Microneedling sessions will be performed 1 month after the CAF procedure to ensure initial flap healing. The micro-needling technique will be performed under local anesthesia, by using Dr. Pen Ultima M8 MN pen (Dr. Pen; Phoenix, AZ, USA) using 16-Pins gauge with a diameter of 0.18 mm adjusted with 1.5 mm depth at the 6th mode speed of 700 cycles/min. The MN needles are vertically inserted into the keratinized tissue reaching the bone, for 30-40 s per tooth using an intermittent motion along the keratinized tissue. Then, cross-linked hyaluronic acid will be injected in a volume of 0.2mm of a 20 mg/ml concentration with particle size 400 μm. HA injection will be administrated until blanching of gingiva is evident. To ascertain that the HA is distributed evenly the region will be gently massaged for 2 to 3 min with a sterile gauze soaked in saline. This Microneedling technique with HA injection will be repeated four times at 10-day intervals.

Microneedling sessions will be performed 1 month after CAF procedure to ensure initial flap healing. The micro-needling technique will be performed under local anesthesia, by using Dr. Pen Ultima M8 MN pen (Dr. Pen; Phoenix, AZ, USA) using 16-Pins gauge with a diameter of 0.18 mm adjusted with 1.5 mm depth at the 6th mode speed of 700 cycles/min. The MN needles are vertically inserted into the keratinized tissue reaching the bone, for 30-40 s per tooth using an intermittent motion along the keratinized tissue. This method will be repeated four times at 10-day intervals.

Microneedling sessions will be performed 1 month after the CAF procedure to ensure initial flap healing. The micro-needling technique will be performed under local anesthesia, by using Dr. Pen Ultima M8 MN pen (Dr. Pen; Phoenix, AZ, USA) using 16-Pins gauge with a diameter of 0.18 mm adjusted with 1.5 mm depth at the 6th mode speed of 700 cycles/min. The MN needles are vertically inserted into the keratinized tissue reaching the bone, for 30-40 s per tooth using an intermittent motion along the keratinized tissue. Then, cross-linked hyaluronic acid will be injected in a volume of 0.2mm of a 20 mg/ml concentration with particle size 400 μm. HA injection will be administrated until blanching of gingiva is evident. To ascertain that the HA is distributed evenly, the region will be gently massaged for 2 to 3 min with a sterile gauze soaked in saline. This Microneedling technique with HA injection will be repeated four times at 10-day intervals.

using a No.15 endodontic spreader with a silicon stopper placed 2 mm apical to the gingival margin at the mid-buccal aspect; depth of penetration measured with a ruler to the nearest 0.5 mm.