Is combined laser treatment effective for patients with periodontal disease?

INTERVENTION: The study will use a split‐mouth design, with each patient serving as their own control. Each quadrant (right upper jaw, left upper jaw, left lower jaw, right lower jaw) will be randomly allocated into four test groups (A group, B group, C group) or control group (D group). A group will receive Er:YAG laser plus low level diode laser treatment (LLLT), B group will receive Er:YAG laser only, C group will receive LLLT only, while the control quadrants will receive traditional treatment only. CONDITION: Moderate or severe periodontitis ; Oral Health PRIMARY OUTCOME: ; 1. Probing depth (PD) measured using periodontal probing at baseline, 3 months, and 6 months; 2. Clinical attachment level (CAL) measured using periodontal probing at baseline, 3 months, and 6 months; SECONDARY OUTCOME: ; 1. Bleeding index (BI) measured using periodontal probing at baseline, 3 months, and 6 months; 2. Plaque index (PLI) assessed by an examiner using a scale of 0 to 3 (where 0= No plaque, 1= Cannot see plaque but plaque can be detected with probe, 2= Moderate plaque can be seen, and 3= Lots of plaque can be seen) at baseline, 3 months, and 6 months; INCLUSION CRITERIA: 1. Aged 35‐70 years 2. Minimum of 20 teeth (4 per quadrant) 3. It is clinically diagnosed as extensive stage III‐IV periodontal disease: the heaviest site of interproximal attachment loss is =5 mm, radiologic bone loss extends to 1/3 of the root and above, PD = 6mm, vertical bone absorption =3 mm, cumulative bone resorption >30% 4. Good general health