scholarly journals Bone Coverage around Hydroxyapatite/Poly(L-Lactide) Composite Is Determined According to Depth from Cortical Bone Surface in Rabbits

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1458
Author(s):  
Kazuaki Morizane ◽  
Koji Goto ◽  
Toshiyuki Kawai ◽  
Shunsuke Fujibayashi ◽  
Bungo Otsuki ◽  
...  
Keyword(s):  
Foreign Body ◽  
Bone Formation ◽  
Cortical Bone ◽  
Mature Male ◽  
Bone Surface ◽  
New Bone Formation ◽  
Screw Head ◽  
Ultrahigh Strength ◽  
Foreign Body Reactions ◽  
Bone Coverage

Composites of unsintered hydroxyapatite (HA) and poly(L-lactide) (PLLA) reinforced by compression forging are biodegradable, bioactive, and have ultrahigh strength. However, foreign body reactions to PLLA and physical irritation can occur when not covered by bone. We aimed to confirm the relationships between the depth of the implanted HA-PLLA threaded pins and the new bone formation. We inserted HA-PLLA composite threaded pins (diameter: 2.0 or 4.5 mm) into the femoral and tibial bones of 32 mature male Japanese white rabbits (weight 3.0–3.5 kg) with the pin head 1 or 0 mm below or protruding 1 or 2 mm above surrounding cortical bone. Eight euthanized rabbits were radiologically and histologically assessed at various intervals after implantation. Bone bridging was complete over pins of both diameters at ~12 weeks, when inserted 1 mm below the surface, but the coverage of the pins inserted at 0 mm varied. Bone was not formed when the pins protruded >1 mm from the bone surface. No inflammation developed around the pins by 25 weeks. However, foreign body reactions might develop if composites are fixed above the bone surface, and intraosseous fixation would be desirable using double-threaded screws or a countersink to avoid screw head protrusion.

scholarly journals Lack of repair of rat skull critical size defect treated with bovine morphometric protein bound to microgranular bioabsorbable hydroxyapatite

2004 ◽  
Vol 15 (3) ◽  
pp. 175-180 ◽  
Author(s):  
Gabriel Ramalho Ferreira ◽  
Tania Mary Cestari ◽  
José Mauro Granjeiro ◽  
Rumio Taga
Keyword(s):  
Foreign Body ◽  
Bone Formation ◽  
Bone Morphogenetic Proteins ◽  
Bone Repair ◽  
Critical Size ◽  
Bovine Bone ◽  
New Bone Formation ◽  
Body Type ◽  
Granulomatous Reaction ◽  
Post Surgery

The ability of a pool of bovine bone morphogenetic proteins bound to synthetic microgranular hydroxyapatite (BMPb-HA) to stimulate bone repair was determined in rat critical size defects. An 8-mm diameter defect was created in the calvaria of 25 rats. In 15 rats, the defects were filled with BMPb-HA homogenized with blood (experimental group), and in 10 rats the defects were filled only with blood clots (control). The calvariae of experimental rats were collected 1, 3 and 6 months after surgery and of the control rats at the end of surgery and 6 months thereafter. The morphometric results obtained in the radiographs showed an absence of new bone formation at 1 and 3 months post-surgery and, histologically, the defects were filled with fibrous connective tissue and numerous foci of a foreign body-type granulomatous reaction around hydroxyapatite agglomerates. At the end of 6 months, the number and size of the granulomatous foci decreased and the area of the defects was reduced by 22% compared to the 0-hour control due to the formation of new bone at their borders, although the mean area was similar to the 6-month control. We conclude that the use of BMPb-HA in the treatment of critical size bone defects of the rat skull leads to the formation of a foreign body-type granulomatous reaction that markedly inhibits new bone formation, suggesting that synthetic microgranular hydroxyapatite does not represent a good carrier for BMP-induced bone formation.

scholarly journals Neutralized Dicalcium Phosphate and Hydroxyapatite Biphasic Bioceramics Promote Bone Regeneration in Critical Peri-Implant Bone Defects

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 823 ◽  
Author(s):  
Hao-Hueng Chang ◽  
Chun-Liang Yeh ◽  
Yin-Lin Wang ◽  
Kang-Kuei Fu ◽  
Shang-Jye Tsai ◽  
...  
Keyword(s):  
Bone Formation ◽  
Bone Regeneration ◽  
Bone Defects ◽  
Dicalcium Phosphate ◽  
Control Group ◽  
New Bone Formation ◽  
Control Groups ◽  
Fast Bone ◽  
And Control ◽  
Bone Coverage

The aim of this study was to evaluate the efficacy of bone regeneration in developed bioceramics composed of dicalcium phosphate and hydroxyapatite (DCP/HA). Critical bony defects were prepared in mandibles of beagles. Defects were grafted using DCP/HA or collagen-enhanced particulate biphasic calcium phosphate (TCP/HA/Col), in addition to a control group without grafting. To assess the efficacy of new bone formation, implant stability quotient (ISQ) values, serial bone labeling, and radiographic and histological percentage of marginal bone coverage (PMBC) were carefully evaluated four, eight, and 12 weeks after surgery. Statistically significant differences among the groups were observed in the histological PMBC after four weeks. The DCP/HA group consistently exhibited significantly higher ISQ values and radiographic and histological PMCB eight and 12 weeks after surgery. At 12 weeks, the histological PMBC of DCP/HA (72.25% ± 2.99%) was higher than that in the TCP/HA/Col (62.61% ± 1.52%) and control groups (30.64% ± 2.57%). After rigorously evaluating the healing of biphasic DCP/HA bioceramics with a critical size peri-implant model with serial bone labeling, we confirmed that neutralized bioceramics exhibiting optimal compression strength and biphasic properties show promising efficacy in fast bone formation and high marginal bone coverage in peri-implant bone defects.

Bone Regeneration at Cortical Bone Defect with Unidirectional Porous Hydroxyapatite In Vivo

2008 ◽  
Vol 396-398 ◽  
pp. 11-14 ◽  
Author(s):  
Masashi Iwasashi ◽  
Masataka Sakane ◽  
Yasushi Suetsugu ◽  
Naoyuki Ochiai
Keyword(s):  
Bone Formation ◽  
Cortical Bone ◽  
Bone Defect ◽  
Proximal Tibia ◽  
New Bone Formation ◽  
Porous Hydroxyapatite ◽  
Japanese White Rabbit ◽  
Great Possibility ◽  
Porous Area

Unidirectional porous hydroxyapatite (UDPHAp) was developed which has microstructure in that cross sectionally oval pores 100 ~ 300µm in diameter penetrate through the material, and that is suitable for osteogenesis and angiogenesis.The porosity of the UDPHAp was 75 % and the compression strength was 14 MPa. A cortical bone defect was made at proximal tibia of Japanese white rabbit, and a trapezoidal prisms shaped UDPHAp was implanted. By histlogical evaluation, 2 weeks after implantation, new bone and new capillary was observed inside UDPHAp. Twelve weeks after implantation, new bone formation was observed in 41.6 % of the porous area. The results of this study suggest a great possibility of utilizing it in actual clinical setting as a bone substitution.

scholarly journals In Vivo Study for Clinical Application of Dental Stem Cell Therapy Incorporated with Dental Titanium Implants

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 381
Author(s):  
Hyunmin Choi ◽  
Kyu-Hyung Park ◽  
Narae Jung ◽  
June-Sung Shim ◽  
Hong-Seok Moon ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Formation ◽  
Alveolar Bone ◽  
Human Mesenchymal Stem Cells ◽  
Titanium Implants ◽  
Osteogenic Potential ◽  
Induction Medium ◽  
Radiographic Analysis ◽  
New Bone Formation

The aim of this study was to investigate the behavior of dental-derived human mesenchymal stem cells (d-hMSCs) in response to differently surface-treated implants and to evaluate the effect of d-hMSCs on local osteogenesis around an implant in vivo. d-hMSCs derived from alveolar bone were established and cultured on machined, sandblasted and acid-etched (SLA)-treated titanium discs with and without osteogenic induction medium. Their morphological and osteogenic potential was assessed by scanning electron microscopy (SEM) and real-time polymerase chain reaction (RT-PCR) via mixing of 5 × 106 of d-hMSCs with 1 mL of Metrigel and 20 μL of gel-cell mixture, which was dispensed into the defect followed by the placement of customized mini-implants (machined, SLA-treated implants) in New Zealand white rabbits. Following healing periods of 2 weeks and 12 weeks, the obtained samples in each group were analyzed radiographically, histomorphometrically and immunohistochemically. The quantitative change in osteogenic differentiation of d-hMSCs was identified according to the type of surface treatment. Radiographic analysis revealed that an increase in new bone formation was statistically significant in the d-hMSCs group. Histomorphometric analysis was in accordance with radiographic analysis, showing the significantly increased new bone formation in the d-hMSCs group regardless of time of sacrifice. Human nuclei A was identified near the area where d-hMSCs were implanted but the level of expression was found to be decreased as time passed. Within the limitations of the present study, in this animal model, the transplantation of d-hMSCs enhanced the new bone formation around an implant and the survival and function of the stem cells was experimentally proven up to 12 weeks post-sacrifice.

Sign in / Sign up

Export Citation Format

Share Document