Early Enamel Lesion: Part II. – Histo-morphology and Prevention

Abstract

The enamel demineralization defect has a lower mineral distribution in the surface layer in comparison to the adjacent sound enamel and also a lower interprismatic mineral content. The first stage of enamel demineralization is characterized by removal of interprismatic mineral content and in the subsequent stages a well defined surface layer formation occurs which constitutes early caries lesion (4).Although early investigators like Hollander and Saper (47) in 1935 had noticed this subsurface demineralization white opaque spot, they mistook it to be a photographic artifact. However the work of various other researchers like Applebaum, Thewlis, Besic, Coolidge et al., Gray and Francis (3,12,21,41,87), on white opaque enamel lesion and new experimental techniques like microradiography (42), polarized light experiments (23, 78), microhardness data (30), and electron microscopy shed new light in understanding the early caries lesion in enamel. These studies have demonstrated that a porous and mineral-rich surface layer covers an enamel lesion and the morphology differs a little from that of sound enamel while body of the lesion which comprises the subsurface area has low mineral content (10-70 vol %). The early caries lesion in enamel is characterized by a prominent perikymata pattern and focal holes (6,44,88). The main drawback of the numerous experimental techniques is that they are static measurements of caries progression at a particular time period whereas the carious process is time-dependent and is in a constant state of dynamic equilibrium wherein a balance is struck between demineralization and remineralization. Surface layer (SL) covering early enamel lesionsThe early investigators who observed the white opaque spots attributed the presence of these lesions to artifacts. They believed that the surface layer (SL) could be due to sound enamel which has a higher mineral content. These explanations were proved false by subsequent investigations by Langdon et al. (55). Their studies on pressed pellets of hydroxyapatite demonstrated that subsurface lesion could occur in an acidic gel system with 2 ppm fluoride. They also concluded that organic matrix is not important for subsurface lesion formation, and that neither a preferred crystallite orientation in the enamel prisms nor an uneven ion/mineral distribution in enamel were essential for the formation of a subsurface lesion since these are absent in pressed apatites. This is in contrast to earlier reports by Brudevold et al. (15). Mechanism of subsurface lesion formation and progressThe bacteria in the oral plaque are acidogenic and form organic acids, including lactic, formic, acetic, and propionic acids from fermentable carbohydrates which diffuse into the enamel (30), dentin, or cementum, partially dissolving the mineral crystals (57). When this process goes unchecked minerals like calcium and phosphate diffuse out of the tooth resulting in frank cavitation. In the initial stages, demineralization can be reversed by influx of calcium, phosphate, and fluoride...

Morphological evaluation of the effectiveness of the “Icon” resin infiltration method in acute and chronic superficial dental caries

“…Despite the introduction of the latest technologies for preventing dental caries, there has been an increase in the incidence in recent years, which has no tendency to stabilize. Unfortunately, the implemented comprehensive caries prevention measures do not always demonstrate high efficiency (Kudiyirickal & Ivancaková, 2008). The demand for aesthetic dentistry has led to the development of new methods of treating dental caries at the stage of white spots.…”

“…The loss of mineral, which leads to the dissolution of the hard tissues of the tooth, causes tooth decay, which can be seen clinically. Significant pH fluctuations in the biofilm on the tooth surface are a natural phenomenon, the result of which can be recorded in the tooth tissues only at the chemical or ultrastructural level (subclinical level) (Kidd & Fejerskov, 2004;Ivancaková, 2008;Kudiyirickal & Ivancaková, 2008;Bin-Jardan et al, 2023).…”

Management of Enamel White Spot Lesions

“…The first stage of enamel demineralization is characterized by removal of interprismatic mineral content and in the subsequent stages a well-defined surface layer formation occurs which constitutes early caries lesion. 2 The main types of enamel demineralization include incipient lesions and 'surface-softened defect' which are also some of the various terms that have been used to describe early caries lesions. It is important to differentiate incipient lesion from arrested lesions.…”

Remineralización del esmalte con casein fosfato

“…Es el tejido más duro, frágil y altamente mineralizado. Debido a su complejidad química y a su comportamiento biológico ha sido estudiado por numerosos investigadores (14). El problema a conocer es la importancia que tienen las estructuras del esmalte en relación a la susceptibilidad cariosa y establecer si las mismas corresponden a un factor constitutivo.…”