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1.
Mechanical characterization and ion release of bioactive dental composites containing calcium phosphate particles.
Natale, LC, Rodrigues, MC, Alania, Y, Chiari, MDS, Boaro, LCC, Cotrim, M, Vega, O, Braga, RR
Journal of the mechanical behavior of biomedical materials. 2018;:161-167
Abstract
OBJECTIVE to verify the effect of the addition of dicalcium phosphate dihydrate (DCPD) particles functionalized with di- or triethylene glycol dimethacrylate (DEGDMA or TEGDMA) on the degree of conversion (DC), post-gel shrinkage (PS), mechanical properties, and ion release of experimental composites. METHODS Four composites were prepared containing a BisGMA/TEGDMA matrix and 60 vol% of fillers. The positive control contained only barium glass fillers, while in the other composites 15 vol% of the barium was replaced by DCPD. Besides the functionalized particles, non-functionalized DCPD was also tested. DC after 24 h (n = 3) was determined by FTIR spectroscopy. The strain gage method was used to obtain PS 5 min after photoactivation (n = 5). Flexural strength and modulus (n = 10) were calculated based on the biaxial flexural test results, after specimen storage for 24 h or 60 days in water. The same storage times were used for fracture toughness testing (FT, n = 10). Calcium and phosphate release up to 60 days was quantified by ICP-OES (n = 3). Data were analyzed by ANOVA/Tukey test (alpha: 5%). RESULTS Composites containing functionalized DCPD presented higher DC than the control (p < 0.001). The material containing DEGDMA-functionalized particles showed higher PS than the other composites (p < 0.001). After 60 days, only the composite with DEGDMA-functionalized DCPD presented fracture strength similar to the control, while for flexural modulus only the composite with TEGDMA-functionalized particles was lower than the control (p < 0.001). FT of all composites containing DCPD was higher than the control after 60 days (p < 0.005). Calcium release was higher for the composite with non-functionalized DCPD at 15 days and no significant reductions were observed for composites with functionalized DCPD during the observation period (p < 0.001). For all the tested composites, phosphate release was higher at 15 days than in the subsequent periods, and no difference among them was recorded at 45 and 60 days (p < 0.001). CONCLUSIONS DCPD functionalization affected all the studied variables. The composite with DEGDMA-functionalized particles was the only material with strength similar to the control after 60 days in water; however, it also presented the highest shrinkage. The presence of DCPD improved FT, regardless of functionalization. DCPD functionalization reduced ion release only during the first 15 days.
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2.
Prospective and Randomized Evaluation of ChronOS and Bio-Oss in Human Maxillary Sinuses: Histomorphometric and Immunohistochemical Assignment for Runx 2, Vascular Endothelial Growth Factor, and Osteocalcin.
Bonardi, JP, Pereira, RDS, Boos Lima, FBDJ, Faverani, LP, Griza, GL, Okamoto, R, Hochuli-Vieira, E
Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons. 2018;(2):325-335
Abstract
PURPOSE The aim of this study was to compare ChronOS (β-tricalcium phosphate), Bio-Oss, and their addition to an autogenous bone graft in a 1:1 ratio in human maxillary sinus bone augmentation. MATERIALS AND METHODS Thirty maxillary sinuses were divided in 5 groups: group 1 included 6 maxillary sinuses grafted with autogenous bone graft alone; group 2 included 6 maxillary sinuses grafted with ChronOS; group 3 included 6 maxillary sinuses grafted with ChronOS and autogenous bone graft in a 1:1 ratio; group 4 included 6 maxillary sinuses grafted with Bio-Oss; and group 5 included 6 maxillary sinuses grafted with Bio-Oss and autogenous bone graft in a 1:1 ratio. The number of samples for each group was determined by the statistical power test. RESULTS The median areas of new bone formation in groups 1, 2, 3, 4, and 5 were 121,917.0, 83,787.0, 99,295.0, 65,717.0, and 56,230.0 μm2, respectively. Statistically significant differences were found between groups 3 and 5, groups 1 and 4, and groups 1 and 5 (P < .05). The median areas of remaining biomaterial were 2,900.5, 5,291.0, 2,662.0, 56,258.5, and 64,753.5 μm2 in groups 1, 2, 3, 4 and 5, respectively. Statistically significant differences occurred between groups 1 and 5, groups 3 and 5, and groups 2 and 5 (P < .05). Areas of connective tissue were 67,829.0 ± 22,984.6 μm2 in group 1, 97,445.9 ± 18,983.3 μm2 in group 2, 88,256.0 ± 21,820.5 μm2 in group 3, 65,501.8 ± 6,297.6 in group 4, and 70,203.2 ± 13,421.3 μm2 in group 5. CONCLUSIONS ChronOS combined with autogenous bone graft presented a behavior similar to that of autogenous bone graft alone. However, the groups treated with Bio-Oss showed immuno-labeling results indicating maturation of grafted bone.
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3.
A Prospective, Randomized, Multicenter Study Comparing Silicated Calcium Phosphate versus BMP-2 Synthetic Bone Graft in Posterolateral Instrumented Lumbar Fusion for Degenerative Spinal Disorders.
Coughlan, M, Davies, M, Mostert, AK, Nanda, D, Willems, PC, Rosenberg, G, Ferch, R
Spine. 2018;(15):E860-E868
Abstract
STUDY DESIGN A prospective, Phase IV, multicenter, randomized study. OBJECTIVE The aim of this study was to compare vertebral fusion success rates following posterolateral fusion [(PLF)/posterolateral intertransverse fusion (PITF)] surgery. The surgical procedure combined posterior lumbar interbody fusion (PLIF) and PLF with internal fixation over one or two levels using silicated calcium phosphate (SiCaP) or bone morphogenetic protein (BMP)-2 as graft material in patients with a degenerative disorder of the lumbar spine. SUMMARY OF BACKGROUND DATA Few controlled trials have evaluated the bone graft materials available to surgeons treating patients with spinal disorders, including degenerative disc disease, spondylolisthesis, and disc herniation. METHODS Following randomization, the surgical procedure consisting of PLIF and PLF with internal fixation over one or two levels was performed using SiCaP or BMP-2. No other osteoconductive/osteoinductive graft materials were permitted. Spinal fusion was assessed radiographically at ≤24 months. Clinical outcomes (pain on visual analog scale, Oswestry Disability Index, SF-36) and adverse events (AEs) were monitored. RESULTS One hundred three patients were enrolled. At 12 months, fusion was achieved in 25 of 35 (71.4%) of the SiCaP and 20 of 27 (74.1%) of the BMP-2 group, respectively (P = 1.000). At 24 months, the fusion rate was 78.6% and 84.8% for SiCaP and BMP-2, respectively (P = 0.5613). Clinical outcomes improved similarly in both groups over time. AEs were consistent with this surgical population. CONCLUSION SiCaP was safe and well tolerated in patients with degenerative spinal disorders requiring PLF and provided fusion rates similar to BMP-2. LEVEL OF EVIDENCE 2.
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4.
Calcium-Containing Crystals and Osteoarthritis: an Unhealthy Alliance.
Conway, R, McCarthy, GM
Current rheumatology reports. 2018;(3):13
Abstract
PURPOSE OF REVIEW Osteoarthritis (OA) is the most common form of joint disease globally and is associated with significant morbidity and disability. Increasing evidence points to an important inflammatory component in the development and progression of OA. The precise pathways involved in OA inflammatory processes remain to be clarified. Basic calcium phosphate (BCP) and calcium pyrophosphate dihydrate (CPP) crystals can induce inflammation and arthritis and recent studies point to a potential pathogenic role in OA. In the light of this evidence, we explore the relationship and potential mechanistic pathways linking calcium-containing crystals and OA. RECENT FINDINGS CPP crystals induce inflammation through the NLRP3 inflammasome while BCP crystals mediate both NLRP3 dependent and independent effects. BCP crystals have been demonstrated to induce key mitogenic and inflammatory pathways and contribute to cartilage degradation. Calcium-containing crystals induce key inflammatory pathways and may represent an attractive novel target in OA, a condition devoid of effective treatments.
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5.
Growth Factors Release From Concentrated Growth Factors: Effect of β-Tricalcium Phosphate Addition.
Bonazza, V, Hajistilly, C, Patel, D, Patel, J, Woo, R, Cocchi, MA, Buffoli, B, Lancini, D, Gheno, E, Rezzani, R, et al
The Journal of craniofacial surgery. 2018;(8):2291-2295
Abstract
BACKGROUND Platelet concentrates represent a new approach to improve tissue regeneration and can be used alone or together with autogenous bone, recombinant human growth factors, and/or other biomaterials, to enhance tissue regeneration. Among platelet concentrates, concentrated growth factors (CGFs) exhibit an interesting clinical and biotechnological application potential. OBJECTIVE The aim of this study was to evaluate the in vitro release of 4 growth factors (bone morphogenetic proteins [BMP] -2, BMP-7, transforming growth factor [TGF] -β1, and insulin-like growth factor [IGF] -1) by the enzyme-linked immunosorbent assay (ELISA) technique, in CGFs mixed or not with β-tricalcium phosphate (β-TCP), using or not the Round-up device, at different times. METHODS CGFs were obtained from healthy volunteers, mixed or not with β-TCP, using or not the Round-up device. The release of 4 growth factors from these CGFs was then measured at 5 hours, 1, 3, 6, and 8 days, using the ELISA assay. RESULTS Comparison of the results obtained with those achieved for CGFs alone showed that BMP2 and BMP-7 release, significantly increased in CGFs mixed with Round-up and β-TCP, TGF-β1 release was similar to CGFs alone, whereas IG-1 release was lower compared with CGFs alone. CONCLUSION The present data suggest that β-TCP addition to CGF could enhance and improve tissue regeneration, especially bone regeneration, increasing the release of some growth factors that play an important role in osteogenesis.
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6.
Rehabilitation of Postextractive Socket in the Premaxilla: A 12-Year Study on 27 Titanium Plasma Spray Resorbable Calcium Phosphate Coated Single Implants.
Perrotti, V, Vozza, I, Tumedei, M, Pompa, G, Iaculli, F, Quaranta, A
Implant dentistry. 2018;(4):452-460
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Abstract
OBJECTIVES The purpose of this study was to evaluate the peri-implant bone tissue level on postextractive resorbable calcium phosphate coated single implants placed in premaxillary sites grafted with autologous bone, anorganic bovine bone (ABB), platelet-rich plasma (PRP), and keratinized epithelial connective graft over 12 years. MATERIALS AND METHODS A total of 27 patients received a postextractive single implant in premaxillary sites grafted with ABB and PRP. Two months later, a keratinized epithelial connective graft was applied and the implants loaded. Clinical and radiographical evaluations were performed at baseline, 6 and 18 months, 4 and 6 years after the implant insertion, and then every 2 years up to the 12th year. RESULTS After 12 years, a total of 22 implants (81.48%), were available for the final data analysis; the implants achieved a 100% cumulative survival rate, and only a mild degree of periodontal tissue inflammation was recorded. The radiographic evaluation revealed a physiological marginal bone remodeling over the follow-up. CONCLUSION Although a good preservation of the residual bone tissue in postextraction implant sites treated with keratinized epithelial connective tissue grafts was observed, the low number of treated cases does not allow us to propose this experimental protocol to all cases of bone defects but it certainly represents a new option. Further studies on a greater number of patients and using implants with different surface characteristics should be conducted for a better understanding of the indications of the proposed treatment.
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Subchondroplasty: Treatment of Bone Marrow Lesions in the Lower Extremity.
Pelucacci, LM, LaPorta, GA
Clinics in podiatric medicine and surgery. 2018;(4):367-371
Abstract
Bone marrow lesions are associated with pain, disease progression, and cartilage loss in inflammatory and noninflammatory conditions, and are related to mechanical loading and subchondral stress. Treatment, particularly in the foot and ankle, is challenging. In the subchondroplasty procedure, flowable, synthetic, calcium phosphate bone filler is injected into the defect region, improving subchondral bone integrity and allowing remodeling back into healthy cancellous bone. The procedure is a promising treatment option for bone marrow lesions, particularly in the foot and ankle. The benefits are a minimally invasive procedure with early return to weightbearing.
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Calcium phosphate-based nanosystems for advanced targeted nanomedicine.
Degli Esposti, L, Carella, F, Adamiano, A, Tampieri, A, Iafisco, M
Drug development and industrial pharmacy. 2018;(8):1223-1238
Abstract
Synthetic calcium phosphates (CaPs) are the most widely accepted bioceramics for the repair and reconstruction of bone tissue defects. The recent advancements in materials science have prompted a rapid progress in the preparation of CaPs with nanometric dimensions, tailored surface characteristics, and colloidal stability opening new perspectives in their use for applications not strictly related to bone. In particular, the employment of CaPs nanoparticles as carriers of therapeutic and imaging agents has recently raised great interest in nanomedicine. CaPs nanoparticles, as well as other kinds of nanoparticles, can be engineered to specifically target the site of the disease (cells or organs), thus minimizing their dispersion in the body and undesired organism-nanoparticles interactions. The most promising and efficient approach to improve their specificity is the 'active targeting', where nanoparticles are conjugated with a targeting moiety able to recognize and bind with high efficacy and selectivity to receptors that are highly expressed only in the therapeutic site. The aim of this review is to give an overview on advanced targeted nanomedicine with a focus on the most recent reports on CaP nanoparticles-based systems, specifically designed for the active targeting. The distinctive characteristics of CaP nanoparticles with respect to the other kinds of nanomaterials used in nanomedicine are also discussed.
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Formation and transformation of calcium phosphate phases under biologically relevant conditions: Experiments and modelling.
Carino, A, Ludwig, C, Cervellino, A, Müller, E, Testino, A
Acta biomaterialia. 2018;:478-488
Abstract
UNLABELLED The experimental data on calcium phosphates formation were collected in dilute solution at constant pH (7.40) and temperature (37.0 °C) at different levels of ionic strength (IS). The evolution of the solid phase formation is described in detail using a thermodynamic-kinetic model. The thermodynamic model takes into account all relevant chemical species as well as Posner's clusters; the kinetic model, based on the discretized population balance approach, accounts for the solid formation from solution. The experimental data are consistent with an initial formation of dicalcium phosphate dihydrate (DCPD, brushite), which dominates the nucleation rate, and its rapid transformation into octacalcium phosphate (OCP) or hydroxyapatite (HA), which dominates the growth rate. Depending on the experimental conditions and, including the influence of the IS level, OCP may be further transformed into apatite. The classical nucleation theory is able to describe the experimental results very well and the solid phase growth is limited by the diffusion of Ca2+ ions. The precipitation pathway described by a complete thermodynamic-kinetic model is expected to contribute to the understating of the in vivo osteogenesis. STATEMENT OF SIGNIFICANCE The formation mechanism of calcium phosphates under biomimetic conditions is unraveled. The formation pathway is mathematically described based on a thermodynamic-kinetic model in which (i) the nucleation stages (primary and secondary) are dominated by the formation of dicalcium phosphate dihydrate (DCPD) and (ii) the fast growth stage is limited by the diffusion of Ca2+ ions under the driving force of octacalcium phosphate (OCP), or hydroxyapatite (HA), solubility. The obtained solid phase seems correlated to the activity coefficient of phosphate ions, thus to the ionic strength and local phosphate speciation. The model, being able to highlight the details of the precipitation pathway, is expected to contribute to the understanding of the apatitic phase formation in the biomineralization-biodemineralization processes under in-vivo conditions.
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Mesenchymal Stem Cells and Calcium Phosphate Bioceramics: Implications in Periodontal Bone Regeneration.
Millan, C, Vivanco, JF, Benjumeda-Wijnhoven, IM, Bjelica, S, Santibanez, JF
Advances in experimental medicine and biology. 2018;:91-112
Abstract
In orthopedic medicine, a feasible reconstruction of bone structures remains one of the main challenges both for healthcare and for improvement of patients' quality of life. There is a growing interest in mesenchymal stem cells (MSCs) medical application, due to their multilineage differentiation potential, and tissue engineering integration to improve bone repair and regeneration. In this review we will describe the main characteristics of MSCs, such as osteogenesis, immunomodulation and antibacterial properties, key parameters to consider during bone repair strategies. Moreover, we describe the properties of calcium phosphate (CaP) bioceramics, which demonstrate to be useful tools in combination with MSCs, due to their biocompatibility, osseointegration and osteoconduction for bone repair and regeneration. Also, we overview the main characteristics of dental cavity MSCs, which are promising candidates, in combination with CaP bioceramics, for bone regeneration and tissue engineering. The understanding of MSCs biology and their interaction with CaP bioceramics and other biomaterials is critical for orthopedic surgical bone replacement, reconstruction and regeneration, which is an integrative and dynamic medical, scientific and bioengineering field of research and biotechnology.