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Refereed/Peer-reviewed The demand for medical implants globally has increased significantly due to an aging population amongst other reasons. Despite the overall increase in the survivorship of Ti6Al4V implants, implant infection rates are increasing due to factors such as diabetes, obesity, and bacterial resistance to antibiotics. Two commonly found bacteria implicated in implant infections are Staphylococcus aureus and Pseudomonas aeruginosa. Based on prior work that showed nanostructured surfaces might have potential in passively killing these bacterial species, we developed a hierarchical, hydrothermally etched, nanostructured titanium surface. To evaluate the antibacterial efficacy of this surface, etched and as-received surfaces were inoculated with S. aureus or P. aeruginosa at concentrations ranging from 10(2) to 10(9) colony-forming units per disc. Live/dead staining revealed there was a 60% decrease in viability for S. aureus and greater than a 98% decrease for P. aeruginosa on etched surfaces at the lowest inoculum of 10(2) CFU/disc, when compared to the control surface. Bactericidal efficiency decreased with increasing bacterial concentrations in a stepwise manner, with decreases in bacterial viability noted for S. aureus above 10(5) CFU/disc and above 10(6) CFU/disc for P. aeruginosa. Surprisingly, biofilm depth analysis revealed a decrease in bacterial viability in the 2 mu m layer furthest from the nanostructured surface. The nanostructured Ti6Al4V surface developed here holds the potential to reduce the rate of implant infections.

Aim: The aim of this study was to investigate the combined effect of the lateral-compression of host-bone (undersized-osteotomy-preparation) and axial-compression of host-bone (not drilling the full length of the implant) on the primary-implant-stability and the host-bone-architecture. Materials and Methods: In this experimental-study, 44 dental implants (diameter-4.2 mm; length-10 mm; Dyna®) were installed in the femoral-condyles of four cadaver-goats using four different surgical approaches (11 implant/surgical approach; n = 11). Approach-1: Standard preparation according to the manufacturer's guidelines. The bone-cavity was prepared up to 10 mm in depth and 4 mm in diameter. Approach-2: Preparation up to 8 mm in depth and 4 mm in diameter. Approach-3: Preparation up to 10 mm in depth. Approach-4: The bone-cavity was prepared up to 8 mm in depth and 3.6 mm in diameter. Insertion torque (n = 11), removal torque (n = 7) and % bone-implant contact (n = 4) measurements were recorded. Bone architecture was assessed by micro-computer tomography and histological analysis (n = 4). Results: For approaches 2, 3, and 4 (P

Objective The present work was aimed to evaluate the effect of valproic acid (VPA)，Parathyroid hormone (1–34) (PTH)+VPA on Ti rods osseointegration in ovariectomized rats and further investigation of the possible mechanism. Methods The MC3T3-E1 cells were co-cultured with VPA，PTH ​+ ​VPA and induced to osteogenesis, and the cell viability，mineralization ability were observed by MTT and ALP staining，Alizarin Red staining and Western blotting. Twelve weeks after bilateral ovariectomy, all animals were randomly divided into four groups: group OVX and VPA，PTH ​+ ​VPA, and all the rats received Ti implants and animals belong to group VPA，PTH ​+ ​VPA received valproic acid (300 ​mg/day), valproic acid (300 ​mg/day) plus Parathyroid hormone (1–34) every 3 days (60 ​μg/kg), respectively, treatment until death at 12 weeks. Micro-CT, histology, biomechanical testing, bone metabolism index and Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis were used to observe the therapeutic effect and explore the possible mechanism. Results Results shown that VPA decreased new bone formation around the surface of titanium rods and push-out force other than group OVX. Histology, Micro-CT and biochemical analysis results showed combined application of systemic VPA showed harmful effects than OVX group on bone formation in osteopenia rats, with the worse effects on CTX-1, P1NP and microarchitecture as well as biomechanical parameters by down-regulated gene expression of Runx2, OCN, Smad1, BMP-2 and OPG, while up-regulated RANKL. However, after PTH treatment, the above indicators were significantly improved. Conclusions The present study suggests that systemic use of VPA may bring harm to the stability of titanium implants in osteoporosis, PTH can reverse the negative effect of VPA on the osseointegration of titanium rods in ovariectomized rats. Translational potential of this article According to our research, when patients with epilepsy have osteoporotic fractures, after joint replacement or internal fixation, continue to use sodium valproate for anti-epileptic therapy, the possibility of postoperative loosening increases, again on the basis of It can be reversed with the anti-osteoporosis drug parathyroid hormone (1-34).

Background Implant-associated infections (IAI) remain a challenging complication in osteosynthesis. There is no consensus or clear evidence whether titanium offers a relevant clinical benefit over stainless steel. Purpose In this systematic review, we sought to determine whether the implant properties of titanium reduce the susceptibility to IAI compared to stainless steel in fracture management. Methods A systematic literature search in German and English was performed using specific search terms and limits. Studies published between 1995 and 1st June 2020 in the Cochrane library, MEDLINE and Web of Science databases were included. Only clinical studies comparing titanium and stainless steel implants regarding the susceptibility to infections were selected for detailed review. Results Five studies out of 384 papers were identified and reviewed. From the studies meeting inclusion criteria one study was a systematic review, two studies were randomized controlled studies (RCT) and two studies were of retrospective comparative nature of level IV evidence. Conclusion Our results show that currently, no proven advantage for titanium implants in respect to IAI can be seen in contemporary literature. Implants preserving periosteal blood-flow and minimising soft-tissue trauma show statistically significant benefits in reducing the incidence of IAI. Clinical studies providing reliable evidence regarding the influence of titanium implants on IAI and investigating the susceptibility of titanium to infection are necessary

In the design of multifunctional orthopedic biomaterials, enhanced biological activities, reinforced mechanical property, improved hydrophilicity and osteo-compatibility are the essential criteria. For achieving these goals, here a bioactive multifunctional Ti6Al4V implant with nanowire structured surface topography is designed and fabricated using 3D printing technique. Selective laser melting (SLM) is applied to fabricate scaffold materials with diamond cellular structures to meet the requirements of load-bearing function of bone tissue. With the alkali treatment of sodium hydroxide, osteogenic layer of Na2Ti6O13 is generated on the porous Ti6Al4V, on which apatite is easily deposited and immobilized. Clusters of Na2Ti6O13 exhibits excellent hydrophilicity and surface roughness with precise control of alkali treatment time. Additionally, the compressive strength of the modified porous Ti6Al4V (121.2 MPa-84.5 MPa) decreases due to the corrosion of sodium hydroxide, while it can satisfy the basic mechanical requirement of cortical bone. The results prove that the surface-modified 3D printed porous Ti6Al4V possesses balanced mechanical strength and osteogenic function, promising for potential application in complex multifunctional bone defects.

Treatment of implant-associated infection is becoming more challenging, especially when bacterial biofilms form on the surface of the implants. Developing multi-mechanism antibacterial methods to combat bacterial biofilm infections by the synergistic effects are superior to those based on single modality due to avoiding the adverse effects arising from the latter. In this work, TiO2 nanorod arrays in combination with irradiation with 808 near-infrared (NIR) light are proven to eradicate single specie biofilms by combining photothermal therapy, photodynamic therapy, and physical killing of bacteria. The TiO2 nanorod arrays possess efficient photothermal conversion ability and produce a small amount of reactive oxygen species (ROS). Physiologically, the combined actions of hyperthermia, ROS, and puncturing by nanorods give rise to excellent antibacterial properties on titanium requiring irradiation for only 15 min as demonstrated by our experiments conducted in vitro and in vivo. More importantly, bone biofilm infection is successfully treated efficiently by the synergistic antibacterial effects and at the same time, the TiO2 nanorod arrays improve the new bone formation around implants. In this protocol, besides the biocompatible TiO2 nanorod arrays, an extra photosensitizer is not needed and no other ions would be released. Our findings reveal a rapid bacteria-killing method based on the multiple synergetic antibacterial modalities with high biosafety that can be implemented in vivo and obviate the need for a second operation. The concept and antibacterial system described here have large clinical potential in orthopedic and dental applications., Graphical abstract In this work, TiO2 nanorod arrays in combination with irradiation with 808 near-infrared (NIR) light are proven to eradicate biofilms by combining photothermal therapy, photodynamic therapy, and physical killing of bacteria.Image 1, Highlights • Various TiO2 nanostructures were prepared on titanium. • The TiO2 nanorod arrays exhibited excellent antibacterial properties under the irradiation of 808 nm NIR light. • The combined actions of hyperthermia, ROS, and puncturing produced superior antibacterial activity in vitro and in vivo. • In this antibacterial system, besides the biocompatible TiO2 nanorod arrays, an extra photosensitizer is not needed.

This study aimed to evaluate the effects of two types of provisional resin cements on the color and retentive strength of two different all-ceramic restorations cemented onto customized zirconia abutments. Forty-two crowns were made of monolithic zirconia and lithium disilicate ceramics (n = 21 per group) and cemented on customized zirconia abutments by using two provisional resin cements of TempBond Clear and Implantlink Semi, and TempBond serving as the control (n = 7 per cement subgroup). The specimens’ color was measured before and after cementation and after thermocycling. The color difference was calculated by using CIEDE2000 formula (ΔE00). The tensile force was applied to assess the retentive strength. Kruskal-Wallis, Dunn’s post-hoc, and Mann-Whitney non-parametric tests were used to compare ΔE00(1) and ΔE00(2) and two-way ANOVA followed by one-way ANOVA and Tukey’s HSD post hoc test and T-test were used to compare retentive strength between subgroups. In the lithium disilicate group, ΔE00 of the control subgroup (TempBond) was significantly higher than that of Implantlink Semi cements subgroup (P = 0.001). But, in the monolithic zirconia group, ΔE00 of the control subgroup (TempBond) was significantly higher than that of Implantlink Semi (P = 0.020) and TempBond Clear cements (P = 0.007). In the monolithic zirconia group, the control subgroup (TempBond) was significantly more retentive than TempBond Clear (P = 0.003) and Implantlink Semi cement (P = 0.001). However, in the lithium disilicate group, Implantlink Semi cement was significantly more retentive than TempBond Clear (P = 0.019) and TempBond (control) (P = 0.001). The final color of both restorations was significantly affected by the provisional resin cement type. The retentive strength was influenced by both the type of cement and ceramic.

Objectives: To evaluate the effect of cone-beam computed tomography (CBCT) tube current (mA) on the magnitude of artefacts at different distances from titanium or zirconia implants, with and without activation of a proprietary metal artefact reduction (MAR). Material and methods: Human mandibles were scanned on an OP300 Maxio CBCT unit (Instrumentarium, Tuusula, Finland) before and after the installation of dental implants, with four different tube currents (4 mA, 6.3 mA, 8 mA and 10 mA), with and without activation of proprietary MAR. The effect of mA on the standard deviation (SD) of gray values and contrast to noise ratio (CNR) were assessed in regions of interest located 1.5 cm, 2.5 cm, and 3.5 cm from implants. Results: In the presence of titanium implants, a significant decrease in SD was found by increasing tube current from 4 mA to 6.3 mA or 8 mA. For zirconia implants, 8 mA yielded better results for all distances. MAR improved CNR in the presence of zirconia implants at all distances, whereas no differences were observed with the use of MAR for titanium implants. Conclusion: Increased tube current can improve overall image quality in the presence of implants, at all the distances tested. When a zirconia implant is present, such increase in mA should be higher in comparison to that for examinations with titanium implants. Activation of OP300 Maxio proprietary MAR improved image quality only among examinations with zirconia implants. Clinical relevance: Artefact-generating implants are common in the field of view of CBCT examinations. Optimal exposure parameters, such as tube current, ensure high image quality with lowest possible radiation exposure.

Dental implants are the usual therapy of choice in the dental clinic to replace a loss of natural teeth. Over recent decades there has been an important progress in the design and manufacturing of titanium implant surfaces with the goal of improving their osteointegration. In the present work, the aim was to evaluate the usefulness of hDPSCs (human dental pulp stem cells), in combination with autologous plasma components, for in vitro bone generation on biomimetic titanium dental implant materials. In this context, the combination of hDPSCs stimulated by PRGF or PRF and cultured on standard Ti6A14V and biomimetic BAS™ (Avinent Implant System) titanium surfaces were studied in order to evaluate possible enhancements in the osteoblastic differentiation process out of human mesenchymal cells, as well as bone matrix secretion on the implant surface. The results obtained in this in vitro model of osteogenesis suggested a combination of biomimetic rough titanium surfaces, such as BAS™, with autologous plasma-derived fibrin-clot membranes such as PRF and/or insoluble PRGF formulations, but not with an addition of water-soluble supplements of plasma-derived growth factors, to maximise osteoblastic cell differentiation, bone generation, anchorage and osteointegration of titanium-made dental implants.

Aim. To study the effect of exometabolites of Bifidobacterium bifidum on the biological properties of causative agents of purulent-septic complications in trauma and orthopedic practice and to evaluate their effect on reparative bone tissue regeneration in the peri-implant zone in the postoperative period. Materials and methods. Using the museum cultures of B. bifidum 791, S. aureus 25923 ATCC, P. aeruginosa 27853 ATCC and antibiotic-resistant hospital strains, isolated from patients with periprosthetic infection and osteomyelitis (S.aureus 889, S. epidermidis 2041, P. aeruginosa 9672). The supernatant (exometabolites) of B. bifidum 791 was obtained from a broth culture, which was centrifuged and passed through a membrane filter. In studying the effect of exometabolites of bifidobacteria on the proliferative activity of bacteria, the two-day supernatant of B. bifidum was co-incubated for 24 cultures of museum and hospital strains. The biofilm formation in vitro experiment was studied after 24 and 96 hours. Treatment of implants with exometabolites of bifidobacteria was carried out for 30 minutes. Experimental research was carried out on rabbits of breed «Flandr». Titanium implants without coating (control) and with porous SBKFM coating treated with exometabolites of B. bifidum (experiment) were screwed into the tibial bones of animals. Histological examination and computed microtomography were performed using a SkyScan 1172 instrument (BRUKER). Result. Depending on the time of cultivation of bifidobacteria, the supernatant B. bifidum 791 had a bacteriostatic and bactericidal effect to varying degrees, and also inhibited the biofilm formation of the studied microorganism cultures, including antibiotic-resistant strains. In in vivo experiments, the use of porous SBKFM coatings on titanium implants treated with the supernatant of bifidobacteria made it possible to maintain the mineral density indices of the peri-implantation zone at a high level in comparison with the use of control titanium implants without coating. Conclusion. Positive results of preclinical experiments are promising for further clinical research in trauma and orthopedic practice, which ultimately will reduce the risk of developing septic complications and prevent the migration of metal structures and instability of endoprostheses in the postoperative period.

Preparation of paraspinal tissue of patients with implants for elemental analysis is a challenge because it contains titanium in the ionic form, as well as metallic debris. Most literature reports focus on dissolving the tissue, but the impact of digestion conditions on metallic debris of Ti has not been investigated. In our work, various digestion conditions, including systems, compositions of oxidising mixture, and time, were tested aiming (i) to digest the tissue without digestion of metallic titanium to quantify soluble Ti and (ii) to digest metallic titanium debris to asses total Ti content in tissue. The experiments were performed in a closed mode using a microwave-assisted system and a carbon heating block. Our study revealed that total digestion of titanium was impossible in the tested conditions and the maximal level of digested titanium was below 70%. The mineralisation with the use of concentrated nitric acid was optimal to prepare paraspinal samples to analyse the soluble titanium form because metallic titanium passivated and did not migrate to the solution. The elaborated conditions were applied to determine titanium ion in the periimplant tissue of patients with three different titanium-based surgical systems, including traditional growing rod (TGR), guided growth systems (GGS), and vertical expandable prosthesis titanium rib (VEPTR).

This study aimed to analyze fracture strength in vitro by varying the axial height of the titanium insert and the labial height of the zirconia abutment in an internal connection implant to identify the titanium insert axial height with optimal mechanical stability. Sixty implants with an internal connection system were used. Two-piece zirconia abutments were used with the titanium inserts. Combinations of different titanium insert axial heights (mm) and zirconia abutment labial heights (mm) constituted five groups: Gr1 (1–3), Gr2 (3–3), Gr3 (3–5), Gr4 (5–3), and Gr5 (5–5). After thermocycling, a fracture load test was performed with a universal testing machine. The initial deformation load and the fracture load were measured and analyzed. The fractured surface and cross-section of the specimens were examined by scanning electron microscopy (SEM). The groups of titanium inserts with axial heights of 3 mm and 5 mm showed significantly greater initial deformation load and fracture load than the group with an axial height of 1 mm (p < 0.05), but there was no significant difference between the two groups with axial heights of 3 mm and 5 mm. The labial height of the zirconia abutment had no significant influence on the initial deformation load and fracture load. In some specimens in Gr4 and Gr5, cracking or bending of the titanium insert and abutment screw was observed on SEM. The axial height of the titanium insert should be designed to not be less than 3 mm to increase the fracture strength and promote the long-term stability of implants.

Background: Concepts of Chiari malformation Type 1 (CM1) surgery in the present time significantly different. The most common complications are pseudomeningocele (12%) and postoperative CSF leak (5%). The development of pseudomeningocele may be associated with inappropriate restoration of bone and muscles relations. Methods: The pilot study involved 11 patients aged 24–64 years with a diagnosis of CM1 who had indications for surgical treatment. Special titanium implant enabling fixation of the occipital and cervical muscles at the projections of their normal attachments was developed, it was placed to occipital bone on the final stages of surgical intervention. Surgical technique promoted tightened wound closure neutralizing formation of “dead space” at the place of occipital craniectomy and between muscle layers. The implant was produced by direct metal laser sintering method for each patient individually. Results: There were no complications during the hospitalization and follow-up period. Postoperative MRI demonstrated adequate formation of the cisterna magna and the absence of pseudomeningocele. During follow-up period there were no signs of pseudomeningocele, CSF leak, surgical scar complications, implant-associated infections, and other complications. Conclusion: In the study group, no pseudomeningocele cases as long as any other complications associated with surgery had been revealed. The efficacy of the proposed surgical technique using the developed implant should be evaluated in clinical trials with larger patient samples. To simplify preoperative planning and manufacturing of the implant for each patient individually, a set of implants with different specified sizes was developed.

Cellularized scaffold is emerging as the preferred solution for tissue regeneration and restoration of damaged functionalities. However, the high cost of preclinical studies creates a gap between investigation and the device market for the biomedical industry. In this work, bone-tailored scaffolds based on the Ti6Al4V alloy manufactured by electron beam melting (EBM) technology with reused powder were investigated, aiming to overcome issues connected to the high cost of preclinical studies. Two different elementary unit cell scaffold geometries, namely diamond (DO) and rhombic dodecahedron (RD), were adopted, while surface functionalization was performed by coating scaffolds with single layers of polycaprolactone (PCL) or with mixture of polycaprolactone and 20 wt.% hydroxyapatite (PCL/HA). The mechanical and biological performances of the produced scaffolds were investigated, and the results were compared to software simulation and experimental evidence available in literature. Good mechanical properties and a favorable environment for cell growth were obtained for all combinations of scaffold geometry and surface functionalization. In conclusion, powder recycling provides a viable practice for the biomedical industry to strongly reduce preclinical costs without altering biomechanical performance.

Objective During the insertion of dental implants in the bone tissue, different torque values can be applied. However, the high applied torque can cause damage to the implant connection. Our study sought to evaluate, by measuring the angle of rotation of the insertion drive and, later microscopic observation, possible changes in the structure of implants of different diameters with 3 different types of connections after the application of 4 different torque intensities. Materials and methods Three hundred tapered dental implants and three hundred insertion drivers were used in the present study. Implants of 3.5 and 4 mm in diameter with 3 connection models were tested: external hexagon (EH), internal hexagon (IH) and Morse taper (MT). Then, sis groups were performed: EH3 group, EH4 group, IH3 group, IH4 group, MT3 group and MT4 group. The samples were submitted to the torque/torsion force at 4 intensities (n = 10 samples per group and intensity): 60, 80, 100 and 120 Ncm. The turning angle of the insertion driver was measured in each test. In addition, in 10 samples from each group, the maximum torque value supported by each implant model was measured. After the tests, all samples were inspected microscopically to describe the observed changes. Results The maximum torque supported by the different implant models showed statistically significant difference (p < 0.0001). The values of the measured angles showed statistically significant differences between the torque values applied within each group (p < 0.001) and between groups with the same torque value (p < 0.001). Conclusions Within the limitations of the present study in vitro, the results showed that high torque values cause mechanical damage to the implants.

Introduction Implant material is a more important factor for periprosthetic tibial bone resorption than implant design after total knee arthroplasty (TKA). The virtual perturbation study was planned to perform using single case of proximal tibia model. We determined whether the implant materials’ stiffness affects the degree of periprosthetic tibial bone resorption, and whether the effect of material change with the same implant design differed according to the proximal tibial plateau areas. Materials and methods This three-dimensional finite element analysis included two cobalt-chromium (CoCr) and two titanium (Ti) tibial implants with different designs. They were implanted into the proximal tibial model reconstructed using extracted images from computed tomography. The degree of bone resorption or formation was measured using the strain energy density after applying axial load. The same analysis was performed after exchanging the materials while maintaining the design of each implant. Results The degree of periprosthetic tibial bone resorption was not determined by the type of implant materials alone. When the implant materials were changed from Ti to CoCr, the bone resorption in the medial compartment increased and vice versa. The effect of material composition’s change on anterior and posterior areas varied accordingly. Conclusions Although the degree of bone resorption was associated with implant materials, it differed depending on the design of each implant. The effect on the degree of bone resorption according to the materials after TKA should be evaluated while concomitantly considering design.

The present work was aimed to evaluate the effect of valproic acid(VPA), simvastatin (SIM)+VPA on Ti(titanium) rods osseointegration in ovariectomized(OVX) rats and further investigation of the possible mechanism. The MC3T3-E1 cells were co-cultured with VPA, SIM + VPA and induced to osteogenesis, and the cell viability, mineralization ability were observed by MTT and ALP staining, Alizarin Red staining and Western blotting. Twelve weeks after bilateral ovariectomy, all animals were randomly divided into three groups: group OVX and VPA, SIM + VPA, and all the rats received Ti implants and animals belong to group VPA, SIM + VPA received valproic acid(300 mg/kg/day), valproic acid(300 mg/kg/day) plus SIM (25 mg/kg/day), respectively, treatment until death at 12 weeks. Micro-CT, histology, biomechanical testing, bone metabolism index and Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis were used to observe the therapeutic effect and explore the possible mechanism. Results shown that VPA decreased new bone formation around the surface of titanium rods and push-out force other than group OVX. Histology, Micro-CT and biochemical analysis results showed combined application of systemic VPA showed harmful effects than OVX group on bone formation in osteopenic rats, with the worse effects on CTX-1, P1NP and microarchitecture as well as biomechanical parameters by down-regulated gene expression of Runx2, OCN, Smad1, BMP-2 and OPG, while up-regulated RANKL. However, after SIM treatment, the above indicators were significantly improved. The present study suggests that systemic use of VPA may bring harm to the stability of titanium implants in osteoporosis, SIM can reverse the negative effect of VPA on the osseointegration of titanium rods in ovariectomized rats.

Oxidative stress (OS) is a redox homeostasis disorder that results in oxidation of cell components and thus disturbs cell metabolism. OS is induced by numerous internal as well as external factors. According to recent studies, dental treatment may also be one of them. The aim of our work was to assess the effect of dental treatment on the redox balance of the oral cavity. We reviewed literature available in PubMed, Medline, and Scopus databases, including the results from 2010 to 2020. Publications were searched according to the keywords: oxidative stress and dental monomers; oxidative stress and amalgam; oxidative stress and periodontitis, oxidative stress and braces, oxidative stress and titanium; oxidative stress and dental implants, oxidative stress and endodontics treatment, oxidative stress and dental treatment; and oxidative stress and dental composite. It was found that dental treatment with the use of composites, amalgams, glass-ionomers, materials for root canal filling/rinsing, orthodontic braces (made of various metal alloys), titanium implants, or whitening agents can disturb oral redox homeostasis by affecting the antioxidant barrier and increasing oxidative damage to salivary proteins, lipids, and DNA. Abnormal saliva secretion/composition was also observed in dental patients in the course of OS. It is suggested that the addition of antioxidants to dental materials or antioxidant therapy applied during dental treatment could protect the patient against harmful effects of OS in the oral cavity.

Simple Summary The scientific literature repeatedly insists on the success of titanium implants. Nevertheless, the so-called tribocorrosion process releases titanium ions into the surrounding tissues, which can trigger a cascade of reactions, localized or at a distance, or even systemic reactions. Consequently, guidelines should be drawn up before starting treatment; when a hypersensitivity reaction following titanium dental implant placement occurs, a range of treatment alternatives should be clearly established and made available. Abstract The purpose of this scoping review was to describe the current state of knowledge and understanding of allergies to titanium dental implants. A scoping review was conducted following the Prisma Extension for Scoping Reviews checklist. An electronic search was performed in five databases complemented by manual and grey literature searches. Fifty-two relevant papers were included for final review. Titanium particles can be released from the surfaces of dental implants in a process called tribocorrosion, which may contribute to bone loss due to inflammatory reaction. Diverse mechanisms have been described that may trigger allergy to titanium, as well as the clinical signs that manifest as the allergy develops. Allergies to titanium are uncommon but represent a real possibility that should not be overlooked in patients requiring prosthodontic rehabilitation with dental implants. Allergy can trigger a range of symptoms. Patients who have already been diagnosed with allergies to other metals will be more predisposed to suffering an allergy to titanium. Further investigation is needed in order to measure the true scope of these allergies.

PURPOSE: The aim of this study was to evaluate the influence of different density and amplitude of electric current on the percentage of bone-implant contact (BIC) using the finite element method. MATERIALS AND METHODS: Numerical models were performed on commercially pure titanium grade IV implants connected to a 1.5 V battery with an electrical resistance (R) at 150 kΩ on 10 µA or at 75 kΩ on 20 µA. The percentage of simulated BIC was analysed by varying the electric current from 1 up to 60 µA. The variation of electric current application was simulated for coronal and apical peri-implant regions. RESULTS: The findings showed that a direct and constant electric current source below 10 μA does not provide a proper current density for osseointegration (BIC < 55%). Electric current sources ranging from 10 to 20 μA resulted in an increase in BIC above 60% while BIC reached 90% on 30 to 40 μA. Also, the application of the current source on 20 μA at the apical peri-implant region resulted in a high BIC percentage at around 86.1%. CONCLUSIONS: The location and intensity of the electrical current source can increase the resultant electrical current density at the implant-bone interface and enhance the bone healing process. Although the model is a simplified version of the biological process in the bone-implant interface, such findings can predict a magnitude of electrical current density required to stimulate osseointegration. ispartof: COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING vol:23 issue:14 pages:1041-1051 ispartof: location:England status: published

PurposePlacement of one-piece ceramic dental implants requires precision, which can be enhanced by using a computer-guided system. This prospective clinical study examines the accuracy of partially guided implantation in the placement of one-piece ceramic implants in the anterior region.Materials and methodsOne-piece ceramic dental implants were placed in 20 patients who were missing a central or lateral incisor. Partially guided dental implant placements were performed in all cases. The deviations in the implant positions were analyzed by superimposing post-operative cone beam computed tomography images over pre-operative treatment planning images. The results were reported as deviations (mean ± standard deviation) for three aspects (3D offset, mesio-distal, labio-lingual, and apico-coronal) and in three dimensions (the angle, coronal, and apical parts).ResultsImplants were successfully placed in 20 patients. The mean angular deviation was 4.23±1.84°, whereas the mean coronal 3D offset was 0.98±0.48 mm, and the mean apical 3D offset was 1.57±0.46 mm.ConclusionsA prospective clinical study involving 20 patients was conducted to measure the accuracy of computer-guided implantation of one-piece ceramic dental implants. Accuracy was determined by comparing the planned implant position to the actual position. Greater accuracy can be expected at the coronal part than at the apical part. The coronal 3D offset was found to be the most accurate.

Effective biofilm removal from surfaces in the mouth is a clinical challenge. Cavitation bubbles generated around a dental ultrasonic scaler are being investigated as a method to remove biofilms effectively. It is not known how parameters such as surface roughness and instrument distance from biofilm affect the removal. We grew Strepotococcus sanguinis biofilms on coverslips and titanium discs with varying surface roughness (between 0.02-3.15 μm). Experimental studies were carried out for the biofilm removal using high speed imaging and image analysis to calculate the area of biofilm removed at varying ultrasonic scaler standoff distances from the biofilm. We found that surface roughness up to 2 μm does not adversely affect biofilm removal but a surface roughness of 3 μm caused less biofilm removal. The standoff distance also has different effects depending on the surface roughness but overall a distance of 1 mm is just as effective as a distance of 0.5 mm. The results show significant biofilm removal due to an ultrasonic scaler tip operating for only 2s versus 15-60s in previous studies. The technique developed for high speed imaging and image analysis of biofilm removal can be used to investigate physical biofilm disruption from biomaterial surfaces in other fields.

Titanium materials are essential treatment modalities in the medical field and serve as a tissue engineering scaffold and coating material for medical devices. Thus, there is a significant demand to improve the bioactivity of titanium for therapeutic and experimental purposes. We showed that ultraviolet light (UV)-pre-treatment changed the protein-adsorption ability and subsequent osteoconductivity of titanium. Fibronectin (FN) adsorption on UV-treated titanium was 20% and 30% greater after 1-min and 1-h incubation, respectively, than that of control titanium. After 3-h incubation, FN adsorption on UV-treated titanium remained 30% higher than that on the control. Osteoblasts were cultured on titanium disks after 1-h FN adsorption with or without UV-pre-treatment and on titanium disks without FN adsorption. The number of attached osteoblasts during the early stage of culture was 80% greater on UV-treated and FN-adsorbed (UV/FN) titanium than on FN-adsorbed (FN) titanium, osteoblasts attachment on UV/FN titanium was 2.6- and 2.1-fold greater than that on control- and UV-treated titanium, respectively. The alkaline phosphatase activity of osteoblasts on UV/FN titanium was increased 1.8-, 1.8-, and 2.4-fold compared with that on FN-adsorbed, UV-treated, and control titanium, respectively. The UV/FN implants exhibited 25% and 150% greater in vivo biomechanical strength of bone integration than the FN- and control implants, respectively. Bone morphogenetic protein-2 (BMP-2) adsorption on UV-treated titanium was 4.5-fold greater than that on control titanium after 1-min incubation, resulting in a 4-fold increase in osteoblast attachment. Thus, UV-pre-treatment of titanium accelerated its protein adsorptivity and osteoconductivity, providing a novel strategy for enhancing its bioactivity.

Background Clinical evidence indicates that sitagliptin treatment improves bone quality in diabetic patients, but the mechanisms involved remain elusive. Here, we studied the role of angiogenesis with sitagliptin treatment in diabetes-induced poor osteointegration of titanium implants and the underlying mechanisms. Methods In vitro, Human Umbilical Vein Endothelial Cells (HUVECs) incubated on titanium (Ti) surface were subjected to 1) normal milieu (NM); 2) diabetic milieu (DM); 3) DM + sitagliptin; 4) NM + macrophage; 5) DM + macrophage; or 6) DM + macrophage + sitagliptin. Microphage and HUVECs were cultured alone or co-cultured in a Transwell system. In vivo, DM was induced by high-fat diet and administration of streptozotocin (STZ) in rats. Titanium screws were implanted in the femurs of rats in three groups: Control, DM, Sitagliptin-treated DM. Results In vitro, when cells were incubated alone, DM caused M1 polarization of macrophage, evidenced by the increased iNOS and decreased CD206 expressions, and obvious dysfunctions of HUVECs. The DM-induced injury of endothelial cells were significantly worsened when the two cells were co-cultured. The addition of sitagliptin markedly reversed the changes of macrophage but not of HUVECs in DM when cells were cultured alone. When cells co-cultured, however, both the abnormal macrophage polarization and the endothelial impairment in DM was significantly alleviated by sitagliptin. In vivo, compared with normal animals, DM animals showed imbalanced M1/M2 polarization, angiogenesis inhibition and poor bone formation on the bone-implant interface (BII), which were significantly ameliorated by sitagliptin treatment. Conclusion Our results demonstrate macrophage polarization imbalance as a crucial mechanism underlying the impaired angiogenesis and bone healing in diabetes, and provide sitagliptin as a promising novel drug for biomaterial-engineering to improve the osteointegration of titanium implants in diabetic patients.

OBJECTIVES:The propose was to compare this new implant macrogeometry with a control implant with a conventional macrogeometry. MATERIALS AND METHODS:Eighty-six conical implants were divided in two groups (n = 43 per group): group control (group CON) that were used conical implants with a conventional macrogeometry and, group test (group TEST) that were used implants with the new macrogeometry. The new implant macrogeometry show several circular healing cambers between the threads, distributed in the implant body. Three implants of each group were used to scanning electronic microscopy (SEM) analysis and, other eighty samples (n = 40 per group) were inserted the tibia of ten rabbit (n = 2 per tibia), determined by randomization. The animals were sacrificed (n = 5 per time) at 3-weeks (Time 1) and at 4-weeks after the implantations (Time 2). The biomechanical evaluation proposed was the measurement of the implant stability quotient (ISQ) and the removal torque values (RTv). The microscopical analysis was a histomorphometric measurement of the bone to implant contact (%BIC) and the SEM evaluation of the bone adhered on the removed implants. RESULTS:The results showed that the implants of the group TEST produced a significant enhancement in the osseointegration in comparison with the group CON. The ISQ and RTv tests showed superior values for the group TEST in the both measured times (3- and 4-weeks), with significant differences (p < 0.05). More residual bone in quantity and quality was observed in the samples of the group TEST on the surface of the removed implants. Moreover, the %BIC demonstrated an important increasing for the group TEST in both times, with statistical differences (in Time 1 p = 0.0103 and in Time 2 p < 0.0003). CONCLUSIONS:Then, we can conclude that the alterations in the implant macrogeometry promote several benefits on the osseointegration process.

Fixation materials used in the surgical treatment of subcondylar fractures contribute to successful clinical outcomes. In this study, we simulated the mechanical properties of four fixation materials [titanium (Ti), magnesium alloy (Mg alloy), poly-L-lactic acid (PLLA), and hydroxyapatite/poly-L-lactide (HA-PLLA)] in a finite-element analysis model of subcondylar fracture. Two four-hole plates were fixed on the anterior and posterior surfaces of the subcondyle of the mandible. In the simulation model of a subcondylar fracture, we evaluated the stress distribution and mechanical deformation of fixation materials. The stress distribution conspicuously appeared on the condylar neck of the non-fractured side and the center of the anterior plate for all materials. More stress distribution to the biologic component appeared with HA-PLLA than with Ti or Mg alloy, but its effects were less prominent than that of PLLA. The largest deformation was observed with PLLA, followed by HA-PLLA, Mg alloy, and Ti. The results of the present study imply the clinical potential of the HA-PLLA fixation material for open reduction of subcondylar fractures.

Additive manufactured, porous bone implants have the potential to improve osseointegration and reduce failure rates of orthopaedic devices. Substantially porous implants are increasingly used in a number of orthopaedic applications. HA plasma spraying–a line of sight process—cannot coat the inner surfaces of substantially porous structures, whereas electrochemical deposition of calcium phosphate can fully coat the inner surfaces of porous implants for improved bioactivity, but the osseous response of different types of hydroxyapatite (HA) coatings with ionic substitutions has not been evaluated for implants in the same in vivo model. In this study, laser sintered Ti6Al4V implants with pore sizes of Ø 700 μm and Ø 1500 μm were electrochemically coated with HA, silicon-substituted HA (SiHA), and strontium-substituted HA (SrHA), and implanted in ovine femoral condylar defects. Implants were retrieved after 6 weeks and histological and histomorphometric evaluation were compared to electrochemically coated implants with uncoated and HA plasma sprayed controls. The HA, SiHA and SrHA coatings had Ca:P, Ca:(P+Si) and (Ca+Sr):P ratios of 1.53, 1.14 and 1.32 respectively. Electrochemically coated implants significantly promoted bone attachment to the implant surfaces of the inner pores and displayed improved osseointegration compared to uncoated scaffolds for both pore sizes (p

This study evaluated the von Mises stress (MPa) and equivalent strain occurring around monolithic yttria-zirconia (Zir) implant using three clinically simulated finite element analysis (FEA) models for a missing maxillary central incisor. Two unidentified patients' cone-beam computed tomography (CBCT) datasets with and without right maxillary central incisor were used to create the FEA models. Three different FEA models were made with bone structures that represent a healed socket (HS), reduced bone width edentulous site (RB), and immediate extraction socket with graft (EG). A one-piece abutment-implant fixture mimicking Straumann Standard Plus tissue level RN 4.1 X 11.8mm, for titanium alloy (Ti) and Zir were modeled. 178 N oblique load and 200 N vertical load were used to simulate occlusal loading. Von Mises stress and equivalent strain values for around each implant model were measured. Within the HS and RB models the labial-cervical region in the cortical bone exhibited highest stress, with Zir having statistically significant lower stress-strain means than Ti in both labial and palatal aspects. For the EG model the labial-cervical area had no statistically significant difference between Ti and Zir; however, Zir performed better than Ti against the graft. FEA models suggest that Ti, a more elastic material than Zir, contributes to the transduction of more overall forces to the socket compared to Zir. Thus, compared to Ti implants, Zir implants may be less prone to peri-implant bone overloading and subsequent bone loss in high stress areas especially in the labial-cervical region of the cortical bone. Zir implants respond to occlusal loading differently than Ti implants. Zir implants may be more favorable in non-grafted edentulous or immediate extraction with grafting.

Numerous in vivo, in vitro and clinical studies report on beneficial effects of strontium with respect to increased bone growth. Based on this knowledge the aim of this study was to evaluate early and late osseointegration stages of functionalized titanium implants showing sustained release of strontium (Sr) and further investigate its potential systemic effect. Strontium functionalized (Ti-Sr-O) and Grade 4 (Control) titanium implants were inserted in the femoral condyle of New Zealand White rabbits. The Ti-Sr-O coating was characterized using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectrometry (EDX) for structure, coating thickness and chemical composition. Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) was used to evaluate released strontium in vitro while Atomic Absorption Spectrometry (AAS) was utilized to monitor serum levels of strontium and calcium. Additionally, histological and tomographic analysis of bone-to-implant contact (BIC%) and bone formation (BF%) was performed, following implantation periods of two or twelve weeks, respectively. Median values for BIC% for Ti-Sr-O revealed significant differences within the two-and twelve-week observation periods, while exceeding BF% was discovered especially after twelve weeks when performing the histological evaluation. The results from the micro-computed tomography (mu-CT) showed no significant differences, when comparing the experimental groups. AAS measurements did not indicate a systemic effect by the local strontium release. Within the limitations of the study, it was shown that a Ti-Sr-O coating with sustained release characteristics of strontium, accelerates bone apposition and represents a potential potent surface modification for endosseous medical implant devices.Statement of SignificanceThis study presents first data with respect to early and late in vivo response on a strontium functionalized titanium surface comprising a nanotopography manufactured by a magnetron sputtering process. We investigated different osseointegration stages of screw-shaped implants with dental implant geometries in a rabbit femur model observing beneficial effects of the functionalized surface on bone-to-implant contact and bone formation caused by tailored release of the bone anabolic strontium. Histomorphometrical data revealed that a functionalized titanium surface with controlled liberation of strontium accelerates osseointegration while spectrometry measurements did not indicate a potential systemic effect of this osteoinductive agent and could thus have impact on modifications of medical implant devices. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND.

The defects of the skull cause mechanical vulnerability of the brain, esthetic disfigurement, and transmission of vibrations and pulsation of the brain. Subsequent cranioplasty may be required to compensate for the defect and to alleviate various signs and symptoms. When long-term outcome of biomaterial use in pediatric cases is limited, alloplastic cranioplasty in adults are supported by several large case series. This case report narrates cranioplasty using titanium alloplastic implant material.

A firm connection of the bone-implant-fixation system is of utmost importance for patients with cranial defects. In order to improve the connection reliability, the current research focuses on finding the optimal fixation method, as well as selection of the implant manufacturing methods and the used materials. For the latter, implementation of bioactive materials such as hydroxyapatite or other calcium phosphates has also been considered in the literature. The aim of this study was to investigate the effect of gradual osseointegration on the biomechanical performance of cranial Ti6Al4V implants with a deposited HA coating as the osseointegration agent. This effect was assessed by two different computational approaches using finite element method (FEM) modeling. The values of key input parameters necessary for FEM were obtained from experimental plasma spray deposition of HA layers onto Ti6Al4V samples. Immediately upon implantation, the HA layer at the bone-implant contact area brought only a slight decrease in the values of von Mises stress in the implant and the micro-screws when compared to a non-coated counterpart; importantly, this was without any negative trade-off in other important characteristics. The major benefit of the HA coatings was manifested upon the modeled osseointegration: the results of both approaches confirmed a significant reduction of investigated parameters such as the total implant displacements (reduced from 0.050 mm to 0.012 mm and 0.002 mm while usingApproach IandII, respectively) and stresses (reduced from 52 MPa to 10 MPa and 1 MPa) in the implanted components in comparison to non-coated variant. This is a very promising result for potential use of thermally sprayed HA coatings for cranial implants.

Objective: Patient specific implants have been used for the reconstruction of large skull bone defects. Several therapeutic effects have been suggested in current literature but were never objectified. The aim of the current study was to evaluate the change in quality of life, pain, aesthetics, and the surgical and medical outcomes after reconstruction of large skull bone defects with titanium or polyetheretherketone (PEEK) implants.Methods: We retrospectively evaluated 29 consecutive patients receiving a patient specific skull implant between November 2004 and December 2015. Twenty-one patients received PEEK implants and eight received titanium implants. Data was acquired regarding quality of life, aesthetics, pain, demographics and complications. Quality of life was measured using the Glasgow Benefit Inventory (GBI). Additional questions were asked concerning pain, satisfaction and aesthetics.Results: The mean total GBI-score was +26.1 (95%CI 16.8-35.4, p Conclusion: Reconstruction of skull bone defects with PEEK and titanium patient specific implants gave a statistically significant improvement in quality of life. Furthermore, it decreased pain and headaches and gave aesthetically good results. (C) 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Phage therapy offers a potential alternate strategy for the treatment of peri-prosthetic joint infection (PJI), particularly where limited effective antibiotics are available. We undertook preclinical trials to investigate the therapeutic efficacy of a phage cocktail, alone and in combination with vancomycin, to reduce bacterial numbers within the infected joint using a clinically-relevant model of Staphylococcus aureus-induced PJI. Infected animals were randomised to 4 treatment groups, with treatment commencing 21-days post-surgery: bacteriophage alone, vancomycin alone, bacteriophage and vancomycin, and sham. At day 28 post-surgery, animals were euthanised for microbiological and immunological assessment of implanted joints. Treatment with phage alone or vancomycin alone, led to 5-fold and 6.2-fold reductions, respectively in bacterial load within peri-implant tissue compared to sham-treated animals. Compared to sham-treated animals, a 22.5-fold reduction in S. aureus burden was observed within joint tissue of animals that were administered phage in combination with vancomycin, corresponding with decreased swelling in the implanted knee. Microbiological data were supported by evidence of decreased inflammation within the joints of animals administered phage in combination with vancomycin, compared to sham-treated animals. Our findings provide further support for phage therapy as a tolerable and effective adjunct treatment for PJI.

Introduction Sandblasting is one of the oldest implant surface modifications to enhance osseointegration. Regarding its superiority over machined surface controversies still exist. Our objective was to compare implant failures (IF) and marginal bone level (MBL) changes between sandblasted and machined dental implants by a meta-analysis utilizing the available data. The PROSPERO registration number of the meta-analysis is CRD42018084190. Methods The systematic search was performed in Cochrane, Embase and Pubmed. Inclusion criteria included participants with neither systemic diseases, nor excessive alcohol consumption, nor heavy smoking. We calculated pooled Risk Ratio (RRs) with confidence intervals of 95% (CIs) for dichotomous outcomes (implant failure) and weighted mean difference (WMD) CIs of 95% for continuous outcomes (marginal bone level change). We applied the random effect model with DerSimonian-Laird estimation. I2 and chi2 tests were used to quantify statistical heterogeneity and gain probability-values, respectively. Results Literature search revealed 130 records without duplicates. Out of these, seven studies met the inclusion criteria and all were included in data synthesis, involving 362 sand-blasted and 360 machined implants. The results indicate that there is an 80% (RR = 0.2 95% CI:0.06–0.67; I2 = 0.0% p = 0.986) lower among sandblasted compared to machined implants after one year of use and 74% (RR = 0.26 95% CI:0.09–0.74; I2 = 0.0% p = 0.968) five years of use, respectively. In contrast, there is no significant difference in MBL (WMD:-0.10mm, 95% CI:-0.20, 0.01; p>0.05; I2 = 0.0%, p = 0.560 and WMD:-0.01mm, 95% CI:-0.12, 0.09; p>0.05; I2 = 26.2%, p = 0.258) between the two implant surfaces after one and five years of use. Conclusions This meta-analysis reveals that sandblasting is superior over machined surface in implant failure but not in marginal bone level in healthy subjects. It also points out the need for further randomized clinical trials with large sample size for objective determination of the clinical benefits of certain implant surface modifications.

Despite high biocompatibility of titanium and its alloys, this metal causes various side effects in the human body. It is believed that titanium biomaterials may induce an innate/adaptive immune response. However, still little is known about changes caused by titanium mandible implants, particularly with regard to bone healing. The latest studies showed disturbances in the antioxidant barrier, increased oxidative/nitrosative stress, as well as mitochondrial abnormalities in the periosteum covering titanium mandible fixations; nevertheless, the impact of titanium implants on free radical production, inflammation, and mandible apoptosis are still unknown. Because severe inflammation and apoptosis are among the main factors responsible for disturbances in osteointegration as well as implant rejection, this study is the first to evaluate pro-oxidant enzymes, cytokines as well as pro- and anti-apoptotic proteins in the periosteum of patients with a broken jaw, treated with titanium miniplates and miniscrews. The study group consisted of 29 patients with double-sided fracture of the mandible body requiring surgical treatment. We found significantly higher activity of NADPH oxidase and xanthine oxidase as well as enhanced rate of free radical production in the periosteum of patients in the study group compared to the control group. The markers of inflammation [interleukin 1 (IL-1), interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), transforming growth factor β (TGF-β) and β-glucuronidase (GLU)] as well as apoptosis [Bax, Bax/Bcl-2 ratio, caspase-3 (CAS-3) and nitric oxide (NO)] were significantly elevated in periosteum covering titanium fixations compared to the control group. In the study group, we also demonstrated an increased content of titanium on the periosteum surface, which positively correlated with CAS-3 activity. The study led us to the conclusion that titanium mandible implants increase the production of pro-inflammatory cytokines, and enhance free radical generation in the periosteum covering titanium miniplates and miniscrews. Additionally, exposure to Ti6Al4V titanium alloy induces apoptosis in the mandible periosteum. However, no clinical signs of the said phenomena have been observed.

This article belongs to the Special Issue Clinical Implants and the Biocompatibility of Biodegradable Biomaterials Manipulation of implant surface characteristics constitutes a promising strategy for improving cell growth and tissue response on a variety of materials with different surface topographies. Mesenchymal progenitor cells with a capacity to respond to titanium surface stimuli and differentiate into osteoblasts were used to perform comparative tests between two different implant topographies, including their functional interaction with pre-osteoblasts directly seeded onto the implants. Functional analysis of nanostructured implant surfaces was performed by in vitro assay analysis. The machined surface of titanium implants (mach group) was used as a control and compared with a nanoparticle HA activated surface implant (nano group), developed by the deposition of pure crystalline hydroxyapatite. Cell culture on the nano group surface resulted in higher cell adhesion and cultured osteoblast viability compared with the mach group. Scanning electron microscope (SEM) images revealed a stable interaction, indicated by the presence of focal cell adhesion formation. These results together with positive mineralization assays showed the nano group to be an excellent scaffold for bone-implant integration.

Titanium-based materials are widely employed by the biomedical industry in orthopedic and dental implants. However, when placed into the human body, these materials are highly susceptible to degradation processes, such as corrosion, wear, and tribocorrosion. As a consequence, metallic ions or particles (debris) may be released, and although several studies have been conducted in recent years to better understand the effects of their exposure to living cells, a consensual opinion has not yet been obtained. In this work, we produced metallic based wear particles by tribological tests carried out on Ti-6Al-4V and Ti-15Zr-15Mo alloys. They were posteriorly physicochemically characterized according to their crystal structure, size, morphology, and chemical composition and compared to Ti-6Al-4V commercially available particles. Finally, adsorbed endotoxins were removed (by applying a specific thermal treatment) and endotoxin-free particles were used in cell experiments to evaluate effects of their exposure to human osteoblasts (MG-63 and HOb), namely cell viability/metabolism, proinflammatory cytokine production (IL-6 and PGE2), and susceptibility to internalization processes. Our results indicate that tribologically-obtained wear particles exhibit fundamental differences in terms of size (smaller) and morphology (irregular shapes and rough surfaces) when compared to the commercial ones. Consequently, both Ti-6Al-4V and Ti-15Zr-15Mo particles were able to induce more pronounced effects on cell viability (decrease) and cytokine production (increase) than did Ti-6Al-4V commercial particles. Furthermore, both types of wear particles penetrated osteoblast membranes and were internalized by the cells. Influences on cytokine production by endotoxins were also demonstrated., This work was supported by Fundacao de Amparo a Pesquisa do Estado de Sao Paulo - FAPESP (2015/50280-5 and 2017/24300-4), Fundacao para a Ciencia e Tecnologia - FCT (UID/EEA/04436/2013), Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior - CAPES (Finance Code 0001), FCT/CAPES Joint Research Project (99999.008666/2014-08), FCT COMPETE 2020 (POCI-01-0145-FEDER-006941 and POCI-01-0145-FEDER-007265) and M-ERA-NET (0001/2015).

Objectives: The aim of this study was to perform an in vivo histological comparative evaluation of bone formation around titanium (machined and treated surface) and zirconia implants. For the present study were used 50 commercially pure titanium implants grade IV, being that 25 implants with a machined surface (TiM group), 25 implants with a treated surface (TiT group) and, 25 implants were manufactured in pure zirconia (Zr group). The implants (n = 20 per group) were installed in the tibia of 10 rabbits. The implants distribution was randomized (n = 3 implants per tibia). Five implants of each group were analyzed by scanning electron microscopy and an optical laser profilometer for surface roughness characterization. Six weeks after the implantation, 10 implants for each group were removed in counter-torque for analysis of maximum torque value. The remaining samples were processed, included in historesin and cut to obtain non-decalcified slides for histomorphological analyses and histomorphometric measurement of the percentage of bone-implant contact (BIC%). Comparisons were made between the groups using a 5% level of significance (p &lt, 0.05) to assess statistical differences. The results of removal torque values (mean &plusmn, standard deviation) showed for the TiM group 15.9 &plusmn, 4.18 N cm, for TiT group 27.9 &plusmn, 5.15 N cm and for Zr group 11.5 &plusmn, 2.92 N cm, with significant statistical difference between the groups (p &lt, 0.0001). However, the BIC% presented similar values for all groups (35.4 &plusmn, 4.54 for TiM group, 37.8 &plusmn, 4.84 for TiT group and 34.0 &plusmn, 6.82 for Zr group), with no statistical differences (p = 0.2171). Within the limitations of the present study, the findings suggest that the quality of the new bone tissue formed around the titanium implants present a superior density (maturation) in comparison to the zirconia implants.

Optimal treatment of bone fractures with minimal complications requires implant alloys that combine high strength with high ductility. Today, TiAl6V4 titanium and 316L steel are the most applied alloys in bone surgery, whereas both share advantages and disadvantages. The nickel-free, high-nitrogen austenitic steel X13CrMnMoN18-14-3 (1.4452, brand name: P2000) exhibits high strength in combination with superior ductility. In order to compare suitable alloys for bone implants, we investigated titanium, 316L steel, CoCrMo and P2000 for their biocompatibility and hemocompatibility (according to DIN ISO 10993-5 and 10993-4), cell metabolism, mineralization of osteoblasts, electrochemical and mechanical properties. P2000 exhibited good biocompatibility of fibroblasts and osteoblasts without impairment in vitality or changing of cell morphology. Furthermore, investigation of the osteoblasts function by ALP activity and protein levels of the key transcription factor RUNX2 revealed 2x increased ALP activity and more than 4x increased RUNX2 protein levels for P2000 compared to titanium or 316 steel, respectively. Additionally, analyses of osteoblast biomineralization by Alizarin Red S staining exhibited more than 6x increased significant mineralization of osteoblasts grown on P2000 as compared to titanium. Further, P2000 showed no hemolytic effect and no significant influence on hemocompatibility. Nanoindentation hardness tests of Titanium and 316L specimens exposed an indentation hardness (HIT) of about 4 GPa, whereas CoCrMo and P2000 revealed HIT of 7.5 and 5.6 GPa, respectively. Moreover, an improved corrosion resistance of P2000 compared to 316L steel was observed. In summary, we could demonstrate that the nickel-free high-nitrogen steel P2000 appears to be a promising alternative candidate for applications in bone surgery. As to nearly all aspects like biocompatibility and hemocompatibility, cell metabolism, mineralization of osteoblasts and mechanical properties, P2000 was similar to or revealed advantages against titanium, 316L or CoCrMo. CA extern

BackgroundTitanium (Ti) and its alloys possess high biocompatibility and corrosion resistance due to Ti ability to form a passive oxide film, i.e. TiO2, immediately after contact with oxygen. This passive layer is considered stable during function in the oral cavity, however, emerging information associate inflammatory peri-implantitis to vast increases in Ti corrosion products around diseased implants as compared to healthy ones. Thus, it is imperative to identify which factors in the peri-implant micro-environment may reduce Ti corrosion resistance.MethodsThe aim of this work is to simulate peri-implant inflammatory conditions in vitro to determine which factors affect corrosion susceptibility of Ti-6Al-4V dental implants. The effects of hydrogen peroxide (surrogate for reactive oxygen species, ROS, found during inflammation), albumin (a protein typical of physiological fluids), deaeration (to simulate reduced pO2 conditions during inflammation), in an acidic environment (pH 3), which is typical of inflammation condition, were investigated. Corrosion resistance of Ti-6Al-4V clinically-relevant acid etched surfaces was investigated by electrochemical techniques: Open Circuit Potential; Electrochemical Impedance Spectroscopy; and Anodic Polarization.ResultsElectrochemical tests confirmed that most aggressive conditions to the Ti-6Al-4V alloy were those typical of occluded cells, i.e. oxidizing conditions (H2O2), in the presence of protein and deaeration of the physiological medium.ConclusionsOur results provide evidence that titanium's corrosion resistance can be reduced by intense inflammatory conditions. This observation indicates that the micro-environment to which the implant is exposed during peri-implant inflammation is highly aggressive and may lead to TiO2 passive layer attack. Further investigation of the effect of these aggressive conditions on titanium dissolution is warranted.

Purpose To compare the longevity and marginal bone loss of narrow-diameter (≤3.3-mm) versus standard-diameter implants supporting single crowns. Material and methods The MEDLINE (via PubMed), Scopus, and SciELO databases were searched for relevant publications. In addition, the scientific references provided by each of the implant companies that appeared in the search were reviewed. Intervention studies comparing longevity and bone loss between narrow-diameter and standard-diameter implants were included. Results The search was limited to in vivo studies in humans. The query returned 1931 results, of which 4 met the inclusion criteria. The implant success rate ranged from 93.8% to 100% over a maximum follow-up of 3 years, with no difference between narrow- and standard-diameter implants. Meta-analysis of all included studies showed greater bone loss in narrow-diameter implants as compared with standard ones; however, when analysis was restricted to randomized trials, no such difference was present. Conclusion The meta-analysis showed no difference in longevity between narrow implants and standard implants when supporting single crowns. However, narrow-diameter implants may be associated with greater marginal bone loss. These findings should be regarded cautiously due to the short follow-up duration and methodological heterogeneity of the primary studies.

BackgroundMost manufacturer manuals do not verify the use of dual energy X-ray absorptiometry for body composition analysis in subjects with a metal implant. This study aimed to quantify the effects of a spinal implant on body composition, and to determine whether unadjusted lean mass estimates are valid for patients with a spinal implant.MethodsA total of 30 healthy subjects were recruited. Three consecutive scans were performed for each participant, one with and two without extraneous spinal implant, without repositioning between scans. Lean, fat and bone estimates in the total body, trunk and limb were measured.ResultsPrecision errors for all total and regional body compositions were within the recommended ranges. Bone masses in the trunk and total body were significantly increased with spinal implant, and the increases exceeded the least significant change. For total and regional lean and fat estimates, the measurements between subjects with and without metal implants were in substantial to almost perfect agreement and the differences were not significant and did not exceed the least significant change.ConclusionsSpinal metal artifacts significantly increased the total body and trunk bone mass but the differences in lean- and fat-related estimates at total and regional body levels and all estimates in the extremity remained within the clinical acceptable range. Thus, a spinal implant may not compromise screening of patients for fat and lean masses using dual energy X-ray absorptiometry. Application of image reconstruction or a filtering algorithm may help reduce the effect of metallic artifacts and further study is needed.

Made available in DSpace on 2019-10-06T16:33:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 Objectives: Evaluate the modulating effect of ionizing radiation, blood cytokine levels, and bone remodeling of the interface around the implant to understand the radiation mechanisms which can impair the implants receptor site. Material and methods: Sixty rats were submitted to grade V titanium implants in the femurs and were divided into the following groups: no-irradiation (N-Ir): control group with implant only; early-irradiation (E-Ir): implant + irradiation after 24 h; late-irradiation (L-Ir): implant + irradiation after 4 weeks; and previous-irradiation (P-Ir): irradiation + implant after 4 weeks. The animals in the E-Ir, L-Ir, and P-Ir groups were irradiated in two fractional stages of 15 Gy. At 3 days, 2 weeks, and 7 weeks after the final procedure, five animals were randomly euthanized per group. Serum levels of TNF-ɑ, IL-1β, TGF-β, IL-6, M-CSF, and IL-10 were measured from blood collected prior to euthanasia using the ELISA test. The pieces containing the implants were subjected to immunohistochemical labeling using the tartrate acid resistant to phosphatase, osteocalcin, and caspase-3 markers and mCT. The ANOVA test was used for statistical analysis, and the Tukey multiple comparison test (p < 0.05) was applied. Results: The results indicated that ionizing radiation modifies the production of pro- and anti-inflammatory serum cytokines, the expression of proteins involved in bone remodeling and cellular apoptosis, as well as changes in bone formation. Conclusions: The results suggests that a longer period between radiotherapy and implant placement surgery when irradiation occurs prior to implant installation would allow the recovery and renewal of bone cells and avoid future failures in osseointegration. Clinical relevance: The search for modifications caused by ionizing irradiation in bone tissue can indicate the ideal period for implant placement without affecting the osseointegration process. Department of Bioscience and Oral Diagnosis Institute of Science and Technology of São José dos Campos Sao Paulo State University (Unesp), Av. Engenheiro Francisco José Longo, 777 Department of Dental Materials and Prosthodontics Institute of Science and Technology of São José dos Campos Sao Paulo State University (Unesp) Department of Aerospace Science and Technology Institute of Advanced Studies Technological Institute of Aeronautics Graduated student of Institute of Science and Technology of São José dos Campos Sao Paulo State University (Unesp) Department of Bioscience and Oral Diagnosis Institute of Science and Technology of São José dos Campos Sao Paulo State University (Unesp), Av. Engenheiro Francisco José Longo, 777 Department of Dental Materials and Prosthodontics Institute of Science and Technology of São José dos Campos Sao Paulo State University (Unesp) Graduated student of Institute of Science and Technology of São José dos Campos Sao Paulo State University (Unesp)