(PR92) Effect of Humidity on Volume Changes of Root Canal Sealer

Objectives: In single-cone obturation the volume changes of the root canal sealer affect tightness. In this study the effect of humidity on volume changes was investigated using extracted human teeth. Materials and

Methods: A cavity of φ3 mm and 5 mm depth was prepared in 36 extracted wisdom teeth using a diamond bur with the standard forming device (approved by Ethics Committee of the Nippon Dental University). The tooth was placed in a petri dish and the cavity was filled with a sealer, Bio-C Sealer (angelus: Bio), Meta SEAL Soft Paste (SUN MEDICAL: MS) and AHplus Jet (Dentsply Sirona: AH). Then,the tooth was placed in humid or dry conditions in a 37℃ incubator. Humidity groups (-h) were placed in saline solution and dry groups(-d) without. The volume changes in each group (n=6) were measured every 12 hours by irradiating of laser beam to the sealer surface. Measurements were compared multiply by the Kruskal-Wallis test (p < 0.05).

Results: The Bio-h and MS-h groups indicated greater expansion then the other groups. There were significant differences between Bio-h and Bio-d, MS-h and MS-d, no significant differences between Bio-h and MS-h, AH-h and AH-d.

Conclusions: Bio-C Sealer and Meta SEAL Soft Paste are suggested to be suitable for single-cone obturation due to their in vivo expandability caused by humidity surrounded the teeth.