Calcium Ion-release From “Bioactive” Dental Restorative Materials

Objectives: Previous studies have demonstrated that calcium ions released from dental materials have a profound effect on the durability and longevity of clinical restorations. The objective of this study is to measure the concentration of calcium ions released from three “bioactive” restorative materials: TheraCal-LC; Activa; and Dycal.
Methods: Discs (n=3; 1mmX8mm) of each material were made using a custom mold. Discs of each material were submerged in reverse osmosis (RO) water. Ion-release was measured using a calcium ion-selective electrode (ISE) (LIS-146 CACM Micro Calcium Electrode, Lazar Research Laboratories, Inc., Los Angeles, CA). Measurements were performed every 24 hours for at least 7 days with discs removed and placed into fresh RO water after each measurement.
Results: All 3 materials released the highest amount of Ca²⁺ ions on day 1. The amount of Ca-ions released from TheraCal-LC release over a period of time is significantly higher than both Activa and DyCal. Over a 7 day period, TheraCal-LC released a total of 9µg Ca²⁺ ions/mm². This is about 2 times more than DyCal and about 13 times more than Activa.
Conclusions: The amount of calcium released may have a positive effect on cell in a physiological environment. By providing cell with additional calcium, we expect to see an increase in cell growth, measured by cell attachment, proliferation, and differentiation.