Article

Morphological evaluation of rat incisor enamel and dentin induced by pregnancy and lactation using a scanning electron microscope.

Department of Oral Diagnosis, School of Dentistry, Hacettepe University Sihhiye, Ankara, Turkey.
Journal of Veterinary Medical Science (impact factor: 0.85). 10/2009; 71(10):1273-7. pp.1273-7
Source: PubMed

ABSTRACT This study assessed the effects of pregnancy and lactation on the morphology of the dentine tubules and external enamel surface of rat incisor teeth using a scanning electron microscope (SEM) equipped with an energy dispersive x-ray (EDX) system. Twenty-four female Wistar rats were divided into three groups; group A rats were at the end of pregnancy, group B rats were in the post-lactation period and group C rats, the control group, were unmated. The outer enamel surface and openings of the dentine tubules at the neck regions of the incisors were observed under the SEM and photographed. Examination of the incisor teeth of pregnant and post-lactation rats revealed scratches on the enamel surface. There were few eroded areas and slight changes and the dentine tubules of the pregnant group were fully or partially occluded on the entire surface of the enamel in the lactating rats. Almost all dentine tubules of the rats in this group were open. During the study, EDX analysis of calcium, phosphate and magnesium was also performed at 20 kV and 0 degree tilt. The results of EDX analyses of magnesium were significantly lower in the pregnant group compared with the lactation and control groups for the dentine in the neck region (p<0.05). The calcium values increased in the lactation group compared with those of the rats in the other two groups (p<0.05). These results might indicate that changes during pregnancy and lactation affect the content and morphology of mineralized dental hard tissue.

0 0
 · 
0 Bookmarks
 · 
23 Views
  • Source
    Article: Can dental microwear textures record inter-individual dietary variations?
    Gildas Merceron, Gilles Escarguel, Jean-Marc Angibault, Hélène Verheyden-Tixier
    [show abstract] [hide abstract]
    ABSTRACT: Dental microwear analyses are commonly used to deduce the diet of extinct mammals. Conventional methods rely on the user identifying features within a 2D image. However, recent interdisciplinary research has lead to the development of an advanced methodology that is free of observer error, based on the automated quantification of 3D surfaces by combining confocal microscopy with scale-sensitive fractal analysis. This method has already proved to be very efficient in detecting dietary differences between species. Focusing on a finer, intra-specific scale of analysis, the aim of this study is to test this method's ability to track such differences between individuals from a single population. For the purposes of this study, the 3D molar microwear of 78 individuals from a well-known population of extant roe deer (Capreolus caprelous) is quantified. Multivariate statistical analyses indicate significant seasonal and sexual differences in individual dental microwear design. These are probably the consequence of seasonal variations in fruit, seed and leaf availability, as well as differences in feeding preference between males and females due to distinct energy requirements during periods of rutting, gestation or giving birth. Nevertheless, further investigations using two-block Partial Least-Squares analysis show no strong relationship between individual stomach contents and microwear texture. This is an expected result, assuming that stomach contents are composed of food items ingested during the last few hours whereas dental microwear texture records the physical properties of items eaten over periods of days or weeks. Microwear 3D scale-sensitive fractal analysis does detect differences in diet ranging from the inter-feeding styles scale to the intra-population between-season and between-sex scales. It is therefore a possible tool, to be used with caution, in the further exploration of the feeding biology and ecology of extinct mammals.
    PLoS ONE 01/2010; 5(3):e9542. · 4.09 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

0 degree tilt
 
control groups
 
EDX analyses
 
EDX analysis
 
enamel surface
 
energy dispersive x-ray
 
entire surface
 
external enamel surface
 
female Wistar rats
 
group B rats
 
group C rats
 
lactating rats
 
mineralized dental
 
neck region
 
outer enamel surface
 
post-lactation period
 
post-lactation rats
 
rat incisor teeth
 
scanning electron microscope
 
two groups