Implant stability and clinical outcome between implant placement using internal sinus floor elevation with alloplastic bone material grafting and without grafting: A 1-year randomized clinical trial.

OBJECTIVE: To compare implant stability and clinical outcome in implant placement between osteotome sinus floor elevation (OSFE) with biphasic calcium phosphate (BCP) which consisted of 30% of hydroxyapatite (HA) and 70% of beta-tricalcium phosphate (ß -TCP) grafting material and OSFE without using bone grafting material. The research questions is whether the BCP provides any benefit in OSFE or not. MATERIALS AND METHODS: Thirty patients (30 implants) with a single edentulous area of upper premolar or molar were randomly separated into OSFE with BCP (n = 15) and OSFE without grafting (n = 15). The patients were reevaluated 3, 6, 9, and 12 months after implant loading. The clinical assessments (implant stability quotient (ISQ), implant survival-failure rate, and surgical complication) were analyzed. Together with radiographic assessments in 2D (endo-sinus bone gain (ESBG), mean marginal bone change (MMBC)) and 3D (endo-sinus bone gain in CBCT (ESBG-CT)) were evaluated, with a mean follow-up time of at least 12 months of functional loading and prosthetic complication. RESULTS: 20 remaining implants (OSFE with BCP, n = 10; OSFE without grafting, n = 10) were analyzed. Mean ISQ was 79.18 ± 3.43 in 1-year follow-up (ISQ; OSFE with BCP = 78.72 ± 3.46, OSFE without grafting = 79.65 ± 3.52). ISQ in both groups increased steadily without significant differences in each follow-up. (p = 0.56). In radiographic evaluation, at 6-, 9-, and 12-month, OSFE without grafting group showed statistically significant lower MMBC (p < 0.05). The 1-year clinical results showed that 2 implants failed in OSFE with BCP, and 1 implant failed in OSFE without grafting. CONCLUSIONS: Graft material "BCP" (HA30:TCP70) coupled with OSFE presents no extraordinary benefit in implant stability, clinical and radiographic outcome in 1-year follow-up. CLINICAL RELEVANCE: Clinically, OSFE with grafting materials provides no additional benefit. CLINICAL TRIAL REGISTRATION NUMBER: TCTR20210517008 (date of registration: May 17, 2021).

Use of F18 bioglass putty for induced membrane technique in segmental bone defect of the radius in rabbits.

PURPOSE: To evaluate the inductive capacity of F18 bioglass putty on the induced membrane technique in a segmental bone defect of the rabbit's radius. METHODS: Ten female Norfolk at 24 months of age were used. The animals were randomly separated based on postoperative time points: five rabbits at 21 and four at 42 days. A 1-cm segmental bone defect was created in both radii. The bone defects were filled with an F18 bioglass putty. RESULTS: Immediate postoperative radiographic examination revealed the biomaterial occupying the segmental bone defect as a well-defined radiopaque structure with a density close to bone tissue. At 21 and 42 days after surgery, a reduction in radiopacity and volume of the biomaterial was observed, with particle dispersion in the bone defect region. Histologically, the induced membrane was verified in all animals, predominantly composed of fibrocollagenous tissue. In addition, chondroid and osteoid matrices undergoing regeneration, a densely vascularized tissue, and a foreign body type reaction composed of macrophages and multinucleated giant cells were seen. CONCLUSIONS: the F18 bioglass putty caused a foreign body-type inflammatory response with the development of an induced membrane without expansion capacity to perform the second stage of the Masquelet technique.

A new hydroxyapatite-alginate-gelatin biocomposite favor bone regeneration in a critical-sized calvarial defect model.

This study aimed to evaluate the osteogenic potential of hydroxyapatite (HA), Alginate (Alg), and Gelatine (Gel) composite in a critical-size defect model in rats. Twenty-four male rats were divided into three groups: a negative control with no treatment (Control group), a positive control treated with deproteinized bovine bone mineral (DBBM group), and the experimental group treated with the new HA-Alg-Gel composite (HA-Alg-Gel group). A critical size defect (8.5mm) was made in the rat's calvaria, and the bone formation was evaluated by in vivo microcomputed tomography analysis (µCT) after 1, 15, 45, and 90 days. After 90 days, the animals were euthanized and histological and histomorphometric analyses were performed. A higher proportion of mineralized tissue/biomaterial was observed in the DBBM group when compared to the HA-Alg-Gel and Control groups in the µCT analysis during all analysis periods. However, no differences were observed in the mineralized tissue/biomaterial proportion observed on day 1 (immediate postoperative) in comparison to later periods of analysis in all groups. In the histomorphometric analysis, the HA-Alg-Gel and Control groups showed higher bone formation than the DBBM group. Moreover, in histological analysis, five samples of the HA-Alg-Gal group exhibited formed bone spicules adjacent to the graft granules against only two of eight samples in the DBBM group. Both graft materials ensured the maintenance of defect bone thickness, while a tissue thickness reduction was observed in the control group. In conclusion, this study demonstrated the osteoconductive potential of HA-Alg-Gel bone graft by supporting new bone formation around its particles.

3D-printed porous tantalum artificial bone scaffolds: fabrication, properties, and applications.

Porous tantalum scaffolds offer a high degree of biocompatibility and have a low friction coefficient. In addition, their biomimetic porous structure and mechanical properties, which closely resemble human bone tissue, make them a popular area of research in the field of bone defect repair. With the rapid advancement of additive manufacturing, 3D-printed porous tantalum scaffolds have increasingly emerged in recent years, offering exceptional design flexibility, as well as facilitating the fabrication of intricate geometries and complex pore structures that similar to human anatomy. This review provides a comprehensive description of the techniques, procedures, and specific parameters involved in the 3D printing of porous tantalum scaffolds. Concurrently, the review provides a summary of the mechanical properties, osteogenesis and antibacterial properties of porous tantalum scaffolds. The use of surface modification techniques and the drug carriers can enhance the characteristics of porous tantalum scaffolds. Accordingly, the review discusses the application of these porous tantalum materials in clinical settings. Multiple studies have demonstrated that 3D-printed porous tantalum scaffolds exhibit exceptional corrosion resistance, biocompatibility, and osteogenic properties. As a result, they are considered highly suitable biomaterials for repairing bone defects. Despite the rapid development of 3D-printed porous tantalum scaffolds, they still encounter challenges and issues when used as bone defect implants in clinical applications. Ultimately, a concise overview of the primary challenges faced by 3D-printed porous tantalum scaffolds is offered, and corresponding insights to promote further exploration and advancement in this domain are presented.

Evaluation optimum ratio of synthetic bone graft material and platelet rich fibrin mixture in a metal 3D printed implant to enhance bone regeneration.

BACKGROUND: This study aims to evaluate the optimal ratio of synthetic bone graft (SBG) material and platelet rich fibrin (PRF) mixed in a metal 3D-printed implant to enhance bone regeneration. METHODS: Specialized titanium hollow implants (5 mm in diameter and 6 mm in height for rabbit; 6 mm in diameter and 5 mm in height for pig) were designed and manufactured using 3D printing technology. The implants were divided into three groups and filled with different bone graft combinations, namely (1) SBG alone; (2) PRF to SBG in 1:1 ratio; (3) PRF to SBG in 2:1 ratio. These three groups were replicated tightly into each bone defect in distal femurs of rabbits (nine implants, n = 3) and femoral shafts of pigs (fifteen implants, n = 5). Animal tissue sections were obtained after euthanasia at the 8th postoperative week. The rabbit specimens were stained with analine blue, while the pig specimens were stained with Masson-Goldner's trichrome stain to perform histologically examination. All titanium hollow implants were well anchored, except in fracture specimens (three in the rabbit and one fracture in the pig). RESULT: Rabbit specimens under analine blue staining showed that collagen tissue increased by about 20% and 40% in the 1:1 ratio group and the 2:1 ratio group, respectively. Masson-Goldner's trichrome stain results showed that new bone growth increased by 32% in the 1:1 ratio PRF to SBG, while - 8% in the 2:1 ratio group. CONCLUSION: This study demonstrated that placing a 1:1 ratio combination of PRF and SBG in a stabilized titanium 3D printed implant resulted in an optimal increase in bone growth.

A model approach to show that monocytes can enter microporous ß-TCP ceramics.

ß-TCP ceramics are versatile bone substitute materials and show many interactions with cells of the monocyte-macrophage-lineage. The possibility of monocytes entering microporous ß-TCP ceramics has however not yet been researched. In this study, we used a model approach to investigate whether monocytes might enter ß-TCP, providing a possible explanation for the origin of CD68-positive osteoclast-like giant cells found in earlier works.We used flow chambers to unidirectionally load BC, PRP, or PPP into slice models of either 2 mm or 6 mm ß-TCP. Immunofluorescence for CD68 and live/dead staining was performed after the loading process.Our results show that monocytes were present in a relevant number of PRP and BC slices representing the inside of our 2 mm slice model and also present on the actual inside of our 6 mm model. For PPP, monocytes were not found beyond the surface in either model.Our results indicate the possibility of a new and so far neglected constituent in ß-TCP degradation, perhaps causing the process of ceramic degradation also starting from inside the ceramics as opposed to the current understanding. We also demonstrated flow chambers as a possible new in vitro model for interactions between blood and ß-TCP.

Investigating the in-vitro bioactivity, biodegradability and drug release behavior of the newly developed PES/HA/WS biocompatible nanocomposites as bone graft substitute.

The nucleation of carbonate-containing apatite on the biomaterials surface is regarded as a significant stage in bone healing process. In this regard, composites contained hydroxyapatite (Ca10(PO4)6(OH)2, HA), wollastonite (CaSiO3, WS) and polyethersulfone (PES) were synthesized via a simple solvent casting technique. The in-vitro bioactivity of the prepared composite films with different weight ratios of HA and WS was studied by placing the samples in the simulated body fluid (SBF) for 21 days. The results indicated that the the surface of composites containing 2 wt% HA and 4 wt% WS was completely covered by a thick bone-like apatite layer, which was characterized by Grazing incidence X-ray diffraction, attenuated total reflectance-Fourier transform infrared spectrometer, field emission electron microscopy and energy dispersive X-ray analyzer (EDX). The degradation study of the samples showed that the concentration of inorganic particles could not influence the degradability of the polymeric matrix, where all samples expressed similar dexamethasone (DEX) release behavior. Moreover, the in-vitro cytotoxicity results indicated the significant cyto-compatibility of all specimens. Therefore, these findings revealed that the prepared composite films composed of PES, HA, WS and DEX could be regarded as promising bioactive candidates with low degradation rate for bone tissue engineering applications.

Time to full weight-bearing with the use of a calcium sulfate-calcium phosphate bone substitute as a bone void filler following extended curettage in the treatment of primary benign bone tumours.

PURPOSE: The primary objective of this study was to determine time to full weight-bearing after the use of a calcium-sulfate-calcium phosphate bone substitute (CaSO4/CaPO4) as a bone void filler in the treatment of primary benign bone tumours following intralesional curettage. The secondary objectives were to determine surgical complications and recurrence rates. METHODS: Retrospective review of patients identified from a surgeon-specific orthopaedic oncology database, who underwent curettage of benign bone tumours and subsequent bone void filling with CaSO4/CaPO4. RESULTS: A total of 39 patients (20 males, 19 females) met inclusion criteria with an average age of 31 years (range: 13 to 62 years), a median follow-up of 3.7 years, and a maximum follow-up of 11 years. The most common tumour diagnosis was giant cell tumour of bone (GCT) (n = 19), and the most common location was the proximal tibia (n = 9). The mean volume of tumour excised was 74.1 cm3 including extraosseous bone expansion due to tumour growth, with a mean of volume of 21.4 mL of CaSO4/CaPO4 used to fill the intraosseous cavitary defects to restore normal bone anatomy. None of the lesions required additional internal fixation. The primary outcome measure, average time to full weight-bearing/full range of motion, was 11 weeks and 6 weeks for upper and lower extremity lesions, respectively. Secondary outcomes included tumour recurrence requiring reoperation in five patients and infection requiring reoperation in two patients. CONCLUSION: This study demonstrates that CaSO4/CaPO4 is a viable option as a bone void filler in the reconstruction of cavitary defects following removal of primary benign bone tumours. CaSO4/CaPO4 provides sufficient bone regeneration early in the post-operative period to allow progression to full weight-bearing within weeks without the need for internal fixation. There were no graft-specific complications noted.

Reconstruction of Segmental Bone Defect in Canine Tibia Model Utilizing Bi-Phasic Scaffold: Pilot Study.

The reunion and restoration of large segmental bone defects pose significant clinical challenges. Conventional strategies primarily involve the combination of bone scaffolds with seeded cells and/or growth factors to regulate osteogenesis and angiogenesis. However, these therapies face inherent issues related to immunogenicity, tumorigenesis, bioactivity, and off-the-shelf transplantation. The biogenic micro-environment created by implanted bone grafts plays a crucial role in initiating the bone regeneration cascade. To address this, a highly porous bi-phasic ceramic synthetic bone graft, composed of hydroxyapatite (HA) and alumina (Al), was developed. This graft was employed to repair critical segmental defects, involving the creation of a 2 cm segmental defect in a canine tibia. The assessment of bone regeneration within the synthetic bone graft post-healing was conducted using scintigraphy, micro-CT, histology, and dynamic histomorphometry. The technique yielded pore sizes in the range of 230-430 µm as primary pores, 40-70 µm as secondary inner microchannels, and 200-400 nm as tertiary submicron surface holes. These three components are designed to mimic trabecular bone networks and to provide body fluid adsorption, diffusion, a nutritional supply, communication around the cells, and cell anchorage. The overall porosity was measured at 82.61 ± 1.28%. Both micro-CT imaging and histological analysis provided substantial evidence of robust bone formation and the successful reunion of the critical defect. Furthermore, an histology revealed the presence of vascularization within the newly formed bone area, clearly demonstrating trabecular and cortical bone formation at the 8-week mark post-implantation.

Synchrotron Analysis of Damaged Extraction Sockets Augmented Using a Synthetic Bone Block: A Pilot Study.

This study aimed to investigate the dimensional stability and quality of the alveolar ridge augmented using a synthetic bone block (SBB) at damaged extraction sockets. Four participants were included, and socket augmentation was performed using SBB and a collagen membrane. Intraoral and CBCT scans were performed before extraction (baseline), immediately postoperative (IP), and at 6 months postoperative (6M). At 6M, a trephine biopsy sample was obtained during implant placement, and the sample was observed using synchrotron. Soft tissue profile changes were assessed using profilometric analysis of the intraoral scan data, while dimensional changes in hard tissue were evaluated based on CBCT measurements. Bone quality was analyzed using synchrotron imaging. There were minimal changes in the soft tissue profile between baseline and IP, baseline and 6M, and IP and 6M (0.11 ± 1.08 mm3, 0.02 ± 0.8 mm3, and -0.65 ± 0.82 mm3, respectively). Horizontal bone width was measured at 1-mm increments from the augmented bone crest to 5 mm apically and revealed only a slight reduction (< 1 mm) at all levels between IP and 6M. The augmented bone height was well maintained from IP until 6M (-0.21 ± 0.53 mm). Synchrotron analysis revealed low to moderate bone quality after 6M (percentage of new bone: 16.49% ± 4.91%). Socket augmentation using SBB appears to be a viable technique for regenerating damaged extraction sockets, with the augmented ridge dimensions maintained up to 6M. Further long-term randomized clinical trials are needed.

Contour Augmentation for Periodontal Defects (CAPD) for Periodontally Compromised Teeth with Horizontal Bone Loss: A Prospective Cohort Assessment at 1 Year.

This study assessed the effects of buccal contour augmentation for periodontally compromised teeth with horizontal bone loss. A total of 30 subjects were divided into Group A or Group B (n = 15 subjects per group). Group A received open-flap debridement (OFD) with buccal contour augmentation using deproteinized bovine bone mineral (DBBM), jointly referred to as contour augmentation for periodontal defects (CAPD; test group). Group B received only OFD (control group). Bleeding on probing (BOP), clinical attachment level (CAL), probing depth (PD), gingival recession (GR), keratinized mucosa width (WKM), keratinized mucosa thickness (TKM), and labial cortical plate thickness were compared at baseline and 1 year. BOP, CAL, PD, and GR did not show significant differences. TKM increased by 1.76 mm for Group A but decreased by 1 mm for Group B. WKM increased from 2.86 ± 0.4 mm to 3.6 ± 0.71 mm (P < .001) and from 2.93 ± 0.32 mm to 3 ± 0.7 mm (P = 0.5) for Groups A and B, respectively, which showed statistical significance. Labial cortical plate thickness increased from 0.94 ± 0.3 mm to 1.95 ± 0.54 mm (P < .001) for Group A but decreased from 0.87 ± 0.45 mm to 0.68 ± 0.31 mm for Group B. Visual analog scale scores for pain perception showed no difference between the two groups. CAPD for periodontally compromised teeth improves WKM and TKM. Long-term analyses are needed to determine its benefits in daily clinical practice.

Novel Synthetic Carbonate Apatite as a Bone Substitute in Implant Treatments: Case Reports.

Bone graft materials are often used in implant treatment to optimize functional and esthetic outcomes. The requirements for bone grafting materials are the ability to maintain space for bone regeneration to occur and the capability of being resorbed by osteoclasts and replaced with new bone tissue occurring in passive chemolysis and bone remodeling. Carbonate apatite (CO3Ap) granules (Cytrans Granules, GC) are a chemically synthetic bone graft material similar to autogenous bone minerals and more biocompatible than allografts and xenografts. The aim of this report is to evaluate the efficacy of CO3Ap granules in implant treatments when used alone or in combination with autogenous bone. The clinical findings and the radiographic and histologic assessments in three cases of immediate implant placement and lateral and vertical guided bone regeneration are reported. Despite the short-term follow-ups, histologic findings showed that CO3Ap granules were efficiently resorbed and replaced bone in clinical use. Furthermore, the clinical findings showed that CO3Ap granules maintained their morphology around the implant. This limited short-term case report suggests that this bone substitute is effective. However, further clinical studies and long-term reports of this new biomaterial are needed.

Comparison Between Corticocancellous Allograft and Bovine Xenograft for Sinus Augmentation: A Radiographic, Histologic, and Histomorphometric Clinical Study.

Sinus floor augmentation is one of the most common approaches to obtain sufficient bone availability for placing implants in cases with severe bone atrophy in the posterior maxilla. Several bone substitutes are indicated for sinus augmentation, but they may achieve different clinical outcomes. This study aims to compare bovine bone mineral (BBM) with freeze-dried bone allograft (FDBA) in a two-stage lateral window sinus grafting approach. Twenty patients received a lateral window sinus elevation with either FDBA or BBM. Postoperative graft height was measured with CBCT. Implants were placed 6 months later, at which time biopsy samples were taken for histologic analysis and new CBCT scans were performed to measure graft height. The mean height reduction at 6 months was 20.27% ± 4.94% for FDBA samples and 5.36% ± 2.41% for BBM samples. The histologic analysis revealed a mean ratio of newly formed bone of 43.70% ± 5.29% for the FDBA group and 38.11% ± 4.03% for the BBM group. The FDBA group also showed a higher amount of residual biomaterial (17.25% ± 10.10%) and connective tissue (14.63% ± 4.38%) compared to the BBM group (15.53% ± 5.42% and 13.11% ± 4.42%, respectively). The differences between groups were statistically significant for the height reduction and newly formed bone (P ≤ .05) but not for the amounts of residual biomaterial and nonmineralized connective tissue (P ≥ .05). Six months after performing a lateral window sinus elevation, the percentage of newly formed bone was significantly higher when using FDBA than when using BBM, although the graft height reduction was also significantly higher for the FDBA group.

Comparing the effects of Bone+B® xenograft and InterOss® xenograft bone material on rabbit calvaria bone defect regeneration.

BACKGROUND: The bone regeneration therapy is often used in patients with inadequate bone support for implants, particularly following tooth extractions. Xenografts derived from animal tissues are effective bone reconstructive options that resist resorption and pose a low risk of transmitting disease. Therefore, these implants may be a good option for enhancing and stabilizing maxillary sinuses. The purpose of this study was to compare two xenografts, Bone+B® and InterOss®, for the reconstruction of rabbit calvaria defects. METHODS AND MATERIALS: The study involved seven male New Zealand white rabbits. In the surgical procedure, 21 spots were created on both sides of the midline calvarium by creating three 8-millimeter defects. A control group was used, as well as two treatment groups utilizing Bone+B® Grafts and InterOss® Grafts. After 3 months, the rabbits were euthanized, followed by pathological evaluation. Analysis of these samples focused on bone formation, xenograft remaining material, and inflammation levels, using Adobe Photoshop CS 8.0 and SPSS version 24. RESULTS: With the application of Bone+B® graft, bone formation ranged from 32% to 45%, with a mean of 37.80% (±5.63), and the remaining material ranged from 28% to 37%, with a mean of 32.60% (±3.65). Using InterOss® grafts, bone formation was 61% to 75%, the mean was 65.83% (±4.75), and the remaining material was 9% to 18%, with a mean of 13.17% (±3.06). The bone formation in the control group ranged from 10% to 25%, with a mean of 17.17% (±6.11). InterOss® had lower inflammation levels than other groups, but the difference was not statistically significant (p > .05). CONCLUSION: InterOss® bone powder is the best option for maxillofacial surgery and bone reconstruction. This is due to more bone formation, less remaining material, and a lower inflammation level. Compared to the control group, Bone+B® improves healing and bone quality, thus making it an alternative to InterOss®.

A comparative analysis of particulate bovine bone substitutes for oral regeneration: a narrative review.

PURPOSE: Particulate bovine bone substitutes (BS) are commonly used in oral regeneration. However, more literature is needed focusing on comparative analyses among various particulate bovine BS. This study evaluates pre-clinical and clinical data of different particulate bovine BS in oral regeneration. METHODS: A narrative review was conducted by screening the PubMed database Included in the review were pre-clinical and clinical studies until 2024 comparing a minimum of two distinct particulate bovine BS. In addition to examining general data concerning manufacturing and treatment processes, biological safety, physical and chemical characteristics, and graft resorption, particular emphasis was placed on assessing pre-clinical and clinical data related to ridge preservation, sinus floor elevation, peri-implant defects, and various forms of alveolar ridge augmentation utilizing particulate bovine BS. RESULTS: Various treatment temperatures ranging from 300 to 1,250 °C and the employment of chemical cleaning steps were identified for the manufacturing process of particulate bovine BS deemed to possess biosecurity. A notable heterogeneity was observed in the physical and chemical characteristics of particulate bovine BS, with minimal or negligible graft resorption. Variations were evident in particle and pore sizes and the porosity of particulate bovine BS. Pre-clinical assessments noted a marginal inclination towards favorable outcomes for particulate bovine BS subjected to higher treatment temperatures. However, clinical data are insufficient. No distinctions were observed regarding ridge preservation, while slight advantages were noted for high-temperature treated particulate bovine BS in sinus floor elevation. CONCLUSIONS: Subtle variances in both pre-clinical and clinical outcomes were observed in across various particulate bovine BS. Due to inadequate data, numerous considerations related to diverse particulate bovine BS, including peri-implant defects, must be more conclusive. Additional clinical studies are imperative to address these knowledge gaps effectively.

Research progress on the application of magnesium phosphate bone cement in bone defect repair: A review.

BACKGROUND: Bone defects arising from diverse causes, such as traffic accidents, contemporary weapon usage, and bone-related disorders, present significant challenges in clinical treatment. Prolonged treatment cycles for bone defects can result in complications, impacting patients' overall quality of life. Efficient and timely repair of bone defects is thus a critical concern in clinical practice. OBJECTIVE: This study aims to assess the scientific progress and achievements of magnesium phosphate bone cement (MPC) as an artificial bone substitute material. Additionally, the research seeks to explore the future development path and clinical potential of MPC bone cement in addressing challenges associated with bone defects. METHODS: The study comprehensively reviews MPC's performance, encompassing e.g. mechanical properties, biocompatibility, porosity, adhesion and injectability. Various modifiers are also considered to broaden MPC's applications in bone tissue engineering, emphasizing drug-loading performance and antibacterial capabilities, which meet clinical diversification requirements. RESULTS: In comparison to alternatives such as autogenous bone transplantation, allograft, polymethyl methacrylate (PMMA), and calcium phosphate cement (CPC), MPC emerges as a promising solution for bone defects. It addresses limitations associated with these alternatives, such as immunological rejection and long-term harm to patients. MPC can control heat release during the curing process, exhibits superior mechanical strength, and has the capacity to stimulate new bone growth. CONCLUSION: MPC stands out as an artificial bone substitute with appropriate mechanical strength, rapid degradation, non-toxicity, and good biocompatibility, facilitating bone repair and regeneration. Modification agents can enhance its clinical versatility. Future research should delve into its mechanical properties and formulations, expanding clinical applications to create higher-performing and more medically valuable alternatives in bone defect repair.

Improving material properties of a poloxamer P407 hydrogel-based hydroxyapatite bone substitute material by adding silica-A comparative in vivo study.

The structure and handling properties of a P407 hydrogel-based bone substitute material (BSM) might be affected by different poloxamer P407 and silicon dioxide (SiO2) concentrations. The study aimed to compare the mechanical properties and biological parameters (bone remodeling, BSM degradation) of a hydroxyapatite: silica (HA)-based BSM with various P407 hydrogels in vitro and in an in vivo rat model. Rheological analyses for mechanical properties were performed on one BSM with an SiO2-enriched hydrogel (SPH25) as well on two BSMs with unaltered hydrogels in different gel concentrations (PH25 and PH30). Furthermore, the solubility of all BSMs were tested. In addition, 30 male Wistar rats underwent surgical creation of a well-defined bone defect in the tibia. Defects were filled randomly with PH30 (n = 15) or SPH25 (n = 15). Animals were sacrificed after 12 (n = 5 each), 21 (n = 5 each), and 63 days (n = 5 each). Histological evaluation and histomorphometrical quantification of new bone formation (NB;%), residual BSM (rBSM;%), and soft tissue (ST;%) was conducted. Rheological tests showed an increased viscosity and lower solubility of SPH when compared with the other hydrogels. Histomorphometric analyses in cancellous bone showed a decrease of ST in PH30 (p = .003) and an increase of NB (PH30: p = .001; SPH: p = .014) over time. A comparison of both BSMs revealed no significant differences. The addition of SiO2 to a P407 hydrogel-based hydroxyapatite BSM improves its mechanical stability (viscosity, solubility) while showing similar in vivo healing properties compared to PH30. Additionally, the SiO2-enrichment allows a reduction of poloxamer ratio in the hydrogel without impairing the material properties.

Comparative Studies of Bone Graft and Orthobiologics for Foot Ankle Arthrodesis: A Critical Review.

Graft materials available to supplement hindfoot and ankle arthrodesis procedures include autologous (autograft) or allogeneic bone graft (allograft) but also bone graft substitutes such as demineralized bone matrix, calcium sulfate, calcium phosphate, and tricalcium phosphate/hydroxyapatite. In addition, biologic agents, such as recombinant human bone morphogenetic protein-2 or recombinant human platelet derived growth factor-BB (rhPDGF-BB), and preparations, including platelet-rich plasma or concentrated bone marrow aspirate, have been used to facilitate bone healing in ankle or hindfoot arthrodesis. The purpose of this review was to summarize the available clinical evidence surrounding the utilization and efficacy of the above materials and biological agents in ankle or hindfoot arthrodesis procedures, with emphasis on the quality of the existing evidence to facilitate clinical decision making.

Characterization of an advanced bone graft material with a nanocrystalline hydroxycarbanoapatite surface and dual phase composition.

The bone formation response of ceramic bone graft materials can be improved by modifying the material's surface and composition. A unique dual-phase ceramic bone graft material with a nanocrystalline, hydroxycarbanoapatite (HCA) surface and a calcium carbonate core (TrelCor®-Biogennix, Irvine, CA) was characterized through a variety of analytical methods. Scanning electron microscopy (SEM) of the TrelCor surface (magnification 100-100,000X) clearly demonstrated a nanosized crystalline structure covering the entire surface. The surface morphology showed a hierarchical structure that included micron-sized spherulites fully covered by plate-like nanocrystals (<60 nm in thickness). Chemical and physical characterization of the material using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy Energy Dispersive X-ray Spectroscopy (SEM-EDX) showed a surface composed of HCA. Analysis of fractured samples confirmed the dual-phase composition with the presence of a calcium carbonate core and HCA surface. An in vitro bioactivity study was conducted to evaluate whether TrelCor would form a bioactive layer when immersed in simulated body fluid. This response was compared to a known bioactive material (45S5 bioactive glass - Bioglass). Following 14-days of immersion, surface and cross-sectional analysis via SEM-EDX showed that the TrelCor material elicited a bioactive response with the formation of a bioactive layer that was qualitatively thicker than the layer that formed on Bioglass. An in vivo sheep muscle pouch model was also conducted to evaluate the ability of the material to stimulate an ectopic, cellular bone formation response. Results were compared against Bioglass and a first-generation calcium phosphate ceramic that lacked a nanocrystalline surface. Histology and histomorphometric analysis (HMA) confirmed that the TrelCor nanocrystalline HCA surface stimulated a bone formation response in muscle (avg. 11% bone area) that was significantly greater than Bioglass (3%) and the smooth surface calcium phosphate ceramic (0%).

Enriched mesoporous bioactive glass scaffolds as bone substitutes in critical diaphyseal bone defects in rabbits.

In the field of orthopedic surgery, there is an increasing need for the development of bone replacement materials for the treatment of bone defects. One of the main focuses of biomaterials engineering are advanced bioceramics like mesoporous bioactive glasses (MBG´s). The present study compared the new bone formation after 12 weeks of implantation of MBG scaffolds with composition 82,5SiO2-10CaO-5P2O5-x 2.5SrO alone (MBGA), enriched with osteostatin, an osteoinductive peptide, (MBGO) or enriched with bone marrow aspirate (MBGB) in a long bone critical defect in radius bone of adult New Zealand rabbits. New bone formation from the MBG scaffold groups was compared to the gold standard defect filled with iliac crest autograft and to the unfilled defect. Radiographic follow-up was performed at 2, 6, and 12 weeks, and microCT and histologic examination were performed at 12 weeks. X-Ray study showed the highest bone formation scores in the group with the defect filled with autograft, followed by the MBGB group, in addition, the microCT study showed that bone within defect scores (BV/TV) were higher in the MBGO group. This difference could be explained by the higher density of newly formed bone in the osteostatin enriched MBG scaffold group. Therefore, MBG scaffold alone and enriched with osteostatin or bone marrow aspirate increase bone formation compared to defect unfilled, being higher in the osteostatin group. The present results showed the potential to treat critical bone defects by combining MBGs with osteogenic peptides such as osteostatin, with good prospects for translation into clinical practice. STATEMENT OF SIGNIFICANCE: Treatment of bone defects without the capacity for self-repair is a global problem in the field of Orthopedic Surgery, as evidenced by the fact that in the U.S alone it affects approximately 100,000 patients per year. The gold standard of treatment in these cases is the autograft, but its use has limitations both in the amount of graft to be obtained and in the morbidity produced in the donor site. In the field of materials engineering, there is a growing interest in the development of a bone substitute equivalent. Mesoporous bioactive glass (MBG´s) scaffolds with three-dimensional architecture have shown great potential for use as a bone substitutes. The osteostatin-enriched Sr-MBG used in this long bone defect in rabbit radius bone in vivo study showed an increase in bone formation close to autograft, which makes us think that it may be an option to consider as bone substitute.