Calcium ions in dental hydroxyapatite (Ca2+ (HAp))

Calcium ions (Ca2+) are the primary cationic component of dental hydroxyapatite (Ca10(PO4)6(OH)2), which constitutes approximately 70% of dentin by weight (StatPearls, 2023). These ions are essential for maintaining the mechanical strength and acid resistance of the tooth structure (PubChem, CID 14781). In the oral environment, calcium ions exist in a dynamic equilibrium between the tooth mineral and the surrounding saliva. When the local pH drops below 5.5 due to bacterial acid production, these ions are released from the lattice, leading to demineralization and the formation of dental caries (NIH, 2022). Therapeutic agents like fluoride target these sites to facilitate remineralization, replacing hydroxyl groups to form fluorapatite, which is more resistant to acid (PubMed, PMID 30634444). Additionally, calcium-based compounds are used to treat dentin hypersensitivity by occluding exposed dentinal tubules. For example, arginine-calcium carbonate technology deposits calcium-rich minerals to block fluid movement within the tubules (Journal of Clinical Dentistry, 2009). This mineral deposition effectively reduces the transmission of painful stimuli to the dental pulp.

Other names

Hydroxyapatite calciumDentin calciumTooth mineral calciumCrystalline calcium in dentin

Promotion of remineralization through the formation of fluorapatite or hydroxyapatite-like layers, and the physical occlusion of dentinal tubules to prevent fluid movement and nerve stimulation (PubMed, PMID 30634444; Journal of Clinical Dentistry, 2009).