In Vitro Calcium Release of Dicalcium\tricalcium Silicate Resin-modified Materials

Objectives: To evaluate in vitro the calcium release and hardness of TheraCal LC and PT in restoration in human teeth.
Methods: Freshly extracted human molars received two preparations deep into the pulpal horns using the protocol of a previous study on human subjects. After buccal access the pulpal chambers were thoroughly cleansed and filled with sterile foam pellets and deionized water. TheraCal LC or TheraCal PT were placed in the preparations contacting the blue pellets, light cured and then the buccal and occlusal access closed with composite and additional light cured.
After 14 days in deionized water, the teeth were cut in half by a low-speed saw (See Pic 1 and 2). The blue foam pellets were taken out, and with the two halves of teeth together submerged into 10 ml deionized water in a container. The container was under ultrasound for 5 min to accelerate calcium release. Teeth were taken out and dried for micro-hardness testing. The calcium amount (calcium release) in the water was measured by Thermo Scientific Orion 720A+. The micro-hardness test on TheraCal LC and TheraCal PT (tested on outer, middle, and inner part; outer part is closer to curing light) was conducted by SHIMADZU DUH-W201S. Data were analyzed by one-way ANOVA followed by Student t-test.
Results:


The mean (standard deviation) micro-hardness (GPa) of TheraCal LC and TheraCal PT at the different levels were not significantly different. TheraCal LC had a greater Calcium release than TheraCal PT.



Conclusions: Microhardness of the resin modified dicalcium/tricalcium materials were not significantly different at the different depths of the restoration. Calcium release was greater for the TheraCal LC over TheraCal PT but not by a statistically significant value.