patients were treated with zinc substituted hydroxyapatite graft combined with platelet rich fibrin block using a full thickness mucoperiosteal flap surgical technique.

After the pretreatment phase, patients were recalled under local anesthesia an intrasulcular incision was performed with #15 blade elevating a full-thickness mucoperiosteal flap and after removing all the inflammatory granulation tissue we put in the defect Zinc substituted nano-hydroxyapatite graft combined in platelet-rich fibrin block (A-PRF +I-PRF+graft ).

Zinc substituted nano hydroxyapatite graft was taken in a bone well, to which i-PRF was mixed and the cut pieces of the A-PRF membrane were incorporated. The resulted cohesive, packable graft "PRF block" which were placed into the defect.

Then the mucoperiosteal flap returned to its position in both groups and sutured using silk suture size (4/0).

patients were treated with zinc substituted nano-hydroxyapatite graft using a full thickness mucoperiosteal flap surgical technique.

patients were treated with a nano-hydroxyapatite graft using a full thickness mucoperiosteal flap surgical technique.

After the pretreatment phase, patients were recalled under local anesthesia an intrasulcular incision will performed with #15 blade elevating a full-thickness mucoperiosteal flap and after removing all the inflammatory granulation tissue we put in the defect Zinc substituted nano-hydroxyapatite graft combined in platelet-rich fibrin block (A-PRF +I-PRF+graft ). Zinc substituted nano hydroxyapatite graft was taken in a bone well, to which i-PRF was mixed and the cut pieces of the A-PRF membrane were incorporated. The resulted cohesive, packable graft "PRF block" which were placed into the defect. Then the mucoperiosteal flap returned to its position in both groups and sutured using silk suture size (4/0).

Gingival index (Loe et al.,1963):

Score Criteria:

0- No inflammation.

1. Mild inflammation, slight change in color, slight edema, no bleeding on probing.
2. Moderate inflammation, moderate glazing, redness, bleeding on probing.
3. Severe inflammation, marked redness and hypertrophy, ulceration, tendency to spontaneous bleeding.

• Plaque index (Silness et al.,1964):

We determine the amount of plaque on the tooth surface using a scale from 0 to 3:

0- No plaque

1. A film of plaque adhering to the free gingival margin and adjacent area of the tooth, which could not be seen with the naked eye. But only by using disclosing solutions or by using probe.
2. Moderate accumulation of deposits within the gingival pocket, on the gingival margin and/ or adjacent tooth surface, which could be seen with the naked eye.
3. Abundance of soft matter within the gingival pocket and/or on the tooth and gingival margin.

Probing pocket depth :

Probing pocket depth (PD) is measured by using William's graduated probe from the free gingival margin to the base of the periodontal pocket.

The clinical attachment level (CAL) is measured by using periodontal probe from the cemento - enamel junction to the bottom of the pocket at each selected site.