Magnesium and Calcium Released From an Apatite-Modified Glass Ionomer Cement

Objectives: The objective of this study was to investigate magnesium ion(Mg2+) and calcium ion(Ca2+) released from a glass ionomer cement (GIC, Fuji IX GP®) (control, C) and a magnesium carbonate apatite (MgCO₃Ap) modified GIC (test, T).
Methods: MgCO₃Ap was synthesized using a gradient magnesium supply system and mixed to GIC powder (2.5% w/w). The powder was encapsulated mixed with Fuji IX GP® liquid (P/L=3.6:1) (4,000rpm) for 6s and packed into silicone molds (6.0±0.1mmx 4.0±0.1mm) (n=3/group) on a glass plate covered with celluloid strip, pressed with another glass plate and stored at 37°C 100% humidity for 1h. Specimens were de-molded and suspended into individually capped containers with 20mL deionized water at 37°C. At 1,2,6,12 hours and 1,7,14 days, specimens were removed, dried with filter paper and transferred into new containers with 20mL fresh deionized water. The concentration of Mg2+Ca2+was measured from 10mL eluate using Inductively Couple Plasma-Optical Emission Spectrophotometer (ICP-OES, OPTIMA 7300, PerkinElmer, Shelton, CN, USA).
Results: The peak release of both Mg2+and Ca2+was found at the second hour, Mg2+was released to only 48h but Ca2+was released to day14. The accumulated release of Mg2+ (48h) was 0.31ppm(T) and 0.16ppm(C) and for Ca2+was 2.25ppm(T) and 0.83ppm(C).
Conclusions: Magnesium and calcium ion released from MgCO3Ap modified GIC was superior than the conventional GIC. With the Increased evidences indicated the role of ionic dissolution products to the behavior of the materials in the context of tissue engineering applications, our result indicated the potential of this novel GIC to pulp-dentin regeneration.