-
1.
PEEK versus metal cages in posterior lumbar interbody fusion: a clinical and radiological comparative study.
Cuzzocrea, F, Ivone, A, Jannelli, E, Fioruzzi, A, Ferranti, E, Vanelli, R, Benazzo, F
Musculoskeletal surgery. 2019;(3):237-241
Abstract
BACKGROUND Low back pain and sciatica represent a common disabling condition with a significant impact on the social, working and economic lives of patients. Transforaminal lumbar interbody fusion (TLIF) is a surgical procedure used in degenerative spine conditions. Several types of cages were used in the TLIF procedure. PURPOSE To determine whether there is a difference in terms of symptomatology improvement, return to daily activities and fusion rate between metal cages and polyetheretherketone (PEEK) cages. METHODS We have retrospectively reviewed 40 patients who have undergone TLIF from October 2015 to May 2016. All patients were clinically evaluated with questionnaires and were assessed with CT scan and standing X-ray films of the full-length spine. RESULTS We found no significant functional differences in the two groups. At 1-year follow-up, osteolysis was present in 50% of cases of the PEEK cages and in 10% cases of the metal cages. The degree of fusion at 1 year was evaluated as complete in 40% cases of the metal cages and 15% cases of the PEEK cages. CONCLUSIONS We have found a better fusion rate and prevalence of fusion in the group treated with metal cages, reflecting the well-known osteoinductive properties of titanium and tantalum.
-
2.
Solid-State NMR and MD Study of the Structure of the Statherin Mutant SNa15 on Mineral Surfaces.
Buckle, EL, Prakash, A, Bonomi, M, Sampath, J, Pfaendtner, J, Drobny, GP
Journal of the American Chemical Society. 2019;(5):1998-2011
-
-
Free full text
-
Abstract
Elucidation of the structure and interactions of proteins at native mineral interfaces is key to understanding how biological systems regulate the formation of hard tissue structures. In addition, understanding how these same proteins interact with non-native mineral surfaces has important implications for the design of medical and dental implants, chromatographic supports, diagnostic tools, and a host of other applications. Here, we combine solid-state NMR spectroscopy, isotherm measurements, and molecular dynamics simulations to study how SNa15, a peptide derived from the hydroxyapatite (HAP) recognition domain of the biomineralization protein statherin, interacts with HAP, silica (SiO2), and titania (TiO2) mineral surfaces. Adsorption isotherms are used to characterize the binding affinity of SNa15 to HAP, SiO2, and TiO2. We also apply 1D 13C CP MAS, 1D 15N CP MAS, and 2D 13C-13C DARR experiments to SNa15 samples with uniformly 13C- and 15N-enriched residues to determine backbone and side-chain chemical shifts. Different computational tools, namely TALOS-N and molecular dynamics simulations, are used to deduce secondary structure from backbone and side-chain chemical shift data. Our results show that SNa15 adopts an α-helical conformation when adsorbed to HAP and TiO2, but the helix largely unravels upon adsorption to SiO2. Interactions with HAP are mediated in general by acidic and some basic amino acids, although the specific amino acids involved in direct surface interaction vary with surface. The integrated experimental and computational approach used in this study is able to provide high-resolution insights into adsorption of proteins on interfaces.
-
3.
Elastic, electronic, chemical bonding and thermodynamic properties of the ternary nitride Ca4TiN4: Ab initio predictions.
Boucenna, S, Haddadi, K, Bouhemadou, A, Louail, L, Soyalp, F, Khenata, R
Journal of molecular graphics & modelling. 2019;:74-85
Abstract
In order to shed light on the unexplored properties of the ternary nitride Ca4TiN4, we report for the first time the results of an ab initio study of its structural, electronic, elastic, chemical bonding and thermodynamic properties. Calculated equilibrium structural parameters are in excellent concordance with available experimental data. Electronic properties were explored through the calculation of the energy band dispersions and density of states. It is found that Ca4TiN4 has an indirect band gap (Z-Γ) of 1.625 (1.701) eV using LDA (GGA). Nature of the chemical bonding was studied via Mulliken population analysis and charge density distribution map. It is found that the Ca-N bond is dominantly ionic, whereas the Ti-N one is dominantly covalent. Elastic properties of both single-crystal and polycrystalline phases of the title compound were explored in details using the stain-stress approach. Analysis of the calculated elastic moduli reveals that the title compound is mechanically stable, ductile and elastically anisotropic. Temperature and pressure dependencies of the unit-cell volume, bulk modulus, heat capacities, volume thermal expansion coefficient, Grüneisen parameter and Debye temperature were investigated based on the quasiharmonic Debye model.
-
4.
Photodegradation using TiO2-activated borosilicate tubes.
Khalaf, S, Shoqeir, JH, Scrano, L, Karaman, R, Bufo, SA
Environmental science and pollution research international. 2019;(19):19025-19034
Abstract
This study examines the photocatalytic activity of titanium dioxide (TiO2) semiconductor supported on borosilicate tubes (cut-off 290 nm) towards removal of a mix of persistent organic pollutants (POPs) from water. For this purpose, two widely used analgesic and anti-inflammatory drugs (NSAIDs), ibuprofen (IBU) and mefenamic acid, along with MCPA sodium monohydrate, which is a common herbicide frequently used in the agricultural activities, were selected as a case study. Borosilicate tubes were coated with titanium oxide through two different approaches: sol-gel dip-coating and a hybrid nanoparticle dip-coating and plasma-enhanced chemical vapour deposition (PECVD) process. The photochemical reactor that hosts the titania-coated tubes was designed to permit continuous throughput of liquid feed stream. The photodegradation experiments were performed in laboratory conditions under artificial irradiation simulating solar light. The efficiency of direct photolysis and heterogeneous photocatalysis (TiO2) was investigated, and the performance of each coating method was evaluated. Kinetic studies for each experiment were accomplished, the overall results showed poor efficiency and insufficient removal for NSAIDs through direct photolysis, whereas applying heterogeneous photacatalysis with TiO2 coated on borosilicate tubes was found to accelerate their degradation rate with complete decomposition. Concomitantly, kinetic experimental results showed a critical difference of performance for the two coating methods used; in particular, the degradation rates of pollutants by the sol-gel-coated tubes were much faster than the degradation by the nanoparticle/PECVD-coated tubes. Using TiO2 supported on borosilicate tubes appears to be a promising alternative to conventional TiO2 suspension and avoid post-separation stages. The results achieved in this study can be used to optimise large-scale applications, and expanding the study to cover a wide range of pollutants will lead to achieve more representative results.
-
5.
Immobilization of Denosumab on Titanium Affects Osteoclastogenesis of Human Peripheral Blood Monocytes.
Beck, F, Hartmann, ES, Koehler, MI, Redeker, JI, Schluessel, S, Schmitt, B, Fottner, A, Unger, M, van Griensven, M, Michael, J, et al
International journal of molecular sciences. 2019;(5)
Abstract
Immobilization of proteins has been examined to improve implant surfaces. In this study, titanium surfaces were modified with nanofunctionalized denosumab (cDMAB), a human monoclonal anti-RANKL IgG. Noncoding DNA oligonucleotides (ODN) served as linker molecules between titanium and DMAB. Binding and release experiments demonstrated a high binding capacity of cDMAB and continuous release. Human peripheral mononuclear blood cells (PBMCs) were cultured in the presence of RANKL/MCSF for 28 days and differentiated into osteoclasts. Adding soluble DMAB to the medium inhibited osteoclast differentiation. On nanofunctionalized titanium specimens, the osteoclast-specific TRAP5b protein was monitored and showed a significantly decreased amount on cDMAB-titanium in PBMCs + RANKL/MCSF. PBMCs on cDMAB-titanium also changed SEM cell morphology. In conclusion, the results indicate that cDMAB reduces osteoclast formation and has the potential to reduce osteoclastogenesis on titanium surfaces.
-
6.
Bulking for stress urinary incontinence in men: A systematic review.
Toia, B, Gresty, H, Pakzad, M, Hamid, R, Ockrim, J, Greenwell, T
Neurourology and urodynamics. 2019;(7):1804-1811
Abstract
AIMS: An updated literature review on outcomes in men treated with currently commercially available bulking agents was performed to determine whether this is a reasonable option in selected patients. METHODS The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses framework of systematic reviews. A comprehensive search of PubMed, Medline, and Embase was undertaken. Abstracts were independently screened by two investigators to include men with stress urinary incontinence treated with a peri-urethral injection of bulking agents currently available in the market. RESULTS Only eight original articles met the inclusion criteria. The bulking agents used were Macroplastique in five studies (total 123 patients), Opsys, Durasphere, and Urolastic in one study each (10, 7, and 2 patients, respectively). Only one study was randomized; Macroplastique vs AUS in men with mild or total incontinence. The included populations were heterogeneous and encompassed endoscopic, perineal, abdominal and laparoscopic prostate surgery as well as spinal cord injuries and urethral sphincter insufficiency. Significant dissimilarity was evident for the duration of incontinence (9-108 months), mean volume of bulking agent used (2.3-13.5 mL), number of cushions (1-5), depth and position of the cushions. The outcomes varied significantly, with reported dry rates between 0% and 83%. Outcomes were limited by relatively short follow-up in most studies. CONCLUSION Following initial enthusiasm and then dismay with collagen-based compounds, sparse and heterogeneous literature data were produced on newer non-migrating and nonabsorbable bulking agents. Some studies have suggested encouraging, if short term outcomes, however, future studies are needed in this field to support recommendations for widespread use.
-
7.
Recovery of ilmenite mud as an additive in commercial Portland cements.
Llanes, MC, González, MJG, Moreno, SMP, Raya, JPB
Environmental science and pollution research international. 2018;(25):24695-24703
Abstract
This work is focused on the manufacture of commercial cement using as additive ilmenite mud, a waste generated during TiO2 pigment production. The cements were produced by adding different proportions of mud (2.5, 5 and 10 wt%) to ordinary Portland cement (OPC). The ilmenite mud and the ilmenite mud cements (IMCs) were characterised physico-chemically by X-ray fluorescence (XRF), inductively coupled plasma mass spectrometry (ICP-MS) and X-ray diffraction (XRD). Moreover, the technological properties of the IMCs were evaluated and compared with a reference material (OPC). Since waste from the TiO2 industry is classified as a NORM (naturally occurring radioactive material), the concentrations of radionuclides were measured by high-resolution low-background gamma and alpha spectrometry techniques. Finally, the TCLP leaching test (Toxicity Characteristic Leaching Procedure, USEPA), the radiological index ("I") and the Ra equivalent concentration were also calculated to evaluate the environmental risks. As a final conclusion, it can be pointed out that the addition of ilmenite mud to OPC plays a beneficial role since it reduces the heat of hydration, the final setting time, the expansion and the linear retraction compared to standard OPC. The compression strength improves with the addition of up to 5 wt% mud. Moreover, the environmental impact of IMC2.5 and IMC5 can be considered negligible.
-
8.
Titanium and polyether ether ketone (PEEK) patient-specific sub-periosteal implants: two novel approaches for rehabilitation of the severely atrophic anterior maxillary ridge.
Mounir, M, Atef, M, Abou-Elfetouh, A, Hakam, MM
International journal of oral and maxillofacial surgery. 2018;(5):658-664
Abstract
The aim of this study was to assess two new protocols for single-stage rehabilitation of the severely atrophic maxillary ridge using customized porous titanium or polyether ether ketone (PEEK) sub-periosteal implants. Ten patients with a severely atrophic anterior maxillary alveolar ridge were divided randomly into two groups (five patients in each) to receive customized sub-periosteal implants fabricated via CAD/CAM technology: group 1, porous titanium implants; group 2, PEEK implants. Prosthetic loading with fixed acrylic bridges was performed 1 month postoperative. The implants were followed-up for 12 months and evaluated for the presence of any sign of radiographic bone resorption, mobility, infection, prosthetic fracture, or implant exposure. The immediate postoperative period was uneventful except for one case complicated by wound dehiscence in group 1. At 12 months, all implants were functionally stable and the patients were comfortable with the prostheses. No signs of radiographic bone resorption, mobility, infection, or prosthetic fracture were observed. Within the limitations of this study, the application of customized porous titanium and PEEK sub-periosteal implants produced through CAD/CAM technology appears to be an acceptable method for single-stage prosthetic rehabilitation of the severely atrophic edentulous anterior maxilla. This study was awarded the best case study at the academy of osseintegration annual meeting 2017, Orlando, Florida.
-
9.
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
-
-
Free full text
-
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.
-
10.
Osteoblastic differentiating potential of dental pulp stem cells in vitro cultured on a chemically modified microrough titanium surface.
DE Colli, M, Radunovic, M, Zizzari, VL, DI Giacomo, V, DI Nisio, C, Piattelli, A, Calvo Guirado, JL, Zavan, B, Cataldi, A, Zara, S
Dental materials journal. 2018;(2):197-205
-
-
Free full text
-
Abstract
Titanium surface modification is critical for dental implant success. Our aim was to determine surfaces influence on dental pulp stem cells (DPSCs) viability and differentiation. Implants were divided into sandblasted/acid-etched (control) and sandblasted/acid-etched coated with calcium and magnesium ions (CaMg), supplied as composite (test). Proliferation was evaluated by MTT, differentiation checking osteoblastic gene expression, PGE2 secretion and matrix formation, inflammation by Interleukin 6 (IL-6) detection. MTT and IL-6 do not modify on test. A PGE2 increase on test is recorded. BMP2 is higher on test at early experimental points, Osterix and RUNX2 augment later. Alizarin-red S reveals higher matrix production on test. These results suggest that test surface is more osteoinductive, representing a start point for in vivo studies aiming at the construction of more biocompatible dental implants, whose integration and clinical performance are improved and some undesired effects, such as implant stability loss and further surgical procedures, are reduced.