The persistent and chronic apical periodontitis has caused great difficulties for clinical physicians. Ensuring rapid and successful healing of the extensively damaged periapical region is a pressing issue that needs to be addressed. The treatment options include traditional apical surgery, simultaneous placement of bone powder and membrane after apical surgery, and simultaneous placement of sticky bone (bone powder mixed with concentrated growth factors gel) and membrane. However, high-quality evidence regarding these various treatment options is scarce. The purpose of this study is to compare the advantages and disadvantages of each treatment option, in order to guide clinical physicians in the application of apical surgery.

This prospective study will recruit 72 patients with chronic periapical periodontitis in their anterior teeth or premolars, all of which have received comprehensive root canal treatment. The patients will be randomly divided into four groups: Group A, which will undergo only apical surgery (including apicoectomy, inflammation debridement, and retrofilling of the root apex); Group B, which will undergo apical surgery plus bone powder; Group C, which will undergo apical surgery plus CGF (concentrated growth factors); and Group D, which will undergo apical surgery plus bone powder and CGF gel. Each group will consist of 18 patients, and all surgeries will be performed by the same experienced doctor. The participants will receive a 1-year follow-up with the assistance of a professional doctor, including questionnaire data and daily records of pain and swelling at 2, 6, and 12 hours and 7 days after the intervention. Cone-beam computed tomography (CBCT) images will also be taken before the surgery, immediately after the surgery, and at 2, 3, 4, 6, and 12 months post-surgery.

Inclusion Criteria:

• 18 years old or above.
• Tooth with significant symptoms or with root apex bone tissue destruction that cannot be treated by non-surgical methods.
• The affected tooth is either an anterior tooth or a premolar.
• The size of the lesion during preoperative cone beam computed tomography (CBCT) coronal acquisition is at least 6 mm but not more than 12 mm.
• The affected tooth has undergone successful root canal treatment.
• CBCT shows intact lingual side bone plate in the apical region, with only buccal alveolar bone defect present.
• Good oral hygiene and compliance with medical instructions.

Exclusion Criteria:

• Severe periodontal destruction, with over 1/3 of the root length absorbed by alveolar bone.
• CBCT shows root fracture or root canal perforation.
• After root apex surgery, crown-root ratio ≤1:1.
• Presence of surgical contraindications, systemic and local factors that affect wound healing.
• Pregnant women and females planning to conceive within the next two years.