Hydroxyapatite in Oral Care Products—A Review

Abstract

Calcium phosphate compounds form the inorganic phases of our mineralised tissues such as bone and teeth, playing an important role in hard tissue engineering and regenerative medicine. In dentistry and oral care products, hydroxyapatite (HA) is a stable and biocompatible calcium phosphate with low solubility being used for various applications such as tooth remineralisation, reduction of tooth sensitivity, oral biofilm control, and tooth whitening. Clinical data on these products is limited with varied results; additionally, the effectiveness of these apatite compounds versus fluoride, which has conventionally been used in toothpaste, has not been established. Therefore, this review critically evaluates current research on HA oral care, and discusses the role and mechanism of HA in remineralisation of both enamel and dentine and for suppressing dentine sensitivity. Furthermore, we position HA’s role in biofilm management and highlight the role of HA in dental applications by summarising the recent achievement and providing an overview of commercialised HA dental products. The review also indicates the existing limitations and provides direction for future research and commercialisation of apatite-based oral care products.

Remineralization and protection from demineralization: effects of a hydroxyapatite-containing, a fluoride-containing and a fluoride- and hydroxyapatite-free toothpaste on human enamel in vitro

“…Various toothpastes with added HAP have been available for several years. Since there is a great chemical similarity of HAP with human enamel, the active ingredient HAP is supposed to adhere to the tooth surface during tooth brushing, thus forming a protective layer against bacteria and acids, and also repairing enamel areas attacked by acid [ 14 ]. However, little is known about the interaction of HAP with tooth structure.…”

“…Similarly, whether HAP is an agent that can affect caries, erosion, or plaque formation is currently not fully understood [ 12 ]. In the literature, some studies can be found that were able to show comparable, positive effects of HAP and fluoride in terms of remineralization and caries prevention; however, the vast majority of studies were unable to demonstrate statistically significant better remineralization features of HAP compared to fluoride [ 14 ].…”

Rehardening and the Protective Effect of Gamma-Polyglutamic Acid/Nano-Hydroxyapatite Paste on Surface-Etched Enamel

“…Various studies reported the use of γ-PGA as a nutrition supplement in dietary products for enhanced Ca 2+ solubility, explaining its role in increased calcium absorption in the small intestine [ 31 , 32 ]. Another widely available material, nano-HAp, has applications in biomedical areas such as dentistry and orthopedics, [ 33 ] owing to its excellent biocompatible, osteoconductive, and bioactive behavior [ 34 , 35 ]. The enamel has a complex structure for remodeling and comprises basic building blocks of ~20–40 nm HAp nanoparticles.…”

Bioglass: A New Era in Modern Dentistry

“…• Hydroxyapatite can bind to microorganisms by interacting with the bacterial adhesin thus agglutinating the microorganism. 45 Fluoride Bioglass may be recommended for treatment of dentin hypersensitivity. It can be used daily by individuals with a compromised periodontal status and individuals with a compromised enamel surface.…”