Tricalcium phosphate (-containing) biomaterials in the treatment of periodontal infra-bony defects: A systematic review and meta-analysis

OBJECTIVES

This study aimed to investigate the additional clinical benefit of tricalcium phosphate (TCP) (-containing) biomaterials compared to open flap debridement (OFD) in periodontal infra-bony defects.

DATA

A literature search was conducted in Pubmed, Embase and Cochrane library for entries published up to 14th July 2021. All randomized controlled trials (RCTs) that compared a TCP (-containing) material with OFD and studies that assessed a beta-TCP group alone, with vertical defect sites with PPD of ≥ 6 mm and/or presence of infra-bony defects of ≥ 3 mm and a minimum follow-up of 6 months were included. Risk of bias was assessed with the Oxford scale. The random-effects (RE) model was synthesized as differences between weighted average (MD) for probing pocket depth (PPD) and clinical attachment level (CAL) between TCP and OFD groups. An RE analysis was also performed for the beta-TCP group alone.

STUDY SELECTION

Data from 16 RCTs were included in the analysis. Six studies that represented 151 patients and sites were selected for meta-analysis. The overall MD with 95% CI at 6 months was calculated to be -0.47 [-0.83, -0.12; P = 0.0087] and -1.06 [-1.67, -0.46; P = 0.0006] for PPD and CAL, respectively. Whereas MD at 12 months for PPD and CAL was -0.89 [-1.54, -0.23; P = 0.0078] and -1.25 [-1.85, -0.66; P<0.0001], respectively. All results were in favor of TCP (-containing) group over OFD.

CONCLUSIONS

The results of the study suggest that the use of a TCP (-containing) material may have the potential for additional clinical improvement in PPD and CAL compared with OFD in infra-bony defects, given the limitations of the included evidence.

CLINICAL SIGNIFICANCE

The use of TCP as a bone graft substitute is becoming increasingly common. Therefore, it would be advantageous if an adjunctive benefit in the regeneration of infra-bony defects could be demonstrated to facilitate material selection.

Assessment of novel surgical procedures using decellularised muscle and bioactive ceramic: a histological analysis

Tissue regeneration and neovascularisation in cases of major bone loss is a challenge in maxillofacial surgery. The hypothesis of the present study is that the addition of resorbable bioactive ceramic Silica Calcium Phosphate Cement (SCPC) to Declluraized Muscle Scaffold (DSM) can expedite bone formation and maturation. Two surgical defect models were created in 18 nude transgenic mice. Group 1(n = 6), with a 2-mm decortication calvarial defect, was treated with a DSM/SCPC sheet over the corticated bone as an onlay then seeded with human Mesenchymal Stromal Cells hMSC in situ. In Group 2 (n = 6), a critical size (4 mm) calvarial defect was made and grafted with DSM/SCPC/in situ human bone marrow stromal cells (hMSCs). The control groups included Group 3 (n = 3) animals, with a 2-mm decortication defect treated with an onlay DSM sheet, and Group 4 (n = 3) animals, treated with critical size defect grafted with plain DSM. After 8 weeks, bone regeneration in various groups was evaluated using histology, immunohistochemistry and histomorphometry. New bone formation and maturation was superior in groups treated with DSM/SCPC/hMSC. The DMS/SCPC scaffold has the ability to augment and induce bone regeneration and neovascularisation in cases of major bone resorption and critical size defects.

The Effect of Application of Combined Bovine-Derived Anorganic Bone Graft and Hemostatic Plant Extract on Bone Regeneration

PURPOSE

To evaluate the effect of bovine-derived anorganic bone graft (ABB) in combination with hemostatic plant extract (ABS) on bone regeneration.

MATERIALS AND METHODS

Three bone defects were created via an extraoral approach on the mandibles of nine domestic pigs. The first defects were filled with ABS solution (0.3 mL/defect) in a transporting agent of ABB (0.3 cc/defect), whereas the second defects were filled with ABS (0.3 mL/defect) in microcapsules for controlled drug release, combined with ABB (0.3 cc/defect) again. The third defects were left empty. After a 10-week healing period and the sacrification, undecalcified sections were prepared for histomorphometric analysis.

RESULTS

The mean total area of hard tissue was 29.54% ± 3.2% in the control group, 59.78% ± 5.4% in the conventional group, and 63.67% ± 4.2% in the microsphere group (P < .001). The mean area of newly formed bone was 29.54% ± 3.2% in the control group, 34.79% ± 3.9% in the conventional group, and 37.95% ± 5.3% in the microsphere group (P = .003). The mean residual graft area was 24.99% ± 2.4% in the conventional group and 25.71% ± 4.4% in the microsphere group (P = .730).

CONCLUSION

The combined usage of ABS and ABB in both ways increased bone regeneration statistically. However, there was no significant difference between the two methods for ABS delivery systems in terms of new bone regeneration.

Incidence of Sinus Mucosa Perforations During Healing After Sinus Elevation Using Deproteinized Bovine Bone Mineral as Grafting Material: A Histologic Evaluation in a Rabbit Model

PURPOSE

To examine the reaction of mucosa over time to a close contact with biomaterial after sinus elevation performed with deproteinized bovine bone mineral (DBBM) granules of two different sizes.

MATERIALS AND METHODS

Bilateral sinus mucosa elevation was performed in 18 New Zealand rabbits through access on the nasal dorsum. DBBM with granule dimensions of either 1 to 2 mm (large group) or 0.250 to 1.0 mm (small group) were used to randomly fill the subantral hollow spaces. Biopsy specimens of the experimental sites from six animals in each group were obtained 2, 4, and 8 weeks after the surgery.

RESULTS

The integrity of the sinus mucosa was clinically evaluated during surgery using a ×2.5 magnifying visual device. The sinus mucosa in contact with the biomaterial granules was found to be thinned compared with the pristine mucosa in all periods examined. Three hundred fifty-two thinned zones were found considering all 36 sinuses treated. Perforations of the sinus mucosa with extrusion of granules toward the sinus were observed, increasing in number over time. In the 8-week healing period, five perforations in three sinuses and eight perforations in four sinuses were found in the large and small groups, respectively. No differences were seen between the large and small groups. The differences between 2 and 8 weeks were statistically significant for the thinned mucosa width in both the large and the small groups and for the number of sinuses and perforations for the small group.

CONCLUSION

Thinning zones and perforations of the sinus mucosa were seen increasing in number over time in regions in contact with graft granules in both the large and small groups.

PGS/HAp Microporous Composite Scaffold Obtained in the TIPS-TCL-SL Method: An Innovation for Bone Tissue Engineering

In this research, we synthesize and characterize poly(glycerol sebacate) pre-polymer (pPGS) (1H NMR, FTiR, GPC, and TGA). Nano-hydroxyapatite (HAp) is synthesized using the wet precipitation method. Next, the materials are used to prepare a PGS-based composite with a 25 wt.% addition of HAp. Microporous composites are formed by means of thermally induced phase separation (TIPS) followed by thermal cross-linking (TCL) and salt leaching (SL). The manufactured microporous materials (PGS and PGS/HAp) are then subjected to imaging by means of SEM and µCT for the porous structure characterization. DSC, TGA, and water contact angle measurements are used for further evaluation of the materials. To assess the cytocompatibility and biological potential of PGS-based composites, preosteoblasts and differentiated hFOB 1.19 osteoblasts are employed as in vitro models. Apart from the cytocompatibility, the scaffolds supported cell adhesion and were readily populated by the hFOB1.19 preosteoblasts. HAp-facilitated scaffolds displayed osteoconductive properties, supporting the terminal differentiation of osteoblasts as indicated by the production of alkaline phosphatase, osteocalcin and osteopontin. Notably, the PGS/HAp scaffolds induced the production of significant amounts of osteoclastogenic cytokines: IL-1β, IL-6 and TNF-α, which induced scaffold remodeling and promoted the reconstruction of bone tissue. Initial biocompatibility tests showed no signs of adverse effects of PGS-based scaffolds toward adult BALB/c mice.

Effect of Different Bone Grafting Materials and Mesenchymal Stem Cells on Bone Regeneration: A Micro-Computed Tomography and Histomorphometric Study in a Rabbit Calvarial Defect Model

This study evaluated the new bone formation potential of micro-macro biphasic calcium phosphate (MBCP) and Bio-Oss grafting materials with and without dental pulp-derived mesenchymal stem cells (DPSCs) and bone marrow-derived mesenchymal stem cells (BMSCs) in a rabbit calvarial bone defect model. The surface structure of the grafting materials was evaluated using a scanning electron microscope (SEM). The multipotent differentiation characteristics of the DPSCs and BMSCs were assessed. Four circular bone defects were created in the calvarium of 24 rabbits and randomly allocated to eight experimental groups: empty control, MBCP, MBCP+DPSCs, MBCP+BMSCs, Bio-Oss+DPSCs, Bio-Oss+BMSCs, and autogenous bone. A three-dimensional analysis of the new bone formation was performed using micro-computed tomography (micro-CT) and a histological study after 2, 4, and 8 weeks of healing. Homogenously porous structures were observed in both grafting materials. The BMSCs revealed higher osteogenic differentiation capacities, whereas the DPSCs exhibited higher colony-forming units. The micro-CT and histological analysis findings for the new bone formation were consistent. In general, the empty control showed the lowest bone regeneration capacity throughout the experimental period. By contrast, the percentage of new bone formation was the highest in the autogenous bone group after 2 (39.4% ± 4.7%) and 4 weeks (49.7% ± 1.5%) of healing (p < 0.05). MBCP and Bio-Oss could provide osteoconductive support and prevent the collapse of the defect space for new bone formation. In addition, more osteoblastic cells lining the surface of the newly formed bone and bone grafting materials were observed after incorporating the DPSCs and BMSCs. After 8 weeks of healing, the autogenous bone group (54.9% ± 6.1%) showed a higher percentage of new bone formation than the empty control (35.3% ± 0.5%), MBCP (38.3% ± 6.0%), MBCP+DPSC (39.8% ± 5.7%), Bio-Oss (41.3% ± 3.5%), and Bio-Oss+DPSC (42.1% ± 2.7%) groups. Nevertheless, the percentage of new bone formation did not significantly differ between the MBCP+BMSC (47.2% ± 8.3%) and Bio-Oss+BMSC (51.2% ± 9.9%) groups and the autogenous bone group. Our study results demonstrated that autogenous bone is the gold standard. Both the DPSCs and BMSCs enhanced the osteoconductive capacities of MBCP and Bio-Oss. In addition, the efficiency of the BMSCs combined with MBCP and Bio-Oss was comparable to that of the autogenous bone after 8 weeks of healing. These findings provide effective strategies for the improvement of biomaterials and MSC-based bone tissue regeneration.

Comparison of Autogenous Tooth Materials and Other Bone Grafts

Autogenous odontogenic materials are a new, highly biocompatible option for jaw restoration. The inorganic component of autogenous teeth acts as a scaffold to maintain the volume and enable donor cell attachment and proliferation; the organic component contains various growth factors that promote bone reconstruction and repair. The composition of dentin is similar to that of bone, which can be a rationale for promoting bone reconstruction. Recent advances have been made in the field of autogenous odontogenic materials, and studies have confirmed their safety and feasibility after successful clinical application. Autogenous odontogenic materials have unique characteristics compared with other bone-repair materials, such as the conventional autogenous, allogeneic, xenogeneic, and alloplastic bone substitutes. To encourage further research into odontogenic bone grafts, we compared the composition, osteogenesis, and development of autogenous odontogenic materials with those of other bone grafts. In conclusion, odontogenic bone grafts should be classified as a novel bone substitute.

Alveolar Ridge Preservation with Deproteinized Bovine Bone Mineral and Xenogeneic Collagen Matrix: A 12-Month Clinical and Histomorphometric Case Series

The aim of the present study was to evaluate the efficacy of alveolar ridge preservation (ARP) protocol using deproteinized bovine bone mineral (DBBM) covered with a collagen matrix (CM), as well as to clinically and histologically analyze the alveolar bone healing at 12 months, prior to implant placement. Six patients had bone biopsy samples harvested and underwent implant placement at 12 months following ARP. At 12 months, DBBM granules represented a mean 29.52% ± 6.09% of the specimens and were embedded in the newly formed bone, which represented a mean 27.72% ± 5.64% of the sample. Data suggest that 12 months of ARP using DBBM granules covered with a CM may be considered a predictable technique providing favorable conditions for implant placement in the anterior maxilla.

[Bone transplantation or biomaterials? : An analysis of 99,863 surgical procedures in orthopedic and trauma surgery in Germany from 2018]

BACKGROUND

The aims of this study were (1) to analyze the total number of interventions with autologous or allogeneic bone transplantation as well as biomaterials, (2) to investigate the different types of biomaterials, autologous and allogeneic bone transplantations and (3) to analyze the additional use of an antibiotic additive in biomaterials.

METHODS

Data were obtained from the Federal Statistical Office for the year 2018. The surgery and procedure codes 5‑784 "bone transplantation and transposition" and 5‑785 "implantation of alloplastic bone substitutes" were used to analyze the procedure frequency of implantation of biomaterials, such as calcium phosphate ceramics, calcium sulphate, calcium phosphate cements and polymethyl methacrylate as well as autologous and allogeneic bone for defect reconstruction of the extremities and pelvis.

RESULTS

In 2018 a total of 99,863 procedures were performed using autografts (54,784, 55%), biomaterials (23,838, 24%) and allografts (21,241, 21%). For both autografts and allografts cancellous bone grafting was used most frequently (77% and 79%, respectively). For biomaterials, ceramics (42%) were used more frequently than bone cements (37%, other biomaterials 21%). In 16,027 cases (67%) with biomaterials no antibiotic supplement was used. Antibiotic supplementation was mainly used for bone cements (6612 cases, 75%).

CONCLUSION

In 2018 bone transplants or biomaterials were used in a considerable number of the 99,863 bone defect reconstruction procedures. Autologous bone was used in more than half of the cases (55%), biomaterials in approximately one quarter (24%) and allogenic bone in approximately one fifth (21%). Ceramics (42%) were more often used as biomaterials than cements (37%). The addition of antibiotics was mainly used with cements (75%).

Hyperbaric Oxygen Therapy: An Effective Auxiliary Treatment Method for Large Jaw Cysts

Background: To evaluate hyperbaric oxygen therapy (HBOT) on infection rates and repair rates during the treatment of large jaw cysts. Methods: A prospective randomized, non-blinded, controlled clinical trial included 90 patients with jaw cysts, randomly divided into three groups. Patients were treated with enucleations and bone substitute was used in the experimental and control groups. The experimental group received HBOT. The primary predictor variable was HBOT. The infection rate, repair rate, preoperative volume of the jaw cysts, age, and sex were statistically analyzed. The Fisher exact test was used to compare the infection rate and postoperative complications. The repair rate of the bone defects was analyzed using the repeated-measures analysis of variance and the least significant difference tests. The Kendall's coefficient of concordance and Kappa statistics were calculated to evaluate the consistency between the two investigators. Results: The infection rate was 3.4% in the experimental group, 14.3% in the blank group, and 32.1% in the control group (P<0.05). The repair rate in the experimental group was significantly higher than in the control and blank groups at 1, 3 and 6 months after surgery (P<0.05). Conclusion: The results showed that HBOT reduced the postoperative infection rate following the enucleation of large jaw cysts with bone substitute filling, and it also improved the bone repair rate.

Comparison of Bone Formation After Sinus Membrane Lifting Without Graft or Using Bone Substitute "Histologic and Radiographic Evaluation"

PURPOSE

Sinus floor elevation without using autogenous bone graft or bone substitute will eliminate donor site morbidity and reduce the cost and the risk of infection. We evaluated the bone gain after sinus membrane elevation without graft or using bone substitute in the same maxilla. Dental implants were inserted simultaneously as a 1-stage procedure.

PATIENTS AND METHODS

In a split-mouth design, we conducted a randomized double-blinded clinical trial performing sinus lifts and simultaneous implant insertion in 10 healthy patients (n = 20). On the 1 site, we performed graft-less sinus lift (group 1) and on the other site Cerabone was used as bone substitute (group 2), respectively. The quantity and quality of bone gained in each sinus were evaluated and compared radiologically and histomorphometrically.

RESULTS

After 6 months, the average gain of bone height was 6.21 and 9.58 mm in group 1 and 2, respectively, as measured radiologically (P < .001, P < .001). Histomorphometric examination showed significantly higher thickness of trabeculae and bone formation in group 1 (P = .003 and P = .002). However, the neovascularization was higher, but not significantly (P = .288).

CONCLUSIONS

Radiological bone gain was similar in both groups. However, histomorphometric examination showed superior bone formation in graft-less group as compared to the Cerabone group. The blood clot seems to be an adequate filler and excellent medium for bone formation. More studies in split-mouth design are needed to compare different bone substitutes.

Giant Cell Tumor of Bone in the Talus Treated by Extended Curettage and Synthetic Bone SubstituteReport of a Rare Case

Giant cell tumor of bone is extremely rare in the talus and is usually observed in the third decade of life. Herein, we report a case of a 19-year-old male with a giant cell tumor of bone in the talus mimicking a simple bone cyst that was treated by intralesional curettage and, for the first time, bone grafting with a synthetic bone substitute. The patient had no evidence of recurrence at 7-year follow-up but did have non-progressing mild degenerative joint disease and slightly limited range of movement at the ankle joint.

Radiographic and clinical outcomes of silicate-substituted calcium phosphate (SiCaP) bone grafts in spinal fusion: Systematic review and meta-analysis

Pseudarthrosis continues to affect a nontrivial proportion of spine fusion patients. Given its ties to poorer patient outcomes and high reoperation rates, there remains great interest in interventions aimed at reducing the rates of nonunion. Recently, silicate-substituted calcium phosphate (SiCaP) bone grafts have been suggested to improve fusion rates, yet there exists no systematic review of the body of evidence for SiCaP grafts. Here, we present the first such review along with a meta-analysis of the effect of SiCaP bone grafts on fusion rates. Using the PubMed, Embase, and Web of Science databases, we queried the English-language literature for all studies examining the effect of SiCaPs on spinal fusion. Primary endpoints were: 1) radiographic fusion rate at last follow-up and 2) postoperative improvements in Visual Analog Scale (VAS) pain scores and Oswestry Disability Index (ODI) at last follow-up. Meta-analyses were performed for each endpoint using random effects. Ten articles (694 patients treated with SiCaP bone grafts) were included. Among SiCaP-treated patients, 93% achieved radiographic fusion (range: 79-100%), with comparable rates across subgroups. Meta-analysis of the three randomized controlled trials demonstrated no difference in fusion rates between SiCaP-treated patients and patients receiving grafts with recombinant human bone morphogenetic protein-2 (rhBMP-2) (OR: 1.11; p = 0.83). Patients treated with SiCaP bone grafts experienced significant improvements in VAS back pain (-3.3 points), VAS leg pain (-4.8 points), and ODI (-31.6 points) by last follow-up (p < 0.001 for each). Additional high-quality research is needed to evaluate the relative cost-effectiveness of SiCaP bone grafts in spinal fusion.

Biodegradable materials for bone defect repair

Compared with non-degradable materials, biodegradable biomaterials play an increasingly important role in the repairing of severe bone defects, and have attracted extensive attention from researchers. In the treatment of bone defects, scaffolds made of biodegradable materials can provide a crawling bridge for new bone tissue in the gap and a platform for cells and growth factors to play a physiological role, which will eventually be degraded and absorbed in the body and be replaced by the new bone tissue. Traditional biodegradable materials include polymers, ceramics and metals, which have been used in bone defect repairing for many years. Although these materials have more or fewer shortcomings, they are still the cornerstone of our development of a new generation of degradable materials. With the rapid development of modern science and technology, in the twenty-first century, more and more kinds of new biodegradable materials emerge in endlessly, such as new intelligent micro-nano materials and cell-based products. At the same time, there are many new fabrication technologies of improving biodegradable materials, such as modular fabrication, 3D and 4D printing, interface reinforcement and nanotechnology. This review will introduce various kinds of biodegradable materials commonly used in bone defect repairing, especially the newly emerging materials and their fabrication technology in recent years, and look forward to the future research direction, hoping to provide researchers in the field with some inspiration and reference.

Orthotopic Bone Formation by Streamlined Engineering and Devitalization of Human Hypertrophic Cartilage

Most bones of the human body form and heal through endochondral ossification, whereby hypertrophic cartilage (HyC) is formed and subsequently remodeled into bone. We previously demonstrated that HyC can be engineered from human mesenchymal stromal cells (hMSC), and subsequently devitalized by apoptosis induction. The resulting extracellular matrix (ECM) tissue retained osteoinductive properties, leading to ectopic bone formation. In this study, we aimed at engineering and devitalizing upscaled quantities of HyC ECM within a perfusion bioreactor, followed by in vivo assessment in an orthotopic bone repair model. We hypothesized that the devitalized HyC ECM would outperform a clinical product currently used for bone reconstructive surgery. Human MSC were genetically engineered with a gene cassette enabling apoptosis induction upon addition of an adjuvant. Engineered hMSC were seeded, differentiated, and devitalized within a perfusion bioreactor. The resulting HyC ECM was subsequently implanted in a 10-mm rabbit calvarial defect model, with processed human bone (Maxgraft^®) as control. Human MSC cultured in the perfusion bioreactor generated a homogenous HyC ECM and were efficiently induced towards apoptosis. Following six weeks of in vivo implantation, microcomputed tomography and histological analyses of the defects revealed an increased bone formation in the defects filled with HyC ECM as compared to Maxgraft^®. This work demonstrates the suitability of engineered devitalized HyC ECM as a bone substitute material, with a performance superior to a state-of-the-art commercial graft. Streamlined generation of the devitalized tissue transplant within a perfusion bioreactor is relevant towards standardized and automated manufacturing of a clinical product.

Ridge Preservation Using a Novel Freeze-dried Enzyme-deantigenic Bone Paste: A Histomorphometric-retrospective Pilot Case Series

AIM AND OBJECTIVE

The aim of this study is to provide preliminary retrospective evidence concerning the histologic and histomorphometric outcome of a novel freeze-dried equine-derived bone paste (EDEBEX) for ridge preservation of sockets following tooth extraction.

MATERIALS AND METHODS

This pilot retrospective case series describes the histologic and histomorphometric outcome of three patients who received the equine-derived bone paste in post-extractive sockets to allow the preservation of the alveolar ridge. Patients were later rehabilitated with monolithic-zirconia, implant-supported prostheses.

RESULTS

All patients healed uneventfully. The collected biopsies showed a prevalence of bone formation at 4 months, compact lamellar bone, with well-defined lamellae surrounding Haversian and Volkmann's canals at 6 months, and an intermediate degree of maturation in active anabolic phase at 7 months after grafting. The amount of mineralized matrix was 63.3-70.7%, whereas medullar spaces were 26.0-30.7%.

CONCLUSION

Histologic examination showed that the bone paste was fully biocompatible. Bone regeneration occurred within the first 4 months from grafting, with 63.3-70.7% mineralized bone matrix. The residual biomaterial, when present, did not exceed, on average, 2%.

CLINICAL SIGNIFICANCE

Ridge preservation using bone substitutes as an alternative to autogenous bone is known to be effective. However, available clinical evidence still does not indicate the biomaterial, if any, that should be preferred to carry it out. The equine bone paste used in the present study appears to be a good candidate for further investigation because it is easy to handle in the clinical setting and it displays a good bone formation rate.

In vivo evaluation of interactions between biphasic calcium phosphate (BCP)-niobium pentoxide (Nb2O5) nanocomposite and tissues using a rat critical-size calvarial defect model

Natural or synthetic biomaterials are increasingly being used to support bone tissue repair or substitution. The combination of natural calcium phosphates with biocompatible alloys is an important route towards the development of new biomaterials with bioperformance and mechanical responses to mimic those of human bones. This article evaluated the structural, physical, mechanical and biological properties of a new mechanical improved nanocomposite elaborated by association of fish biphasic calcium phosphate (BCP) and niobium pentoxide (Nb₂O₅). The nanocomposite (Nb-BCP) and the pure BCP, used as a positive control, were obtained by powder metallurgy. The density, porosity and microhardness were measured. The structural analysis was determined by X-ray diffraction (XRD) and the biological properties were studied in histological sections of critical size calvaria defects in rats, 7, 15, 30, 45 and 60 days after implantation of disks of both materials. Morphological description was made after scanning electron microscopy (SEM) and optical microscopy analysis. After sintering, the Nb-BCP nanocomposite presented four crystalline phases: 34.36% calcium niobate (CaNb₂O₆), 21.68% phosphorus niobium oxide (PNb₉O₂₅), 42.55% β-tricalcium phosphate (Ca₃(PO₄)₂) and 1.31% of niobium pentoxide (Nb₂O₅) and exhibited increases of 17% in density, 66% in Vickers microhardness and 180% in compressive strength compared to pure BCP. In vivo study, showed biocompatibility, bioactivity and osteoconductivity similar to pure BCP. SEM showed the formation of globular accretions over the implanted nanocomposites, representing one of the stages of bone mineralization. In conclusion, the BCP and Nb₂O₅ formed a nanocomposite exhibiting characteristics that are desirable for a biomaterial, such as bioperformance, higher β-TCP percentage and improved physical and mechanical properties compared to pure BCP. These characteristics demonstrate the promise of this material for supporting bone regeneration.

An innovative strategy to treat large metaphyseal segmental femoral bone defect using customized design and 3D printed micro-porous prosthesis: a prospective clinical study

Five patients with segmental irregular-shaped bone defect of the femur were recruited in this study from 2017.12 to 2018.11. All patients were treated by customized design and 3D printed micro-porous prosthesis. And the procedure was divided into stages: radical debridement and temporary fixation (the first stage); the membrane formation and virtual surgery (intervening period for 6-8 weeks); definite reconstruction the defects (the second stage). Routine clinical follow-up and radiographic evaluation were done to assess bone incorporation and complications of internal fixation. The weight-bearing time and the joint function of the patients were recorded. The patients were followed up for an average of 16.4 months. The average length of bone defect and the distal residual bone was 12 cm and 6.5 cm. The average time of partial weight-bearing and full weight-bearing was 12.7 days and 2.6 months. X-ray demonstrated good osseous integration of the implant/bone interface. No complications occurred such as implant loosening, subsidence, loss of correction and infection. At the last follow-up, Harris score of hip joint was excellent in 2 cases, good in 2 cases, fair in 1 case; HSS score of knee joint was good in 4 cases, middle in 1 case. From our study, we concluded that meticulous customized design 3D printed micro-porous prosthesis combined with intramedullary nail may be a promising and an alternative strategy to treat metaphyseal segmental irregular-shaped femoral bone defect, especially for cases with massive juxta-articular bone loss.

In-vivo evaluation of a partially resorbable poly l-lactic acid/ braided bioactive glass fibers reinforced composite for load bearing fracture fixation

Our previous studies have been focused on the design, optimization and manufacture of a partially resorbable composite bone plate consisting of a poly l-lactic acid matrix reinforced with braided fabrics bioactive glass fibers (PLLA/BG). In the present study, the response of the composite samples, the degradation rate, the inflammatory response, fibrous capsule formation and tissue-implant bonding to the in-vivo environment were assessed via implantation in the rabbit subcutaneous tissue. Despite the presence of both enzymatic degradation and hydrolysis processes within the body, the rate of the molecular weight loss as an indicator of degradation did not show a significant difference with the in-vitro conditions. It was predicted that strength loss would show the same trend since it was a consequence of molecular chain disruption and the loss of molecular weight. Inexistence of chronic inflammation, as confirmed by our previous results on the controlled degradation rate, also showed the maintenance of the physiological pH in the peripheral environment of the implant. Moreover, lack of the fibrous capsule tissue around the implant indicated that the implant was bioactive. In addition, given the composition of the bioactive glass fibers, that could be bonded to soft and hard tissues, tissue bonding with the PLLA/BG composite samples was also observed, thereby confirming the bioactivity and biocompatibility of the proposed bone plate.

The Effect of Autologous Platelet Concentrates on Maxillary Sinus Augmentation: A Meta-Analysis of Randomized Controlled Trials and Systematic Review

INTRODUCTION

To assess the efficacy of the autologous platelet concentrates (APCs) combined with autologous bone or bone substitute for the maxillary sinus floor lifting by a meta-analysis.

MATERIALS AND METHODS

Electronic databases (PUBMED, Web of Science, EMBASE through OVID, and Cochrane Library) were searched until Dec 31, 2019, and only randomized controlled trials (RCTs) in English were identified. Outcome variables included histologic evaluation, the implant stability quotient values, and radiographic evaluation. Data were analyzed by Revman5.3; the estimate of effect sizes was expressed as the 95% confidence interval; and the risk of bias was evaluated using the Cochrane Collaboration tool.

RESULTS

11 RCTs involving 141 patients (214 sites) were included in our meta-analysis, which indicated that the differences in the percentage of contact length among newly formed bone (2.61%, 95% CI, -1.18% to 7.09%), soft tissue area (-0.15%, 95% CI, -0.54% to 0.24%), and residual bone substitute material (-5.10%, 95% CI, -10.56% to 0.36%) in the APC group lacked statistical significance. Besides, there was the same effect on the implant stability quotient (ISQ) values of APC group who underwent implant placement 4 months after sinus augmentation and control group who received implant placement 8 months after sinus augmentation (-0.48, 95% CI, -1.68 to 0.72). No significant effect of APCs on the bone density was found (1.05%, 95% CI, -1.69% to 3.82%).

CONCLUSIONS

The use of APCs in sinus augmentation may be further shorten the time required for bone graft maturation and allow earlier implant placement, but cannot enhance the bone formation in the long term. It is not currently recommended for routine use APCs as an osteoinductive material to bone grafting in sinus augmentation.

Treatment of fracture-related infection of the lower extremity with antibiotic-eluting ceramic bone substitutes: case series of 35 patients and literature review

INTRODUCTION

The current treatment concepts of fracture-related infection (FRI) [Consensus Conference (Anti-Infection Task Force (AITF)) on the definition of acute or chronic osteomyelitis (cOM)] are associated with unsolved challenges and problems, underlining the need for ongoing medical research.

METHOD

Literature review of treatments for FRI and description of own cases.

RESULTS

We could include eight papers with 394 patients reporting treatments and outcome in FRI. The infection was resolved in 92.9% (mean) of all treatments. The mean follow-up was 25 months with a persistent non-union in 7% of the patients. We diagnosed 35 (19f/16m; 56.4 ± 18.6 years) patients with bone infections anatomically allocated to the proximal and distal femur (12×), the pelvis (2×), distal tibia (3×), tibial diaphysis (11×), the ankle joint (4×) and calcaneus (3×). These 35 patients were treated (1) with surgical debridement; (2) with antibiotic-eluting ceramic bone substitutes; (3) bone stabilization (including nail fixation, arthrodesis nails, plates, or external ring fixation), (4) optionally negative pressure wound therapy (NPWT) and (5) optionally soft tissue closure with local or free flaps. The mean follow-up time was 14.9 ± 10.6 months (min/max: 2/40 month). The overall recurrence rate is low (8.5%, 3/35). Prolonged wound secretion was observed in six cases (17.1%, 6/35). The overall number of surgeries was a median of 2.5.

CONCLUSION

The results in the literature and in our case series are explicitly promising regarding the treatment of posttraumatic fracture-related infection.

The effect of housing environment on bone healing in a critical radius defect in New Zealand White rabbits

In animal studies on bone healing, the effect of housing space and physical activity are seldom taken into account. Bone formation was evaluated in New Zealand White rabbits (mean ± SEM BW: 3.9 ± 0.11 kg) with a critical bone defect after 12 weeks of rehabilitation in pair-housing in 3 m² large floor pens (Floor, n = 10) or standard single housing in 0.43 m² cages (Cage, n = 10). In the randomised full-factorial study, a bone replica of calcium phosphate cement (CPC, n = 10) or autologous bone (AB, n = 10) was implanted in the unilateral 20 mm radius defect. Post-mortem, the oxidative capacity was measured by citrate synthase (CS) activity in M. quadriceps and the defect filling volume and density evaluated by microcomputer tomography (μ-CT). Histology sections were evaluated by subjective scoring and histomorphometry. Fourteen rabbits remained until the end of the study. Group Floor (n = 7; 3 CPC + 4 AB) had a higher CS activity and a larger bone defect filling volume and lower density by μ-CT measurements than group Cage (n = 7; 3 CPC + 4 AB). Three out of four rabbits in AB-Floor presented fusion of the defect with reorganisation of trabecular bone, whereas three of four in AB-Cage showed areas of incomplete healing. Floor rabbits had a higher score of bony fusion between the radius and ulna than Cage rabbits. There were no differences between groups in histomorphometry. The study found that a larger housing space increased physical activity and promoted bone formation.

Phycogenic bone substitutes for sinus floor augmentation: Histomorphometric comparison of hydroxyapatite and biphasic calcium phosphate in a randomised clinical pilot study

Aims: While numerous materials are available for sinus floor elevation, plant-based alternatives still hold promise of overcoming concerns about allogeneic or xenogeneic materials. Thus, the present authors designed a randomised clinical trial to histologically compare an almost pure hydroxyapatite (HA) to a biphasic calcium phosphate comprising 80% β-tricalcium phosphate (β-TCP) and 20% hydroxyapatite (β-TCP/HA), all of phycogenic origin. Materials and methods: Twenty patients scheduled for lateral window sinus floor elevation were randomised to either an HA or a β-TCP/HA group. Biopsy specimens were taken 3 months after sinus floor elevation and during implant surgery after 6 months. One ground section per biopsy specimen (N = 40) was stained, scanned and histomorphometrically analysed for new bone, old bone, soft tissue, graft, bone infiltration of graft, bone-to-graft contact and penetration depth. Results: At 6 months, more new bone was seen in the β-TCP/HA group (P = 0.011), whereas more residual graft was present and in more extensive contact with new bone in the HA group. More pronounced alterations, and smaller particle sizes, of graft surrounded and infiltrated by bone were seen in the β-TCP/HA group. The less extensive bone-to-graft contact in the β-TCP/ HA group reflected a more advanced state of resorption, while infiltration of residual graft material by bone was also increased in this group. Conclusions: Proper healing was seen in both groups, with the graft materials guiding the formation of new bone, which grew especially well through the particles of the highly osteoconductive and resorptive β-TCP/HA material. HA was very stable, without significant resorption, but was extensively in contact with new bone after 6 months.

Fabrication of porous carbonate apatite granules using microfiber and its histological evaluations in rabbit calvarial bone defects

Carbonate apatite (CO₃ Ap) granules are known to show good osteoconductivity and replaced to new bone. On the other hand, it is well known that a porous structure allows bone tissue to penetrate its pores, and the optimal pore size for bone ingrowth is dependent on the composition and structure of the scaffold material. Therefore, the aim of this study was to fabricate various porous CO₃ Ap granules through a two-step dissolution-precipitation reaction using CaSO₄ as a precursor and 30-, 50-, 120-, and 205-μm diameter microfibers as porogen and to find the optimal pore size of CO₃ Ap. Porous CO₃ Ap granules were successfully fabricated with pore size 8.2-18.7% smaller than the size of the original fiber porogen. Two weeks after the reconstruction of rabbit calvarial bone defects using porous CO₃ Ap granules, the largest amount of mature bone was seen to be formed inside the pores of CO₃ Ap (120) [porous CO₃ Ap granules made using 120-μm microfiber] followed by CO₃ Ap (50) and CO₃ Ap (30). At 4 and 8 weeks, no statistically significant difference was observed based on the pore size, even though largest amount of mature bone was formed in case of CO₃ Ap (120). It is concluded, therefore, that the optimal pore size of the CO₃ Ap is that of CO₃ Ap (120), which is 85 μm.

Short-term use of resveratrol in alloplastic graft material applied with calvarial bone defects in rats

PURPOSE

The effects of resveratrol administration on calvarial bone defects with alloplastic graft material was investigated for osteoinductive reaction and bone development in rats.

METHODS

Healthy male rats were randomly divided into 3 groups consisting of 10 rats. Groups were as follows: control (defect) group, defect + graft group, and defect + graft + resveratrol group. A calvarial bone defect was created in all groups, alloplastic bone grafts were applied to the defect in the 2nd and 3rd group, resveratrol (5 mg/kg/day) was added to the drinking water of the animals following graft application for 28 days in the 3rd group.

RESULTS

Increase in osteoclasts and necrotic changes were observed histopathologically in the control group. In the 2nd group, reduction of inflammation, congestion of blood vessels, increased osteblastic activity, osteoinductive effect, progression of osteocyte development and increased collagen fibers in connective tissue were observed. In the 3rd group, osteoblasts seemed to secrete bone matrix and accelerate osteoinductive effect with increased osteopregenitor activity and positive osteopontin and osteonectin expressions.

CONCLUSION

Resveratrol treatment was thought to be an alternative and supportive drug for implant application by inducing new bone formation in the calvaral defect region as a result of short-term treatment.