method for enamel separation and purification in large quantity by a modified bromoform floatation method

An improved bromoform floatation method which permits the separation of relatively large amounts of enamel from ground tooth crowns, in a short time has been developed. Clean tooth crowns were dried, crushed and centrifuged at 2000 rpm for 2 minutes repeated two, times in bromoform. Enamel deposits were separated. They were dull grey in color. Two washes with acetone plus three washes with water succeeded in minimizing the bromide content of the separated enamel to be comparable with the bromide content of mechanically separated enamel. After purification the enamel became slightly off-white in color. The yield of purified separated enamel was 34 percent from the powdered crowns

Ultrastructural study of surface morphology of cultured cells treated with sodium fluoride and formocresol

Cultured BHK21/C13 cells treated with different concentration of sodium fluoride and formocresol were studied with both light and scanning electron microscopy. Cells treated with sodium fluoride showed signs of hydropic degeneration, while formocresol treated cells demonstrated a type of coagulative necrosis. On the other hand cytotoxic changes in scanning electron microscopic morphology of treated cells correlated; to a great extent with the light microscopic findings

method for assessing the mesio distal width of maxillary and mandibular anterior teeth in a group of Egyptian population

The purpose of this study was to evaluate the correlation between the maxillary and mandibular anterior teeth in a group of Egyptian population with normal occlusion and Angle class I malocclusion and to describe an equation between the maxillary and mandibular anterior teeth which may help in localization of the intermaxillary tooth size discrepancy. The study group consisted of 100 individuals classified into 4 subgroups according to sex and type of occlusion. Using a sharply pointed Bolley gauge the maximum mesiodistal widths of the maxillary [I[1] +I[2] +C] and mandibular [I[1] +I[2] +C+ +bic[1]] were measured on the properly trimmed casts to the nearest 0.1 mm. A high correlation was detected between the sum of mesiodistal width of maxillary and mandibular anterior teeth among all the 4 groups. No statistical significant sex difference was detected in both the normal occlusion group and Angle Class 1 malocclusion group, whereas a significant statistical difference was found between the normal occlusion group and Angle Class I malocclusion in both sexes. The relation between the maxillary and mandibular anterior teeth will be defined as the difference between the anterior mesiodistal widths in the lower jaw [I[1] +I[2] +C +bic[1]] and the tooth widths in a corresponding segment in the upper jaw [I[1] +I[2] +C]. In the normal occlusion, the mean of the difference is 3.2 mm and stripping or reproximation of teeth may be done if the discrepancy is within 2-3 mm

Mesiodens and paramolar supernumerary teeth: histological observations and a prevalence study in Egyptian children

Sixteen mesiodens and paramolar teeth were collected from 14 children after examining 1080 Egyptian children. The prevalence of these supernumeraries in Egyptian children was found to be 1.296%. Light microscopic examination of their hard tissues was carried out. Numerous structural abnormalities were observed including: some variation in enamel thickness, multidirectional arrangement of enamel prism bundles at some sites, absence of amelodentinal junction and incremental lines of Retzuis at the incisal and the small cusp tip regions, interlacing of the inner ends of enamel prisms and the branching terminal ends of dentinal tubules at sites where A.D.J. is absent with numerous enamel spindles, observation of an outer surface layer of enamel having a honeycomb appearance on top of the longitudinally arranged enamel prisms in paramolar sections, numerous interglobular dentine spaces in the crown and sometimes in the root portions, sparce cellular cementum, presence of dark granules in acellular cementum in mesiodens, increased thickness of acellular cementum at the wide apical region of paramolar roots containing irregular large spaces, presence of hard structureless and clear network across paramolar pulp cavity, detection of an enamel-like mass containing longitudinally and transeversly sectioned enamel prisms and embedded in the crown dentine of some paramolar sections

Effect of different doses of zinc and copper on gingival tissues

The effect of zinc and copper ions on the gingival tissues were studied histologically. White rate were let to drink water contained zinc sulphate or copper sulphate each of 25, 50 and 100 ppm. Histological examinations of gingivial tissues revealed that zinc and copper sulphates at 100 ppm only, increased epithelial thickness, elongate rete pegs and affect lamina propria. Lower concentration, of each element caused no histologic change in rat gingival tissues