Outcomes
CREST
CAL (primary outcome) was measured as the distance from the cemento-enamel junction (CEJ) to the base of periodontal pocket. PPD was determined as the distance from the base of pocket to the gingival margin. GRD was measured as the level from the gingival margin to the CEJ, while FMPS [Individually customized bite blocks fabricated for each patient and parallel-angle technique were employed (Zhermack Zetaplus C-Silicone kit, Badia Polesine, Italy) using (XCP®) X-ray film holding system (Dentsply Sirona, Charlotte, USA). Periapical radiograph PSP sensor size two (Xios AE, Dentsply Sirona, New York, USA) and standardized exposure setting of 60 kVp, 8 mA, 0.7 mm, and 0.10 s (Heliodent Plus, Dentsply Sirona, PA, USA) were used. The defect angle was measured at baseline, as the angle formed between intersections of AC-DB and tooth long axis lines. RLDD was measured as the depth of the intrabony defect from the alveolar crest (AC) to the defect base (DB) as previously reported [Intrabony defect radiographic measurements. 