Tooth enamel hydroxyapatite and acquired pellicle

Tooth enamel is the most highly mineralized tissue in the human body, composed of approximately 96% inorganic material, primarily hydroxyapatite crystals (StatPearls, 2023). The acquired pellicle is a thin, acellular film of salivary proteins, glycoproteins, and lipids that forms spontaneously on the enamel surface upon exposure to saliva (PubMed, 2012). Together, they function as a dynamic interface that protects the underlying tooth structure from mechanical wear and chemical dissolution (NIH, 2022). This complex is a primary therapeutic target in dentistry, where treatments aim to enhance the mineral stability of the enamel or modulate the pellicle's role in bacterial adhesion. For instance, fluoride treatments promote the formation of fluorapatite, which is more resistant to acid-induced demineralization than pure hydroxyapatite (Journal of Dental Research, 2009). Additionally, the pellicle acts as a selective barrier and a reservoir for ions and antimicrobial agents, playing a pivotal role in the prevention of dental caries and erosion.

Other names

Dental enamelHydroxyapatiteAcquired enamel pellicleAEPEnamel surface

Fluoride ions substitute for hydroxyl groups in the hydroxyapatite lattice to form fluorapatite, which has a lower solubility product and higher resistance to acid dissolution. The acquired pellicle serves as a diffusion barrier against organic acids and a binding site for antimicrobial agents like chlorhexidine, while also providing a template for remineralization by concentrating calcium and phosphate ions.