Ação antimicrobiana de medicações intracanal sobre dentina infectada de dentes decíduos e permanentes

Objetivo: o objetivo deste estudo foi avaliar a efetividade antimicrobiana de medicações intracanal em dentina infectada de dentes decíduos e permanentes. Métodos:blocos de dentina foram inoculados com Enterococcus faecalis a cada 72 horas durante 60 dias; após, foram irrigados,secos e completamente preenchidos com uma das misturas a seguir: 1) pó de hidróxido de cálcio, própolis e propilenoglicol, 2) pó de hidróxido de cálcio e propilenoglicol,3) pó de hidróxido de cálcio e água destilada,4) própolis e propilenoglicol, 5) própolis e água destilada.Após 30 dias, as amostras foram lavadas com água destilada esterilizada, imersas em Letheen broth e incubadas por 48 horas a 37ºC. Resultados e Conclusão: a hipótese de que a associação do hidróxido de cálcio com própolis poderia ser mais eficaz do que os outros medicamentos não foi confirmada, pois os resultados indicaram que todas as misturas testadas não foram capazes de inibir o biofilme de E. faecalis, tanto nos blocos de dentina de dentes decíduos como permanentes

Structure and microstructure of coronary dentin in non-erupted human deciduous incisor teeth

The dentin structure of non-erupted human deciduous mandibular and maxillary central and lateral incisor teeth was studied employing light and scanning electron microscopy. For light microscopy, nitric-acid-demineralized and ground sections were used. The sections were stained by hematoxylin-eosin, picrosirius and azo-carmim methods, and ground specimens were prepared using a carborundum disk mounted in a handpiece. For SEM study, teeth were frozen in liquid nitrogen and fractured at longitudinal and transversal directions. Structurally, demineralization and ground methods revealed tubules with primary and secondary curvatures, canaliculi, giant tubules, interglobular dentin, predentin, and intertubular dentin. Scanning electron microscopy showed three-dimensional aspects of dentinal tubules, canaliculi, peritubular dentin, intertubular dentin, and predentin. This study contributes to knowledge about dentin morphology showing characteristics of teeth not yet submitted to mastication stress

A sem study of prismless enamel in non-erupted human deciduos teeth

The frequency, structure, and thickness of the prismless enamel layer in the bucal and lingual surfaces of nonerupted anterior deciduous teeth were described. The samples were fixed in a modified Karnovsky solution, longitudinally fractured in liquid nitrogen and observed by scanning electron microscopy. The aprismatic area was observed in the incisal and perpendicular to the enamel outer surface. Some depressions were observed on the enamel surface. The statistical analysis showed no significant differences related to prismless enamel thickness among upper and lower central incisors, lateral incisors and canines, which varied from 4,19 to 5.15um.