22 research outputs found
The application of bone graft substitutes for alveolar ridge preservation after orthodontic extractions and for augmentation of residual cleft defects
The use of bone substitute materials in orthodontics is to be considered prior to
orthodontic space closure after tooth extraction during the treatment of marked
crowding as well as for treatment of residual defects in cleft-lip-and-palate children.
In both cases the common objective is structure preservation or augmentation
of the alveolar ridge. The demands to be made on the synthetic bone
graft substitute comprise not just complication-free and safe use but also the
chance of early tooth movement into the treated defect area with sufficient
stability of the new tooth position
Bone graft substitutes in periodontal and peri-implant bone regeneration
Regenerative medicine provides different therapy alternatives alongside gold standard
autogenous grafts for the treatment of periodontal or peri-implant osseous
defects. Continuing progress in the field of alloplastic bone substitutes
has yielded promising solutions to the appropriate indications with the membrane
technique either alone or in combination with enamel matrix derivatives.
Their clinical outcomes, however, still require critical discussion
The clinical application of a new synthetic bone grafting material in oral and maxillofacial surgery
A novel bone formation material based on hydroxyapatite-xerogel is presented.
With the use of the innovative sol-gel technology this material is produced in the
low-temperature range by the addition of silicon dioxide; in its structure it mimics
to a great extent the natural bone matrix. This results in high osteoconductivity
and an osteoprotective effect as well as in complete biodegradation corresponding
to bone formation in the course of natural bone remodelling. Two case reports
are presented
The manufacture of synthetic non-sintered and degradable bone grafting substitutes
A new synthetic bone grafting substitute (NanoBone®, ARTOSS GmbH, Germany)
is presented. This is produced by a new technique, the sol-gel-method. This
bone grafting substitute consists of nanocrystalline hydroxyapatite (HA) and
nanostructured silica (SiO2). By achieving a highly porous structure good osteoconductivity
can be seen. In addition, the material will be completely biodegraded
and new own bone is formed. It has been demonstrated that NanoBone® is
biodegraded by osteoclasts in a manner comparable to the natural bone remodelling
process
The biodegradation of hydroxyapatite bone graft substitutes in vivo
Hydroxyapatite (HA) ceramics are widely used for bone reconstruction. They are
osteoconductive and serve as structural scaffolds for the deposition of new bone.
Generally, scaffold materials should be degradable as they affect the mechanical
properties of the reconstructed bone negatively. Degradation by osteoclasts
during the bone remodelling process is desirable but often does not take place.
In the current study we analysed by light microscopy the degradation of two
granular HA implants in critically sized defects in the mandibula of Goettingen
mini-pigs five weeks after implantation. Bio-Oss® consists of sintered bovine
bone and NanoBone® is a synthetic HA produced in a sol-gel process in the
presence of SiO2. We found that both biomaterials were degraded by osteoclasts
with ruffled borders and acid phosphatase activity. The osteoclasts created
resorption lacunae and resorptive trails and contained mineral particles. Frequently,
resorption surfaces were in direct contact with bone formative surfaces
on one granule. Granules, especially of NanoBone®, were also covered by osteoclasts
if located in vascularised connective tissue distant from bone tissue.
However, this usually occurred without the creation of resorption lacunae. The
former defect margins consisted of newly formed bone often without remnants
of bone substitutes. Our results show that the degradation of both biomaterials
corresponds to the natural bone degradation processes and suggest the possibility
of complete resorption during bone remodelling
Bone functions and the requirements for bone grafts and substitutes in the orofacial region
Bone is the largest calcium storage, has distinctive plasticity and adaptability and
is part of the supporting tissue. An adequate composition is thus necessary. The
bone matrix consists of organic and anorganic structures. Osteoblasts, osteoclasts
and osteocytes are responsible for bone formation, resorption and metabolism.
The periosteum, endosteum and bone tissue are a functional unit and provide
protection, nutrition and growth. Bone is subject to continuous remodelling
Wound management after the application of bone grafting substitutes in the orofacial region
Surgical dressing after the application of bone grafting material depends on the
type and size of the defect. A complete and tension-free wound closure has
proved to be successful. In this context the infection problem needs special
attention. Bone graft substitutes with an adequate surface structure, porosity
and chemical properties, in combination with sufficient blood circulation, hold
osteoconductive potential. They serve as a guide rail for the osteoblast-induced
formation of new bone tissue, which at best may lead to complete replacement
of the grafting material
Critical considerations on the diagnostic appraisal, adaptation and remodelling of bone graft substitutes
The diagnostic assessment of skeletal defects has a long-standing tradition. As
a result of the development of new bone grafting materials, the demands on
diagnostic assessment have also increased. The mode and quality of diagnostic
appraisal are crucial to further clinical use and outcome prediction. Alongside
traditional clinical and biological techniques, molecular biological methods have
gained a broad scope of application and will be used even more frequently in
the future
The influence of procarbazine and thiocyanate on embryonic bone maturation
The substance procarbazine (Natulan®) is a teratogen known to induce cleft palates in rats on day 14 post-conception. The application of thiocyanate (SCN-) alone to rats on day 10 and 14 of pregnancy had no effects on fetal bone maturation. However, when procarbazine was used, the maturation and growth of fetal bones was delayed. Upon additional application of thiocyanate, the effects of procarbazine (Natulan¿) were increased. Thus, no antiteratogenic effect of thiocyanate occurs. We propose that charge and metabolites of teratogenic agents play a key role in developing the effects of thiocyanate