Introduction
dentine erosion, dentine loss, dentine, erosion, mineral loss, tooth
DEMINERALIZATION, EROSION, DENTAL EROSION
Frequent contact of tooth surfaces with acids not originated from bacteria results in mineral loss, called dental erosion. With the progression of this condition, enamel is continuously lost and the exposition of the underlying dentine occursDentine contains 20% of organic material (mainly collagen), which reduces the amount of dentine loss to a certain degreeSome substances, such as polyphenols, can inhibit the action of MMPs, reducing the degradation of the organic matrix, and slowing the progression of dentine erosion. Polyphenols can inactivate the collagenases by binding to them through hydrogen bonding and hydrophobic interaction, which inhibits collagen degradationThe progression of dental erosion is also controlled by the acquired salivary pellicle, which forms by the adsorption of proteins, peptides, lipids and other macromolecules present in saliva to the tooth surfaceTo counteract the limited protection from the pellicle, this organic layer can be modified for enhanced protection. This has already been tested for the protection of enamel against dental erosionPlant extracts rich in polyphenols have promising potential to protect dentine against erosion, since they will potentially have a dual action: they can bind to salivary proteins and modify the salivary pellicle, as well as bind to collagen in dentine and increase its resistance to degradation. However, up to the present moment, no study has tested this possible dual action. Therefore, the present study investigated the effect of some polyphenol-rich plant extracts on the protection of dentine against demineralization, both acting on the dentine and on the salivary pellicle. The specific aims of the present study were: (1) to verify if the plant extracts have a direct effect on the dentine, causing less dentine loss; (2) to verify if plant extracts can modify the salivary pellicle, improving its protective effect against dentine erosion; (3) to analyze the amount of degraded collagen after collagenase treatment. The null hypotheses were: (1) the plant extracts do not have a direct effect on the dentine, protecting it against erosion; (2) the plant extracts do not modify the salivary pellicle, improving its protective effect; (3) the plant extracts do not reduce the amount of collagen degradation.