The aim of this study is to compare two biomaterials used for retrograde obturation during apical surgery. This surgery is indicated in healthy patients when root canal treatment (endodontics) has failed to eliminate a periapical lesion (a persistent infection in the root of the tooth).

The main question it seeks to answer is:

- Is TotalFill® BC-RRM Fast Set Putty more effective than ProRoot® MTA in periapical surgery in terms of the degree of healing?

The study will include patients who need this type of surgery and meet specific clinical criteria. Each patient will have one of the two materials applied as part of the standard surgical procedure. Subsequently, clinical and radiographic follow-up will be performed to assess the degree of healing of the periapical lesion with a 1-year follow-up.

Inclusion Criteria:

• Patients over 18 years of age.
• Patients giving consent for surgical intervention, for radiographic evaluation with HCT preoperatively and at least one more time after 12 months, and for participation in the study.
• Medical history not relevant to the diagnosis and surgical treatment (ASA classes I and II).
• Previous non-surgical endodontic treatment or retreatment with clinical and/or radiographic evidence of persistence or recurrence of apical periodontitis. The minimum time since the last non-surgical treatment shall be 6 months.
• Teeth not previously treated with periapical surgery.
• Lesion less than 10 mm in diameter.
• Restorable teeth.
• Periodontally sound teeth or teeth with treated periodontal pathology (mobility 1, probing depth < 5mm).
• Teeth with no root resorption.

Exclusion Criteria:

• Teeth with vertical fracture.
• Teeth with root perforation.
• Lesions associated with an apicomarginal defect.
• Tunnel lesions.
• Technical errors during surgery that may compromise the outcome.
• Lack of integrity of the dentine walls surrounding the retrograde filling detected with the endoscope.
• Wound dehiscence.
• Postoperative infection.
• Follow-up less than 12 months.

Considerations about sharing individual participant data are ongoing. Any future data sharing will adhere to all institutional policies to ensure participant confidentiality.