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 (ZnCl2) in the drinker water (treated group), and those whose mothers did not receive ZnCl2 (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 mm3 of tissue, in the treated group. Zinc caused changes on the studied epitheliums, according to morphometric and stereological evaluations.
El objetivo de este estudio fue evaluar los efectos del zinc durante la lactancia, sobre el epitelio de unión y la encía insertada del primer molar superior de ratas. Fueron utilizadas ratas macho de un día de edad, divididas en dos grupos: aquellas cuyas madres habían sido tratadas con 300 mg de cloruro de zinc (ZnCl2) con agua del bebedero (grupo tratado) y aquellas cuyas madres no recibieron ZnCl2 (grupo control). Las crías fueron sacrificadas después de 21 días. Utilizando técnicas cariométricas fueron medidos los diámetros mayor (D) y menor (d) de los núcleos de las células de los diferentes estratos del epitelio de unión y de la encía insertada, estimándose el diámetro geométrico medio, la relación D/d, perímetro, área, volumen, relación volumen/área, excentricidad, coeficiente de forma e índice de contorno. Fue usada la rejilla de Merz, de 100 puntos, con la finalidad de evaluar el volumen celular y citoplasmático, la relación núcleo/citoplasma, densidad numérica, relación superficie externa/superficie basal, espesor de las capas epiteliales y densidad de superficie. Los resultados fueron sometidos a análisis estadístico mediante el test de Wilcoxon-Mann-Whitney. En el grupo tratado los núcleos celulares de las estructuras estudiadas fueron significativamente menores y los resultados estereológicos demostraron que las células eran menores, por lo tanto, con mayor número por mm3 de tejido. De acuerdo a los resultados morfométricos y estereológicos, el zinc provocó cambios en los epitelios estudiados.
Subject(s)
Animals , Male , Female , Rats , Zinc/pharmacology , Lactation , Epithelial Attachment/drug effects , Gingiva/drug effects , Rats, WistarABSTRACT
This crossover study aimed to compare plaque removal efficiency of two manual toothbrushes with identical design, the exception being the pattern of bristle arrangement. Twenty-six subjects were selected following inclusion and exclusion criteria. Dental plaque was scored before and after seven days of use of each toothbrush (Sanifill Smooth® T1 andSanifill Active Smooth® T2) employing the Turesky Plaque Index. Plaque Index values were handled with parametrical statistics employing Analysis of Variance (p<0.05) and, later, the Tukey Test. At the end of the trial, each subject was asked which toothbrush they preferred. Results: plaque scores for toothbrush T1 were not statistically different from those for toothbrush T2. Subjects showed a distinct preference for toothbrush T1. Conclusion: there was no differencein terms of plaque removal when toothbrushes T1 and T2 were compared, although patients showed a higher preference for toothbrush T1. Thus the different toothbrushes bristles arrangements did not influence the dental plaque removal.
Este estudo cruzado se propôs a comparar a eficiência de remoção de placa dental de duas escovas manuais com modelos idênticos, exceto para o padrão da disposição das cerdas. Vinte e seis sujeitos foram selecionados de acordo com critérios de inclusão e exclusão. Placa dental foi mensurada antes e após sete dias de uso com cada uma das escovas (Sanifill Smooth® T1 and Sanifill Active Smooth® T2) utilizando-se o Índice de Placa de Turesky. No final do estudo, cada paciente foi questionado sobre qual a escova preferida. Os valores do Índice de Placa para T1 não foram estatisticamente diferentes para os da escova T2. Não houve diferença em termos de remoção de placa quando as escovas T1 e T2 foram comparadas, embora os pacientes tenham demonstrado grande preferência pela escova T1. Assim, as diferenças nas disposições das cerdas das escovas dentais manuais não influenciaram na remoção de placa dental.