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

The remineralization process in the oral environment is the presumption of enamel structural integrity and function. Strong or frequent acid attacks may be followed by pathological alterations. Remineralization of human enamel after phosphoric acid demineralization was investigated. 4 subjects were selected for in-vivo experiments using specialized oral applicators with 52 etched enamel specimen, incorporated for 10 or 28 days and 59 probes remineralized in a synthetic mineral solution over the same period. Mineral deposition and rehardening took place. After 28 days the reparation of acid defects was incomplete. The in-vitro remineralization is less pronounced and does not reflect the complex remineralization mechanism in vivo.

The effectiveness of hand preparation and irrigation of 48 root canals of upper anterior teeth was evaluated by scanning electron microscopy. Independently of instrument (K reamer or combination K reamer and H file), irrigating solution (sodium chloride) and root canal dressing a similar degree of preparing and cleaning effectiveness of root canals was detected. In all groups a homogeneous or inhomogeneous smear layer of different thickness and extent dominated. A scale of preparing and cleaning effectiveness is recommended.

Based upon the present prevalence of root caries an attempt is taken to evaluate the future importance of this carious type. A population sample of 2,261 men and women aged 35 to 74 years were examined. The participation rate was 81%. Root caries was recorded when the lesion was obviously soft and located on cementum. The prevalence of root caries increased for both sexes almost consistently with age and ranged between 49 and 73%. In the mean 1.8 to 2.9 teeth were affected. Root caries was found more often among men than women. Over the sixth decades the reduction of the relative frequency of root caries was stated. Up to this age the rates of tooth extraction were higher than the rates of incidence. If it succeeded that in the future aged people will retain more teeth than nowadays a increase of root caries can be expected.

The glass ceramic "BIOVERIT" is characterised by biocompatibility, bioactivity and distinguished machinable treatment. The single casting in an especially dental technical laboratory pender is possible the individual production of dental implants. Described were the development of the form, the production and operation for these glass ceramic implants and first clinical results.

The surface of wedge shaped defects of 51 extracted teeth was examined with the scanning electron microscope. To study morphology of surfaces of 12 defects in vivo a replication technique was carried out. It was shown that there is a relation between the morphological features and the clinical symptoms. In the progression of the defects there are active and passive phases, what will be reflected on the one side in the clinical symptoms and on the other side in the morphological features.

The absolute values of polymerization shrinkage and its time-dependent course were measured for commercially available composite resins and for composite still under development using a new method measuring the linear shrinkage. The influences of the amounts and of the recipes of the reactive monomer were determined. From the curves the working times of the investigated composite resins were evaluated.

Tissues from squamous cell carcinomas of the oral cavity of 20 patients were transplanted beneath the capsule of the kidney of normal immunocompetent mice (SRCA). The xenografts of all tumors of the control group of animals without chemotherapy show an increasing tumor mass following a 6-day-test-period using a method of measurement given by Bogden et al. (1978). There were different changes of tumor diameters following the application of various antineoplastic drugs. Tumor proliferation however is not reason for these changes. There are reactions of graft's rejection which play an important part in the measured data. The only interpretation of the diameters of the xenografts using the 6-day-SRCA in normal immunocompetent mice cannot be recommended as a criterion in this predictive test.

Clinical diagnostic information was analysed and compared with conventional x-ray and B-scan examination in 90 patients with maxillary sinus diseases of dental origin. In certain diseases (sinusitis, cysts) the ultrasonic sonography offered little additional clinical-relevant information. On the other hand this modern noninvasive, picture yielding and ever reproducible method is predestined for objective confirmation of the late complaint after maxillary sinus operation. But the high apparatus technical investment limits its application in large scale.

Epithelium changes caused by wearing of tissue-borne prosthesis were established on the basis of tissue specimens, taken away from the palate of 22 corpses with own teeth and 18 edentulous corpses with removable prosthesis. The epithelium height of the denture supporting area was reduced especially in the lateral and ventral cuts. The papillary body was significantly reduced.