Zahn-, Mund-, und Kieferheilkunde mit Zentralblatt最新文献

Compared to the normal micromorphologic features of the human periodontium typical histopathologic reaction patterns in different age groups and under various functional conditions, especially in older individuals, are described. It is, therefore, concluded that by characterizing large autoptic material of teeth exhibiting periodontitis, in old human subjects regenerative tissue responses aimed at infection defence are in principle more pronounced. Junctional epithelium attachment at the cement surface and even at dental calculus, active bone formation and reformation, and moderate apposition of cementum are decisive for the pathomorphological picture of marginal periodontitis also in very old human subjects.

A new three-dimensional method--speckle photography--introduced into stomatology. For judgement of occlusive and functional interests we examined 20 young adults (10 male and 10 female) aged from 21 to 25. The clinical results together with speckle-photographic model evaluations yield useful hints about morphological and functional connections in the orofacial system.

Nonprecious alloys (NEM) applied in dental practice often show widely differing material properties after casting. This is caused by subjective and objective differences in manufacturing of these alloys with a given technology as well as by varying composition and structure of the alloys within and in between different lots. For homogeneous composition of crude specimens technologically caused variance of casting condition itself leads to considerable differentiation of casting results. If the original state of crude alloy forms is very different then there will be a levelling out and/or increase of scattering of material parameters after casting. Optimized computed-controlled casting technology in combination with defined muffle ring size could result in reproducible casting results.

In 12 cases a systematical periodontal therapy involved surgical treatment (mod. Widman flap operation). 16 intrabony defects with more than 6 mm pocket depth measured at the beginning of periodontal therapy were filled with porous hydroxyl- (Interpore 200) as well as decalcified freeze dried bone grafts. For judgement of the therapeutic success plaque index, sulcus bleeding index, mobility of teeth treated by surgical methods, pocket depth, attachment level, and x-ray documentation were used before the operation and after 6 month maintenance therapy.

Loss of marginal alveolar bone of the tooth can be caused by periodontal, pulpal-periapical, or a combined pulpal and periodontal disease. The regeneration is supported by the formation of reattachment or new attachment. Reattachment is probably the usual healing process in periapical surgery of the tooth with apicomarginal bone loss caused by pulpal-periapical disease. In animal experiments (rats, dogs) ist was well documented, that the cells which repopulate the periodontal wound adjacent to the root surface determine the nature of the attachment formed.

The posteruptive maturation of enamel is an important factor in caries disposition. In an experimental study the demineralization of enamel as well as its permeability and its morphological features in dependence of eruption stage were examined on extracted premolars. Chemical analysis showed variations in the Ca/P molar ratio. It is possible, that the instability of Ca-ions in crystalline configuration decreased during the time of eruption. The permeability of enamel decreased between 5 and 11.8%. It appears to be useful to concentrate preventive measure on this phase of dentition development.

The investigation deals with earliest chemical changes in outermost enamel surfaces during initial caries development. After in vitro demineralization of enamel samples in acidulated hydroxyethylcellulose solution (pH = 5.1) for periods between 1 and 288 h the Ca/P molar ratios were determined in depths of 0.04 micron using the Rutherford Backscattering spectroscopy. The measured Ca/P ratios oscillate around the initial value. This behaviour is interpreted as a combined de/remineralization process.

In relation to the goals for oral health by the year 2000 a detailed territorial analysis of caries prevalence in 12 years-old children in performed. There from a prognosis of the future caries development in this age group considering regional conditions is given.