Background: the ultimate goal of periodontal therapy is the regeneration of periodontal tissues. Researches had demonstrated the benefits of platelet concentrates bine grafts in osseous regeneration in the areas of periodontal surgery.

Aim of the study: to evaluate the effect of PRF with/without nanohydroxyapatite in periodontal intrabony defects.

Background: the ultimate goal of periodontal therapy is the regeneration of periodontal tissues. The regenerative and wound healing potential of platelets has attracted much attention over the last few years. Researches had demonstrated the benefits of platelet concentrates in osseous regeneration in the areas of periodontal surgery and implantology. In addition, nanohydroxyapatite was shown to be unsheathed by newly formed bone and partly replaced by it, but resorbed very slowly, as shown in animal experiments after 9 months or in clinical studies after a 6-month observation period. The clinical and biochemical studies evaluating the regenerative effect of PRF alone or in combination with nanohydroxyapatite in periodontal intrabony defects are still deficient.

Aim of the study: to evaluate clinical and biochemical effect of PRF with/without nanohydroxyapatite in treatment of human intrabony defects.

Inclusion Criteria:

• All patients are free from systemic illness.
• All patients should be diagnosed as having chronic periodontitis.
• Patients should be cooperative, motivated and willing to follow our treatment protocol and follow up visits.
• Patients selected had not received antibiotics or anti-inflammatory therapy in the 6 months prior to examination.

Exclusion Criteria:

• Presence of areas of periodontal pocket of (probing depth ≥5 and clinical attachment level (CAL) ≥ 3).
• Patients who have received any type of periodontal treatment in the past 6 months prior to examination.