Search PubMed⌕ Search

Biomedical subjects

D Weingart

Publications and source records attributed to D Weingart.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Differential indications for various therapeutic osteosynthesis concepts in mandibular fractures].

The surgical treatment of different types of mandibular fractures requires complex consideration. It can be realised not by the application of only one treatment concept, e.g. miniplates or rigid osteosynthesis, but a differentiated indication of every stability system depending on the individual requirements in each case. Basing on the results of clinical studies the contemporary concept applied at Münster in treatment of mandibular fractures is presented.

Bone Plates↗
PubMed1994

Titanium deposition in regional lymph nodes after insertion of titanium screw implants in maxillofacial region.

The deposition of titanium in regional lymph nodes was studied after insertion of endosseous, plasma-spray-coated titanium screw implants in a total of 19 beagle dogs. Five additional animals with no implants served as the control group. After killing the animals 9 months postoperatively, the regional lymph nodes were carefully excised, and samples were prepared for histologic examination. Other samples were used to identify foreign particles by energy-dispersive x-ray analysis and for measurement of the titanium concentration in the tissue by flameless atomic absorption spectroscopy. Very fine foreign-body particles could be seen in the histologic sections, and they were identified as titanium by energy-dispersive x-ray analysis. The atomic absorption analysis for titanium revealed a significantly higher concentration in the group with implants. The presence of very fine, poorly attached particles on the plasma-sprayed titanium surface suggests that these particles may be mechanically dislodged from the surface on insertion of the implants. This suggests that the fine particles may be transported by phagocytes to the regional lymph nodes, where they could be found without any signs of inflammation or foreign-body reaction.

Animals↗
PubMed1994

ITI implants in combination with bone grafts: design and biomechanical aspects.

In this article we describe the implantation of ITI implants in combination with bone grafts. Two different cases were considered: the augmentation of an atrophic maxilla or mandible where the transplant was fixed by means of ITI implants and the implantation into free transplants fixed by means of the THORP reconstruction plate system. These indications require 2-stage procedures with submerged implants and transplants during the healing period. For this new applications, standard ITI implants were combined with specially developed new transgingival units of high manufacturing precision. The new design resulted in a maximum tightening moment of 4.0 N.m versus 1.25 N.m achievable with a conventional 2-mm screw. Dynamic testing showed that, for the range of tightening moments of 0.25 N.m up to 1.0 N.m, the loosening moment after 2,000,000 cycles remained approximately 10% above the tightening moment. For the clinical application a tightening moment of 0.35-0.5 N.m is recommended. The special design and the high precision of the extension parts results in a tight adaptation between the primary implant and the extension parts, which may be important for microbiological reasons.

Alveolar Ridge Augmentation↗
PubMed1993

Strip ostectomy and radical ostectomy in the treatment of craniosynostosis. An experimental animal study.

In an experimental animal study using rabbits, growth phenomena were simulated which are comparable to craniosynostosis in humans. The radiological and histological findings after surgical management of these artificial craniosynostosis by means of strip ostectomy or radical ostectomy were compared with the findings obtained in control animals. Following strip ostectomy, bone defects were rapidly filled by the formation of suture-like structures. After radical ostectomy, structures consisting of connective tissue dispersed among islands of ossification were preserved over a considerable period of time, making it possible for the calvarium to adapt to the fast-growing brain. In contrast to strip ostectomy, after radical ostectomy growth of both the neurocranium and the viscerocranium, as well as the total sagittal growth of the skull, were almost identical to the corresponding growth in the control animals.

Animals↗
PubMed1993

Antimicrobial effects of the tetrachlorodecaoxygen-anion complex on oropharyngeal bacterial flora: an in vitro study.

The susceptibility of 276 different strains of bacteria derived from the oropharyngeal flora to the tetrachlorodecaoxygen-anion complex (TCDO) was tested using the agar dilution method. The results showed that at therapeutic concentrations of the drug the growth of all the strains tested was inhibited, with the exception of Candida albicans. The pathogenic anaerobes proved to be particularly sensitive to TCDO.

Bacteria↗
PubMed1993

A tomographic technique for the depiction of atrophied alveolar ridges prior to endosseous implant placement.

Radiographic examination is of particular importance prior to the placement of dental implants, especially when the alveolar ridge is severely atrophied. Accurate assessment of the amount of residual bone can be improved with tomography. A method is described which utilizes templates and marking aids to facilitate the correct positioning of the jaws so as to obtain a true cross-section of the alveolar ridge at the intended implant sites. The same template can be used to determine the location and angulation of the implant at surgery.

Alveolar Bone Loss↗
PubMed1992

Restoration of maxillary residual ridge atrophy using Le Fort I osteotomy with simultaneous endosseous implant placement: technical report.

When residual ridge atrophy of the edentulous mandible and maxilla is accompanied by a skeletal Class III jaw relationship, surgical correction is necessary for optimal functional, phonetic, and esthetic results whenever implant-supported prostheses are to be placed. A method is described in which a single procedure combines the endosseous placement of nonsubmerged titanium implants in appropriate prosthetically predetermined locations with defined advancement of the maxilla. Preoperative diagnostic examinations, cast simulation, and transfer of the latter to the site of surgery are of the utmost importance.

Alveolar Bone Loss↗
PubMed1992

[Severe atrophy of the alveolar ridge in edentulous patients. Combined treatment using bone grafts and screw implants].

In cases of advanced alveolar ridge atrophy, when the bone available for endosseous implants is not sufficient, endosseous implants are combined with augmentation of the alveolar ridge by means of autologous bone transplants. Depending on the type of atrophy found, the authors use three different surgical procedures: onlay technique, sandwich technique and alveolar extension technique. In all cases functional loading of the implants was performed by way of an entirely implant-supported bridgework. Results to date indicate that initial postoperative resorption is followed by a virtual standstill once the implants have been loaded.

Alveolar Process↗
PubMed1991

Penicillin concentration in the compact bone of the mandible.

During surgical removal of impacted third molars, the concentration of Penicillin G was determined in the compact bone of the mandible. Fifteen patients received 5 million IU and 15 received 10 million IU of Penicillin G intravenously as a single dose before surgery began. In both groups concentrations of penicillin with a bactericidal effect on most pathogenically relevant oral bacteria were detected during osteotomy. Taking into account the considerable interindividual variation, the one-shot application of 10 million IU of Penicillin G was more effective in certain cases than the 5 million IU dose. The factors influencing the decision on the high single-dose application include expected length of operation, body weight, kidney function, and infusion period. Assuming that in intraoral osteotomies the bone becomes contaminated with bacteria that are highly sensitive to penicillins, the results indicate that preoperative infusion of Penicillin G could be an effective method of preventing wound infection.

Adolescent↗
PubMed1986

[Basal cell nevus syndrome in roentgen diagnosis of the skull].

Besides uni- and multilocular jaw cysts the Gorlin-Goltz-syndrome shows other characteristic radiographic findings which help to ensure diagnosis. These are particularly calcification of the falx cerebri and a so called "bridging" between processus clinoideus anterior und posterior of the sella turcica. The importance of early diagnosis is stressed.

Basal Cell Nevus Syndrome↗
PubMedDate not supplied

[Carcinoma in a 40-year chronic oro-antral communication].

A squamous cell carcinoma developed in a 66 year old patient in the region of a traumatically caused oro-antral fistula that has persisted for 40 years. The clinical course and histological findings are presented. Based on the few case reports in the literature the occurrence of malignancies in chronic traumatic fistulae is discussed. Reference is also made to causal relationships between such a fistula and malignancy under the aspect of forensic medical consultations.

Aged↗
PubMedDate not supplied

[Control of the re-epithelialization of skin defects and burns].

In an experimental study an attempt was made to compare the effect of the tetrachlorodekaoxygen anion complex (TCDO) with an aqueous KCl/CaCl2 solution of a defined molar concentration in hydrogel on the basis of skin defects, irradiated skin defects, and necrectomized burns of the skin of the back of naked euthymic guinea pigs. The wound healing of the irradiated skin defects and the necrectomized burns was found to be generally delayed. The use of the Kcl/CaCl2 solution in hydrogel, however, brought about a faster repair of the defects than the application of TCDO.

Animals↗
PubMedDate not supplied

Fabrication of all-ceramic In-Ceram implant-supported bridges: a case report.

Ceramic restorative materials offer certain advantages over metal-acrylic and metal-ceramic restorations, including low plaque accumulation, corrosion resistance, nonallergenic properties, and excellent aesthetic results. A new ceramic material with a high aluminum content has been recently developed. It addresses the problem of some other materials which absorbed saliva in the oral environment and caused microcracks, rendering them unsuitable for multi-unit suprastructures. The learning objective of this case report is to describe the clinical and laboratory procedures for fabrication of the all-ceramic implant-supported suprastructures for an edentulous patient after orthognathic surgery and the placement of associated endosseous oral implants.

Adult↗