PubMed Health⌕ Search

Biomedical subjects

P Karl

Publications and source records attributed to P Karl.

At least 19 recordsLinked to original sources
PubMed2003

Marginal adaptation and fracture resistance of adhesively luted glass fibre-composite reinforced molar crowns with different inner crown surfaces.

OBJECTIVES: This study compared the influence of different inner crown surfaces on the fracture resistance and marginal adaptation of adhesively fixed glass fibre-reinforced molar crowns. MATERIALS AND METHODS: Vectris/Targis crowns were constructed with an inner framework of glass fibres (directly on the tooth) or an inner veneering composite layer between the fibre-framework and the tooth-substance. Both groups were sandblasted inside using Al(2)O(3); 50 microm grain size (200 kPa, 20 s) and silane coated. A control group had the inner fibre framework, but was neither sandblasted nor silane coated. The crowns were adhesively cemented on extracted human teeth, and thermally cycled and mechanically loaded (TCML: 6000 x 5 degrees C/55 degrees C; 1.2 x 10(6) x 50 N, 1.66 Hz). The marginal adaptation before and after TCML was evaluated and the fracture resistance was investigated using a Zwick universal testing machine. RESULTS: After TCML the proportion of 'perfect margin' of the control group decreased significantly at the interface crown/cement. For the variations with an inner fibre framework or inner composite layer the marginal adaptation or fracture resistance did not decrease significantly after ageing. The fracture resistance values were control: 1509N+/-486; inner fibre framework: 1896N+/-342; inner composite layer: 1754N+/-340. CONCLUSIONS: In the case of the investigated fibre framework and veneering composite, the inner surface of glass fibre-reinforced molar crowns can be covered with a composite layer or with a glass fibre framework. Both methods achieve comparable high fracture strengths and reliable marginal adaptation.

Aluminum Oxide↗
PubMed2000

[Professional profile of the established oromaxillofacial surgeon].

To qualify for further specialist training as a maxillofacial surgeon, a licence to practice in general medicine as well as a licence to practice in dentistry must be obtained beforehand. In addition to the 4-year course to qualify, maxillofacial surgeons can gain the additional qualification in the field of "plastic surgery" in a further course lasting 3 years. By the end of 1998, there were 698 maxillofacial surgeons in private practices in Germany in comparison to 322 hospital-employed maxillofacial surgeons. Of the work done by maxillofacial surgeons (in private practices), 28% is in contracted hospitals; this percentage is relatively high in comparison to other disciplines in which private specialists use contracted hospitals. It is impossible these days for an individual specialist to completely cover all areas of maxillofacial surgery. In our field, joint practices with an internal specialization will increase the spectrum and quality of treatment in the future and will counteract competition from hospital-employed specialists now that day-case surgery has been introduced in these hospitals. Further training by the individual will remain an indispensable necessity as well as personal involvement by every maxillofacial surgeon in the postgraduate medical training of doctors and dentists. This can only be achieved if the economic situation of specialists is maintained in health-politics.

Curriculum↗
PubMed1979

[Antibacterial effect of Ankerplast Spray].

The diffusion test yielded no satisfactory results. In the tube test, both the spray and the solvent (in a dilution of 1:4 and 1:8, respectively) proved to be bacteriostatically active against enterococci, Staphylococcus aureus, Escheria coli, Proteus, and Pseudomonas aeruginosa. These germs were killed within 30 minutes in the test for bactericidal activity, whereas the reference substance (1% phenol) required 1--2 hours, except against the last-named germ. Even the copolymer exerted a bactericidal effect, it is true, but only within 8 or 24 hours. The following results were obtained from the spray test with agar plate cultures: Streptococcus viridans species, streptococci, Diplococcus pneumoniae, Escheria coli, and Proteus were killed, whereas others survived under the plastic film for up to 9 days. Klebsiella and Pseudomonas aeruginosa had grown through the film within 7 days. In vivo experiments demonstrated a very potent antibacterial activity on the skin under the spray film.

Acetates↗
PubMed1979

[Experimental microsurgery of blood vessels and nerves in laboratory animals and their importance for plastic surgery].

The authors give a survey of the suitability and use of different laboratory animals in the transplantation with microvascular and microneurovascular anastomoses of island flaps, muscles and composite grafts as musculo-cutaneous and osteo-musculo-cutaneous ones. This report includes the rat, rabbit, dog and pig. Preferable for learning and training suture techniques of microvessels and nerves are rats. Quite suitable in experimental research is the "epigastric" flap of rats and rabbits. Transplantations of muscles and composite grafts as musculo-cutaneous and osteo-musculo-cutaneous ones, with microvascular and microneurovascular anastomoses have been performed mostly in dogs. In order to find out suitable donor sites for microvascular and microneurovascular free flap transplantation the pig is used, showing a pattern of skin vessels most similar to that of man. But only few laboratories might be able to carry out experiments in pigs.

Animals↗
PubMed1978

[Free skin-adipose tissue flap transplantation in rats].

An important precondition for the clinical application of the free flap transplantation with microvascular anastomoses is the training in the animal experiment. With some fundamental anatomical observations concerning the vessels of the skin and types of flaps the suitability of different laboratory animals is demonstrated. The technique of the free composite flap transplantation utilizing the abdominal flap of the rat is described. This flap model is not only suitable for test the success of the microvascular suture, but is also useful in cases of special pharmacological, pathological and physiological problems of the free flap transplantation.

Abdomen↗
PubMed1977

[The technic of microvascular anastomoses: the rat as a model].

During the last few years microvascular surgery has assumed an increasingly important role in the modern plastic surgery. For persons still learning without much experience a step by step training program for learning end-to-end anastomosis in very small vessels is recommended. The technique of microvascular suture is described using the Arteria and Vena femoralis of the rat.

Animals↗
PubMed1976

[Resistance to chemotherapy of aerobic bacteria from nonspecific odontogenic infections].

Germs in patients suffering from nonspecific odontogenous infections described in a previous paper were analysed with regard to their resistance to chemotherapy (1964 to 1971). At the same time it was discovered that in the bacteria groups: staphyloccocus aureus, streptococci and pneumococci and enterobacteriaceae plus pseudomonas (344 strains) their sensitivity to penicillin, streptomycin, chloramphenicol, oxytetracyclin, erythromycin, polymyxin B and nifurantin varied in several and significant ways. Significant changes were established in the resistance of staphylococcus aureus to all the potentially effective antibiotics, while from 1969 to 1971 the strains with the least resistance appeared. In the 1970 to 1971 period strepto- and pneumococci showed insensitivity to penicillin and streptomycin more frequently than before. From 1969 to 1971 entero-bacteriaceae and pseudomonas also showed evidence of increasing loss of sensitivity to chloramphenicol and oxytetracyclin, whereas the frequency of strains resistant to polymyxin B and nifurantine diminished. The findings are being discussed.

Anti-Bacterial Agents↗
PubMed1976

[Bacteriological findings in materials from patients with nonspecific odontogenic infections].

The results of bacteriological studies made between 1964 and 1971 by workers at the Varia Laboratory, Institute of Medical Microbiology on 767 patients treated at the Clinic of Gnathofacial Surgery, Department of Medicine, Friedrich Schiller University at Jena, are evaluated. The testees (x=275) were included in groups with specific diagnoses, and a breakdown was made according to the detection of aerobic pus-forming germs. Gram-positive cocci were detected in 92% of the cases and their pathogenetic representatives, 76,5% of the cases. Rodshaped germs (Enterobacteriaceae, Pseudomonas) were observed only in 37,9% of the cases. Staphylococcus aureus, which accounted for 62,5%, was the most frequently observed species. It was followed, in order of frequency of detection, by greening streptococci and Staphylococcus epidermidis. Monoinfection was far more frequently observed than multi-infection. Also, the problems associated with the differentiation of streptococci are pointed out since other investigators found streptococci to be the most frequent agents producing odontogenic infections.

Bacterial Infections↗
PubMed1976

[Basal cell carcinoma (basalioma solidum) on a tubed pedicle flap in the oral cavity (author's transl)].

A report is given on the formation of a basal cell carcinoma (Basalioma solidum) on a tubed pedicle flap of acromiopectoral transplanted into the oral cavity. This plastic successfully covered a vast perforation of the palate after a severe wounding by shell splinters 33 years ago. The histologically proofed basal cell carcinoma (Basalioma solidum) was entirely brought to disappearance by 6000 R tumor-dose telecobalt. After 1 1/2 years the patient was without any complaint and recurrence. Etiology and pathogenesis of basal cell carcinoma (Basalioma solidum) are discussed in the light of the literature.

Acromion↗