Histological Evaluation of Sodium Iodide-Based Root Canal Filling Materials in Canine Teeth

A novel water-soluble root canal filling material based on sodium iodide (NaI) has been developed to overcome the limitations of existing iodine-based formulations. However, the biological stability of this approach in animal studies remains unverified. This study evaluated the biocompatibility of NaI compared to commercial root canal filling materials (Calcipex II and Vitapex^®) in pulpectomized canine teeth to assess its clinical applicability. Following a four-week observation period, none of the experimental groups exhibited tooth mobility or fistula formation. Radiographic and micro-CT analyses revealed no radiolucency in periapical lesions. Histopathologic evaluation demonstrated the absence of inflammatory responses in periapical regions across all material groups, with histological inflammation scoring 0. High-magnification histological examination of periapical areas showed well-preserved periodontal ligament tissue in all groups. Despite certain limitations of NaI-based fillings in the pulp cavity, including loss of radiopacity and tooth discoloration, NaI demonstrates potential as a safe and effective alternative for pulp filling material, particularly due to its minimal risk of root resorption and inflammatory response.