THE DISINTEGRATION OF SUPEREBA CEMENT IN SOLUTIONS WITH ADJUSTED PH AND OSMOLARITY

This study determined the disintegration of fast-set SuperEBA cement u sing ANSI/ADA Specification No. 30 (Spec #30) as well as modifications in pH, osmolarity, time before immersion, and duration of immersion t hat mimic the clinical, endodontic application of this material. After immersion intervals of 24 h, 1 wk, 1 m, 3 m, or 6 m, specimens were d esiccated and weighed. The preimmersion and postdehydration weights we re obtained to the nearest 1.0 mg and the percent weight loss from pre immersion levels was calculated. Adjusting the osmolarity to the physi ologic level of 300 mOsm/kg resulted in significantly less weight loss (p < 0.05) than the control group in distilled water (no modification of Spec #30). The pH of the storage solution was found to be a signif icant factor in weight loss. As the acidity and the time of immersion increased, the weight loss also significantly increased with the great est weight loss of 19.81% at pH 5.5 after 6 m storage. Immersion withi n 10 min of mixing was not significantly different (p > 0.05) in weigh t from the control of 1 h set-time. The 24 h weight loss measurements for the pHs of 5.5 and 6.4 were greater than the 1.5% allowed by Spec #30. All other 24 h measurements were less than the 1.5%.