Effectiveness of dental resin composites containing calcium orthophosphate particles on dentin remineralization.

To assess the remineralization of artificial dentin lesions achieved with composites containing dicalcium phosphate dihydrate (DCPD) particles. Composites (42 vol% inorganic fraction) were tested: barium glass (BG; control), DCPD or 1DCPD:1BG. Degree of conversion (DC) was measured by FTIR. Ca2+ release was monitored using inductively coupled plasma optical emission spectrometry and scanning electrochemical microscopy (n=3). Artificial lesions were restored and kept in simulated body fluid for 28 days. Remineralization was assessed by mineral-to-matrix ratio (MMR; n=5) and nanoindentation (n=6). Data were analyzed using parametric tests (α=5%). DC ranged between 56.2 and 58.1% (p>0.05). Ca2+ release was 40.0±1.5 ppm and 18.4±1.6 ppm, respectively, for DCPD-only and DCPD+BG (p<0.001). Ca2+ release near the specimen surface reached 32 ppm within minutes after immersion. No differences in MMR were observed. Specimens in the DCPD-only group reached an elastic modulus higher than the control in the outer lesion (p<0.01). DCPD-containing composites may represent a promising approach to support dentin remineralization.