Biomedical subjects
Publications and source records attributed to P Tetsch.
Various controlled defects were inflicted under cooled conditions in the femur and humerus of sheep. Radiologic, histologic, and fluorescence microscopic examinations showed that an internally cooled fraise was advantageous. The positive effects, particularly in deeper areas of bone, were determined via quantitative analysis.
The exact investigation of the bone-implant border necessitates a combined study of foreign material and host tissue. All the stages of the procedure and their special problems are described and an artificial substance of low viscosity is introduced, which is suitable for implanting larger test probes.
An animal experimental study was undertaken where the embedding of extension implants with a smooth or porous surface was histologically examined. Under extreme functional stress there occurs a mobility of the implants with the formation of a broad connective tissue zone, inflammatory reactions and ingrowth of epithelium, which is independent of the surface structure. Implants under less stress show a narrower connective tissue layer which narrows itself further if the surface is porous. The possible causes of this tissue reaction are discussed.
After removal of all teeth in grown up mini-pigs, extension implants were anchored into the dental area of the lower jaw and connected to a battery unit, one implant always forming the cathode and the other the anode. Clinical, radiological and histological results show completely different reactions of the implant site. In the region of the anode there occurs osteolysis which results in considerable looseness of the implant. The implants used as cathodes are clinically firm and when compared to implants not stimulated show increased bone regeneration.
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It was possible to examine over 500 jaw implants which were anchored in bone after varying duration of wear. The average failure rate of these implants after up to seven years after insertion lies approximately 40% above the complication rate given in the majority of publications. The time of occurrence and the symptoms of failures are discussed as well as their possible causes.
In addition to radiographs and clinical diagnostic-methods, exfoliative cytology can be used as a testing method for the evaluation of implants. The simple and gentle method of sample taking permits regular follow-ups. While in the area of stable grafts a normal cytogram is obtained, the cytogram of the area of loose grafts shows all the signs of inflammation on the cellular level: "a shift to the left", low indices of keratinization and eosinophilia, cellular alterations, presence of bacteria, leukocytes, and lymphocytes.
Three hemangiopericytomas of the head and neck region with different clinical development are presented. In one patient the tumor was benign, in the two others malignant. In contrast to the opinion prevailing in the literature, histological criteria were found by means of which the degree of malignancy of these three tumors could be established. Irrespective of the degree of malignancy, radical surgery is recommended as therapy. Postoperative radiotherapy follows in those cases where a safety margin of clinically non-involved tissue surrounding the tumor could not be removed.
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Because of a lack of denture retention, great difficulties are often encountered in edentulous patients who require prosthetic treatment of defects in the maxillo-facial region. The use of enossal implants may enable temporary rehabilitation with regard to mastication and speech. The possible range of indication is considerably limited in cases of extensive defects of the alveolar process, advanced atrophy and by radiological therapy of malignant tumors. The duration of therapeutic success is contingent upon most accurate implantation techniques and prosthetic treatment as well as the patient's oral hygiene.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.