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C Hämmerle

Publications and source records attributed to C Hämmerle.

15 recordsLinked to original sources
PubMed1999

Radiologic and mechanical properties of inactivated ossicle homografts.

OBJECTIVE: This study examined the effects of old and new inactivation (sterilization) techniques on the radiologic and mechanical properties of ossicle homografts. MATERIALS AND METHODS: Ninety normal incuses and malleuses received either treatment with 1) 5% formaldehyde/cialit, 2) 1N NaOH, 3) 0.9% LpH, or 4) autoclaving at 134'C, or no treatment. All ossicles were assessed radiologically by high-resolution computed tomography. After imaging, all ossicles underwent mechanical testing by destructive axial compression in a mechanical testing machine measuring force and displacement. RESULTS: Ossicles treated with cialit, NaOH, or autoclaving showed a significant decrease of ultimate force and stiffness compared with controls. LpH treatment caused no such changes in these structural properties. Material properties of yield strength, ultimate strength, and elastic modulus were also altered by cialit, NaOH, and autoclaving, but were much more difficult to assess because of uncertainty in parameter estimates. There was a significant increase in radiologic density in autoclaved ossicles, a reduction in cialit- and LpH-treated ossicles, and no change in NaOH-treated ossicles. CONCLUSIONS: All tested inactivation procedures changed the biomechanical and/or radiologic properties of ossicle homografts. However, the new procedures used to inactivate infectious agents produced changes similar to the older treatments with formaldehyde/cialit. Human allografts are able to withstand harsh but safe sterilization procedures. The NaOH treatment seems to be the most suitable method for the future. The biologic (osteogenic) potentials of ossicle homografts treated with these new preservation/inactivation methods are still unknown. Further investigations are necessary to re-evaluate the clinical use of ossicle homografts in middle ear reconstructive surgery.

Adult↗
PubMed1998

Histological evaluation of Bio-Oss in a 2-stage sinus floor elevation and implantation procedure. A human case report.

Deproteinized cancellous bovine bone (Bio-Oss) was placed as a grafting material for sinus floor elevation in the right posterior maxilla. After 6 months of healing, 3 cylindrical titanium-plasma coated implants were inserted. Six months later at the abutment connection, it was realized that 1 of the implants could not be reconstructed due to unfavorable positioning. This implant was removed along with a small portion of the surrounding peri-implant tissues. The specimen was processed according to standard techniques for hard tissue histology. In both the grafted area and the previously existing area of the sinus floor the bone was primarily of lamellar structure. Intimate contact between newly formed bone and the particles of the graft was present. No overt signs of resorption of the graft particles were visible. Histomorphometric analysis revealed 63% of implant-bone contact in the zone of pre-existing bone, and 73% in the grafted zone. The area density of bone amounted to 27% in the non-grafted as compared to 28% in the grafted area. In conclusion, this case report documented that deproteinized bovine bone, when used as a grafting material for augmentation of the sinus floor, may lead to proper osseointegration of a dental implant.

Animals↗
PubMed1990

Fixed reconstructions in partially edentulous patients using two-part ITI implants (Bonefit) as abutments.

Fixed reconstructions on implant abutments may be a welcome modality in the treatment of partially edentulous patients following the principles of a prophylactically oriented comprehensive care. The option to create artificial tissue integrated abutments widens the range of indications for fixed reconstructions. Risky long-span bridges as well as the preparation of intact teeth for bridge abutments may frequently be avoided. Never should the contours of the prosthesis interfere with the patient's performance of optimal plaque control. Furthermore, supportive periodontal therapy with regular maintenance visits must be provided to optimize a long-term prognosis of the dention as well as the tissue-integrated artificial abutments.

Dental Abutments↗