To evaluate the healing effect of advanced platelet-rich fibrin (blood clot charged with growth factors) taken from the patient own blood on the extraction site.

This is a randomized double-blind clinical study. A preoperative and radiographic evaluation will be done in order to select the patients.

Inclusion criteria are healthy patients above 18 years old with vertical or mesioangular bilateral impacted mandibular third molars. Exclusion criteria are missing second molars or indicated for extraction (un-restorable and remaining roots), patients under immunosuppressant and patients with acute infection. Those who fail to attend for follow-up appointments will be excluded.

The probing depth (PD) and clinical attachment level (CAL) distal to the second molar will be measured before each procedure. All patients will undergo bilateral removal of 3rd molar in a single appointment. Envelope flap with distal extension and a full-thickness mucoperiosteal flap will be utilized and the teeth will be removed with elevators. Bone removal will be utilized if needed.

Following the extraction, venous blood will be withdrawn to fill 2 tubes of 10mL each (sterile vacuum plain tube for A-PRF™ +). The blood tubes will be spun in the centrifugation machine for 13 minutes at 1300 rpm then it is pressed in PRF Box to form PRF clots which will be placed in one the extraction socket while the other socket will not receive a PRF (control).Randomization will be done using a coin toss.

Both extraction cavities will be closed using 3-4 interrupted sutures using 3.0 chromic gut sutures.

Postoperatively, all patients will be treated with oral antibiotic amoxicillin 500 mg and non-steroidal anti-inflammatory medications ibuprofen 600mg in case. also, all patients will be instructed to rinse with 0.2 % Chlorhexidine mouthwash for seven days postoperative.

On the 7th,15th and 90th days, patients will be asked about pain using visual analog scale (VAS) and whether they have any concern related to extraction socket statuses like halitosis, empty socket, open socket, dehiscence, and infection signs including swelling, pus, or fever.

They will also undergo a clinical examination at this visit and the consecutive visits. The following measures will be assessed during each clinical examination: the presence of a pocket distal to the adjacent second molar measuring the pocket depth and clinical attachment level and any signs of infection.

Data will be analyzed using statistical software. Analysis of multivariate regression will be used. The healing status will be compared between the graft site and the control site. Results will be interpreted to be statistically significant if they have a P-value of less than 0.05

Inclusion Criteria:

• Healthy patients above 18 years old with mirror image vertical or mesioangular bilateral impacted mandibular third molars

Exclusion Criteria:

• Missing second molars or indicated for extraction (un-restorable and remaining roots).
• Patients under immunosuppressant and patients with acute infection.
• Patients who fail to attend for follow-up appointments.