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Biomedical subjects

H B van der Lubbe

Publications and source records attributed to H B van der Lubbe.

8 recordsLinked to original sources

Plasma-sprayed coatings of tetracalciumphosphate, hydroxyl-apatite, and alpha-TCP on titanium alloy: an interface study.

In order to study the interaction of calcium phosphate coatings with bone tissue, coated titanium cylinders with a standard size were implanted in dog femora. Coatings were made by plasma spraying powders of hydroxylapatite, beta-whitlockite, and tetracalciumphosphate particles. The plasma spraying process turns beta-whitlockite into alpha-TCP. Bone bonding and bone formation were evaluated by mechanical push-out tests and histological observations. Hydroxylapatite and tetracalciumphosphate coatings show an interface strength after 3 months of implantation of 34.3 +/- 6.5 MPa and 26.8 +/- 3.9 MPa, respectively, while alpha-TCP and blanco titanium lead to an interface strength of 10.0 +/- 3.5 MPa and 9.7 +/- 1.3 MPa, respectively. Histological examinations revealed that hydroxylapatite and tetracalciumphosphate give rise to an excellent bone formation, while alpha-TCP and blanco titanium evoked remodeling and less bone contact.

Alloys↗

Tissue response to percutaneous implants in rabbits.

This study reports on certain aspects of wound-healing around percutaneous implants. Plasma-sprayed and dense hydroxylapatite, titanium, and carbon test implants were inserted into the tibia and the cranium of 12 rabbits. Four and 8 months after insertion, the animals were sacrificed and the implants with their surrounding tissues were processed histologically. Light- and transmission electron microscopic investigations were performed. It is found that direct and indirect bone-anchoring favors the longevity of percutaneous implants. No differences in tissue reaction between the various implant materials were observed.

Animals↗

Histological evaluation of biocompatible orthopaedic polymer.

The biocompatibility of biocompatible orthopaedic polymer implant materials was studied in subcutaneous and bony tissue of rats and rabbits. The tissue response was evaluated by histological techniques. No bone induction capacity of biocompatible orthopaedic polymer could be observed. In rabbits, the presence of plasma cells was significantly higher than in rats. The biomaterial showed some signs of biodegradation and was not very biocompatible.

Animals↗

Rib fracture healing after osteosynthesis with wire mesh titanium and screws: a histological study in sheep.

Twenty sheep were placed under general anesthesia and five ribs (6-10) were transected at their lateral angle using a pair of rib shears. The fractures were stabilized by titanium wire mesh plates. After 4, 6, 8, 10 and 12 weeks groups of 4 animals were sacrificed and rib samples were prepared for histological examinations. The study showed that the osteosynthesis stabilized the fractures and that the healing is similar to untreated rib fractures. This osteosynthesis method is a good contribution to severe injured chest treatment.

Animals↗

A simple method for preparing thin (10 microM) histological sections of undecalcified plastic embedded bone with implants.

A simple method for preparing undecalcified thin sections of bone with implants has been developed. After exposing a surface of bone and implant in a plastic block by sawing thick sections, the surface is stained prior to making a thin section. A glass coverslip is affixed with a thin layer of cement to the stained surface to stabilize the tissue and implant during sectioning. A mixture of glycerine and water is used as a coolant and lubricant. The orientation in situ is preserved allowing demonstration of bone architecture and cells, and the tissue-implant interface.

Animals↗

A comparative study of different beta-whitlockite ceramics in rabbit cortical bone with regard to their biodegradation behaviour.

Different beta-whitlockite ceramic cylinders of standard size were implanted in the tibiae of rabbits to study the influence of micropores and chemistry on the biodegradation rate. The materials were evaluated by radiography and light microscopy. Surface chemistry was varied by the addition of impurities, while different applied pressures before sintering and different sintering temperatures gave rise to different micropores. Both factors influenced the biodegradation rate.

Animals↗

Interaction of biodegradable beta-whitlockite ceramics with bone tissue: an in vivo study.

The biodegradation of different porous beta-whitlockite materials are studied by in vivo experiments, radiographic follow-ups and light microscopy observations. The materials were implanted in rabbit tibiae for 16 month. Micropores play an important role in the biodegradation rate. The resorbing materials evoke an inflammation with plasma cells. The resorption starts in the medulla, and the phagocytosed particles are removed to the lymph nodes. Normal bone function can be restored after all the implant material is resorbed.

Animals↗