Biomedical subjects

E H Groeneveld

Publications and source records attributed to E H Groeneveld.

3 recordsLinked to original sources

PubMed2000

Bone morphogenetic proteins in human bone regeneration.

Recently, the first clinical reports on bone regeneration by two recombinant human bone morphogenetic proteins (rhBMPs), BMP-2 and BMP-7 (also named osteogenic protein-1, OP-1) have been published (1-4). Although both BMPs were able to support bone regeneration, a significant variation in individual response was observed with both proteins. Animal studies and laboratory experiments reveal a number of conditions that influence the osteoinductivity of BMP, such as BMP concentration, carrier properties and influence of local and systemic growth factors and hormones. In this paper, these studies and the clinical reports are reviewed, and the conditions that modulate the BMP-dependent osteoinduction are discussed. The information may provide clues as to how the performance of recombinant human BMP as bone-graft substitute in humans can be improved.

Animals↗

PubMed1999

Mineralization processes in demineralized bone matrix grafts in human maxillary sinus floor elevations.

For reconstruction of the severely resorbed lateral maxilla for dental implant placement, one of the successful procedures is to elevate the maxillary sinus floor by implanting demineralized bone matrix (DBM). We studied bone formation in DBM grafts in the lateral maxilla in humans by means of histology and histomorphometry. Six months after grafting, at the time of dental implantation biopsies were taken from the grafted areas of seven patients. All biopsies contained mineralized matrix (MM) in the grafted area. At close inspection, three types of mineralization were found. First, lamellar biomineralization was seen in and near the maxillary host bone. Second, remineralization was observed in some particles that probably had not been completely demineralized. In the area connecting the graft and host bone, where woven bone was formed against DBM particles, a third mechanism was detected. In this case many dotlike foci of remineralization appeared close to the bone-DBM interface. The remineralized DBM and woven bone were both subsequently remodeled. Bone formation was most active in the area adjoining the maxillary host bone. We conclude that in human sinus floor elevation, allogenic DBM increases mineralized tissue volume by osteoconduction that is supported by the remineralization processes. Osteoinduction by this material seems questionable.

Adult↗

PubMed1999

Histomorphometrical analysis of bone formed in human maxillary sinus floor elevations grafted with OP-1 device, demineralized bone matrix or autogenous bone. Comparison with non-grafted sites in a series of case reports.

Bone morphogenetic proteins have proven to be effective bone inductors in animals and are therefore promising as inductors of bone formation in humans. In the present study we investigated the tissue formed after grafting osteogenic protein 1 on a collagen carrier (OP-1-device) in the human sinus floor elevation procedure. Three patients were grafted with OP-1 device. For comparison 3 groups of 3 patients were included in the study receiving respectively, autogenous bone, human freeze-dried demineralized bone matrix (DBM) or no graft. This last group had a sufficient alveolar bone height for dental implantation. Six months after grafting, at the time of implantation, biopsies were taken from the grafted area and/or the future dental positions. Undecalcified sections were used for histological and histomorphometrical analysis. All grafted sinuses showed an increased osteoid percentage when compared to non-grafted sinuses. Autogenous bone grafts all showed lamellar bone formation. In the DBM grafts mostly woven bone had been formed, predominantly by what appeared to be osteo-conduction. The OP-1 device gave rise to bone formation in 2 of the 3 patients. After 6 months implants could only be placed in 1 out of the 3 patients treated with OP-1 device. This patient showed mature lamellar bone formation, comparable to autogenous bone grafts. In the second patient all bone found was woven and the presence of a high osteoid percentage and large osteocyte lacunae indicated that this was recently-formed bone. Remnants of the collagen carrier were rare and new bone was never found against them, suggesting that this bone was formed by osteo-induction. In the third patient no new bone had been formed. The device had been encapsulated with fibrous tissue and inflammatory reaction was present. We conclude that in the human sinus floor elevation OP-1 has potential bone inductive capacity, but that results in the 3 patients tested with the current OP-1 device are inconsistent.

Adult↗