Search

Objectives: This randomised controlled trial compares the 3‐year outcomes, that is, marginal bone‐level (MBL) changes and clinical parameters, between an abutment‐level (AL) and implant‐level (IL) connection for implants with an internal conical connection (ICC) supporting a screw‐retained fixed partial denture. Material and methods: Fifty patients with 119 implants were randomly allocated to either the AL or IL group. Radiographic and clinical examinations were performed after one, two, and 3 years. A linear mixed model was used to evaluate the differences between groups. Results: The MBL change was not significantly different between the groups at any point. The MBL was 0.12 ± 0.31 mm (AL) and 0.23 ± 0.26 mm (IL) after 1 year; 0.15 ± 0.34 mm (AL) and 0.17 ± 0.22 mm (IL) after 2 years; 0.18 ± 0.39 mm (AL) and 0.15 ± 0.21 mm (IL) after 3 years. The bleeding on probing was 43.44 ± 39.24% (AL) and 58.19 ± 41.20% (IL) after 1 year; 35.78 ± 39.22% (AL) and 50.43 ± 41.49% (IL) after 2 years; 51.27 ± 44.63% (AL) and 49.57 ± 37.31% (IL) after 3 years and was significantly different (p =.025) between 1 and 2 years. The probing depth showed a significant difference at each time point while the plaque was not significant between the groups. The overall technical, biological and prosthetic complication rates were 5.04%, 3.36%, and 16.00%, respectively. Conclusions: The MBL change was similar in the groups. The slight differences in the soft tissue complications between the groups are likely not of clinical relevance. An IL connection is considered to be a valid alternative to an AL set‐up in ICC implants. [ABSTRACT FROM AUTHOR]

Medical devices such as orthopedic and dental implants may get infected by bacteria, which results in treatment using antibiotics. Since antibiotic resistance is increasing in society there is a need of finding alternative strategies for infection control. One potential strategy is the use of antimicrobial peptides, AMPs. In this study, we investigated the antibiofilm effect of the AMP, RRP9W4N, using a local drug‐delivery system based on mesoporous titania covered titanium implants. Biofilm formation was studied in vitro using a safranine biofilm assay and LIVE/DEAD staining. Moreover, we investigated what effect the AMP had on osseointegration of commercially available titanium implants in vivo, using a rabbit tibia model. The results showed a sustained release of AMP with equal or even better antibiofilm properties than the traditionally used antibiotic Cloxacillin. In addition, no negative effects on osseointegration in vivo was observed. These combined results demonstrate the potential of using mesoporous titania as an AMP delivery system and the potential use of the AMP RRP9W4N for infection control of osseointegrating implants. [ABSTRACT FROM AUTHOR]

Background: PBSC collection using a blood cell separator in very low weight patients can be frequently complicated by severe adverse effects and technical difficulties. Material and Methods: From March 2013 to January 2017, 14 PBSC collections were performed in 12 children weighing less than 10 kg, affected by different solid tumours. PBSC collection was performed with a "homemade" aseptically assembled circuit. The circuit is composed by a 150 mL collection bag connected with a 4 stopcock ramp, perfused with ACD. This circuit allows collection of a specific total blood amount from CVC, depending on CD34+/kg target. Results: Mean CD34+cell performance per collection was 9.3 × 106/kg. Tolerance to the procedure was very good as none of the patients experienced complications, with the exception of a patient who showed mild cyanosis and pallor after collection. Moreover, no bleeding or thrombotic complications have been observed. To date, 16 PBSC reinfusions have been performed in 7 children with a mean CD34+ cells viability of 98.1% ± 2.7 and mean WBC viability of 57% ± 10. Cell recovery after thawing was 87% ± 10.8. A rapid graft intake for both neutrophils and platelets, between day 7 and 20 after reinfusion was observed. Discussion The procedure of total blood collection without the use of a cell separator is feasible and allows a good PBSC collection without significant side effects in very low‐weight children. Moreover, this method could represent a valid and safe alternative to leukapheresis in patients where classic procedure could be difficult to apply. [ABSTRACT FROM AUTHOR]

Summary: The discrimination between active chronic hepatitis B (CHB) and the clinically quiescent infection (CIB) is not always easy, as a significant portion of patients falls in a "grey" zone. Hepatitis B core‐related antigen (HBcrAg) is a now quantifiable serological marker with potential applications in diagnosis and therapy monitoring. The aim of the present study was to evaluate the HBcrAg serum levels in HBeAg‐negative HBV infection, and its ability in identifying the clinical profile, in comparison with HBsAg serum levels. HBcrAg was retrospectively assessed on serum samples from a population of treatment‐naive HBeAg‐negative patients by ChemiLuminescent Enzyme Immunoassay (CLEIA). HBsAg and HBV‐DNA data were collected. Serological data were associated to clinical profile, defined in the subsequent follow‐up of at least 1 year. In the overall population of 160 HBeAg‐negative patients, HBcrAg results weakly correlated with qHBsAg levels (Spearman r = 0.471, P < 0.0001) and correlated closely with HBV‐DNA (Spearman r = 0.746, P < 0.0001). HBcrAg levels were significantly higher in 85 CHB patients relative to 75 CIB carriers. A value of 2.5 logU/mL produced the optimal cut‐off to identify CIB patients, with diagnostic accuracy comparable to HBsAg levels. In long‐term clinical evaluation, a single measurement of HBcrAg at the established cut‐off was optimally consistent with clinical outcome. Conversely, the HBsAg cut‐off performed well in the true quiescent phase and less in more difficult‐to‐categorize patients. In conclusion, single‐point use of HBcrAg serum levels provides an accurate identification of CIB and represents a useful tool for patient classification. [ABSTRACT FROM AUTHOR]

Abstract: Background: Osseointegration mechanisms are still not entirely understood. Purpose: The present pilot study aims at demonstrating the involvement of the immune system in the process of osseointegration around titanium implants, comparing bone healing in the presence and absence of a titanium implant. Materials and Methods: Fifteen New Zealand White rabbits had one osteotomy performed at each of the distal femurs; on one side, no implant was placed (sham) and on the other side a titanium implant was introduced. Subjects were sacrificed at 10 and 28 days for gene expression analysis (three subjects each time point) and for decalcified qualitative histology (six subjects each time point). At 10 days, the three subjects for gene expression analysis were part of the six subjects for histology. Results: Gene expression analysis: at 10 days, ARG1 was significantly up‐regulated around titanium, indicating an activation of M2‐macrophages. At 28 days CD11b, ARG1, NCF‐1, and C5aR1 were significantly up‐regulated, indicating activation of the innate immune system, respectively M1‐macrophages, M2‐macrophages and group 2‐innate lymphoid cells, neutrophils, and the complement system; on the other hand, the bone resorption markers RANKL, OPG, cathepsin K, and TRAP were significantly down‐regulated around titanium. Histology: at 10 days new bone formation is seen around both sham and titanium sites, separating bone marrow from the osteotomy/implant site; at 28 days no bone trabeculae is seen on the sham site, which is healing at the original cortical level, whereas around titanium implants, bone continues into organization of more mature cortical‐like bone, forming a layer between the implant and the bone marrow. Conclusions: The presence of a titanium implant during bone healing activates the immune system and displays type 2 inflammation, which is likely to guide the host‐biomaterial relationship. At the same time, bone resorption is suppressed around titanium sites compared to sham sites after 4 weeks of implantation, suggesting a shift to a more pronounced bone forming environment. This suggests two important steps in osseointegration: identification of the titanium foreign body by the immune system and the development of a bone forming environment, that at tissue level translates into bone build‐up on the titanium surface and can be perceived as an attempt to isolate the foreign body from the bone marrow space. [ABSTRACT FROM AUTHOR]

This study evaluated the sustained release effect of clarithromycin-loaded in PLGA microspheres in a rabbit calvaria defect model. Four bone defects (ø5.0) were created in the calvaria of New Zealand White rabbits ( n = 21, n = 7/time point). The defects were randomly designated to four groups. Group 1: No augmentation (sham), Group 2: beta-tricalcium phosphate (β-TCP), Group 3: β-TCP with 0.12 µg clarithromycin, and Group 4: β-TCP with 6.12 µg PLGA microspheres loaded with 0.12 µg Clarithromycin. After 2, 4, and 12 weeks of healing, bone regeneration was evaluated using micro-computed tomography (µCT) and histology. Clarithromycin release from PLGA microspheres revealed sustained release for around 4 weeks with ∼50% release during the first week. Histologically, new bone formation was evident at 2 and 4 weeks of healing in all groups and bone formation increased as a function of healing time. At 12 weeks, Group 4 showed significantly higher amount of newly formed bone compared to Group 1. The µCT showed that Group 4 expressed significantly higher bone formation compared to Group 1 at all time points. The in vivo findings showed that β-TCP with clarithromycin-loaded microspheres can enhance bone formation in bone defects. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 201-208, 2018. [ABSTRACT FROM AUTHOR]

Objectives Titanium-zirconium (TiZr) has been proposed as a mechanically stronger alternative to commercially pure titanium for oral and orthopaedic implants. However, not much is known on the osseointegration kinetics of TiZr surfaces. In this study, we aimed to identify the genetic response of bone around TiZr implants compared to pure Ti. Material and methods Microtextured and hydrophilic TiZr implants (tests) and cpTi implants grade IV (controls) were placed in the tibia of 30 New Zealand white rabbits. At 2, 4 and 12 weeks, the implants were subjected to removal torque test ( RTQ). The expression of a panel of genes involved in the process of osseointegration was measured in the bone around the test and control implants by means of quantitative real-time polymerase chain reaction ( PCR) and compared to the control samples. Results The controls yielded statistically significant higher RTQ at 4 weeks, but the RTQ of the tests had a larger increase between 4 and 12 weeks, when both groups reached similar values. The gene expression analysis showed that all selected markers for bone formation, bone remodelling and cytokines were significantly upregulated around TiZr implants after 2 weeks. After 4 weeks of healing, two bone formation markers were significantly more expressed in the test samples, while at 12 weeks, the expression of all genes was similar in the two groups. Conclusions TiZr implants showed comparable biomechanical outcomes to cpTi up to 12 weeks of healing. However, at early healing stages, they showed a significant upregulation of osteogenesis and osteoclastogenesis markers. [ABSTRACT FROM AUTHOR]

Objectives The release of magnesium ions (Mg2+) from titanium surfaces has been shown to boost the initial biological response of peri-implant bone and to increase the biomechanical strength of osseointegration. The objective of the present paper was to investigate if the initial improvement in osseointegration would influence the bone remodeling also during the maturation stage of bone healing. Methods: Titanium implants were coated with mesoporous titania layers and either loaded with Mg2+ (test group) or left untreated (control group). The implants were inserted in the tibiae of 10 New Zealand White rabbits. Osseointegration was assessed after 6 weeks by means of biomechanical testing (RTQ), non-decalcified histology and histomorphometry (BIC%, BA%, NBA%). The expression of genes involved in the bone formation and remodeling was quantified using qPCR. Results: Mg2+ releasing mesoporous titania coatings showed, on average, higher removal torques and histomorphometrical outcomes (RTQ: 17.2 Ncm vs. 15 Ncm; BIC: 38.8% vs. 32.1%; BA%: 71.6% vs. 64%; NBA% 62.5% vs. 54% for the tests vs the controls); however, the differences were not statistically significant. Three osteogenic markers, osteocalcin (OC), collagen 1 alpha 1 (COL1A1), and alkalin phosphatase (ALPL), were respectively 2-fold, 1.53-fold, and 1.13-fold up-regulated in the control group compared to the test. The expression of COL1A1 was particularly high in both groups, while the biomarkers for remodeling and inflammation showed a low expression in both groups. Significance: The results suggested that the initial enhancement in osseointegration induced by magnesium release from mesoporous titania coatings has no detrimental effects during bone maturation. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2118-2125, 2017. [ABSTRACT FROM AUTHOR]

Probabilistic reasoning skills are important in various contexts. The aim of the present study was to develop a new instrument (the Probabilistic Reasoning Scale - PRS) to accurately measure low levels of probabilistic reasoning ability in order to identify people with difficulties in this domain. Item response theory was applied to construct the scale, and to investigate differential item functioning (i.e., whether the items were invariant) across genders, educational levels, and languages. Additionally, we tested the validity of the scale by investigating the relationships between the PRS and several other measures. The results revealed that the items had a low level of difficulty. Nonetheless, the discriminative measures showed that the items can discriminate between individuals with different trait levels, and the test information function showed that the scale accurately assesses low levels of probabilistic reasoning ability. Additionally, through investigating differential item functioning, the measurement equivalence of the scale at the item level was confirmed for gender, educational status, and language (i.e., Italian and English). Concerning validity, the results showed the expected correlations with numerical skills, math-related attitudes, statistics achievement, IQ, reasoning skills, and risky choices both in the Italian and British samples. In conclusion, the PRS is an ideal instrument for identifying individuals who struggle with basic probabilistic reasoning, and who could be targeted by specific interventions. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background & Aims The treatment of chronic hepatitis B infection ( CHB) in children is still an area of great uncertainty. Vitamin E is an immunostimulating/antioxidant compound proven to be safe and effective for the treatment of adult CHB. The aim of this phase 2 controlled study was to evaluate the safety and efficacy of vitamin E for the treatment of paediatric HBeAg-positive CHB. Methods Forty-six children were randomized in a 1:1 ratio to receive vitamin E at a dose of 15 mg/kg/day (in galenic preparation) or no treatment for 12 months and were monitored for the subsequent 12 months. Clinical, biochemical, haematological and serovirological evaluations were carried out every 3 months. Results No significant side effects were associated with the vitamin E treatment. At the end of the study, anti- HBe seroconversion was obtained in 7 of 23 (30.4%) of vitamin E-treated versus 1 of 23 (4.3%) of the control patients ( P = 0.05), while a virological response (≥2 log decrease in HBV- DNA from baseline) was observed in 9 of 23 (39.1%) vs. 2 of 23 (8.7%) respectively ( P = 0.035). Conclusions Vitamin E administration for the treatment of paediatric CHB at the tested dosage has no significant side effects and may induce anti- HBe seroconversion. Vitamin E could represent a tool for the treatment of paediatric CHB. [ABSTRACT FROM AUTHOR]

Objectives When implants are inserted, the initial implant stability is dependent on the mechanical stability. To increase the initial stability, it was hypothesized that bone condensation implants will enhance the mechanical stability initially and that the moderately rough surface will further contribute to the secondary stability by enhanced osseointegration. It was further hypothesized that as the healing progresses the difference in removal torque will diminish. In addition, a 3D model was developed to simulate the interfacial shear strength. This was converted to a theoretical removal torque that was compared to the removal torque obtained in vivo. Material and methods Condensation implants, inducing bone strains of 0.015, were installed into the left tibia of 24 rabbits. Non-condensation implants were installed into the right tibia. All implants had a moderately rough surface. The implants had an implantation time of 7, 28, or 84 days before the removal torque was measured. The interfacial shear strength at different healing time was estimated by the means of finite element method. Results At 7 days of healing, the condensation implant had an increased removal torque compared to the non-bone-condensation implant. At 28 and 84 days of healing, there was no difference in removal torque. The simulated interfacial shear strength ratios of bone condensation implants at different implantation time were in line with the in vivo data. Conclusions Moderately rough implants that initially induce bone strain during installation have increased stability during the early healing period. In addition, the finite element method may be used to evaluate differences in interlocking capacity. [ABSTRACT FROM AUTHOR]

Background Mesoporous coatings enable incorporation of functional substances and sustainedly release them at the implant site. One bioactive substance that can be incorporated in mesoporous is magnesium, which is strongly involved in bone metabolism and in osteoblast interaction. Purpose The aim of this experimental study was to evaluate the effect of incorporation of magnesium into mesoporous coatings of oral implants on early stages of osseointegration. Material and Methods Titanium implants were coated with thin films of mesoporous TiO2 having pore diameters of 6 nm and were loaded with magnesium. The implant surfaces were extensively characterized by means of interferometry, atomic force microscopy, scanning electron microscopy, and energy-dispersive spectroscopy and then placed in the tibiae of 10 rabbits. After 3 weeks of healing, osseointegration was evaluated by means of removal torque testing and histology and histomorphometry. Results Histological and biomechanical analyses revealed no side effects and successful osseointegration of the implants. The biomechanical evaluation evidenced a significant effect of magnesium doping on strengthening the implant-bone interface. Conclusions A local release of magnesium from the implant surfaces enhances implant retention at the early stage of healing (3 weeks after implantation), which is highly desirable for early loading of the implant. [ABSTRACT FROM AUTHOR]

Background Clinically, there is a demand for mechanically stronger alloyed implants; however, not much evidence exists with regard to these materials. Purpose To test the osseointegration property of TiZr1317 implants in a rabbit model. Materials and Methods Hydrophilic titanium-zirconium alloy ( TiZr1317) implants with sand-blasted and acid-etched surface (test) and hydrophilic cpTi implants with the same treatment (control) were placed pairwise in the hind limbs (two in each tibia and one in each femur) of 36 Swedish lop-eared rabbits. After 2, 4, and 12 weeks ( n = 12/time point), the bone samples were subjected to removal torque ( RTQ, proximal tibia and femur) and histologic/histomorphometric (distal tibia) testings. Results The control presented significantly higher RTQ than the test at 2 weeks (55 vs 36 Ncm). No differences were observed for other time points. The test presented higher mean BIC than the control (19.25 vs 13.89 %) at 4 weeks; however, there were no statistical differences for the following time point tested in vivo.The new bone area was significantly higher for the test at 4 weeks in the marrow areas. Conclusion The TiZr1317 implants presented comparable biologic outcomes to that of the cpTi implants through a 12-week evaluation period. [ABSTRACT FROM AUTHOR]

Aim Dental implant-supported reconstructions demonstrate significantly less physiological flexibility for loading and traumatic forces compared with a normal dentition because of their rigid integration with the adjacent bone. Ethylene vinyl acetate ( EVA) material has become widely accepted as a mouthguard material; however, many studies indicate the necessity of improving the impact absorption ability by considering the design and developing new materials. The aim of this study was to compare the shock-absorbing ability of a novel dual component material comprising EVA and porous rubber with that of EVA alone. Materials and methods Three groups of samples were tested: Group 1 = EVA (thickness, 4 mm), Group 2 = type 1 material (2-mm thick porous rubber sheet sandwiched between two sheets of 1-mm thick EVA sheets), and Group 3 = type 2 material (1-mm thick porous rubber sheet sandwiched between EVA sheets with 1 and 2-mm thickness, respectively). Shock absorption was determined by means of a hammer impact testing device equipped with strain gauge, accelerator, and load cell. Results The value of shock-absorbing ability of group 2 (40.6 ± 12.5%) was significantly higher than those of group 1 (15.6 ± 2.1%) and group 3 (21.2 ± 9.2%). The material with thicker rubber sheet showed significantly higher shock-absorbing ability compared with that of the material with thinner rubber sheet. Conclusions The novel dual material was superior to conventional EVA material in shock-absorbing ability depending on the thickness of porous rubber, and it may be potentially effective as mouthguard material, in particular, for patients wearing implant-supported constructions. [ABSTRACT FROM AUTHOR]

In two experiments, we tested some of the central claims of the empathizing-systemizing (E-S) theory. Experiment 1 showed that the systemizing quotient (SQ) was unrelated to performance on a mathematics test, although it was correlated with statistics-related attitudes, self-efficacy, and anxiety. In Experiment 2, systemizing skills, and gender differences in these skills, were more strongly related to spatial thinking styles than to SQ. In fact, when we partialled the effect of spatial thinking styles, SQ was no longer related to systemizing skills. Additionally, there was no relationship between the Autism Spectrum Quotient (AQ) and the SQ, or skills and interest in mathematics and mechanical reasoning. We discuss the implications of our findings for the E-S theory, and for understanding the autistic cognitive profile. [ABSTRACT FROM AUTHOR]

Firm success is often associated with the development of better products. Private firms undertake applied R&D seeking market advantage, by capitalizing on the freely accessible results of basic research. But unpatentable basic research often fails to address applied R&D open problems. What is the role of the incentives in improving the innovative performance of an economy by matching partially motivated public researchers to their mission? Sometimes government-funded research projects are mission-directed, and yet in many cases the public sector academics indulge in carrier-driven research. An innovation system where, as in the United States, basic research is also driven by patents implicitly sets an ex-post incentive to the researchers guided by invisible hand. For a public innovation system – like the European one – designing an incentive scheme to motivate public researchers is of key importance for fostering the performance of the economic system. This paper extends the Schumpeterian multisector growth model with vertical innovation by highlighting a link between the degree of ‘targetness’ of public research and aggregate innovation. A positive effect of social capital is also proved. [ABSTRACT FROM AUTHOR]