Development and characterization of waste equine bone-derived calcium phosphate cements with human alveolar bone-derived mesenchymal stem cells

Calcium phosphate cements (CPCs) are regarded as promising graft substitutes for bone tissue engineering. However, their wide use is limited by the high cost associated with the complex synthetic processes involved in their fabrication. Cheaper xenogeneic calcium phosphate (CaP) materials derived from waste animal bone may solve this problem. Moreover, the surface topography, mechanical strength, and cellular function of CPCs are influenced by the ratio of micro- to nano-sized CaP (M/NCaP) particles. In this study, we developed waste equine bone (EB)-derived CPCs with various M/NCaP particle ratios to examine the potential capacity of EB-CPCs for bone grafting materials. Our study showed that increasing the number of NCaP particles resulted in reductions in roughness and porosity while promoting smoother surfaces of EB-CPCs. Changes in the chemical properties of EB-CPCs by NCaP particles were observed using X-ray diffractometry. The mechanical properties and cohesiveness of the EB-CPCs improved as the NCaP particle content increased. In an in vitro study, EB-CPCs with a greater proportion of MCaP particles showed higher cell adhesion. Alkaline phosphatase activity indicated that osteogenic differentiation by EB-CPCs was promoted with increased NCaP particle content. These results could provide a design criterion for bone substitutes for orthopedic disease, including periodontal bone defects.

Guided bone regeneration with osteoconductive grafts and PDGF: A tissue engineering option for segmental bone defect reconstruction

Regeneration and reconstruction of segmental bone defects (SBD) is a clinical challenge in maxillofacial surgery and orthopedics. The present study evaluated efficacy of guided bone-regeneration (GBR) of rat femoral SBD using osteoconductive equine-bone (EB) and beta-tricalcium phosphate (beta-TCP) grafts, either with or without platelet-derived growth-factor (PDGF). Following ethical-approval, 50 male Wistar-Albino rats (aged ~12-15 months and weighing ~450-500 g) were included. A 5 mm femoral critical-size SBD was created and animals were divided into five groups depending on the graft material used for GBR (EB, EB + PDGF, Autograft, beta-TCP, beta-TCP + PDGF; n = 10/group). Following 12-weeks of healing, animals were sacrificed and femur specimens were analyzed through qualitative histology and quantitative histomorphometry. There was new bone bridging femoral SBD in all groups and qualitatively, better bone formation was seen in autograft and EB + PDGF groups. Histomorphometric bone-area (BA %) was significantly high in autograft group, followed by EB + PDGF, beta-TCP + PDGF, EB, and beta-TCP groups. Addition of PDGF to EB and beta-TCP during GBR resulted in significantly higher BA%. After 12-weeks of healing, EB + PDGF for GBR of rat femoral segmental defects resulted in new bone formation similar to that of autograft. Based on this study, GBR with EB and adjunct PDGF could be a potential clinical alternative for reconstruction and regeneration of segmental bone defects.

Aligned Nanofiber-Guided Bone Regeneration Barrier Incorporated with Equine Bone-Derived Hydroxyapatite for Alveolar Bone Regeneration

Post-surgery failure of dental implants due to alveolar bone loss is currently critical, disturbing the quality of life of senior dental patients. To overcome this problem, bioceramic or bone graft material is loaded into the defect. However, connective tissue invasion instead of osteogenic tissue limits bone tissue regeneration. The guided bone regeneration concept was adapted to solve this problem and still has room for improvements, such as biochemical similarity or oriented structure. In this article, an aligned electrospun-guided bone regeneration barrier with xenograft equine bone-derived nano hydroxyapatite (EBNH-RB) was fabricated by electrospinning EBNH/PCL solution on high-speed rotating drum collector and fiber characterization, viability and differentiation enhancing properties of mesenchymal dental pulp stem cell on the barrier was determined. EBNH-RB showed biochemical and structural similarity to natural bone tissue electron microscopy image analysis and x-ray diffractometer analysis, and had a significantly better effect in promoting osteogenesis based on the increased bioceramic content by promoting cell viability, calcium deposition and osteogenic marker expression, suggesting that they can be successfully applied to regenerate alveolar bone as a guided bone regeneration barrier.

Horizontal bone grafting using equine-derived cancellous bone blocks is associated with severe complications: A prospective clinical and histological pilot study

AIMS

The aim of this prospective, clinical study was to evaluate the clinical performance and histological outcome of a new equine hydroxyapatite collagenated bone block (eHAC) for horizontal bone grafting prior to implant placement.

MATERIALS AND METHODS

Five patients (two male/three female) with a mean age of 51.6 years (range 22-66 years) and a reduced horizontal bone width of the alveolar ridge (mean 3.5 mm) underwent horizontal bone grafting using eHAC at 10 grafting sites. Reentry was performed 6.9 months after the horizontal grafting procedure. Clinical follow-up (mean 28.9 month) considered width gain of the alveolar ridge, soft tissue healing, and complications. To evaluate graft incorporation, four additional patients underwent histological assessment of equine blocks adjacent to autologous blocks 3 and 6 months after grafting.

RESULTS

The study was terminated after graft failure was observed in four of five patients. Mean horizontal bone width had increased by 3.6 ± 1.22 mm. Three out of nine implants placed had to be removed due to graft failure. Histological evaluation revealed large amounts of soft connective tissue within the grafts (mean 67.3 ± 9.5%). The proportion of new bone formation 3 months after the lateral grafting procedure revealed an average of 8.6%, compared to 11.4% after 6 to 7 months.

CONCLUSION

Lateral ridge grafting using eHAC achieved measurable horizontal width gain but revealed high rates of severe complications.

CLINICAL IMPLICATIONS

Within the limitations of this study, eHAC bone blocks cannot be recommended for horizontal bone grafting.

Guided Bone Regeneration of an Atrophic Mandible with a Heterologous Bone Block

The aim of this work was to test the effectiveness of using enzymatically deantigenated equine bone block as a scaffold for guided bone regeneration (GBR) during a horizontal augmentation of the lower jaw. A partially edentulous atrophic mandible was augmented using an equine-derived block with an expanded polytetrafluoroethylene membrane. After 8.5 months, two bone core samples were collected at the augmentation site, and implants were placed. A definitive prosthesis delivered 6 months after implant placement provided excellent functional and aesthetic rehabilitation throughout the follow-up period. Histological and histomorphometrical analysis of the biopsies showed newly formed bone to be present and the residual biomaterial was still undergoing remodeling. Comparison of cone beam computed tomography scans taken before augmentation and 26 months later showed maintenance of ridge width and possible corticalization of the vestibular augmented ridge side. The equine-derived bone block placed in accordance with GBR principles provided a successful clinical, radiographic, and histological outcome.

Prognosis of Deantigenated Equine Bone Used for Bone Augmentation: A Multicenter Retrospective Study on Early and Late Postsurgical Complications in 81 Consecutive Patients

PURPOSE

To evaluate the clinical outcome of deantigenated equine bone (DEB) grafts in a series of patients treated with DEB at six months postaugmentation.

MATERIALS AND METHODS

One hundred DEB grafts were inserted in 81 patients between January 2004 and December 2006. Thirty-two DEBs were blocks and 68 were granules (52 sinus lift and 16 guided bone regeneration [GBR] procedures performed). A total of 147 implants were inserted. A Pearson chi-square test was used to detect any statistically significant correlation between the studied variables and early and/or late failures.

RESULTS

There were 6 early and 26 late graft failures and another 16 failures after prosthesis placement. The overall failure rate was 25% in the GBR procedures, 31.9% in sinus lift, and 54.3% with blocks, for a total complication rate of 39.5%. A statistically significant relation was detected with respect to graft type and early complications (p = .005), with a worse outcome for DEB blocks compared to granules. After provisional prosthesis restoration, 23 implants were lost, and another 41 failed after definitive prosthesis delivery, for an overall failure rate of 43.5%. The follow-up period was 3 years after surgery.

CONCLUSIONS

DEB grafting material had a very high rate of complications. Blocks had more than 50% failures, mainly in the immediate postoperative period. Other procedures such as GBR and sinus lift also showed more than 25% infections and resorption, and late failures (i.e., after-implant placement) were also common. Our results show that DEB is less than ideal for crestal bone reconstruction.