Structural Aspects of Dental Caries

Mirocrystal Arrangement in Human Deciduous Dental Enamel Studied by Electron Paramagnetic Resonance

“…The low degree of microcrystal arrangement in deciduous teeth means a higher degree of disorder in the enamel structure. The abrupt increase of disorder in microcrystal alignment has been observed [Hamilton et al, 1973;Scott et al, 1974] in the interprismatic space. Since we know that the interprismatic space represents the main chan nel for diffusion of molecules and for the advance of the caries process [Fosdick, 1963;Linden, 1968;Keckaert, 1973], we can assume that the low degree of micro crystal arrangement in deciduous teeth en amel means greater porosity and a larger number of transport pathways in enamel of deciduous teeth, as predicted by Morti mer [1970],…”

Structure of the So-Called ‘Prismless’ Enamel in Human Deciduous Teeth

“…Indeed, Whittaker [1982] noted the term aprismatic enamel might not mean that prisms were totally absent but the term was a con venient one for descriptive purposes. Furthermore, Shiota et al [1963] and Scott et al [1974] showed a transmission or scanning electron micrograph of an aprismatic area contaminated with several arcadeshaped prisms.…”

“…The same structures as the well-founded photo micrograph used for the description by Horsted et al [1976], however, had already been seen in the polariz ing microscopic investigations by Terasaki and Shiota [1957], and Schmidt and Keil [1971], Terasaki and Shiota [1957] noted an arrangement of indistinct prism-like structures that was, in some cases, ob served in a surface layer where prism structures could not be seen by ordinary light. Certainly, Scott et al [1974] illustrated a scanning electron micrograph of the prismless enamel in acid-etched human enamel parallel and close to the surface where some prisms were seen. Whittaker [1982], who examined polished and etched sections of human enamel by scanning electron microscopy, reported an aprismatic zone containing indistinct prism boundaries.…”

A Scanning Electron Microscopic Study of Progressive Stages of Enamel Caries in vivo

“…Light mi croscopic examination gave rise to the the ory that the carious attack enters the enamel along the striae of Retzius [Darl ing, 1958]. Ultrastructural studies con ducted later were not able to confirm Darl ing 's [1958] hypothesis, but suggested that structural configurations at the prismatic level represented major potential path ways for diffusion [Frank and Brendel, 1966;Johnson, 1967;Mortimer and Tran ter, 1971;Scott et al, 1974;Jongehloed et al, 1975a, b;Haikelel al., 1983;Theuns et al, 1982;Ingram and Fejerskov, 1984], Some workers using the transmission electron microscope also noted that carious destruction may not be as dependent on the structural detail of the tissue as previously believed [Johnson, 1967]; and that carious invasion is, in ad dition to larger pathways, able to follow narrow lanes, such as intercrystalline spaces [Frank and Brendel, 1966]. Ultrastructural studies aimed at the effect of acids on individual enamel crystals have focussed mainly on the role of disloca tions [Daculsi and Kerehel, 1977], with particular emphasis on the preferential central dissolution of individual crystals [Johnson, 1967;Simmelink et al, 1974;Jongehloed et al, 1975a, b;Arends and Jongehloed, 1977;Voegel and Frank, 1977].…”