Periapical healing following endodontic microsurgery with collagen‐based bone‐filling material: A randomized controlled clinical trial

Aim To evaluate two‐ and three‐dimensionally the effect of resorbable collagen‐based bone‐filling material on periapical healing of endodontic lesions with four‐wall defects following endodontic microsurgery (EMS). Methodology This parallel, randomized controlled superiority clinical trial involved 86 lesions with the strictly endodontic origin and four‐wall defect morphology. EMS procedures were performed by calibrated postgraduate residents. Before flap closure, osteotomies were randomized to the control or treatment group. In the control group, the flap was repositioned with no material added. In the treatment group, a collagen‐based bone‐filling augmentation material was placed into the osteotomy. Clinical and radiographic examinations were completed after 12 months. Periapical healing was evaluated by blinded evaluators using periapical (PA) radiographs according to Molven's criteria and cone beam computed tomography (CBCT) scans according to PENN's 3D criteria. Cortical plate healing was scored according to the RAC/B index. The data were analysed using Fisher's exact test, Logistic regression models and Chi‐squared test. The significance level was predetermined at p