Impact of Austere Hot and Humid Conditions on the Physical and Biological Properties of Endodontic Sealers in Military Use.

INTRODUCTION: Nearly 15 million root canals are performed annually for the treatment of diseased and infected tooth pulp, allowing teeth to be functionally and esthetically maintained. Non-surgical root canal therapy ties directly into dental readiness and the maintenance of US posture by preventing and successfully treating endodontic disease. However, this therapy has a 5-20% failure rate with approximately 60% of these failures attributed to incomplete obturation of the root canal. The composition and performance of endodontic sealers are vital for successful root canal treatments and may be affected by storage or transit conditions. Although most sealers in civilian settings are stored at ambient temperatures, military environments often expose dental materials to extreme heat, humidity, and other environmental stressors. Understanding the durability of endodontic sealers under such conditions is essential for optimizing material selection and ensuring reliable performance during deployment. The hypothesis for this study was that austere environmental conditions during transit, storage, or use alter the physical and biological properties of endodontic sealers thereby impacting their expected performance.

MATERIALS AND METHODS: This in vitro study examined one brand of 4 different sealer classes (resin, silicone, bioceramic, and zinc oxide-eugenol) exposed to hot and humid environmental conditions. Physical and biological tests were performed in accordance with manufacturers' guidelines and International Organization for Standardization (ISO) testing protocols, including flow, working time, film thickness, radio-opacity, solubility, setting time, antimicrobial activity, and cytotoxicity.

RESULTS: This study showed significant changes in sealers' physical and biological performance after hot and humid storage. Of the tested sealers, GuttaFlow2 was the most physically durable although EndoSequence BC was the least. AH Plus Jet had the highest sample variation among tests (physical and biological) performed, indicating an innate lower level of durability and consistency in this sealer that is exacerbated by hygrothermal stress. Pulp Canal Sealer experienced changes in all properties but few were statistically significant.

CONCLUSIONS: This study showed that endodontic sealers are subject to potentially clinically significant changes in physical and biological properties after exposure to hot and humid conditions. Those composed of silicone and zinc oxide-eugenol materials could be most ideal for hot and humid areas of operation with more dependable solubility, setting time, and cytotoxic characteristics. Military and civilian clinicians can use the results of this study when choosing which endodontic sealers may be best suited for unique performance requirements and improving endodontic therapy success rates.