this study is to evaluate the use of advanced platelet rich fibrin (A-PRF) + nano-crystalline hydroxyapatite bone substitute combined with open flap debridement (OPD) versus open flap debridement alone in the management of mandibular molar grade II defects.

In the management of mandibular molar grade II furcation defects, no difference exists in gain of horizontal clinical attachment level between the use of advanced platelet rich fibrin (A-PRF) + with nano-crystalline hydroxyapatite bone substitute combined with open flap debridement (OPD) and open flap debridement (OPD) alone .

Inclusion Criteria:

Patient-related criteria:

• Systemically healthy patients.
• Compliance with oral hygiene instructions and the maintenance program provided.
• Accepts the 6 months follow-up period.
• Provide informed consent.

Teeth related criteria:

• Mature permanent tooth.
• Asymptomatic mandibular molar with buccal Glickman class II furcation involvement.
• Probing depth (PD) ≥ 5 mm and vertical PD ≥ 3 mm after Phase I therapy (scaling and root planing).
• Presence of radiolucency in the furcation area on an intra-oral periapical radiograph

Exclusion Criteria:

Patient-related criteria:

• Patients taking drugs known to interfere with periodontal wound healing in the last six months.
• Pregnant or nursing women.
• Smokers.
• Uncooperative patients.

Teeth related criteria:

• Teeth with interproximal supra-bony or intrabony defects.
• Teeth with gingival recession.
• Teeth with grade II or III mobility.