Deutsche zahnarztliche Zeitschrift最新文献

The opacity of 5 self-curing and 11 light-curing composite resins was measured 24 hours after sample/preparation and after 6 months of storage (dry or in water) by means of an UV-visible spectrophotometer. The opacity of the investigated hybrid composite resins was between 47.3 and 62.4%. The opacity of the microfilled composite resins ranged from 48 to 64.4%. The opacity was not influenced by the polymerization time. The spectral opacity decreased with greater wavelengths, particularly in microfilled composite resins. All materials except Durafill, which became more translucent, were more opaque after 180 days of storage in water. Storage in water for 180 days caused greater changes of the opacity than dry storage for the same time. The opacity changes resulting from storage in water can be reduced by increasing the polymerization time.

Compared with a step-by-step procedure, the one-step excavation of deep carious lesions in primary molars proved to be the treatment of choice in a clinically, microbiologically and histologically controlled trial. The stepwise method failed to produce any significant reduction in pulp exposure. Sensitivity assessment and percussion findings did not result in a reliable and unambiguous evaluation of treatment success. Histology showed inflammation-free pulps in 67% of the deciduous molars irrespective of the treatment method used. Microbiological examination revealed slightly softened dentin to be significantly more infected than clinically acceptable, hard dentin; although only 59.3% of the cavity floors were free of microorganisms. Chronic pulp inflammations were correlated with the presence of streptococci and lactobacilli, whereas actinomycetes were associated with inflammation-free pulps.

This in vitro study assessed the marginal behavior of the "Kulzer"-inlay using two different resin luting agents (Adhesive cement resp. Tulux-Cem). SEM-evaluation after combined mechanical and thermal loading revealed significant differences in the marginal seal of the inlays depending on the luting composite resin used. "Kulzer"-inlays luted with Adhesive cement showed of rate a excellent margins of more than 90% even after in vitro load application, while the rate of perfect margins were less than 80% for "Kulzer"-inlays inserted with Tulux-Cem.

The reproducibility of movement recordings obtained with the Condylocomp LR 2 was tested on three different types of articulator (Dentatus, SAM 2, Stuart). Additionally, reproducibility of TMJ movement recordings was tested on 18 subjects. Differences of +/- 2 degrees to the real angles, when working carefully, seem to be precise enough. The Condylocomp LR 2 seems to be a useful means for diagnosing and documenting TMJ movements, because it allows dynamic recordings with high resolution and correction of geometric errors.

Ceramic inlays have shown good marginal seal as long as the margins of the cavities are located in enamel. The purpose of this study was to investigate the marginal seal of ceramic inlays with the cervical margins situated in dentin and to determine the effectiveness of dentin bonding agents. Sintered ceramic inlays were adhesively luted either without dentin bonding agents or with the use of Gluma or Miragebond. After thermocycling and incubation in a colored dye the penetration depth of the dye was measured on sequential sections. The used dentin bonding agents did not improve marginal seal. The glass ionomer cement base was able to prevent further penetration in most of the cases when deep leakage occurred. Unless a tight marginal seal in dentin can be achieved, the indication for adhesively luted inlays must be limited to cavities with margins located in enamel.

Inhalation of mercury vapor is a potential hazard when handling dental amalgam. To prove the safety of modern capsule systems, we tested 21 brands of dental amalgam. Mercury vapor emission was measured at different stages during handling: a) immediately after opening of a capsule package, b) cumulative emission over 24 h of storage of an open package, c) during trituration and d) for different methods of waste capsule treatment. Highly significant differences between capsule types were found for the measured parameters. Disposable capsules that could be reassembled showed the most favorable results.

Individual controlled sedation using Midazolam proves to be a valuable addition to the range of therapeutic options for non-cooperative children. In a clinical study the oral and rectal routes of administration were compared with each other. Rectal application allowed considerably better dose adjustment. While the quality of sedation and the therapeutic range were equal with both routes, rectal application had the advantage that treatment can be commenced sooner. The sedation was of shorter duration and left the patient with less unpleasant memories. Rectal application was easier and required a smaller amount of Midazolam than oral administration.

200 pregnant women (group 1) attending a four-week cure in a home, 50 pregnant dental office patients (group 2), and 50 non-pregnant patients of the same age were included in this study. The preventive care program (information on oral hygiene, fluoridation and healthy nutrition, instructions and training) showed its greatest effect in the women of group 1, reflected in a reduction in OHI and GPM index and in an improved health awareness. All of the probands of group 1 who had planned during pregnancy to use fluoride tablets for their babies, put this plan into effect. In group 2 this percentage was only 46%. Pregnancy is a phase of increased motivational sensitivity and this should be exploited by doctors and dentists in terms of preventive programs for individuals and groups.

Our function-oriented SEM studies of various stages of wedge-shaped defects on permanent teeth have shown that wedge-shaped defects probably result from parafunctional force application. These dental hard tissue defects are characterized by marginal surface fractures, arch-shaped enamel tears and axial enamel rod fractures with formation of sagittal gaps. The enamel fractures indicate a dynamic process and do not appear to be the result of improper toothbrushing technique.

Butt joint, plain and round beveled MOD cavities were prepared in extracted human molars. Composite resin inlays (SR-Isosit) were fixed adhesively and analysed by quantitative SEM-evaluation after thermocycling and mechanical load application. The marginal adaptation of the inlays differed significantly depending on the type of cavosurface preparation. Best results with a high percentage of perfect margins not only before but also after in vitro load application were obtained with cavities prepared with rounded bevels.