Effects of Zinc During Lactation on the Junctional Epithelium and Inserted Gum in Rats

Abstract

The purpose of this study was to evaluate the effects of zinc, during lactation, on the junctional epithelium and inserted gum of the first upper molar of rats. The study used one-day old male rats, divided into two groups: those whose mother had been treated with 300 mg zinc chloride (ZnCl 2) in the drinker water (treated group), and those whose mothers did not receive ZnCl 2 (control group). After 21 days, the rat pups were sacrificed. Using karyometrical techniques, the greater (D) and smaller (d) nuclear diameters of the different layers of the junctional and inserted gum epithelia were determined, and the mean geometric diameter, D/d ratio, perimeter, area, volume, volume/area ratio, eccentricity, shape coefficient, and the contour index were estimated. The 100-point Merz grid was used with the purpose of evaluating the citoplasmatic and celular volume, the nucleus/citoplasm relationship, number density, outer surface/ basal layer ratio, the thickness of epithelial layers, and the surface density. The results were submitted to statistical analysis using the Wilcoxon-Mann-Whitney test. The nuclei of the studied structures were significantly smaller, and the stereological results demonstrated that there were smaller cells, hence meaning a greater number of cells per mm 3 of tissue, in the treated group. Zinc caused changes on the studied epitheliums, according to morphometric and stereological evaluations.