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Effects of DCPA Nano-Particle Filler Level on Ca-and-PO4- Releasing Dental Composites



Hockin D. Xu, Michael Weir, Limin Sun, S. Takagi, Laurence C. Chow


Dicalcium phosphate anhydrous (DCPA) nano-particles were recently synthesized. The objective of this study was to investigate the effects of filler level on composite mechanical properties and Ca and PO4 release. Nano DCPA and whiskers were used at DCPA:whisker mass ratio of 1:1. The filler mass fractions in the resin ranged from 0 % to 75 %. Flexural strengths (mean sd; n = 6) of the DCPA-whisker composites ranged from (106 39) MPa at 0 % fillers to (114 23) MPa at 75 % fillers, not significantly different from (112 22) MPa of a non-releasing composite (TPH) (p > 0.1). The composite with 75 % fillers yielded a Ca concentration of (0.65 0.02) mmol/L and PO4 of (2.29 0.07) mmol/L at 56 d. At 40 % to 75 % fillers, the composite solutions were supersaturated with respect to hydroxyapatite. Relationships were established between release and DCPA volume fraction in the resin vDCPA: Ca = 4.46 vDCPA1.6, and PO4 = 66.9 vDCPA2.6, indicating that the release increases with vDCPA at a rate faster than being linear. In conclusion, nano DCPA-whisker composites had high strengths and released Ca and PO4 that were supersaturated with respect to hydroxyapatite. They may be useful in stress-bearing and remineralizing restorations.
Journal of Dental Research


Ca and PO4 ion release, dental composite, nano particles, remineralization, whisker reinforcement


Xu, H. , Weir, M. , Sun, L. , Takagi, S. and Chow, L. (2007), Effects of DCPA Nano-Particle Filler Level on Ca-and-PO<sub>4-</sub> Releasing Dental Composites, Journal of Dental Research, [online], (Accessed July 20, 2024)


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Created January 1, 2007, Updated February 17, 2017