Smalțul dentar

Oare dintii de fildes ce smalt au ?

Enamel remineralization
At physiological conditions, the oral fluids (saliva, biofilm fluid) have calcium (Ca) and phosphate (Pi) in supersaturated concentrations with respect to the mineral composition of enamel and, as a result, these ions are continually deposited on the enamel surface or are redeposited in enamel areas where they were lost. This can be considered a natural defense phenomenon promoted by saliva to preserve the mineral structure of enamel in the mouth.6 Therefore, remineralization would be best defined as the redeposition of minerals lost by enamel, and this term has been used as a synonymous of enamel repair or rehardening.
Mineral loss (demineralization) or gain (remineralization) by enamel is a dynamic physicochemical process occurring when oral bacteria form a biofilm on the enamel surface and this biofilm is exposed to fermentable dietary carbohydrates, sucrose being the most cariogenic of them.7 Thus, every time sugar penetrates into a cariogenic biofilm and is converted to acids by bacterial metabolism, the biofilm fluid becomes undersaturated with respect to the enamel mineral, and demineralization occurs.8 A critically low pH for tooth dissolution is maintained for a certain time, but it returns to physiological values when exposure to sugar ceases. Therefore, when the pH is raised and the supersaturating conditions are restored, a certain amount of the mineral lost can be recovered by enamel. This process has been named remineralization. Redeposition of the mineral lost by enamel can occur by Ca and Pi found in the biofilm fluid or by direct action of salivary Ca and Pi soon after the biofilm is removed by toothbrushing. The amount of Ca and Pi gained, however, is lower than that lost, and the net result is a small mineral loss.
If the factors responsible for the disease - biofilm accumulation and frequent sugar exposure - are not controlled, enamel mineral loss cannot be stopped (Graph 1).2 Repeated events of mineral dissolution will eventually surpass the capacity of oral fluids to repair mineral loss, and the disease will show its first clinical signs: white spot lesions. Differences in the progression rate of caries lesions in different individuals or populations can also be the result of other factors which modulate the caries process, since caries is a "multifactorial" or "complex disease", and the risk of developing new lesions is never zero.5 In some individuals, lesions will progress slowly, and the disease might not be clinically detected throughout their lifetime. In others, they will progress rapidly, and the manifestation of the disease will become clinically evident (white spots) before cavitation (Graph 2). Additionally, the progression from non-cavitated to cavitated lesions could be arrested, and the strategies used should consider if the lesions are "active or not".9 This classification is aimed to correctly diagnose caries as a disease, as the basis for treatment decision.9

Periuta de dinti (mai ales cea rotativa pe baterii) strica smaltul prin acea frecare alandala. Dintele e crescut de jos in sus (respectiv dintii de sus care au de sus in jos (iese ciudat propozitia, stiu)) iar smaltul la fel.
off topic De ce te superi asa repede, acum ai pus o poza cu picaciu, mai rau... globalizarea asta