Hydroxyapatite

Scientific Articles of Hydroxyapatite (HAP):

Chen et al. (2021). Hydroxyapatite in Oral Care Products—A Review.

Limeback L, Enax J, Meyer F. (2021). Biomimetic hydroxyapatite and caries prevention: a systematic review and meta-analysis.

Pepla et al. (2014). Nano-hydroxyapatite and its applications in preventive, restorative and regenerative dentistry: a review of literature.

Gómez-Morales et al. (2013). Progress on the preparation of nanocrystalline apatites and surface characterization: overview of fundamental and applied aspects.

Human tooth enamel is composed of hydroxyapatite (HAP) crystals (96–98% based on tooth mass). The crystals are organized into enamel prisms, which you can see in the middle of Figure 1.

Figure 1. Schematic illustrations of the hierarchical structure of giant panda’s tooth enamel (Weng et al; 2016)

Enamel prisms are formed from rods with HAP fibers inside. These fibers are 2800x smaller than the diameter of a normal hair!

Figure source:

Weng et al. (2016). Giant panda’s tooth enamel: Structure, mechanical behavior and toughening mechanisms under indentation.