The pH changes of four different root canal sealers after mixing at various time intervals in vitro.

The purpose of this study was to compare the surface pH level of four different type sealers after mixing at various time intervals in vitro. After cleaning and shaping root canals in 50 recently extracted, single-rooted human teeth, they were divided into six groups. Each of four groups was obturated with Apexit, N2, Sealapex, and Grossman sealers. The remaining groups served as controls. In group 1 nothing was added to the vial of saline solution. In group 2 canals had been instrumented but not obturated with sealer. The pH level of saline solutions was determined at intervals of 1 hour, 4 hours, 1 day, 2 days, 3 days, 1 week, and 4 weeks after teeth were placed in them. The pH levels of the five solutions were compared to each other and to that of saline solution only.