Deutsche zahnarztliche Zeitschrift最新文献

Electric current produced by corrosion of metals or used for diagnostic or therapeutic purposes has to pass through the dentin to reach the pulp. The electric resistance of the dentin, which influences the dentinal current intensity, is poorly documented in the literature. In this study 140 cylindrical dentin samples of human teeth were collected from four different regions of the tooth crown and their specific electrical resistance was measured. The recorded values vary with the orientation of the dentinal tubules ranging between 12.5 ohms and ohms. The linear temperature coefficient of the specific resistance is -0.0132 degrees C-1 for the temperature interval of 20 to 34 degrees C. It is assumed that the mechanism underlying electric conduction in dentin is related to the transport of ions in the dentinal fluid.

In a long-term study the effect of glycerol and phenol-glycerol on rats mandibular nerve was analysed. The substances were applicated perineurally. Nerves treated with glycerol did not show any severe pathological changes. Only the number of desintegrations of myelin seemed to be more pronounced. This, however, was a transitary effect. On the contrary, nerves treated with phenol-glycerol showed the familiar picture of degeneration and regeneration. According to our results it can be stated that the perineural application of glycerol has no toxic and destructive effect on the nerve. Therefore, the perineural glycerol blocking will not cause severe side-effects and the method can be recommended in the therapy of chronic facial pain.

In a prospective, randomised double blind study we recorded the rate of complications in dental anesthesia in more than 1500 patients using 4 commonly known anesthetic solutions. 228 of our patients (18.3%) noted headaches postoperatively. Furtheron we found syncopes, failures of anesthesia and nausea. Double vision was noticed once intraoperatively (Articain) and postoperatively (Lidocain). We found a high standard of security in dental local anaesthesia.

The marginal adaptation of six composites and one resin based inlay system was investigated. For all fillings maximum stress increased with time. Three days after insertion maximum stress increased up to more than 450 N for almost all fillings.

The influence of different local anesthetic fluids in an in-vitro-experiment of periodontal ligament cells was researched. Mepivacain, articain, lidocain and prilocain were used in the study. The common commercial local anesthetic fluids were in a proportion 1:1, 1:10 and 1:30 diluted, before they were placed in the incubator with cultures of periodontal ligament cells. At the 1st and 14th day after the experiment the synthesis of collagen type I, III, V and VI were determined with an ELISA. The mepivacain dilution of 1:30 had, compared with the controls the slightest influence on the collagen synthesis of periodontal ligament cells. Further clinical investigations must show if through dilution of the local anesthetic solution an adequate anesthesia can be reached.

During the past ten years diagnostic ultrasound has dramatically changed obstetric approaches. Improvements in instrumentation have made it possible to identify an increasing number of fetal anatomical structures. Ultrasonography of the fetal face has become important for the detection of major syndromal malformations or chromosomal disorders. In cases with a family history of cleft lip and palate ultrasound can confirm or exclude the diagnosis. Associated anomalies have to be ruled out when cleft lip is present. Positive findings have different obstetrical implications.

In an experimental study on animals the correlation between the pressure created by periodontal ligament injection and the distribution pattern of the anesthetic solution was examined. It was possible to demonstrate the penetration following intraligamental injection by scintiscanning of the mandibular bone. A correlation between pressure and distribution could not be established.

In our study we could discover typical images when measuring patients undergoing dental surgery by pulse oxymetry. Thereby it seems possible to estimate the operative risk and get some better information beyond clinical examination (ASA-classification). The not being well of the patient could be detected this way earlier then by clinical signs. We have to support the fact that dental treatment in local anaesthesia should be limited to 30 min. The monitoring of pulse, mean artery pressure and oxygen saturation could be made more informative by sampling dates for up to 300 sec and displaying them on a monitor. This seems to be very helpful while treating patients with higher risk in the dentist's practice.

In this study the effectiveness of the periodontal ligament injection was tested in rats. Anesthetic solutions with carbon dye were injected into the crestal periodontal ligament space under back-pressure. Vital microscopic observations showed that the solution spreads via an intraosseous path into the vessels of the pulp. These results support the contention that the periodontal ligament injection is intravascular in nature. Therefore, possible cardiovascular responses to periodontal ligament injections containing catecholamines must be considered.

Thirty-four children with chronic renal failure were examined to evaluate the character and frequency of radiographic changes in the jawbones as related to radiographic abnormalities in other skeletal regions and laboratory data. Twenty-seven children showed signs of renal osteodystrophy on the roentgenograms. Radiographic changes in the jawbones including alterations of the laminae durae were observed in twenty-three children. Total loss of laminae durae was only seen in connection with other skeletal signs of renal osteodystrophy. In all these cases the serum parathyroid hormone (iPTH-C) and alkaline phosphatase levels were remarkably increased so that even in the uremic child total absence of laminae durae cannot be considered a first symptom of renal osteodystrophy. However, radiographic changes in the jawbones are important signs for early detection of renal insufficiency in childhood, as these symptomes appeared with similar frequency as pathologic changes in other skeletal regions and were already present in stage of preterminal renal insufficiency.