Infective endocarditis caused by Veillonella of dental origin.

The purpose of this investigation was to examine whether Veillonella could cause transitory bacteriemia and endocarditis in both pure and mixed cultures when the port of entrance for infection was made in rats' incisors. Incisors of 54 male Zgr: whistar conventional rats were inoculated with pure culture of Veillonella (18 animals) and with mixed culture of S. mutans and Veillonella (18 animals). Remaining 18 incisors (the control group) were treated with saline solution. The animals were sacrificed after 7, 21 and 52 days respectively. Two positive hemocultures were obtained in mixed infection after 21 days of experimental procedure. Histopatological analysis of endocardial tissue revealed changes in 7 (12.96%) cases. Occurrence of acute endocarditis (one case) and chronical (four cases) ones depended on duration of mixed infections. For chronical endocarditis that appears in two animals with pure Veillonela culture we are at a loss of explanation. In conclusion, on the rats model Veillonella can penetrate into circulation in association with S. mutans via the pulp tissue and could be involved in infective endocarditis.

Trichomonas tenax proteolytic activity.

In this study, proteolytic activity of Trichomonas tenax collected directly from patient's dentobacterial plaque was examined. Electrophoretic method involving polyacrylamide gels (Commassie Brilliant Blue R-250) and electrophoretic method involving gelatin-containing polyacrylamide gels, have been used to analyse Trichomonas tenax proteolytic activity. The most obvious and the fastest activities were obtained when gels were incubated in pH 4.6; followed by results of incubating in pH 5.6; while in pH 2.8 activity was less effective but still obvious. Proteolytic activities were the most effective in area of protein MW 36 kDa. Different activities of enzymes depending on pH of incubated media indicate the presence of different endopeptidases in cell lysates of protozoon Trichomonas tenax from dentobacterial plaque.

Occupational tooth-wear in clothing industry workers.

A research on tooth-wear was done in a clothing factory, focusing on the teeth of the inter-canine sector in 59 workers who had volunteered for the research. The subjects were in the habit of cutting the thread with their teeth instead of using scissors as was prescribed in the production process. In 53 (89.83%) of the subjects, damages of the incisal portion of the tooth were found, whereas in the remaining 6 (10.17%) there were no such changes. No significant difference could be established in the incidence of tooth-wear between the women workers who cut the thread with their teeth constantly and those who only did that occasionally (p > 0.05). Because of the action of pulling a thread across the incisal edge of the incisor, defects--in the form of solitary, oval or multiple cuts (attributed the values 1, 2 and 3)--had been inflicted on the incisal portion of the teeth. Most frequently those were the defects of the enamel (type 2, 1), but in some cases dentin (type 3), also was affected. A somewhat more severe degree of damage was observed from workers biting the purely polyester-made thread (p < 0.05) than from biting the regular sewing type of thread. Education of the workers seems to be the only useful prevention, since we are dealing with only a bad habit. Therefore, the workers should be warned that the seemingly innocent cutting of thread with their teeth could lead to esthetic, functional and restorative problems.

Some anatomical and anthropological measures of mandibular ramus in our population.

Beside the already analysed bioanthropometric characteristics of the lower jaw, additional measurement of parameters insufficiently discussed in reference literature were performed in our study. On the basis of the obtained data it was possible to define relevant biometrical relations in the region of the lower jaw branch and anatomical regions that are especially important to the use of conduction anaesthesia. All measurements were defined on the basis of anteroposterior (horizontal) and vertical directions. The relation between different anatomical structures of the lower jaw interior branch and foramen mandibulae served as a focal point. When related to anteroposterior plane the mandibular foramen was located precisely in the middle of the distance between crista temporalis and posterior ramus ridge. Viewed in vertical direction the lowest point of mandibular opening was slightly closer to the mandibular angle than to incisure of mandible, meaning that in the majority of macerated skulls mandibular foramen had a relatively low position.