Bio-Oss Group Research Articles

Biocompatibility and osteoconductivity of PLCL coated & non‐coated xenografts‐ an in‐vitro and pre‐clinical trial

Background Cells, scaffolds and growth-factors are the key components required to generate engineered tissues. A scaffold can deliver growth factors, and supports cell attachment. The material composition, topography and architecture influence cell behavior and intercellular interactions, and overall performance of the scaffolds. Bovine deproteinized bone matrix has become a very popular grafting material for various oral indications including socket preservation due to its large availability. Aim/Hypothesis To compare viability and proliferation of mesenchymal stem cells (MSCs) seeded onto two commercial xenografts- Bio-Oss (BO) and Bioactive Bone Bovine (BB). Next, these materials were compared for histomorphometric bone formation in a socket preservation model in rats. Material and Methods MSCs were seeded onto monolayers of BO or BB granules that covered the bottom of 96 well plates. Both materials were used with the same granules size (0.25–1 mm granules). Cell viability and proliferation was evaluated after incubation of 0, 2, 20 and 48 hours. 24 Sprague Dawley rats underwent unilateral extraction of maxillary molars. Rats were randomly divided into three groups- natural healing (non-grafted socket) or socket preservation with either BO or BB. Rats were sacrificed after 8 weeks and evaluation of the socket preservation region was performed from each specimen, under a light microscope. Images were analyzed using software. The following values were measured- (i) total bone area (ii) connective tissue (iii) residual bone graft. The measurements were expressed as percentages of the total sample area. To compare between the group regarding the metabolic activity and histomorphometric parameters one way analysis of variance was used. A P-value < 0.05 was selected to determine Results Differences in the metabolic activity of MSCs that were seeded onto BO or BB was observed at 2 hours after seeding- the metabolic activity was elevated compared to baseline in the BB (P = 0.046) and not changed in the BO wells (P = 0.84). After 20 hours, the metabolic activity of MSCs seeded onto BO was decreasing (P = 0.005) while cell viability was not changed in the BB group (P = 0.356). Intergroup comparison revealed higher metabolic activity of MSCs seeded on BB after 48 hours compared with BO (P = 0.016). The in-vivo results demonstrated differences in socket healing between the groups- percentage of new bone was higher in the BB compare to BO group (39.1% ± 14.3 vs. 23.7% ± 10.8, respectively, P = 0.096). Connective tissue portion was higher in the BO group compared with BB (73.7% ± 11.1 vs. 49.6% ± 13.7 respectively P = 0.018). Residual grafting martial was higher in the BB (11.34% ± 4.18 vs. 2.62% ± 1.23, p =0.011). Conclusions and Clinical Implications The results of this study demonstrating higher vitality and proliferation of MSCs seeded onto BB. Furthermore, following ridge preservation, higher percentage of new bone and lower residual scaffold were found in the BB compared with BO. This enhanced regenerative response might be the result of an enhancement of metabolic activity in cells attached to it. Further research will be needed to understand the precise mechanism.

Wicking Property of Graft Material Enhanced Bone Regeneration in the Ovariectomized Rat Model.

Recruitment and homing cells into graft materials from host tissue is crucial for bone regeneration. Highly porous, multi-level structural, hydroxyapatite bone void filler (HA-BVF) have been investigated to restore critical size bone defects. The aim was to investigate a feasibility of bone regeneration of synthetic HA-BVF compared to commercial xenograft (Bio-Oss). HA-BVF of 0.7mm in average diameter was prepared via template coating method. Groups of animals (n = 6) were divided into two with normal (Sham) or induced osteoporotic conditions (Ovx). Subsequently, subdivided into three treated with HA-BVF as an experiment or Bio-Oss as a positive control or no treatment as a negative control (defect). The new bone formation was analyzed by micro-CT and histology. At 4weeks post-surgery, new bone formation was initiated from all groups. At 8weeks post-surgery, new bone formation in the HA-BVF groups was greater than Bio-Oss groups. Extraordinarily greater bone regeneration within the Ovx-HA group than Sham-Bio-Oss or Ovx-Bio-Oss group (p < 0.05). This study suggests that the immediate wicking property of HA-BVF from host tissue activates a natural healing cascade without the addition of exogeneous factors or progenitor cells. HA-BVF may be an effective alternative for repairing bone defects under both normal and osteoporotic bone conditions.

Biocompatibility and osteoconductivity of PLCL coated and noncoated xenografts: An in vitro and preclinical trial

Cells, scaffolds, and growth factors are the key components in bone tissue engineering. Scaffold composition, topography, and architecture influence the amount of regenerated bone in the implantation site. The aims of the study were to compare viability and proliferation of mesenchymal stem cells (MSCs) seeded onto two commercial xenografts: Bio-Oss (BO) and bioactive bone bovine (BB). Next, these materials were compared for histomorphometric bone formation in a socket preservation model in rats. MSCs were seeded onto monolayers of BO or BB granules. Cell viability and proliferation were evaluated after incubation of 0, 2, 20, and 48h. A total of 24 Sprague Dawley rats underwent unilateral extraction of maxillary molars. Rats were randomly divided into three groups: natural healing (nongrafted socket) or socket preservation with either BO or BB. Rats were sacrificed after 8weeks, and histomorphometric analysis was done to evaluate bone formation and residual scaffold at the extraction site. Differences in the metabolic activity of MSCs that were seeded onto BO or BB was observed at 2h after seeding: the metabolic activity was elevated compared to baseline in the BB (P=.046) and not changed in the BO wells (P=.84). After 20h, the metabolic activity of MSCs seeded onto BO was decreasing (P=.005), while cell viability was not changed in the BB group (P=.356). Intergroup comparison revealed higher metabolic activity of MSCs seeded on BB after 48h compared with BO (P=.016). The in vivo results demonstrated differences in socket healing between the groups: percentage of new bone was higher in the BB compared to BO group (39.1±14.3 vs. 23.7±10.8%, respectively, P=.096). Connective tissue portion was higher in the BO group compared with BB (73.7±11.1 vs. 49.6±13.7%, respectively, P=.018). Residual grafting martial was higher in the BB (11.34±4.18 vs. 2.62±1.23%, P=.011). The results of this study demonstrating higher vitality and proliferation of MSCs seeded onto BB. Furthermore, following ridge preservation, higher percentage of new bone and lower residual scaffold were found in the BB compared with BO. This enhanced regenerative response might be the result of an enhancement of metabolic activity in cells attached to it. Further research will be needed to understand the precise mechanism.

Effects of bone regeneration materials and tooth movement timing on canine experimental orthodontic treatment.

To evaluate the effects of bone regeneration materials and orthodontic tooth movement (OTM) timing on tooth movement through alveolar bone defects treated with guided bone regeneration (GBR) utilizing xenografts (Bio-Oss) and alloplast (β-TCP). Twenty-four standard alveolar bone defects in six male beagle dogs were treated by GBR using either Bio-Oss or β-TCP (experimental), whereas the control defects were left empty. The defects were further grouped into early or late subgroups, depending on OTM timing after GBR (ie 1 month or 2 months, respectively). Rates of OTM were measured intraorally, while computed tomography scan images were used to assess bone density, alveolar bone height, second premolar displacement, and tipping tendency. Generally, the Bio-Oss early and Bio-Oss late subgroups recorded the lowest amount of tooth movement compared with other modes of GBRs assessed. Before OTM, the control group registered significantly lower bone height compared with the Bio-Oss and β-TCP groups ( P < .01). The control group was inferior on bone density and bone height compared with Bio-Oss and β-TCP. The Bio-Oss group had favorable radiologic features (higher alveolar bone level and bone density with less premolar tipping) but showed slower OTM than the control group. The late OTM subgroup had favorable radiologic features and showed faster tooth movement than the early OTM in the β -TCP group.

Bio-Oss® modified by calcitonin gene-related peptide promotes osteogenesis in vitro.

Bio-Oss® and α-calcitonin gene-related peptide (CGRP) are involved in osteogenesis. However, it has remained to be assessed how α-CGRP affects the effect of Bio-Oss. In the present study, primary osteoblasts were incubated with α-CGRP, Bio-Oss, α-GGRP-Bio-Oss or mimic-α-CGRP. The proliferation rate, mineralization nodules, alkaline phosphatase (ALP) activity and the expression of osteogenic genes were measured by a Cell Counting Kit-8 assay, Alizarin Red-S staining, ALP activity detection and reverse-transcription quantitative PCR as well as western blot analysis, respectively. The proliferation rate, ALP activity and the number of mineralization nodules were significantly increased in the α-CGRP-modified Bio-Oss group compared to that in the Bio-Oss group. The mRNA and protein levels of osteocalcin, Runt-related transcription factor-2 and ALP were significantly upregulated in the α-CGRP-Bio-Oss group compared with those in the Bio-Oss group. Furthermore, the effect of mimic-α-CGRP on osteogenesis was reduced as it carried a mutation. In conclusion, the present study was the first to demonstrate that Bio-Oss modified with CGRP contributed to osteogenesis and may provide a novel formulation applied in the clinic for restoration of large bone defects.

Assessment of bone repair in critical-size defect in the calvarium of rats after the implantation of tricalcium phosphate beta (β-TCP)

ObjectivesEvaluating the osteoconductive property of tricalcium phosphate beta (β-TCP) in comparison to that of inorganic bovine bone for repair in a critical-size defect in the rat calvarium.Materials and MethodsCritical-size defects of 7mm were made with a trephine in the calvaria of 48 Wistar rats. The animals were divided into four groups, and the defects in each group were filled with tricalcium phosphate beta (β-TCP), inorganic bovine bone (Bio-Oss), autogenous bone, or left empty. The animals were euthanized at two different time points (30 and 60days post-operation). All defects were recovered with a absorbable membrane of bovine cortical bone. Histological, histometric, and immunohistochemical (osteocalcin) assessments were carried out at 30 and 60days post-operation. ResultsAt 30days post-operation, all groups showed areas of bone formation, predominantly when autogenous grafts were used. However, there were no statistically significant differences between the treatment groups (p>0.05). After 60days, there were similarities in the bone formation patterns between the β-TCP (26.32±) and Bio-Oss (17.35±) groups (p=0.549). In terms of the immunohistochemical assessment of osteocalcin, the clot group showed light to moderate staining at 30 and 60days. The autogenous group showed moderate staining at 30days and moderate to intense staining after 60days. The Bio-Oss group showed light to moderate staining after 30days and intense staining at 60days. The β-TCP group showed moderate staining at 30 and 60days post-operation. Conclusionβ-TCP is a good osteoconductive material with similar effects to those of inorganic bovine bone graft and is suitable for utilization in the repair of bone defects.

Real-Time Assessment of Guided Bone Regeneration in Standardized Calvarial Defects in Rats Using Bio-Oss With and Without Collagen Membrane: An In Vivo Microcomputed Tomographic and Histologic Experiment.

In vivo microcomputed tomography (μCT) enables real-time assessment of bone regeneration. The aim of this μCT and histologic experiment was to assess guided bone regeneration (GBR) around standardized calvarial defects in rats using particulate graft material (Bio-Oss) with and without collagen membranes (CMs). Eighteen female Sprague-Dawley rats aged 6 weeks and weighing 300 g were used. With the rats under general anesthesia, calvaria were exposed and a full-thickness standardized defect was created on the parietal bone. For treatment, rats were randomly assigned to the following three groups: (1) CM group; (2) Bio-Oss group; and (3) Bio-Oss + CM group. Bone volume and bone mineral density (BMD) of newly formed bone (NFB) and remnant bone particles were measured at baseline and 2, 4, 6, and 10 weeks after the operations using real-time in vivo μCT. At 10 weeks, all animals were sacrificed and calvarial tissues were assessed histologically. In the CM group, a significant increase in mean ± standard deviation (SD) BMD of NFB was observed at 6 weeks (0.32 ± 0.02 g/mm(3)) (P < .01) compared with baseline. In the Bio-Oss group, mean ± SD volume (3.03 ± 0.14 mm(3)) (P < .05) and BMD (0.14 ± 0.01 g/mm(3)) of NFB significantly increased at 6 weeks compared with baseline (P < .01). In the Bio-Oss + CM group, mean ± SD volume (0.98 ± 0.19 mm(3)) and BMD (0.13 ± 0.01 g/mm(3)) of NFB significantly increased at 4 weeks compared with baseline (P < .01). In th Bio-Oss + CM group, mean ± SD volume (3.5 ± 0.7 mm(3)) and BMD (0.44 ± 0.03 g/mm(3)) of remnant bone particles were significantly reduced at 10 weeks compared with baseline values (5.8 ± 0.96 mm(3) and 1.3 ± 0.02 g/mm(3)) (P < .05). Although histologic analysis revealed NFB in all the study groups, the Bio-Oss + CM group exhibited the most. The results of this study revealed that, in real time, new bone formation starts as early as 4 weeks in standardized calvarial defects undergoing GBR with Bio-Oss + CM, compared with new bone formation at 6 weeks in defects undergoing GBR with Bio-Oss alone.

Guided Bone Regeneration in Standardized Calvarial Defects in Rats Using Bio-Oss and β-Tricalcium Phosphate with Adjunct Platelet-Derived Growth Factor Therapy: A Real-Time In Vivo Microcomputed Tomographic, Biomechanical, and Histologic Analysis.

The objective of the present real-time in vivo experiment was to assess guided bone regeneration (GBR) in standardized calvarial defects using particulate graft material (Bio-Oss) and β-tricalcium phosphate (β-TCP) with adjunct recombinant human platelet-derived growth factor (rhPDGF) therapy. Eighteen female Sprague-Dawley rats with a mean age and weight of 8 ± 0.53 weeks and 250 ± 0.49 g, respectively, were used. Following surgical exposure, a full-thickness standardized calvarial defect was created on the parietal bone using a trephine drill with an outer diameter of 4.6 mm. For treatment, rats were randomly divided into three groups (six rats per group): (1) control; (2) rhPDGF + Bio-Oss, and (3) rhPDGF + β-TCP. Volume of newly formed bone (NFB), bone mineral density (BMD) of NFB, volume of remnant bone particles, and BMD of remnant bone particles were assessed using in vivo microcomputed tomography. Measurements were made at baseline and at 2, 4, 6, and 10 weeks after the surgical procedures. At 10 weeks, all animals were sacrificed and calvarial tissues were assessed histologically. In the control group, a significant increase in BMD of NFB was observed at 6 weeks (mean ± standard deviation [SD], 0.32 ± 0.002 g/mm(3)) (P < .01) from baseline, and the defect did not regenerate completely. In the rhPDGF + Bio-Oss group, mean ± SD volume (2.40 ± 0.25 mm(3)) (P < .01) and BMD (0.13 ± 0.01 g/mm(3)) of NFB significantly increased at 4 weeks and 6 weeks, respectively, from baseline (P < .001). In the rhPDGF + β-TCP group, mean ± SD volume (2.01 ± 0.7 mm(3)) and BMD (0.12 ± 0.02 g/mm(3)) of NFB significantly increased at 4 weeks from baseline (P < .01). In the rhPDGF + Bio-Oss and rhPDGF + β-TCP groups, mean ± SD BMD of remnant bone particles (0.31 ± 0.11 g/mm(3) and 0.23 ± 0.01 g/mm(3)) showed significant reduction at 6 and 10 weeks, respectively, compared with baseline values (1.12 ± 0.06 g/mm(3) and 0.92 ± 0.01 g/mm(3), respectively) (P < .001). Histologic results at 10 weeks showed NBF in the rhPDGF + Bio-Oss and rhPDGF + β-TCP groups. In real time assessment, when rhPDGF was added to β-TCP, BMD and bone hardness significantly increased compared with the other two groups.

The Study of the Effect of Concentrated Growth Factors (CGF) on the New Bone Regeneration of Immediate Implant

Objective: To study the effect of concentrated growth factor (CGF) on reducing bone resorption in immediate implant. Methods: 20 immediate implant patients were divided into two groups, each group included 10 patients who were treated by adding CGF or Bio-oss to the gap of implant-bone, respectively; the labial new bone regeneration was evaluated in postoperative 1 years using cone beam CT. Results: The buccal bone width variation of the CGF group was 0.85±0.25mm, and the Bio-oss group was 0.35±0.25mm (p &lt;0.05). Conclusion: The CGF has no significant role in promoting new bone regeneration when was used alone in the gap of implant - bone in immediate implant

Influence of the association between platelet-rich fibrin and bovine bone on bone regeneration. A histomorphometric study in the calvaria of rats

This study aimed to investigate the effects of platelet-rich fibrin (PRF) associated or not with Bio-Oss on bone defects in the calvaria of rats. A critical-size defect of 5-mm diameter was performed in the calvaria of 48 rats. These animals were divided into six groups of eight animals each, according to the treatment received: homogeneous clot, autogenous clot, autogenous PRF, homogeneous PRF, Bio-Oss, or Bio-Oss associated with PRF. The animals were euthanized after 30 or 60 days. Bone regeneration was evaluated by histomorphometric analysis. The highest mean percentages of new bone formation at 30 days (54.05%±5.78) and 60 days (63.58%±5.78) were observed in the Bio-Oss associated with PRF group; in particular, the percentage of new bone at 30 days was significantly higher than that of all of the other groups (P<0.01). At 60 days, the Bio-Oss associated with PRF (63.58%±5.78) and Bio-Oss (57.34%±5.78) groups had similar results, and both showed a statistical difference compared to the other groups. PRF had a positive effect on bone regeneration only when associated with Bio-Oss.

Maxillary Sinus Augmentation with a New Xenograft: A Randomized Controlled Clinical Trial.

Insufficient residual alveolar bone height is a common deterrent in the placement of dental implants in the posterior maxilla. The use of autografts, xenografts, allografts and alloplasts or a combination between them has been demonstrated to be effective for increasing bone height and bone volume in the deficient posterior maxilla. The aim of this clinical trial is to comparatively determine the density of newly formed in sinus floor augmentation bone after a 24-week healing period treatment with a new bovine xenograft. The sinus floor was grafted with Bio-Oss® (n = 10) and Osseous® (n = 10). Histological sections were examined with a focus on the presence of connective tissue (CT) and newly formed bone (NFB). The sections were histomorphometrically evaluated and the definitive crown was inserted after 3 months. After 6 months, the mean value of new bone formation was 24.60 (±2.503), the CT was 42.60 (±4.006) and the remaining biomaterial was 25.40 (±2.547) in Bio-Oss group. In Osseous group, the mean value of new bone formation was 24.90 (±3.542), the CT was 45.70 (±7.040) and the remaining biomaterial was 22.90 (±3.247). Both biomaterials afforded a favorable implant position and the prosthetic rehabilitation.

TRAP-Positive Multinucleated Giant Cells Are Foreign Body Giant Cells Rather Than Osteoclasts: Results From a Split-Mouth Study in Humans.

This study compared the material-specific tissue response to the synthetic, hydroxyapatite-based bone substitute material NanoBone (NB) with that of the xenogeneic, bovine-based bone substitute material Bio-Oss (BO). The sinus cavities of 14 human patients were augmented with NB and BO in a split-mouth design. Six months after augmentation, bone biopsies were extracted for histological and histomorphometric investigation prior to dental implant insertion. The following were evaluated: the cellular inflammatory pattern, the induction of multinucleated giant cells, vascularization, the relative amounts of newly formed bone, connective tissue, and the remaining bone substitute material. NB granules were well integrated in the peri-implant tissue and were surrounded by newly formed bone tissue. Multinucleated giant cells were visible on the surfaces of the remaining granules. BO granules were integrated into the newly formed bone tissue, which originated from active osteoblasts on their surface. Histomorphometric analysis showed a significantly higher number of multinucleated giant cells and blood vessels in the NB group compared to the BO group. No statistical differences were observed in regard to connective tissue, remaining bone substitute, and newly formed bone. The results of this study highlight the different cellular reactions to synthetic and xenogeneic bone substitute materials. The significantly higher number of multinucleated giant cells within the NB implantation bed seems to have no effect on its biodegradation. Accordingly, the multinucleated giant cells observed within the NB implantation bed have characteristics more similar to those of foreign body giant cells than to those of osteoclasts.

Migration of Alloplastic Bone Graft Material in Infected Conditions: A Case Study and Animal Experiment

Distant migration associated with sinus lifting procedures has not been investigated. In the present study, a case of distant migration of graft material was observed, and the potential mechanisms of migration were analyzed using material analysis and in vivo experiments. The migrated graft material was biphasic calcium phosphate-based alloplastic material (BCP), and its physical properties were compared with those of xenogenic material (Bio-Oss). The comparisons of the physical properties were performed using scanning electronic microscopic, x-ray diffraction, and Fourier-transform infrared absorbance spectra analysis. The comparative graft migration study was performed using the subcutaneous pocket model in rats (n = 10). The clinical case was analyzed by histologic section and energy dispersive x-ray (EDX) microanalysis. The observed diffraction patterns from the Bio-Oss revealed characteristic diffractions for the hydroxyapatite phase, and those from the BCP revealed additional diffractions that could be assigned to the tricalcium phosphate phase. In the animal model, the graft migration distances observed in the BCP group were significantly greater than those observed in the Bio-Oss group (P = .012). In the clinical case, the lymphatic vessels of the submandibular gland contained foreign materials that were morphologically similar to those of the maxillary sinus. EDX microanalysis revealed that the particles in the lymphatic vessels exhibited calcium concentrations that were approximately 200 times greater than those in the adjacent glandular tissue. In the present study, BCP-based sinus grafts had migrated into the submandibular glandular area by way of the lymphatic chain in the presented clinical case.

A prospective study on the effectiveness of newly developed autogenous tooth bone graft material for sinus bone graft procedure.

PURPOSEThe purpose of this prospective study was to evaluate the effectiveness of newly developed autogenous tooth bone graft material (AutoBT)application for sinus bone graft procedure.MATERIALS AND METHODSThe patients with less than 5.0 mm of residual bone height in maxillary posterior area were enrolled. For the sinus bone graft procedure, Bio-Oss was grafted in control group and AutoBT powder was grafted in experimental group. Clinical and radiographic examination were done for the comparison of grafted materials in sinus cavity between groups. At 4 months after sinus bone graft procedure, biopsy specimens were analyzed by microcomputed tomography and histomorphometric examination for the evaluation of healing state of bone graft site.RESULTSIn CT evaluation, there was no difference in bone density, bone height and sinus membrane thickness between groups. In microCT analysis, there was no difference in total bone volume, new bone volume, bone mineral density of new bone between groups. There was significant difference trabecular thickness (0.07 µm in Bio-Oss group Vs. 0.08 µm in AutoBT group) (P=.006). In histomorphometric analysis, there was no difference in new bone formation, residual graft material, bone marrow space between groups. There was significant difference osteoid thickness (8.35 µm in Bio-Oss group Vs. 13.12 µm in AutoBT group) (P=.025).CONCLUSIONAutoBT could be considered a viable alternative to the autogenous bone or other bone graft materials in sinus bone graft procedure.

Histologic Evaluation of Osseous Regeneration Following Combination Therapy With Platelet-Rich Plasma and Bio-Oss in a Rat Calvarial Critical-Size Defect Model

Platelet-rich plasma (PRP) is an autogenous source of growth factors shown to facilitate human bone growth. Bio-Oss, an osteoconductive xenograft, is used clinically to regenerate periodontal defects, restore dental alveolar ridges, and facilitate sinus-lift procedures. The purpose of this study was to analyze whether a combination of PRP and Bio-Oss would enhance bone regeneration better than either material alone. PRP and/or Bio-Oss were administered in an 8-mm critical-size defect (CSD) rat calvarial model of bone defect between 2 polytetrafluoroethylene membranes to prevent soft tissue incursion. Eight weeks after the induction of the CSD, histologic sections were stained with hematoxylin and eosin stain and analyzed via light microscopy. Qualitative analyses revealed new bone regeneration in all 4 groups. The Bio-Oss and PRP plus Bio-Oss groups demonstrated greater areas of closure in the defects than the control or PRP-only groups because of the space-maintaining ability of Bio-Oss. The groups grafted with Bio-Oss showed close contact with new bone growth throughout the defects, suggesting a stronger graft. The use of PRP alone or in combination with Bio-Oss, however, did not appear to enhance osseous regeneration at 8 weeks. Areas grafted with Bio-Oss demonstrated greater space-maintaining capacity than controls, and PRP was an effective vehicle for placement of the Bio-Oss. However, at 8 weeks this study was unable to demonstrate a significant advantage of using PRP plus Bio-Oss over using Bio-Oss alone.

Fabrication and Evaluation of Porous Beta‐Tricalcium Phosphate/Hydroxyapatite (60/40) Composite as a Bone Graft Extender Using Rat Calvarial Bone Defect Model

Beta-tricalcium phosphate (β-TCP) and hydroxyapatite (HA) are widely used as bone graft extenders due to their osteoconductivity and high bioactivity. This study aims to evaluate the possibility of using porous substrate with composite ceramics (β-TCP: HA = 60% : 40%, 60TCP40HA) as a bone graft extender and comparing it with Bio-Oss. Interconnectivity and macroporosity of β-TCP porous substrate were 99.9% and 83%, respectively, and the macro-porosity of packed granule after crushing was 69%. Calvarial defect model with 8 mm diameter was generated with male Sprague-Dawley rats and 60TCP40HA was implanted. Bio-Oss was implanted for a control group and micro-CT and histology were performed at 4 and 8 weeks after implantation. The 60TCP40HA group showed better new bone formation than the Bio-Oss group and the bone formation at central area of bone defect was increased at 8 weeks in micro-CT and histology. The percent bone volume and trabecular number of the 60TCP40HA group were significantly higher than those of Bio-Oss group. This study confirms the usefulness of the porous 60TCP40HA composite as a bone graft extender by showing increased new bone formation in the calvarial defect model and improved bone formation both quantitatively and qualitatively when compared to Bio-Oss.

Clinical and radiographic outcomes of delayed implant placements after maxillary sinus floor augmentation with different grafting materials

To evaluate the long-term clinical outcome of delayed implant placements after maxillary sinus floor augmentation with autologous bone or Bio-Oss grafting. Eighteen patients underwent maxillary sinus floor augmentation and delayed implant placements from January, 2002 to December, 2008. Bone grafting and sinus floor augmentation were performed in 21 sides of maxilla and 46 implants were placed 6 - 8 months later. Residual bone height was less than 4 mm. The cases were divided to 2 groups and different materials (autologous bone + Bio-Oss and Bio-Oss alone) were grafted relatively. The bone resorption was assessed by panoramic X-ray and the stability of the implant was reviewed postoperatively. The average follow-up time was 54 months. Only one implant was lost and the implant survival rate was 98%. X-ray showed that the bone resorption was observed in both groups. The absorption ratio of autologous bone + Bio-Oss group was 18.65% and that of the Bio-oss group was 1.93%. The difference was significantly different. The result of maxillary sinus floor augmentation with bone grafting was predictable. More bone absorption occurred in the Bio-Oss than in autologous bone + Bio-Oss.

Osteocyte lacunar density and area in newly formed bone of the augmented sinus

Osteocytes, the most common cells of the bone, are buried in lacunae. Density and area of the osteocyte lacunae change with increasing maturation of the newly formed bone. Evaluation of osteocyte lacunae can therefore provide insights into the process of graft consolidation. Here, we determined the osteocyte lacunar density (number of osteocyte lacunae per bone area; N.Ot/BAr) and the osteocyte lacunar area in μm(2) (Lac.Ar) in histological specimens 6 and 12weeks after the sinuses of 10 minipigs were augmented with Bio-Oss(®) , a deproteinized bovine bone mineral, and Ostim(®) , an aqueous paste of synthetic nanoparticular hydroxyapatite. The region of interest was defined by the following criteria: (i) >1mm from the host bone, (ii) >0.5mm from the sinus mucosa, (iii) minimum area of 0.2mm(2) , and (iv) bone tissue spanning at least two bone substitute particles. The overall osteocyte lacunar density was significantly higher in the Bio-Oss(®) group than in the Ostim(®) group and decreased during the observation period at a similar range in both groups. The osteocyte lacunar area was smaller in the Bio-Oss(®) group than the Ostim(®) group but there was no significant change within the groups over time. These results suggest that bone substitutes affect the osteocyte lacunar density and the osteocyte lacunar area in the newly formed bone within the augmented sinus in this particular model situation. These measures can provide insights into the maturation of newly formed bone in the augmented sinus.

Maxillary sinus floor augmentation using gene-enhanced tissue engineered bone

To evaluate the effect of maxillary sinus elevation with gene-enhanced tissue engineering bone in dogs. bone marrow stromal cells (BMSC) derived from dog marrow were cultured, and transduced with the adenovirus carrying bone morphogenetic protein-2 (BMP-2) gene (AdBMP-2), the adenovirus carrying green fluorescent protein (GFP) gene (AdGFP) in vitro. The bone formation ability of gene modified BMSC with scaffold was examined in nude mice and in elevated maxillary sinus of dog. Student's t-test was used for statistical analysis with SPSS 11.0 software package. Gene transfection efficiency reached up to (83.95 ± 2.43)% as demonstrated by GFP expression. Ectopic bone formation was detected in nude mice. As for maxillary sinus floor elevation in a dog model, new bone formation area in the AdBMP-2 gene transduced BMSC with Bio-Oss group was significantly higher than in BMSC with Bio-Oss group at 120 d (P < 0.05). AdBMP-2 gene transduced BMSC can stimulate ectopic bone formation in nude mice, and promote bone formation and maturation in the dog maxillary sinus.

Increased new bone formation with a surface magnesium‐incorporated deproteinized porcine bone substitute in rabbit calvarial defects

This study investigated the effects of magnesium ion (Mg) incorporation into the surface of deproteinized porcine cancellous bone in the bone healing of rabbit calvarial defects with the expectation of utilizing the integrin-ligand binding enhancement effect of Mg, and compared its bone healing capacity with that of untreated porcine cancellous bone and deproteinized bovine bone (Bio-Oss). Hydrothermal treatment was performed to produce Mg-incorporated porcine bone using an alkaline Mg-containing solution. The surface morphology and chemical composition of the samples were investigated using scanning electron microscopy, energy-dispersive X-ray spectrometry, and X-ray photoelectron spectroscopy. Defects 7 mm in diameter were created in the calvaria of 14 adult male New Zealand White rabbits and were filled with (1) untreated porcine bone (PB), (2) Bio-Oss, and (3) Mg-containing porcine bone (MG). The percentage of newly formed bone (NB%) was evaluated histomorphometrically at 2 and 4 weeks after implantation. Hydrothermal treatment resulted in a Mg-containing surface in porcine bone covered with nanostructures ~100 nm in size. The MG group supported better new bone formation compared with the other groups. Osteoconductive new bone formation was observed in the central defect area in the MG group at an early healing time-point. Histomorphometric analysis revealed significantly greater NB% in the MG group when compared with the untreated PB and Bio-Oss groups at 4 weeks (p < 0.05). The Mg-incorporated porcine bone with surface nanostructures achieved rapid new bone formation in the osseous defects of rabbit calvaria compared with untreated xenografts of porcine and bovine origin.