Single Versus Multiple Visits Regenerative Endodontics in Mature Teeth

The goal of this clinical trial is to learn whether regenerative endodontic treatment (RET) should be performed in one visit or two visits in people with mature permanent teeth with chronic apical periodontitis. RET is a dental treatment used for teeth with necrotic pulp and infection around the root. The procedure disinfects the root canal and promotes the formation of new tissue inside the canal space, which may support healing of the tissues around the tooth root. The main questions this study aims to answer are: Does single-visit RET cause different levels of postoperative pain compared with two-visit RET? Do teeth treated with single-visit or two-visit RET show different levels of healing around the root? Participants will receive RET using either a single-visit or two-visit treatment protocol. Participants will record their pain levels during the first week after treatment using a visual analog scale (VAS). Participants will return for follow-up visits at six months and one year, when dental radiographs will be taken to evaluate healing around the tooth root.