Extracellular calcium ions in dentin smear layer, biofilms, and microbial cell walls (Ca2+)

Extracellular calcium ions (Ca2+) are fundamental structural components within the oral environment, serving as the primary inorganic constituent of dentin hydroxyapatite and the smear layer formed during endodontic procedures (Zehnder, 2006, Journal of Endodontics). Beyond the tooth structure, these ions act as essential cross-linkers within the extracellular polymeric substance (EPS) of microbial biofilms, providing mechanical stability and resistance to antimicrobial agents (Sutherland, 2001, Microbiology). In the context of endodontic therapy, extracellular calcium is a therapeutic target for chelating agents such as ethylenediaminetetraacetic acid (EDTA) and citric acid. These agents sequester calcium ions, leading to the dissolution of the smear layer, opening of dentinal tubules, and the structural collapse of bacterial biofilms (Hülsmann et al., 2003, Endodontic Topics). While effective for cleaning and disinfection, the depletion of calcium must be carefully managed to avoid excessive demineralization, which can compromise the structural integrity and microhardness of the root dentin (Sayin et al., 2007, Journal of Endodontics).

Other names

Calcium ionsDivalent calcium cationsIonic calciumDentin calciumBiofilm calcium matrix

Chelation and sequestration of divalent cations to disrupt structural integrity, facilitate demineralization of the smear layer, and destabilize microbial biofilms.