The authors theorize that periodontal flap surgery therapy with adjunctive DL therapy might bring favourable therapy results (clinical and bacterial parameters) in patients with stage 3-grade C periodontitis. Therefore, the goal of this split-mouth randomized clinical trial was to evaluate and compare the effectiveness of the treatment results for DL assisted modified Widman Flap (MWF) surgery (test site) with MWF surgery alone (control site) in periodontitis patients with stage 3-grade C by determining the changes in clinical parameters and bacterial load of pathogens (P.g., T.d., Camplyobacter rectus (C.r.), Prevotella intermedia (P.i.), T.f., A.a.) at preoperative and following MWF surgery at 6th week, 3rd and 6th months

A randomised control split-mouth study were performed at the Department of Periodontology, Faculty of Dentistry, Bülent Ecevit University, Zonguldak, Turkey, between January 2013 and February 2016.After clinical evaluation, a total of 30 subjects, who showed signs of stage 3-grade C periodontitis, were enrolled to this study at baseline. These patients were underwent a full mouth scaling and root planning (SRP). Six weeks after non surgical periodontal therapy, periodontal assessment was performed to confirm the suitability of the sites for periodontal surgery. This split-mouth study was conducted in 18 patients with stage 3 Grade C periodontitis aged between 22 and 35 years.

Before the surgery, the selected quadrants were randomly allocted (by the toss of a coin) into test and control sites where the control site were treated with MWF+sham application of DL and test sites were treated with MWF+ active DL. Clinical parameters including CAL, PD, plaque index(PI), gingival index(GI), bleeding on probing (BOP) were recorded and microbiological sampling were obtained at preoperative and at 6 weeks, 3 months, 6 months postoperatively. Pain scale assessment (visual analog scale, VAS), pain medication consumption (PM), tissue edema (TE), and tissue color (TC) were evaluated one week following surgery. Microbiological analysis was done by real-time polymerase chain reaction (PCR) for detection of Porphyromonas gingivalis (P.g.), Treponema denticola (T.d.), Tannerella forsythia (T.f.), Camplyobacter rectus (C.r.), Prevotella intermedia (P.i.), Aggregatibacter actinomycetemcomitans (A.a.).

Control sites were treated MWF with sham application of DL, while test sites were treated MWF with the applying of active DL (810nm±5, Picasso-AMD, USA) to the inside of the MWF. The interval between the two surgeries was 3 weeks. The modified Widman flap technique was applied.DL with a wavelength of 810±5 nm and a power of 1 watt in continuous mode was applied to the MWF at the test sites. A 400 micron diameter tip was used to remove all visible epithelium on the inside of the flap from the free gingival edge to the lower apical aspect of the flap (both labial and lingual / palatal). The tip was started using a blue articulating paper. DL irradiation performed at a 45o angle to the soft tissue flap to avoid any laser (810nm±5) contact to the root surface or the alveolar bone . DL therapy was carried out to soft tissue from the coronal to the apical aspect in parallel paths for 10seconds. When irradiation exceeded 10 seconds in time, laser (810nm) emission was be interrupted for 30 seconds. The resultant char layer was be totally removed with moist gauze prior to replacing the flaps. A second laser application with the same laser (810nm±5) was performed on all the surfaces of the flap in continuous mode at 0.1 watts. All surfaces of the flap, inner and outer, exposed bone and exposed root structures involved in the surgery were irradiated, leading to a total dosage of 4 J/cm2 per surface.

The subjects were prescribed 200 mg Ibuprofen (up to 3 tablets) every 8 hours to reduce pain. The subjects were instructed not to eat solid food using the treated area and to not brush the teeth in the treated area. They were told to rinse their mouth with chlorhexidine digluconate (0.2%, CHX) twice a day for 1 min during one week after surgery The sutures were removed at first week . After 1 weeks, the subject started brushing their teeth and oral hygiene training was repeated. Oral hygiene instructions were provided at each postoperative visit.

Inclusion Criteria:

• The inclusion criteria for stage 3-grade C periodontitis patients were interdental CAL ≥ 5 mm and PD ≥ 6 mm on at least 6 teeth and at least three of these six teeth were not molars or incisors.
• They were under 35 years of age.
• These patients had at least two quadrants of maxilla with three teeth each having CAL ≥ 5 mm and PD ≥ 6 mm.

Exclusion Criteria:

• : systemic conditions such as; diabetes mellitus, cancer, cardiovascular and respiratory diseases,
• current and ex-smoking habits,
• undergone non-surgical periodontal therapy and prescription of antibiotics or non-steroidal anti-inflammatory medication within the previous 6 months or surgical periodontal treatment within the preceding year,
• pregnancy, lactation, postmenopause, or immunologic disorders,