Cytotoxity of HeLa Cells Cultured on S-PRG Filler

Objectives: Surface reaction type pre-reacted glass-ionomer (S-PRG) filler is developed and used for adhesive and restorative materials. The use of the S-PRG filler might be most effective for secondary caries inhibition around restorations, however its biocompatibility is not well understood.  The aim of this study was to evaluate ion release from the S-PRG filler and its cytotoxity for HeLa cell in the culture solution.  Methods: The S-PRG filler (mean particle size: 3µm, 0.2g) was immersed in 20ml of the distilled water and culture medium. The amount of ions (F, Al, Na, B, Si, Sr) released from the S-PRG filler was measured by an Inductively Coupled Plasma (IPC) spectro-chemical analyzer (Al, Na, B, Si, Sr), a fluoride ion electrode and pH/ion meter (F).  The cytotoxity of the S-PRG filler was determined by evaluation of HeLa cells viability in comparison to untreated controls (the serum-free medium, cell viability=100%). HeLa cells in culture medium were adjusted to a concentration of 5x10⁴ cells/ml.  The cell viability of the S-PRG filler was in Cell Counting Kit-8 after 24 hours. Results: Results appear below (mean(SD), N=6, µg/ml, ND: No Data).  

                    

Solution	Na	B	Al	Si	Sr	F
Distilled water	16.3(0.4)	25.7(0.5)	2.5(3.7)	2.2(0.1)	45.4(0.9)	27.0(0.3)
Culture medium	ND	30.6(1.0)	0.2(0.0)	1.4(0.0)	97.4(1.0)	30.2(0.4)

The release of each ion from S-PRG filler affected with the solution of distilled water and culture medium (P<0.05, paired comparison t-test). The cell viability of the S-PRG filler resulted in approximately 20% reduction to the control (P<0.05, paired comparison t-test), however its cell viability with 10% diluted culture solution was similar to that of the control. Conclusion: These findings suggested that S-PRG filler components (F, Al, Na, B, Si, Sr) were released in the culture solution from the S-PRG filler, and the S-PRG filler showed very low cytotoxity.