Deutsche Stomatologie (Berlin, Germany : 1990)最新文献

Measurements of the mandible's movements which take its six degrees of freedom into account show that the conventional concept of a condylar hinge axis does not hold: on principle the structure of motion of the condylar hinge axis is not different from that of the incisal edge. The spaces of movement which are related to the condylar hinge axis and the incisal edge are factually enforced by a hinge axis of the neuromuscular system. This neuromuscular hinge axis cannot directly be related to anatomical structures although in the sagittal-vertical plane it reduces the number of the degrees of freedom from three to two.

In 1987, 12 years after fluoridation of drinking water, caries prevalence of Prague school-children is very low, and the goals of WHO have already been reached and undercut. Children from Rostock, where no fluoridation of drinking water was introduced, have an unchanged high caries experience in 1985. Degree of treatment and percentage of successfully treated children show only little differences in both towns. These results emphasize the demand for an introduction and/or a continuation of an effective caries prevention in children once more.

23% of a nonselected group of patients showed wedge shaped defects (9-10 of them per person). The number of teeth with these cervical erosions increases with age. Small accumulation of plaque was found. 65% of the patients with wedge shaped defects had parafunctions and 70% had a chronic pain. A complex of causes underlies the wedge shaped defects. A causal relation appears to exist between wedge shaped defects, occlusal disharmony, parafunctions and strong psychological tension of patients.

Using oral plaque-pH-telemetry the cariogenic potential of a sucrose-solution (10%), a sorbitol-solution (10%), of a roll with honey, a roll with jam together with sweetened coffee and the "Milchschnitte" has been examined. All sugar containing products cause a deep pH-drop in dental plaque. The duration of demineralization (time of plaque-pH below 5.5)-amounts to 75 min. after mouthrinsing with sucrose-solution, 80 min. after consuming a half roll with honey, 140 min. after eating a roll with jam and drinking sweetened coffee and 82 min. after consuming a "Milchschnitte". All these products shouldn't be used as in-between-meals or snacks without a consequent oral hygiene afterwards.

Under practice-related conditions 100 human molars and premolars were prepared with diamond grinding instruments of different grit. We obtained the smoothest surfaces by using the extra-fine grit at 250,000 rpm, thus indicating the suitability of these instruments for finishing cavity walls especially at high rotating speeds. Only slight differences were found between medium and coarse grit. The time saved by choosing the super-coarse grit for preparation is largely compensated because finishing of rough cavity walls will take longer. No constant effect of the rotating speeds on the depth of roughness of cavity walls was observed.

Fifty-one highly disabled inhabitants of a Hessian rest- and nursing home (on an average age of 83 years) have been interviewed and examined with respect to the dental conditions, the need for dental treatment as well as their dental hygienics. The averaged dental status was poor. Most of the senior probands did not have any teeth, all the others would have needed dental treatment because of caries and periodontal disease. None of the inhabitants had fixed partials; the existing removable dentures--mostly worn during the day--showed functional defects. There were no major differences between those persons, who cleaned their partials their own, and those one's, who needed the help of the home's staff.

The fluoride accumulation on the surface enamel of primary incisive using a low dosed fluoridated dentifrice (0.085% F) was determined in vivo in comparison with a placebo dentifrice within a longitudinal study. After 12 months supervised brushing the superior incisive of the preschool children used the fluoridated dentifrice show a fluoride concentration of 609 ppm, after 20 months 612 ppm fluoride. The fluoride concentration of the surface enamel of the placebo group was 380 (after 12 months) and 385 ppm fluoride (after 20 months). Presume the optimal caries prevention should not reach by only using the low dosed fluoridated dentifrice.

The level of interleukin 1 in gingival fluid is determined in 17 volunteers with healthy gingiva and in 58 patients with gingivitis of different severity. Continously increased levels of local IL 1 are found in connection with increased plaque accumulation in the dentogingival sites and with exacerbating gingival inflammation. The relevance of IL 1 in gingival fluid as a sensitive indicator of plaque-associated gingivitis is discussed.

In an experimental study could be shown, that in corrosion investigations by help of the anodic polarization the sensity of the measurement of amperage is important. Testing alloy-systems like Remanium CS, which show passivation on a higher resting potential, mistakes in valuation of the corrosion behaviour by registration in a range of 10-50 muA/cm are possible.

In a prospective, randomized study it was researched whether epinephrine-free Articain 2%-solution is suitable for dental surgery. The estimated local anesthetic effect was subjective considering a dental operation an in comparison with the usual Articain 4% solution with an epinephrine addition of 1:200,000 (Ultracain D-S). The local anesthetic effect of the 2% solution was clearly lower than that of the 4% solution. However, in many cases even the lower doses of the 2% solution was sufficient for dental treatment including surgery. The higher efficiency of the 4% solution is more a result of a higher concentration than of anesthesia. In principle, the epinephrine-free 2% Articain solution is suitable for dental surgery, although, due to a shorter anesthetic duration and an unsure effect additional injections have to be given more often.