Hydroxyapatite [Ca10(PO4)6(OH)2] is the third most abundant element in the human body, and the main component of bone and dental tissues. 

In teeth, hydroxyapatite accounts for 95-97% of the enamel’s weight, 70% of that of the dentin and 50-60% of that of the cementum, qualifying it as the hardest component of the human body. 

Enamel is basically formed by hydroxyapatite crystals, so compact that it looks like glass, which is why it is translucent. In fact, the yellowish-white colour of the teeth comes from the dentin reflecting through the translucent enamel crystals. In other words, hydroxyapatite influences the colour and appearance of the teeth. 

The main function of enamel is to protect the teeth from external aggressions. Despite being the hardest part of the body, in acidic pH conditions it can become demineralised. Specifically, below its critical point, that is, at pH 5.5, the hydroxyapatite begins to lose its mineral content, dissolving mostly into the saliva as Ca²⁺, PO4 and OH- ions. These, and other similar ions present in saliva (supersaturated in calcium and phosphate), in addition to fluoride, may subsequently reincorporate into the enamel during a process of remineralisation. The tooth thus finds itself in a constant balance between demineralisation and remineralisation. A prolonged imbalance tending to demineralisation results in the appearance of caries. 

Fluoride is the element most commonly employed in caries prevention. Its topical application, in the form of fluoride ions, inhibits the demineralisation of the enamel and favours remineralisation. In addition, the combination of fluoride and hydroxyapatite ions results in the development of several compounds, including fluorapatite. Fluorapatite crystals are larger and more resistant to acid dissolution than the original enamel. In fact, the critical point of fluorapatite is one point less than that of hydroxyapatite and begins to demineralise at a pH of 4.5 as opposed to 5.5. Hydroxyapatite is thus a key component in the resistance of teeth to demineralisation, and in combination with fluoride ions, helps to form more resistant compounds and prevent the onset of caries. 

Several factors, including acid erosion, can produce wear and eventual loss of enamel layers, as well as cementum if there is gum recession. In such cases, the dentin is exposed and loses its natural protection. Additionally, if the dentinal tubules exposed are also open, this may lead to dental hypersensitivity. Dentin is more organic and contains less hydroxyapatite (70%) than enamel. It is therefore less resistant, and carious lesions will progress more rapidly in this tissue. The dentin undergoes a natural self-repairing process consisting of the formation of a smear layer. This thin layer forms on the dentin, covering the dentinal tubules, thus preventing external stimuli from affecting the pulp. It is mainly composed of collagen and hydroxyapatite fragments. In other words, hydroxyapatite acts to help prevent dental hypersensitivity. 

Hydroxyapatite thus affects the appearance of the teeth, tooth decay and dental hypersensitivity, meaning that it plays a fundamental role in dental health. 

The DENTAID Research Center has developed the innovative DENTAID technology haprepair. This exclusive technology is based on the incorporation of active hydroxyapatite, a natural element of the tooth, which features the ability to combine with the surface of the enamel and the exposed dentin. The topical application of Active Hydroxyapatite by way of oral hygiene products provides the following benefits: 

- It forms a protective layer on the enamel, and in combination with fluoride, helps increase the enamel’s resistance. 

- It repairs imperfections in the enamel, providing a smoother, brighter surface and, in turn, a whiter appearance. 

- For exposed dentin, Active Hydroxyapatite forms a protective layer that helps cover the dentinal tubules. 

- Active Hydroxyapatite is a mineral reservoir for the tooth, especially in periods of low pH, and prevents enamel demineralisation. 

DENTAID has incorporated DENTAID technology haprepair in the formulation of three specific products to obtain a superior result in the prevention of tooth decay and dental hypersensitivity and in helping the teeth recover their natural whiteness. 

VITIS ANTICARIES 

VITIS anticaries toothpaste and mouthwash provide superior protection against tooth decay since they act at different stages of caries development: 

- Sodium monofluorophosphate: fluoride ions act by inhibiting the demineralisation of enamel and favouring remineralisation, providing enamel with greater resistance to the onset of caries. In fact, fluoride is considered the universal component to combat tooth decay. 

- Xylitol: as of concentrations of 10% in toothpastes and 3.3% in mouthwashes, this can inhibit the growth of cariogenic bacterial species. In addition, xylitol helps increase salivation, which, on the one hand, contributes to the neutralisation of acidic pH, and on the other hand, helps to remineralise enamel. 

- Active Hydroxyapatite: this deposits on the enamel, forming a protective layer. In addition, when combined with fluoride ions, it contributes to the formation of fluorapatite, which is even more resistant to decay. 

Thanks to this full range of formulations, VITIS anticaries offers triple protection against decay and erosion. 

DESENSIN REPAIR 

The Desensin repair range works by reducing dental hypersensitivity, and contains other active ingredients for gum care: 

- Active hydroxyapatite: contributes to the remineralisation of enamel and the exposed dentin, and forms a protective layer which helps cover the exposed dentinal tubules - Potassium nitrate: Potassium acts by gradually desensitising nerve fibres. It is the most commonly applied active ingredient against dental hypersensitivity. 

- Sodium monofluorophosphate: in addition to aiding in the prevention of tooth decay, this remineralises the enamel and exposed dentin, helping to reduce the risk of dental hypersensitivity. 

- Panthenol (provitamin B5), allantoin and vitamin E: these contribute to protecting gum tissues and other oral mucosal tissues. 

VITIS WHITENING 

VITIS whitening toothpaste and mouthwash offer five combined actions to help return teeth to their natural whiteness, thanks to these active ingredients: 

- Polyvinylpyrrolidone: anti-stain action. Deactivates the bonds with chromophores (which produce the stains) and prevents their deposition on the enamel 

- Triple phosphate system: anti-tartar action. Phosphates act by sequestering the Ca²⁺ ions that normally cause biofilm mineralisation, thus preventing the formation of dental calculus, or tartar. 

- Perlite: polishing action. The perlite present in the toothpaste polishes and helps to gently smooth out the enamel, without damaging it and restoring its natural gloss. 

- Sodium monofluorophosphate: anticaries action. Helps prevent the onset of caries, inhibiting the process of demineralisation, and favouring remineralisation of the enamel. 

- Active hydroxyapatite: repair and whitening action. Active Hydroxyapatite deposits on tooth enamel, repairing surface irregularities. This provides a smoother surface, which directly reflects the light, giving teeth a whiter and brighter appearance.