Some proteins found in saliva, such as statherine, PRP (= proline-rich phosphorus), cystatins, or albumins, have a high affinity for HAP and can thus inhibit (re)mineralization [ 18, 19]. Since products that claim to enable remineralization should also be able to induce remineralization in an in vitro model, this study should be considered as a first investigation in this regard. Colgate: marketed by Colgate-Palmolive, it is the first toothpaste in a collapsible tube, introduced in 1896, after having been sold in glass jars since 1873. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. Ajona is a toothpaste that contains neither fluoride nor HAP and is therefore considered a control toothpaste (see Table ​ Table1 1).

KIN: Laboratios KIN is a Spanish brand of Oral hygiene products that focuses on specific needs of the user i. Thus, Karex remineralized highly significantly less compared to the other toothpastes tested ( p< 0. All human specimens were handled strictly according to the “Declaration of Helsinki” (Local ethics protocol code 2021‐608‐f‐N).Several studies have shown a reinforcing effect for fluoride-containing agents by lowering their pH, which is associated with an improved ability to absorb minerals into enamel defects [ 30– 32].

Sozodont: [38] a popular brand of oral hygiene product from the mid-nineteenth century to the early twentieth century.

All images generated by ImageJ ( n = 513) were evaluated independently by two expert observers (LG, AR). In vitro tests have the advantage that they can be carried out under well-controlled experimental conditions. Under the conditions of this in vitro study, a fluoride-containing toothpaste (Elmex) was significantly superior in comparison to a hydroxyapatite-containing (Karex) and a fluoride- and hydroxyapatite-free toothpaste (Ajona) with regard to remineralization potential as well as the extent of protection against renewed demineralization of enamel.