What are the key differences between DCPD and other abrasives like silica for toothpaste formulations?

What are the key differences between DCPD and other abrasives like silica for toothpaste formulations?
DCPD stands out among toothpaste abrasives for its low hardness (Mohs 2-2.5), which minimizes enamel wear compared to silica (hardness 7) or calcium carbonate. It also offers a unique benefit: releasing calcium and phosphate ions that support enamel remineralization, a property not found in silica. However, DCPD presents formulation challenges—it can dehydrate and crystallize over shelf life, and it is incompatible with fluoride compounds, as they react to form fluorapatite, reducing both fluoride efficacy and DCPD's stability. This forces formulators to use alternative anti-caries agents like zeolite, which has a hardness of 3-6 and is costlier. DCPD also tends to separate from water in the paste, requiring humectants like sorbitol for stability. These factors explain why DCPD appears mainly in premium or specialty toothpastes, such as Yunnan Baiyao's gum-care line, rather than mass-market fluoride pastes.