphate was applied. The control group: only Tri-Calcium Phosphate, without Platelets-rich Plasma, was applied. Both groups were observed clinically and radiologically. According to radiological observation, the digital panoramic radiographs were taken before, immediately after surgery, after 3 months, and after 6 months, respectively. Bone density measurements were done through Digora® digital program. The present study showed that there is no statistical difference between the experimental group & the control group, regarding Pain Index and Infection Index; while there was a statistical difference between the experimental group & the control group, regarding bone density after 3 and 6 months after surgery. Within the limitations of the present study, the application of autologous platelets-rich plasma (PRP) accelerates bone regeneration after cystoectomy.