Efficacy of Photodynamic Therapy and LASER Disinfection in Periodontal Therapy for Treatment of Periodontitis

• LASER disinfection (Device): In test group 1, the diode Laser will be used to disinfect the inner layer of the pockets and thus reducing the microbial load. Diode laser (Biolase, EpicX, BIOLASE, Inc, USA) settings will be as follows: wavelength: 940nm; power: 1W; 300μm uninitiated fibers; continuous radiation mode; and energy level: 80 J/s. The laser fibers then will be inserted into the pockets in such a way that they will be in contact with the soft tissue wall of the pockets and parallel to the root surface and then will be moved to the apical surface through a horizontal sweeping motion (1mm/s) while remaining in contact with the soft tissue wall of the pockets.
• Photodynamic therapy (Device): the second test group will receive additional adjunctive aPDT using a ICG photosensitizer activated with diode laser. In details, pockets will be irrigated by a syringe loaded with an ICG photosensitizer solution (Verdye, Diagnostic green, Germany) at a concentration of 5mg/ml. The ICG solution will be allowed to stay in the pockets for 2min, and washing out excess solution from the pockets before laser irradiation. Afterwards, a 300μm bulb optical fibre of the 810nm diode laser unit (QuickLase, United Kingdom) set at 300mw in pulsed mode (100ms ON/100ms OFF) will be inserted along the pocket and activated for 30s with continuous vertical movements from the bottom of the pocket to the gingival margin
• Root surface debridement (Procedure): For all groups, sites with initial PPD 4-6 mm will be treated with RSD using area specific (Graecy) curettes.

Primary outcomes

• Probing Pocket Depth (PPD) [over a period of 3 months.]: PPD will be measured from the gingival margin to the base of the pocket using UNC-15 periodontal probe and the measurements in millimetre .

Secondary outcomes

• Bleeding on probing (BOP) [over a period of 3 months.]: The BOP will be scored as 0 (absent) and 1 (present) after probing within 30s by quadrant using UNC-15 periodontal probe .
• Plaque index (PI) [over a period of 3 months.]: Biofilm will be determined using a dichotomous scoring system as presence (1) or absence (0). Disclosing solution will be used to assess agreement on scoring of biofilm.
• Clinical attachment loss (CAL) [over a period of 3 months.]: CAL will be measured from the cementoenamel junction to the base of the pocket using UNC-15 periodontal probe and the measurements in millimetre .
• Change in bacterial load of F. nucleatum and Fretibacterium fastidiosum [over a period of 3 months.]: Real time PCR will be used to assess the detection of the following periodontal pathogens in the subgingival biofilm samples: F. nucleatum and F. fastidiosum, according to manufacturer's instructions. Identification of target bacteria through PCR will be executed using species specific primers.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Adult subjects (>18 years), non-smoker, with no history of any systemic disease such as diabetes mellitus. Additionally, subjects are not currently under active periodontal therapy or joining other trial in the last 3 months. All patients must be diagnosed with generalized periodontitis with at least 3 teeth in three different sextants (Anterior teeth and premolars) with 4-6 mm PPD and positive BOP. Periodontitis cases will be defined by presence of interdental CAL affecting ≥2 non adjacent teeth or if CAL at buccal/lingual aspects associated with PPD >4mm at ≥2 teeth.

Exclusion Criteria:

* Patients will be excluded if they were not diagnosed with periodontitis, smokers, those consuming antibiotics, regular user of nonsteroidal anti-inflammatory drugs, or receiving periodontal treatment 3-months prior to the study. Additionally, pregnant or mothers in a breastfeeding period, and those not willing to participate will be also excluded.