Methods: IX Ex-AICs were created by replacing 6-20wt% of the IX Ex powder with spherical-shaped hydroxyapatite(HAp, Taihei Chemical Industrial, Inc., Osaka, Japan) and mixed with polyacrylic acid at Powder/Liquid ratio=3.4. Column shaped samples (10mm in diameter and 2mm in thickness) were prepared, grind with silicon-carbide paper and stored in distilled water and renewed every 24 hours. Measurement of fluoride elution was done every 24 hours for 30 days. Moreover, samples measuring 3 mm × 3 mm × 25 mm were prepared for each group. The samples were then subjected to flexural strength test by three-point bending.
Results: All groups of IX Ex AICs tended to have higher dose of fluoride release compared with control GIC for 30 days. Especially, the accumulated fluoride release dose of 18 wt% hydroxyapatite added IX Ex AIC was 20% higher than that of IX Ex control GIC. Although the flexural strength of IX Ex control GIC was significantly lower than IX GP, the flexural strength of IX Ex-AIC containing 6-12 wt% HApS were significantly higher than IX Ex control GIC.
Conclusion: These results indicate that IX Ex AIC has especially higher fluoride release property and mechanical strength. Therefore, AIC may be effective in reducing caries progression by sealing it on the non-cavitated caries.
Acknowledgement: This research is being supported by JSPS Grant-in-Aid for Scientific Research (C) # 24592975.