Outcome Assessment of Teeth with Necrotic Pulps and Apical Periodontitis Treated with Long-term Calcium Hydroxide

The aim of this retrospective, cohort case series was 2-fold: (1) to evaluate the outcomes of teeth with necrotic pulps and apical periodontitis using long-term calcium hydroxide (Ca[OH]₂) (healing was assessed via the periapical index [PAI] system) and (2) to explore the possible association of fractures in relation to long term Ca(OH)₂ exposure.

A total of 242 cases, diagnosed with pulpal necrosis and apical periodontitis, were treated with long-term Ca(OH)₂ using a standardized protocol. Injectable and powdered Ca(OH)₂ were placed sequentially in the root canal system. All cases were re-evaluated within a 3-month period until radiographic healing was observed. Clinical and radiographic evaluations were performed annually. Pre- and postoperative periapical radiographs were evaluated using the PAI system.

Of the 242 cases, 219 participants completed their treatment with annual follow-up. The average Ca(OH)₂ time was 5.4 months with a range of 1-12 months. Overall, by the latest follow-up visit, 90.0% (197/219) were classified as "healed." The overall mean preoperative and postoperative PAI scores were 4.07 (±0.80) and 1.76 (±0.70), respectively. Kappa statistics showed an almost perfect agreement for inter-rater (κ = 0.91) and intrarater (κ = 0.95) reproducibility for both examiners.

Within the limitations of this study, the use of long-term Ca(OH)₂ in the treatment of teeth with necrotic pulps and apical periodontitis resulted in a predictable high outcome. There was no association observed between long-term Ca(OH)₂ use and the incidence of fractures during this study. Ca(OH)₂ is a suitable material of choice as an interappointment dressing for teeth diagnosed with pulpal necrosis and apical periodontitis.