X‐ray microtomographic study of mineral distribution in enamel of mandibular rat incisors

Abstract

 X-ray microtomography was used to study the mineral concentrations in sequential slices of enamel of 5 mandibular incisors which showed an increase from " 1n0 to " 2n7 g cm V $ from the apex towards the incisal end. For points at the same distance from the apex, there were differences up to 0n6 g cm V $ between the teeth. The change of mean concentrations in the slices with distance could be modelled as (different) saturating exponentials. Under the assumption of a uniform growth rate of a mandibular incisor of 0n6 mm per day and a common time origin for the start of maturation (taken as a mineral concentration of 1 g cm V $), the distances were transformed to a common time frame to give a pooled data set. A single saturating exponential could be fitted to this pooled transformed data ; this was : C m l 2n84k1n94 exp (k0n18d ) where C m is the mean mineral concentration (g cm V $) and d the time (days) from the start of maturation. This gives an asymptotic concentration of 2n84 g cm V $ towards the incisal end, with a time constant of 7n7 days. The mineral concentration distribution functions were found to be more positively skewed closer to the apex, but more negatively skewed towards the incisal end. The difference between the higher mineral concentration in the outer enamel and the enamel near the amelodentinal junction (ADJ) was " 3 %. The direction of maximum increase in concentration from the outer enamel surface to the ADJ meets the boundary of the ADJ at " 80m. Three dimensional surface rendering of isodensity contours showed that the previously described C-shaped pattern of mineralisation is not solely a surface phenomenon, but extends through the depth of the enamel.

Characterisation of enamel white spot lesions using X-ray micro-tomography

“…Mineral density studies of enamel have been reported by other reliable methods employing LAC with the mass attenuation coefficient of HAP at the applied photon energy. 24,31,34,36 Our approach is shown to be a reliable alternative in addition to such studies.…”

Effects of CPP-ACP with sodium fluoride on inhibition of bovine enamel demineralization: A quantitative assessment using micro-computed tomography

“…[12][13][14] The technique is also a promising method to assess demineralization or remineralization in enamel or dentine. [15][16][17][18][19] Micro-CT systems are mainly classified into two types; synchrotron radiation micro-CT that can produce parallel monochromatic X-ray beams, 20 and commercial or desktop micro-CT that can produce polychromatic X-rays. 18 Where the polychromatic X-ray source is used, quantitative determination of mineral density requires correction of beam-hardening artifacts, especially in high mineral density tissues such as enamel.…”

Mineral distribution in highly fluorotic and in normal teeth: A synchrotron microcomputer tomographic study

“…The tooth formation in mice was studied by Ravosa et al [19]. Rat incisors were studied by Wong et al with a special emphasis on the dentin-enamel junction [20]. Developing human molars were studied by Avishai et al [21].…”