Journal articles on the topic 'Glas GmbH'

In July of 2007, fire blight symptoms were observed on Cotoneaster dammeri cv. Skogholm in a nursery near Županja, Vukovarsko-Srijemska County, in eastern Croatia. In this region, the first outbreak of fire blight was noted on apple in 1995 (2). Symptoms on cotoneaster were necrotic shoots and petioles. Immunofluorescence assay (IFA) with polyclonal antibodies (Loewe Biochemica GmbH, Sauerlach, Germany) was performed on extracts from blighted C. dammeri cv. Skogholm shoots and were found to be positive for Erwinia amylovora. Round, mucoid, whitish colonies were isolated from extracts of plant tissues with symptoms of fire blight spread on King's medium B and incubated for 2 days at 28°C. Bacterial ooze and necrosis of the inoculation site were observed on immature pear fruits inoculated with a 106 CFU/ml suspension of the isolate. Bacteria were reisolated and the species identity was confirmed by PCR and primers targeting pEA29 DNA (1). E. amylovora was previously reported only on native Cotoneaster spp. (3). To our knowledge, this is the first report of fire blight on C. dammeri cv. Skogholm from a commercial ornamental nursery in Croatia. References: (1) S. Bereswill et al. Appl. Environ. Microbiol. 58:3522, 1992. (2) B. Cvjetković et al. Glas. zaštite bilja 1:13, 1996. (3) E. Halupecki et al. Eur. J. Plant Pathol. 114:435, 2006.

The design of apochromatic systems is difficult because of two problems: the glass sorts compatibility and the c1/ca arbitrary input ratio. The optical glass manufacturers offer a wide range of sorts, so that the choice of triplet compatible glasses becomes itself an important separate problem. The paper provides a solution of mathematical modeling for the glass compatibility and, practically, analyses the sorts presented by Schott GmbH. The original software provided 22 compatible glass triplets. The authors explored the possibilities of enlarging the c1/ca ratio from the value 0.6 indicated in the literature to a range of [0.5?0.8]. Therefore, they designed and analyzed a set of 88 triplets. A correct glass choice can insure twice-larger apertures than the traditional ones for best quality apochromats (diffraction-limited).

This study was designed to evaluate microleakage that appeared on Resin-Modified Glass-Ionomer Cement (RMGIC) restorations. Sixty class V cavities () were cut on thirty extracted third molars, which were randomly allocated to three experimental groups. All the buccal cavities were pretreated with polyacrylic acid, whereas the lingual cavities were treated with three one-step Self-Etch adhesives, respectively, Xeno III (Dentsply Detrey GmbH, Konstanz, Germany), iBond exp (Heraeus Kulzer gmbH & Co. KG, Hanau, Germany), and Adper Prompt-L-Pop (3M ESPE AG, Dental products Seefeld, Germany). All cavities were completely filled with RMGIC, teeth were thermocycled for 800 cycles, and leakage was evaluated. Results were expressed as means standard deviations (SDs). Microleakage scores were analysed by means of generalized linear mixed models (GLMMs) assuming an ordinal logistic link function. All results were considered to be significant at the 5% critical level (). The results showed that bonding RMGIC to dentin with a Self-Etch adhesive rather than using polyacrylic acid did not influence microleakage scores (), except for one tested Self-Etch adhesive, namely, Xeno III (). Nevertheless, our results did not show any significant difference between the three tested Self-Etch adhesive systems. In conclusion, the pretreatment of dentin with Self-Etch adhesive system, before RMGIC filling, seems to be an alternative to the conventional Dentin Conditioner for the clinicians as suggested by our results (thermocycling) and others (microtensile tests).

Mechanical tests were performed at the Klokner Institute on samples of a textile glass reinforcement. These tests will be used for determining the modulus of elasticity of textile glass reinforcements and for assessing the maximal stress that the samples will withstand. Both of these quantities are required for further modeling of the structures and for designing elements made from textile reinforced concrete (TRC). The tests were carried out on a total of 10 samples made from a single piece of 2D net (produced by V. FRAAS, GmbH, Germany). The tests were carried out on AR-glass reinforcement (alkali - resistant glass) textile glass with 2400 TEX [g/km] fineness, which is often supplied with dimensions of 1 x 2 m. The first 5 samples were prepared in the direction of the warp (the direction of the load-bearing reinforcement), and the remaining 5 samples were prepared from the transverse direction (the direction of the weft). These samples were loaded by a constant force increasing up to collapse. Then the modulus of elasticity of the textile glass reinforcement and the stress at the strength limit were determined from the monitored data.

The bioactivity and biocompatibility of a zinc phosphate luting cement (HARVARD, Richter & Hoffmann, Dental-GmbH, Berlin) which was modified by Bioglass® (PerioGlas® Synthetic Bone Graft Particulate, US Biomaterials), was evaluated in vitro with human lung fibroblasts (MRC-5), baby hamster kidney fibroblasts (BHK) and rat pulp cells (RPC) by XTT and BrdU assays. A thin Ca-P layer was grown on the surface of Bioglass®-modified zinc phosphate cement specimens after immersion in SBF for 7 days and remained constant after 16 days immersion time. The incorporation of Bioglass® powder in zinc phosphate specimens resulted in equal or increased cell attachment and activity for almost all cell lines examined without any apparent impact on mechanical or physicochemical properties of the cement, although this needs further documentation. The combination of these two methods in determining the biocompatibility of Bioglass®-modified zinc phosphate cements showed that cells not only attached well on modified specimens but were actively synthesizing DNA after 72h of incubation.

In this study, the wear behavior of glazed zirconia was investigated to the antagonist with human enamel after simulated mastication. Twenty Y-TZP specimens were divided into 4 groups: untreated zirconia (Z), glazed zirconia with IPS e.max Ceram (GZE), glazed zirconia with VITA AKZENT® Plus (GZV), and glazed zirconia with glass (GZG). Glazing glass was mainly composed of SiO2, B2O3, Al2O3, Na2O and K2O (nearly 91 wt%). The surface roughness of the specimens was evaluated using roughness profiler. The maxillary premolar teeth were selected as the antagonist. The wear of human enamel against human enamel was used as a control. Five-disc specimens per group were subjected to chewing stimulation CS-4 (SD Mechatronic GmbH, Germany) for 240,000 cycles against human enamel. The wear loss of antagonistic teeth was calculated using a three-dimensional profiling system and the volume loss of the tooth was scanned using a 3D scanner. 3D data obtained before and after testing were overlapped using 3D software (Dentacian Software, EZplant, Korea). The wear loss of glazed zirconia GZE, GZV and GZG groups showed significantly lower than that of human enamel. Whereas, the zirconia (Z) group exhibits significantly lower volume loss than glazed zirconia and enamel. These results show that the wear of the glazing glass is comparable to other commercial glazing materials. Glazing materials are both more susceptible to wear the antagonist relative to zirconia.

Meningitis is commonly caused by infection with a variety of bacterial or viral pathogens. Acute bacterial meningitis (ABM) can cause severe disease, which can progress rapidly to a critical life-threatening condition. Rapid diagnosis of ABM is critical, as this is most commonly associated with severe sequelae with associated high mortality and morbidity rates compared to viral meningitis, which is less severe and self-limiting. We have designed a microarray for detection and diagnosis of ABM. This has been validated using randomly amplified DNA targets (RADT), comparing buffers with or without formamide, in glass slide format or on the Alere ArrayTubeTM (Alere Technologies GmbH) microarray platform. Pathogen-specific signals were observed using purified bacterial nucleic acids and to a lesser extent using patient cerebral spinal fluid (CSF) samples, with some technical issues observed using RADT and glass slides. Repurposing the array onto the Alere ArrayTubeTM platform and using a targeted amplification system increased specific and reduced nonspecific hybridization signals using both pathogen nucleic and patient CSF DNA targets, better revealing pathogen-specific signals although sensitivity was still reduced in the latter. This diagnostic microarray is useful as a laboratory diagnostic tool for species and strain designation for ABM, rather than for primary diagnosis.

Magnesium matrix syntactic foams (MgMSFs) are emerging lightweight materials with unique capabilities to exhibit remarkable thermal, acoustic, and mechanical properties. In the current study, lightweight glass micro balloon (GMB)-reinforced Mg syntactic foams were synthesized via the powder metallurgy technique using hybrid microwave sintering. The processing employed in the study yielded MgMSFs with refined grain sizes, no secondary phases, and reasonably uniform distributions of hollow reinforcement particles. The developed MgMSFs exhibited densities 8%, 16%, and 26% lower than that of the pure Mg. The coefficient of thermal expansion reduced (up to 20%) while the ignition resistance improved (up to 20 °C) with the amount of GMB in the magnesium matrix. The MgMSFs also exhibited a progressive increase in hardness with the amount of GMB. Although the MgMSFs showed a decrease in the yield strength with the addition of GMB hollow particles, the ultimate compression strength, fracture strain, and energy absorption capabilities increased noticeably. The best ultimate compression strength at 321 MPa, which was ~26% higher than that of the pure Mg, was displayed by the Mg-5GMB composite, while the Mg-20GMB composite showed the best fracture strain and energy absorption capability, which were higher by ~39 and 65%, respectively, when compared to pure Mg. The specific strength of all composites remained superior to that of monolithic magnesium. Particular efforts were made in the present study to interrelate the processing, microstructural features, and properties of MgMSFs.

Introduction Development of white spot lesions (WSLs) during orthodontic treatment is a common risk factor. Fixation of the orthodontic appliances with glass ionomer cements could reduce the prevalence of WSL’s due to their fluoride release capacities. The purpose of this study was to evaluate differences of fluoride release properties from resin-modified and conventional glass ionomer cements (GICs). Methods The resin-modified GICs Fuji ORTHO LC (GC Orthodontics), Meron Plus QM (VOCO), as well as the conventional GICs Fuji ORTHO (GC Orthodontics), Meron (VOCO) and Ketac Cem Easymix (3M ESPE) were tested in this study. The different types of GICs were applied to hydroxyapatite discs according to the manufacturer’s instructions and stored in a solution of TISAB III (Total Ionic Strength Adjustment Buffer III) and fluoride-free water at 37°C. Fluoride measurements were made after 5 minutes, 2 hours, 24 hours, 14 days, 28 days, 2 months, 3 months and 6 months. One factor analysis of variance (ANOVA) was used for the overall comparison of the cumulative fluoride release (from measurement times of 5 minutes to 6 months) between the different materials with the overall level of significance set to 0.05. Tukey’s post hoc test was used for post hoc pairwise comparisons in the cumulative fluoride release between the different materials. Results The cumulative fluoride release (mean ± sd) in descending order was: Fuji ORTHO LC (221.7 ± 10.29 ppm), Fuji ORTHO (191.5 ± 15.03 ppm), Meron Plus QM (173.0 ± 5.89 ppm), Meron (161.3 ± 7.84 ppm) and Ketac Cem Easymix (154.6 ± 6.09 ppm) within 6 months. Analysis of variance detected a significant difference in the cumulative fluoride release between at least two of the materials (rounded p-value < 0.001). Pairwise analysis with Tukey’s post hoc test showed a significant difference in the cumulative fluoride release for all the comparisons except M and MPQM (p = 0.061) and KCE and M (p = 0.517). Conclusion Fluoride ions were released cumulatively over the entire test period for all products. When comparing the two products from the same company (Fuji ORTHO LC vs. Fuji ORTHO from GC Orthodontics Europe GmbH and Meron Plus QM vs. Meron from VOCO GmbH, Mannheim, Germany), it can be said that the resin-modified GICs have a higher release than conventional GICs. The highest individual fluoride release of all GICs was at 24 hours. A general statement, whether resin-modified or conventional GICs have a higher release of fluoride cannot be made.

Background and aims. Pit and fissure sealant placement corresponds to an effective approach of the prevention of caries on occlusal surfaces. Fissure morphology and dental material characteristics are the key factors for sealant effectiveness. The aim of this in vitro study was to compare the penetration ability of two commercially available pit and fissure sealants. Methods. Twenty sound human premolars extracted for orthodontic purpose have been sealed according to manufacturer’s instructions as follows: Group I (n=10), light-cured unfilled resin-based sealant, Admira Seal® (Voco GmbH); Group II (n=10), resin modified glass ionomer sealant without varnish, GC Fuji Triage® (GC Corporation). The teeth have been sectioned buccal-lingually in the middle of the occlusal surface, and the sections were examined at 40x with an inverted microscope. Results. Penetration of the sealants was found to be greater in U-type fissure pattern (91.69%) followed by V-type (75.42%), IK-type (71.24%) and then in I-type (63.98%). The depth of penetration of GC Fuji Triage® (82.85%) demonstrated to be superior to Admira Seal® (76.28%). Conclusion. U fissure design was more common than other fissure patterns and showed significantly higher penetration for the two type of sealants evaluated. Resin modified glass ionomer sealant used in the present study perform comparably with the filled resin sealant.

Introduction. The most common failure in using glass fibre-reinforced composite posts is cementation of the post, i.e. the lack of junction between cement dentine or post. Aim of the study. To compare the bond strength between different glass fibre-reinforced composite (FRC) posts and selected composite cement. Materials and Methods. The following seven types of fiber reinforced composite posts (n =10): Fiber Post (GC Europe N.V., Leuven, Belgium), Glassix (Harald Nordin SA, Chailly s/ Montreux, Switzerland), Rebilda®Post (VOCO GmbH, Cuxhaven, Germany), FibreKleer Serrated Post (Pentron Clinical, Wallingford, USA), ParaPost®Fiber Lux (Coltene/Whaledent Inc., Cuyahoga Falls, USA), RelyX (3M Espe Dental Products, St.Paul, USA) oraz X-Post (Dentsply Maillefer Instruments, Ballaigues, Switzerland) were evaluated. Posts were cemented into metal sleeves with dual-cure resin cement CoreXFlow (Dentsply). The bond strength test based on the coaxial method was performed on the samples using Instron 4485 machine (Instron Corporation, Norwood, USA). Results. The significantly higher values of bond strength were demonstrated for Fiber Post (GC Europe N.V., Leuven, Belgium) with 29.57±1.44 MPa, and the lowest were shown by Glassix (Harald Nordin SA, Chailly s/Montreux, Switzerland) with 17.21±0.87 MPa. The differences were significant (p<0.001). Conclusions. 1. The significantly higher values of bond strength were demonstrated for Fiber Post (GC Europe N.V., Leuven, Belgium) and the lowest were shown by Glassix (Harald Nordin SA, Chailly s/Montreux, Switzerland). 2. The resin methacrylic posts had a stronger junction with cement than with epoxy resin posts.

Commercially available shape memory polymer (SMP) Estane (designation: ETE75DT3 NAT022) is investigated by means of dynamic mechanical thermal analysis (DMTA) technique in torsion mode using the Modular Compact Rheometer MCR-301 (Anton Paar GmbH). Amplitude sweep tests have been run below and above the glass transition temperature to establish the linear viscoelastic range (LVR) in glassy and rubbery phase of this SMP for the correct physical interpretation of DMTA data. Temperature sweep tests were performed at various frequencies to study the influence of this parameter on values of the storage and loss moduli and the storage and loss compliances as well as the viscosities. These tests have been carried out in heating mode with different rates and at different strain amplitudes. The short- and long-term behavior of SMP Estane have been studied by frequency sweep tests performed at different temperatures and data have been transformed into time-domain properties by applying time-temperature superposition principles. All these DMTA data provide the experimental basis for the study of relaxation processes, property-structure relationships, and the shape memory effect in this little-known SMP.

CAD/CAM (computer-aided design/computer-aided manufacturing) for indirect restorative materials has been recently introduced in dentistry. The purpose of this study was to evaluate the change of the surface micro-hardness of different restorative CAD/CAM materials after exposure to a carbonated acidic drink (Coca-Cola, Coca-Cola Company, Milan, Italy). One hundred and eighty specimens of identical size (2 mm thickness) were obtained by sectioning each tested CAD/CAM block of four materials: a hybrid ceramic (CERASMART™, GC Corporation, Tokyo, Japan), a resin nano ceramic (Lava™ Ultimate, 3M, Monrovia, CA, USA), a nanohybrid composite (Grandio blocs, VOCO GmbH, Cuxhaven, Germany), and a zirconia-reinforced lithium silicate glass ceramic (VITA SUPRINITY® PC; VITA Zahnfabrik, Bad Sackingen, Germany). Forty-five specimens of each material were tested. Micro-hardness was measured at baseline, after 7 days and after 28 days. The data were analyzed. The micro-hardness of each material varied significantly after immersion in Coca-Cola. The nanohybrid composite had a high initial micro-hardness and the greatest percentage loss after acid exposure. The hybrid ceramic and the resin nano ceramic had similar percentage losses of micro-hardness values even if the second material had higher initial values. The zirconia-reinforced lithium silicate glass ceramic had the highest baseline values and the lowest percentage loss of micro-hardness. The different CAD/CAM materials presented different micro-hardness values before and after acid exposure.

The reinforcement of acrylic denture base remains problematic. Acrylic prosthesis fractures are commonly observed in prosthodontic practice and have not been reliably resolved. This study compared the resistance to masticatory force of acrylic bases of removable complete conventional prosthesis in 3D upper models. Forty acrylic base test specimens containing two types of reinforcement meshes (20 with glass fiber meshes (FIBER-FORCE®- Synca, Bio Composants MédicauxTM, Tullins, France), 20 with metal meshes (DENTAURUM®-Ispringen, Germany)), 20 with a conventional PMMA acrylic base (LUCITONE 199®-Dentsply Sirona, York, PA, USA), and 20 using a permanent soft reline material (MOLLOPLAST-B®-DETAX GmbH & Co. KG, Ettlingen, Germany) were tested—a total of 80 specimens. Half of the specimens were made for a low alveolar ridge and half for a high alveolar ridge. The data were analysed using one-way analysis of variance and Student’s t-test for independent test specimens. In the high-alveolar-ridge group, the prosthesis reinforced with the glass fiber mesh was the most resistant to fracture, while in the low-alveolar-ridge group, the non-reinforced prosthesis showed the highest resistance masticatory force. Prostheses with the permanent soft reline material showed the lowest resistance to fracture in both high and low-alveolar-ridge groups. The results show that the selection of the right reinforcement material for each clinical case, based on the height of the alveolar ridge, may help to prevent prosthesis fractures.

In this study, hybrid composite consisting of aluminium (Al) shell and magnesium/glass microballoon (Mg-20 wt.% GMB) syntactic composite core was fabricated in a shell-core pattern by combining powder metallurgy and disintegrated melt deposition (DMD) techniques. Physical, microstructural and mechanical properties of as-cast Al and Al/Mg-20GMB hybrid composite were examined. Approximately 13% reduction in density (with respect to aluminium) was realized through the use of a syntactic composite core. Microstructural investigations revealed reasonable interfacial integrity between aluminium shell and Mg-GMB core material and the presence of Al, Mg and GMB phases. The interface region showed a hardness of 109 ± 2 Hv in comparison to the hardness of Al shell region (68 ± 4 Hv) and Mg-20GMB core region (174 ± 5 Hv). In comparison to as-cast Al, the yield strength and ultimate compressive strength of the as-cast Al/Mg-20GMB hybrid composite increased by ~65.4% and ~60%, respectively. Further, the energy absorption under compressive loading for the Al/Mg-20GMB hybrid composite was ~26% higher compared to pure Al. This study validated that Al/Mg-20GMB hybrid composite with superior absolute and specific mechanical properties can be fabricated and used for weight critical applications.

Abstract To select appropriate diet for hamsters used in the uterotrophic and Hershberger assays two rodent diets were compared: Murigran (Agropol, Poland) and Altromin 7010 (Altromin Spezialfutter GmbH&Co., Germany). The contents of bioactive compounds in feeds were evaluated by liquid chromatography, and their oestrogenic activity by yeast enhanced green fluorescent protein assay. In opposition to Altromin, Murigran contained high amounts (μg/kg) of genistein (765 600) and daidzein (132 000), and the oestrogenic activity of these compounds, expressed as 17β-oestradiol equivalent concentration (EEQ), was found to be 9.54 μg EEQ/kg. In in vivo study, Murigran induced a high degree of oestrogenisation in immature hamsters, and females failed to exhibit a normal uterine response to recommended dose of a model oestrogen agonist 17α-ethinyloestradiol. There was no influence of the diet on the weight of five accessory sex organs (ASO): ventral prostate, seminal vesicles with coagulating glands, levator ani bulbocavernosus muscles, Cowper`s glands, and glans penis of control males. However, the impact on ASO response to model androgen agonist, testosterone propionate was observed. The obtained results provide the evidence that phytooestrogen-rich feed modulates the oestrogenic and androgenic response to chemicals.

The aim of the present study was to compare the radiation exposure of the surgeon when using two different kyphoplasty systems for the minimally invasive treatment of osteoporotic vertebral body fractures. There was a preliminary investigation study by a Belgian working group from the ORAMED project (2010), which served as the basis and showed a dose reduction for the surgeon when using a balloon kyphoplasty system with cement delivery systems (CDS). Materials and Methods A bipedicular balloon kyphoplasty system (Medtronic GmbH) with CDS and a unipedicular radiofrequency kyphoplasty system (StabiliT, DFine Europe GmbH) were used in solitary fractures in the thoracolumbar junction in 20 patients each. The patient groups were relatively homogeneous with a mean age of 76.9 years for balloon kyphoplasty and 75 years for radiofrequency kyphoplasty. As expected, the proportion of woman was higher in both groups. The mean BMI value was higher in the radiofrequency kyphoplasty group, and the patient with the highest BMI was also in this group. The workflows were defined in three steps. The working time and the fluoroscopic time were measured in the individual work steps and the dose was measured over all work steps by TLD chips (thermoluminescence detector) on the forehead, on the X-ray apron, on both wrists and on the left ankle. The dose area product was registered for the entire procedure. Results In step 2, the main differences were found in working time and fluoroscopy time in transit. The difference was due to the bipedicular puncture for balloon kyphoplasty and the change of the working cannula, while only a unipedicular puncture was needed in radiofrequency kyphoplasty. The total fluoroscopy time over all procedures was three times longer than in balloon kyphoplasty and this was also reflected in the dose area product, which was more than twice that. The measured surface doses for the lenses were four times higher in balloon kyphoplasty. For the left wrist, the values for balloon kyphoplasty were about 8 times higher. Conclusion Overall, from a radiophysical perspective, the use of a unipedicular kyphoplasty system must be recommended. Should balloon kyphoplasty be used for medical reasons, all radiation protection products (lead gloves, lead glass, radiation protection goggles and CDS) should be used, the surface doses for both hands must be detected by a ring dosimeter and the lens dose must be recorded and documented by a TLD on the radiation protection goggles. Key Points: Citation Format

Purpose The purpose of this in vitro study was to evaluate microleakage around Class V glass-ceramic restorations of different coefficients of thermal expansion after prolonged thermal cycling. Materials and Methods One hundred and twenty non-carious extracted human premolars (patient age range 12–20 years) were randomly assigned to three groups. Standard Class V preparations were cut in the buccal surface using customised Cerana burs, size no. 3. Glass-ceramic inserts from two manufacturers (Cerana, Nordiska Dental AB, Helsingborg, Sweden; Beta-Quartz, Hager & Werken GmbH, Duisburg, Germany) were used to restore the cavities and were luted with a hybrid, high-viscous composite (Tetric Ceram, Ivoclar Vivadent, Schaan, Liechtenstein) and a bonding agent (Excite, Ivoclar Vivadent, Schaan, Liechtenstein). A control group, without inserts, was bulk-filled with the same composite used as the luting agent. In accordance with American Dental Association guidelines, half of the preparation was in enamel, half in dentine/cementum and had a mesio-distal width of 3 mm, an occluso-gingival height of 3 mm, and a depth of 2 mm. All margins had butt joints. Sixty teeth, selected at random, were not thermal cycled; the remaining 60 teeth were thermal cycled 4000 times between water baths held at 5°C and 55°C and the specimens prepared and examined for microleakage using 2.0% Procion Red® (ICI, Slough, UK) dye, buffered at pH7, as a marker. The results were analysed using the Kruskal-Wallis test (ANOVA) at a 95% significance level. Results At the occlusal margins there was no significant difference in microleakage between the three groups (P>0.5) without thermal cycling. After thermal cycling, microleakage at the occlusal margins was significantly less around cavities restored with Cerana glass-ceramic inserts versus Beta-Quartz and Tetric Ceram (P<0.05 in both cases). At the gingival margins, there was no significant difference in microleakge between the groups before thermal cycling (P>0.5). After thermal cycling, there was significantly less microleakage between Cerana inserts and Tetric Ceram (P<0.05). Comparisons between non-thermal cycled and thermal cycled groups showed there was no significant difference with the Cerana inserts (P=0.5590). Clinical Implications The results indicate that, after thermal cycling, restorations restored with Cerana glass-ceramic inserts, which have a coefficient of thermal expansion approximating to that of enamel, show a decrease in marginal microleakage, compared with Beta-Quartz glass-ceramic inserts and Tetric Ceram resin-based composite material. Restorative materials, which have a coefficient of thermal expansion approximating to that of enamel, would seem to be the materials of choice in reducing the problem of marginal microleakege.

In this paper, the feasibility of using an X-ray tube instead of radioisotope sources for measuring volume fractions of gas, oil, and water in two typical flow regimes of three-phase flows, namely, annular and stratified, is evaluated. This study’s proposed detection system is composed of an X-ray tube, a 1 inch × 1 inch NaI detector, and one Pyrex-glass pipe to model different volume fractions for two flow regimes, annular and stratified. Group method of data handling (GMDH), a powerful regression tool, was also implemented to analyze the obtained data. The obtained results in this work indicate that a simple system based on an X-ray tube and just one NaI detector could be a potential alternative to radioisotope-based systems for separate measurements of gas, oil, and water volume fractions in annular and stratified flow regimes of a three-phase flow.

This study evaluated the marginal accuracy of CAD/CAM-fabricated crown copings from four different materials within the same processing route. Twenty stone replicas of a metallic master die (prepared upper premolar) were scanned and divided into two groups. Group 1 (n=10) was used for a pilot test to determine the design parameters for best marginal accuracy. Group 2 (n=10) was used to fabricate 10 specimens from the following materials with one identical CAD/CAM system (GAMMA 202, Wissner GmbH, Goettingen, Germany): A = commercially pure (cp) titanium, B = cobalt-chromium alloy, C = yttria-stabilized zirconia (YSZ), and D = leucite-reinforced glass-ceramics. Copings from group 2 were evaluated for the mean marginal gap size (MeanMG) and average maximum marginal gap size (AMaxMG) with a light microscope in the “as-machined” state. The effect of the material on the marginal accuracy was analyzed by multiple pairwise comparisons (Mann–Whitney, U-test, α=0.05, adjusted by Bonferroni-Holmes method). MeanMG values were as follows: A: 46.92 ± 23.12 μm, B: 48.37 ± 29.72 μm, C: 68.25 ± 28.54 μm, and D: 58.73 ± 21.15 μm. The differences in the MeanMG values proved to be significant for groups A/C (p=0.0024), A/D (p=0.008), and B/C (p=0.0332). AMaxMG values (A: 91.54 ± 23.39 μm, B: 96.86 ± 24.19 μm, C: 120.66 ± 32.75 μm, and D: 100.22 ± 10.83 μm) revealed no significant differences. The material had a significant impact on the marginal accuracy of CAD/CAM-fabricated copings.

The automotive and aerospace industries ask for lightweight and cost effective materials, material combinations and structures for their products. To achieve these goals certain composite material groups have to be optimized with respect to their lightweight potential and production methods.Thermoplastic sandwich composites - which consist of a core structure (transferring the load) and two face-layers (absorbing tensile and compression loads occurring at bending) - suite the need of minimizing weight per area under bending loads. Reduction of process steps can be achieved by connecting the face layers and core in-situ via in mold assembly process using foam injection molding (FIM). FIM uses a single material system and – as within this work – physical blowing agents (PBA) for foaming. To increase the strength and stiffness of FIM parts, (long glass) fibers are in cooperated to create long fiber reinforced thermoplastic (LFT) materials.A commercially available version of the LFT-FIM process is the MuCell® process (Trexel, Inc.). LFT granulate (~ 11 mm length) is fed into the injection molding machine, melted and combined with nitrogen as PBA. To skip the needed compounding process step of the rod granules Fraunhofer ICT developed a Direct LFT-FIM process where polymer and continuous fibers are fed into a twin-screw extruder, melted and mixed with nitrogen. This single phase solution then is transferred to an injection unit.Within this work, these two foam injection molding processes will be compared concerning their achievable fiber length. For that purpose, (foamed) long fiber reinforced polypropylene (PP) blanks were manufactured using identical raw materials such as polymer, additives and glass fibers. The semi-finished product, starting material for the MuCell® process, were manufactured by EASICOMP GmbH using the same raw materials as with the D-LFT process. The different blanks – foamed and fiber reinforced PP (30 wt% and 40 wt %) – were manufactured using one injection unit for the MuCell® process and one for the D-LFT-FIM process. To compare the fiber length the same mold optimized to reduce fiber breakage was used in both processes.

Resonator arrays of periodicially arranged electromagnetic sub-wavelength resonators show a strong frequency filter behaviour which can be controlled by the geometry, size and arrangement of the resonators. The use of several resonator arrays and their integration into a polymer matrix allows the realisation of metamaterials with a specific resonance behaviour. The resonance behaviour can be influenced by material and structural changes enabling a passive sensor function. The considered sensor approach based on metamaterials is investigated to enable structural health monitoring of lightweight structures. In the present case, a double-layer Jerusalem cross (JC) resonator array (RA) is integrated into a glass fibre reinforced plastic (GFRP) to analyse the change of the resonance behaviour under load (strain) using a reflection measurement. The CST (Computer Simulation Technology) Microwave Studio was used to model the resonator array for operation in the microwave frequency range between 15 GHz and 35 GHz as well as for the numerical analysis of the resonance behaviour under load. The numerical results were validated by a tensile test using a tensile test machine (type TIRATEST 28100, Tira GmbH) and by a reflection measurement using two standard gain horn antennas (type Standard Gain Horn Series 862, ARRA Inc) and a vector network analyser (type ZVA50, Rohde&Schwarz). The reflection measurement shows a reflection minimum at 28.6 GHz which moves to higher frequencies under load of the GFRP laminate. With the shift of the minimum, the quality factor decreases and the dip widens. The investigation shows that it is possible to provide a GFRP laminate with a specific electromagnetic behaviour by integrating resonator arrays. It is also shown that the specific electromagnetic behaviour can be influenced by structural changes and thus opens up the possibility of monitoring the condition of lightweight structures.

Abstract Aim of the Study The aim of this study was to evaluate the effect of at-home (Opalesence/Dr. kit 15%, Ultradent, Products, Inc. South Jordan, UT, USA) and in-office (Superoxol 35%, Sultan Chemists, Inc., Englewood, NJ, USA) bleaching on the surface hardness of the following tooth colored restorative materials: composite resin, Point-4 (P4), Kerr Corporation, Orange, CA, USA; ormocer, Admira (AD),VOCO, Germany; compomer Dyract AP (DY), Dentsply DeTrey GmbH, Germany; and resin modified glass ionomer cement, Fuji II LC (FL), GC Corporation, Japan. Methodology Sixty specimens were prepared; 15 specimens of each material (each group n = 5, control after 15 days, at-home and in-office). All specimens were stored in distilled water at room temperature for 24 hrs before testing. A universal testing machine (Micromet 2100 series micro hardness testers) was used for testing Vicker's surface hardness for the three groups for every tested material. All results were statistically analyzed with one way analysis of variance (ANOVA), Post hoc Tukey HSD tests (P<0.05), and percentage changes for Tukey. Results All the tested materials showed an increase in Vicker's surface hardness between base line (24 hrs) and the control group after 15 days storage in distilled water except DY which showed a decrease in surface hardness. All tested materials showed a decrease in surface hardness from control group after 15 days and both at-home and in-office bleaching agents except DY which showed increased values. Significance At-home as well as in-office bleaching agents have a softening effect on some tooth colored restorative material, and the patient must be aware before using them. Citation Taher NM. The Effect of Bleaching Agents on the Surface Hardness of Tooth Colored Restorative Materials. J Contemp Dent Pract 2005 May;(6)2:018-026.

Current elevators are mostly designed as rope-dependent elevators. Main components in the roping system are the deflection sheaves which are conventional manufactured of grey cast iron. Due to the high weight of cast iron sheaves there is a high potential for reducing mass, especially when regarding aspects of effort, safety and ergonomics while assembly and maintenance in the elevator shaft. Within the framework of a R&D co-operation the Chemnitz University of Technology and the AMB Oberlungwitz GmbH developed a fibre-reinforced plastic sheave that comply with the requirements of lightweight design. The technological basic approach to realize that development is compression molding of glass-mat-reinforced thermoplastics (GMT). The project includes the whole development-chain, consisting of part design, tool design, process chain arrangement, parameter studies as well as validation of specimen. In the course of the project appeared a high potential for improvement of the part properties by alternative design solutions. In this context current activities are focused on multi material design methods such as combining GMT with other thermoplastic prepregs. In this manner it is possible to equip every local area with the specific properties that are required. For example the ribs of the sheave, that receive highest values of stress, can be made of materials with continuous-fibre-reinforcement while the basic part body consists of GMT, which is long-fibre-reinforced. This method also enables to avoid process influenced effects like the segregation of the fibre-matrix distribution in GMT. Additionally the input of different materials offers chances to inlay non-preheated prepreg blanks into the compression mould, so that the amount of the preheated material volume can be reduced. In this way cycle times and also lost of temperature due to transfer times of the heated blanks to the mould can be reduced.

Clinical Relevance High-viscosity glass-ionomer cements (HVGICs) used with atraumatic restorative treatment can be repaired with light- or self-cured adhesive systems; however, the repair bond strength of two-step, self-etching and one-step adhesives in the light-cure mode surpass one-step self-cure adhesives. Working on a feasible self-cure approach in the absence of such in rural areas as well as in war zones is of prime importance. SUMMARY Objectives: Despite the success rate of high-viscosity glass-ionomer cements (HVGICs) used in atraumatic restorative treatment (ART) restorations, partial or bulk fracture of the proximal portion has been recorded to be one of the main causes of proximal restoration failures. Repair of these restorative materials requires a practical solution, especially in cases where there is a lack of electricity. Thus, the purpose of this study was to evaluate the repair microshear bond strength (μSBS) of three HVGICs using a resin composite in association with adhesive systems having different curing modes (ie, light- vs self-curing mode). Methods and Materials: A total of 105 discs (12 mm in diameter and 2 mm thick) of three HVGICs: GC Fuji IX GP Fast (GC Corporation, Tokyo, Japan); Fuji IX GP glass-ionomer cement containing chlorhexidine (GC Corporation, Tokyo, Japan); and ChemFil Rock zinc-reinforced HVGIC (Dentsply De-Trey GmbH, Konstanz, Germany) were prepared. Each specimen was divided into three horizontal sections, according to the tested adhesive system or curing mode: Clearfil SE Bond 2 (two-step, self-etch adhesive); (Kuraray Noritake Dental Inc., Tokyo, Japan) in light-cure mode; Clearfil Universal Bond (one-step, self-etch adhesive); (Kuraray Noritake Dental Inc., Tokyo, Japan) in light-cure mode; or Clearfil Universal Bond (one-step, self-etch adhesive); (Kuraray Noritake Dental Inc., Tokyo, Japan) in self-cure mode, mixing it with Clearfil DC Activator (Kuraray Noritake Dental Inc., Tokyo, Japan). A resin composite microcylinder was bonded to each horizontal section of each specimen using starch tubes. The bonded discs were stored in artificial saliva at 37°C for 24 hours. A μSBS test was conducted using a universal testing machine, while failure modes were determined using scanning electron microscopy. Data were statistically analyzed using two-way analysis of variance (ANOVA), one-way ANOVA, and Bonferroni post hoc tests (α=0.05). Results: Two-way ANOVA revealed a statistically significant effect for the adhesive systems (p&lt;0.01) and not for the HVGICs (p=0.05) nor their interactions (p=0.99). When using Clearfil SE Bond 2 and Clearfil Universal in a light-cure mode, significantly higher μSBS values were found when compared with Clearfil Universal in a self-cure mode. Conclusions: The three tested HVGICs can be successfully repaired using two-step or one-step self-etch adhesive systems. The one-step self-etch adhesive system in light-cure mode is preferred when compared with the self-cure mode.

Aims and objectives: The aim of this in vitro study was to investigate the antibacterial and cytotoxic effect of cements: zinc polycarboxylate, glass ionomer, self-adhesive resin cement, eugenol-containing and eugenol-free temporary cements. Materials and methods: The agar-diffusion test was carried out on 4 types of bacteria: Streptococcus mutans ( S. mutans; ATCC 35668), Streptococcus salivarius ( S. salivarius; ATCC 13419), Streptococcus sangius ( S. sangius; ATCC 10556), and Lactobacillus casei ( L. casei; ATCC 27139). Freshly prepared cement samples were placed on a brain heart infusion medium and left at 37°C for 24 hours in a CO2 incubator. Ampicillin disks of 10 mg were used as positive controls. Antimicrobial effects were determined using the zone of inhibition measurement in millimeters at 24 and 48 hours. Cytotoxicity was assessed through a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (SERVA Electrophoresis GmbH, Heidelberg, Germany). To evaluate cell viability, an optical density microplate reader (Tecan™ Sunrise, Männedorf, Switzerland) was used at 24 and 48 hours at 570 and 630 nm, respectively. Results: Except the positive control group, the Adhesor luting cement showed a higher inhibitory effect on S. sangius and L. casei. RelyX Temp E temporary cement showed an inhibitory effect on S. sangius and L. casei, whereas the Cavex temporary cement showed an inhibitory effect on only S. sangius at 24 and 48 hours. At 100% concentration, Cavex temporary cement showed the least toxicity (23.6% pulp cell and 9.9% gingival cell) and highest cell viability (76.4% pulp cell and 90.1% gingival cell) at 24 hours. However, Meron, Adhesor, Panavia SA luting, and RelyX Temp E temporary cements showed the highest toxicity (above 94% gingival cell and 95% pulp cell) at 100% concentration. Conclusions: Meron, Adhesor, Panavia SA luting, and RelyX Temp E temporary cements may have a cytotoxic potential. None of the cements showed an inhibitory effect on S. mutan and S. salivarius, whereas Adhesor luting cement has a higher inhibitory effect than that of S. sangius and L. casei.

Abstract Abstract 4183 Chronic GvHD (cGvHD) still remains a relevant problem after allogeneic stem cell transplantation (SCT), substantially contributing to morbidity and mortality of the procedure. Although manifestations of cGvHD in the genital organs of female patients are well recognized, only very few case reports regarding the involvement of male genital mucosa exist, resulting in the fact that in the organ system assessment forms generated by the NIH Chronic GVHD Consensus Group only female genital tract findings are included. In our observation male findings are present in daily practice if the patient is asked actively for genital problems. Therefore it seems to be a rather under-recognized manifestation of cGVHD. To estimate the prevalence of this problem we prospectively analyzed all male patients presenting in a five month period in our outpatient SCT-clinic for the presence of signs of cGvHD involvement of the genital mucosa or problems in the past. During 9/2010 – 1/2011 in total 250 male patients were seen for follow up after allogeneic SCT, eleven patients out of these (4,4 %) reported present or past signs of cGVHD of the genital mucosa. The clinical presentations varied widely and led from inflammatory processes with local irritation and pain to fibrosis and scarring of the prepuce and glans penis. Depending on their extent of involvement these findings resulted in a serious impact on quality of life and impaired sexual health in particular. In more detail, symptoms varied from: 1. mild inflammatory processes with erythematous changes of the glans (4/11– 36,6%); 2. extensive inflammatory processes with erythema and erosive changes (4/11– 36,6%); 3. phimoses (2/11–18,3%); 4. sclerodermoid processes with penile urethral strictures and urethral meatus stenosis (1/11–9%). In none of the patients any infectious pathogens responsible for the observed findings could be detected. Time between SCT and initial symptoms ranged from 6 months to 6 years after transplantation. Almost all patients with involvement of the genital mucosa showed signs of cGvHD in other mucosal sites, e.g. ocular/oral mucosa (10/11, 90,9%). Cutaneous cGVHD was present in 100%. Inflammatory processes responded mostly to antiinflammatory therapy with local steroid/topical tacrolimus. Since in the course of the disease 6/11 patients (54,5%) eventually developed phimoses, surgical intervention for this condition was required in 4 patients (66,6%). The patient with urethral strictures had a urethrotomy. For normal miction he still has to perform daily dilatations. In the few cases with mucosal biopsies histopatholology showed lichenoid changes (lymphohistiocytic infiltrates between epidermis and dermis with pigmentincontinence) fitting to inflammatory processes of cGvHD and fibrosis. In summary, the presented data implicate that patients after SCT need to be asked actively for genital problems since it is infrequently reported spontaneously. Special caution is required for patients with cutaneous or other mucosal (eyes/oral) cGvHD since they might have developed also unrecognized genital GVHD. Early and interdiscipilinary intervention is necessary to prevent phimoses and sclerodermoid stages as late manifestation. Disclosures: Bertz: Fresenius Biotech GmbH: Lecture remuneration Other.

Since years, fiber reinforced polymer composite (FRPC) parts made by Liquid composite molding (LCM) make up a significant share of the composite market. In LCM dry reinforcing structure gets impregnated with a resin system. Permeability, a material parameter with key influence on all LCM processes, quantifies the conductance of technical textiles for resin flow. Today, when a numerical filling simulation is applied for process design, large experimental test programs are required for characterization of permeability, as the permeability has to be measured for all textiles processed and also the dependency e.g. on the fiber volume content has to be considered. Together with Math2Market GmbH (M2M), the IVW currently develops a novel simulative-experimental approach (SEA), using experimental tests to calibrate a simulation model for replacing a significant amount of the experimental tests through “virtual” measurements. In a first step the functionality of the simulation and the most appropriate methods for textile modelling were investigated. For this, three routes were followed: At first a micro-computer tomograph (μCT)-scan of a glass fiber non-crimp fabric was fed into GeoDict, the material simulation software developed by M2M. Second, a digital model (DM) of the textile was created by computer modelling of basic structure and subsequent virtual compaction. μCT-model and DM were then used for computational fluid flow simulation which gives the direction-dependent permeability as an output. The DM calibrated by experiments represents the SEA and results in the digital twin. Third route was the experimental permeability measurement to generate reference values. Comparing the results of all three routes allows statements about the functionality of the simulation and accuracy of modelling. The rather deficient correlation between the results of experiments and μCT-model based simulations revealed that segmentation is a remarkable source of error despite the use of recognized methods. Different modeling approaches were followed to build up the digital twin. The best results were achieved with models undergoing a virtual compaction step, which takes various imperfections such as yarn deformation and varying nesting behavior into account. With this 2.25 - 6.75% deviation from the experimental results at an average standard deviation of 21.9 - 61.2% were achieved. Hence, the digital twin shows a better correlation than the μCT-model and high potential for substitution of experiments. Even better results are expected when in a next step a local anisotropic permeability will be allocated to the yarns.

During freezing, a solution changes into an amorphous phase at the glass transition temperature of the maximally freeze-concentrated phase (T′g). The solution exhibits a cake-like porous structure under the optimal freeze-drying process. However, if the product temperature is higher than theT′g during the drying phase, the glassy material will undergo viscous flow, resulting in loss of the porous structure. This is defined as the collapse phenomenon and may be related to instability of the freeze-dried products. The purpose of the present study was to investigate the effect of cake collapse on freeze-dried bull spermatozoa. One-way ANOVA was used for comparison of T′g, DNA damage, and blastocyst yield. When the ANOVA was significant, differences among means were analysed by a Tukey test. In Experiment 1, factors affecting the T′g were investigated. Using differential scanning calorimetry, theT′g of an EGTA buffer (10 mM TRIS-HCl, 50 mM EGTA, and 50 mM NaCl, pH8.0) that has been conventionally used for sperm freeze-drying was determined to be –45.0°C. Modification of the EGTA buffer composition by complete removal of NaCl and addition of 0.5 M trehalose (referred to hereafter as mEGTA buffer) resulted in an increase in theT′g up to –27.7°C. The T′g of the mEGTA buffer cooled by direct immersing into liquid nitrogen (–29.4°C) was slightly lower (P < 0.05) than that cooled slowly at 20 and 1°C min–1 (–27.6 and –27.2°C, respectively). In Experiment 2, the integrity of freeze-dried and rehydrated bull spermatozoa was investigated. Spermatozoa from a Japanese Black bull were suspended into mEGTA buffer (3 × 107 cells mL–1), cooled at 20°C min–1, and then processed for drying for 6 h at 0, –15, and –30°C (ALPHA2-4; Martin Christ Gefriertrocknungsanlagen GmbH, Osterode am Harz, Germany). Cakes were collapsed when the sperm suspension was dehydrated either at 0 or –15°C. In vitro-matured bovine oocytes were injected with rehydrated sperm, chemically activated (5 μM ionomycin, 7% ethanol, and 2 mM 6-DMAP), and then cultured for 8 days. Blastocyst yields after injection of sperm dried at 0 and –15°C, calculated from cleaved oocytes, were significantly lower than that of sperm dried at –30°C (0.7–3.7% v. 14.2%; P < 0.05). The level of DNA damage, assessed by the alkaline comet assay, was not different between the sperm populations dried at 0 and –30°C. Transmission electron microscopic observation revealed that the sperm membrane dried at 0°C was more damaged compared with that dried at –30°C (P < 0.05; chi-squared test with Bonferroni correction). In conclusion, incidence of collapse in freeze-dried cake may be a detrimental factor for maintenance of sperm integrity after freeze-drying, and can be inhibited by controlling the T′g of the buffer and drying phase temperature. H. Hara is Research Fellow of the Japan Society for the Promotion of Science (JSPS). This work was supported by a grant-in-aid for basic research from JSPS (no. 24580407) to S. Hochi.

Abstract Abstract 1457 Acute lymphoblastic leukemia (ALL) is the most frequent form of childhood cancer. Although therapy efforts have achieved cure rates of above 80%, about every fifth patient encounters relapse, which is associated with poor outcome. Risk stratification based on prognostic factors is critical for selecting appropriate treatment intensity to improve therapy efficacy and reduce toxicity. However, in spite of new strategies for risk stratification, the majority of relapsed patients are initially stratified into non-high risk groups pointing out the need to identify new prognostic markers that might refer to novel therapeutic targets. We have recently shown in a NOD/SCID/huALL mouse xenotranplant model that early relapse of pediatric B-cell precursor (BCP-) ALL patients is reflected by rapid engraftment (time to leukemia/ TTLshort) of primary ALL cells. In this study we aimed to identify differently expressed and activated proteins in xenograft ALL of distinct engraftment subgroups employing a Reverse Phase Protein Array (RPPA) strategy. Levels of total or activated proteins were analyzed in patient derived xenograft BCP-ALL samples characterized with respect to their NOD/SCID engraftment phenotype (TTLshort n= 7, TTLlong n= 9). The proteome of each sample was immobilized on nitrocellulose coated glass slides and overall protein expression or phosphorylation of 51 key signaling molecules was detected by incubation with the corresponding specific antibodies. Protein expression and/ or activation was quantified and compared between the different engraftment subgroups (TTLshort/ early relapse versus TTLlong/ good prognosis). RPPA results were validated by Western Blot analyses. The association of NOD/SCID/huALL engraftment and clinical patient outcome was analyzed and revealed a significantly inferior survival of patients with the TTLshort in contrast to the TTLlong phenotype also in this subgroup of patients (Kaplan Meier, log rank, P=.003). Upon comparison of the protein expression data (Shrinkage t-test, P <.05, fold change ≥ 1.5) in the TTL subgroups the three proteins CYCLIN B, beta-CATENIN and ANNEXIN I were identified to be overexpressed in TTLshort. In addition, an increased activation of protein-kinase C alpha (phosporylated serine 657, p-PKC alpha S657) was detected in TTLlong leukemia samples. CYCLIN B is a positive regulator of the cell cycle and highly expressed in the G2/M phase. Consistent with its pro-proliferative function, CYCLIN B was identified to be up-regulated in leukemia samples with rapid NOD/SCID/huALL growth (TTLshort/ early relapse phenotype) (P=.013). Interestingly, the level of CYCLIN B protein expression correlates negatively to TTL (Spearman, rs=-.516, P=.041), suggesting a direct association of leukemia cell cycle progression and leukemia engraftment in the NOD/SCID/huALL xenograft model. Beta-CATENIN, a molecule involved in WNT-signaling and cell adhesion but also associated with apoptosis inhibition and cell growth in other hematological malignancies, was found to be over-expressed in TTLshort (P=.006). Furthermore, beta-CATENIN protein levels were reversely correlated to TTL (Spearman, rs=-.557, P=.025). Additionally, ANNEXIN I, involved in the regulation of inflammation and apoptosis and reported to be up-regulated in hairy cell leukemia, showed high protein levels in TTLshort (P=.033). Protein-kinase C alpha was previously reported to induce apoptosis in an ALL- cell line and showed increased activation in non-relapsing pediatric T-ALL patient samples. In line with this, we found higher levels of PKC alpha activation in the TTLlong -group (P= 8.5e–9), indicating an association with good prognosis. Taken together, this study identified differentially expressed proteins in prognostic subgroups of BCP-ALL patients with distinct clinical outcomes, which can be further evaluated as new prognostic markers and therapeutic targets. Disclosures: Debatin: Apogenix GmbH: Patents & Royalties, Research Funding.

Abstract Abstract 5064 Introduction, Multiple myeloma (MM) is characterized by a huge clinical heterogeneity despite the homogenous morphologic appearance of malignant plasma cells (PCs). The advent of interphase fluorescence in situ hybridization (FISH) or MicroArrays (MA) allows an increased rate of aberration detection and identification of some recurrent cryptic changes, which have been increasingly implemented as additional diagnostic and prognostic factors. To heighten sensitivity of Single Nucleotide Polymorphism (SNP) arrays, or FISH it is necessary to have a purified population of cells as starting material. Screening must be performed systematically on the purified CD138+ PCs. After testing different systems for cell purification, we encountered some challenges. We didn't obtain enough PCs for FISH and SNP array studies. This was due to excess M-protein accumulating in the blood stream, increasing hyper viscosity and also due to the morphology and size variations of PCs at various stages of differentiation. Additionally, downstream DNA extraction can be a challenge since EDTA found in most buffers is an inhibitor for chemical PCR reaction for some MA chips. Given the challenges, CERBA laboratory and Miltenyi Biotec GmbH have developed a fully automated process (FAP) for purification for CD138+ PCs. In a study of 100 BM patient samples, we compared the specificity, efficiency, performance, purity, ease of use, technologists' time and the quality of DNA after CD138+ PCs purification. Two methods were compared. In the first method, cells were directly purified from bone marrow samples by FAP using Automated Magnetic Cell Sorter (AMCS). In the second method, mononuclear cells from fresh whole bone marrow (WBM) were enriched by Ficoll, followed by cell selection procedure with anti-CD138+ MicroBeads using the AutoMACS®. Before separation and following the separation, the percentage of PCs was determined by Flow cytometry (FC) on WBM by multiparameter FC (MFC) for CD138/CD38 expression. Additionally, DNA quality on separated cells was assessed by Nanodrop. A fraction of the CD138+ PCs were used after hypotonic shock and Carnoy fixation, applied to glass slides for FISH application and another fraction for DNA extraction for MA (SNP.6 Affymetrix®) FISH was performed with the recommended unbalanced alterations & reciprocal rearrangements: del(13) (q14)(D13S25), del(17)(p13)(TP53),+3(D3Z), +9(D9Z1), +15(D15Z14), t(4;14)(p16;q32)/IGH-FGFR3. Results, the specificity and purity were the same for both process but the efficiency and performance were considerably better for FAP than mononuclear cells enriched by Ficoll (MCEFicoll) process. With FAP, in 95% of the MM cases we obtained enough PCs for performance of the recommended panel of FISH and for 50% of them we could extract DNA for SNP array. For the MCEFicoll, we observed inferior performance, with very few plasma cells after isolation. Having enough PSc for only 65% of the cases and we could only extract DNA for 28% of them. The quality of DNA was the same for both process and the technologists' time was longer by 30' /patient for MCEFicoll process than for FAP. Currently in CERBA lab, we realize more than 20 plasma cells isolation per week for patients with MM and from October 2007 to July 2011 we have separated more than 5.000 specimens using CD138 Whole Blood MicroBeads (CD 138 WBMB) from Miltenyi Biotec, in combination with the AMCS. This has allowed isolation directly from WBM without any sample preparation required, such as density gradient centrifugation (ficoll) or erythrocyte lysis. The detection rate of chromosomal abnormalities and the number of abnormalities per case in MM and PCs dyscrasia significantly improves when there are enough CD138+PCs for analysis. Conclusion, in this report we describe the benefits of fully automated isolations of CD138+ cells from WBM. We have developed an SOP for an automated reliable and standardized method which allows the processing of multiple samples in a single day, while maintaining sample integrity and increasing sensitivity of FISH analysis and WG arrays for a diagnosis lab. Disclosures: No relevant conflicts of interest to declare.

Abstract Adhesively bonded joints are ubiquitous in electronic assemblies that are used in a wide range of applications, which include automotive, medical, military, space and communications. The steady drive to reduce the size of assemblies in all of these applications, while providing increased functionality, generates a need for adhesive joints of higher strength, improved thermal and electrical conductivity and better dielectric isolation. All of these attributes of adhesive joints are degraded by the presence of voids in them. The quest to minimize voids in bonded structures motivated a previous study of their formation in a solvent cast, die bond epoxy film, which undergoes a liquid phase transition during cure. That work is extended in this study by including the effects of various filler morphologies in the adhesive. Fillers are added to adhesives to facilitate handling of thin sheet formats, control bond line thickness and reduce coefficient of thermal expansion. As such, fillers are selected to be inert with respect to the adhesive chemistry, while being readily wetted by it in the liquid state. Common filler morphologies include woven and molded open meshes, fibers chopped to uniform length, and spheres of uniform or distributed diameters. Void formation is influenced by a number factors, which include wettability of the bonded surfaces, adsorbed water, amount of solvent retained in the film, volume of entrapped air, thermal profile of the cure schedule, and clamping pressure during cure. The presence of fillers in the adhesive adds the additional factors of constrained diffusion paths and increased area for void nucleation. We have changed our approach to modeling the diffusion of volatile species in adhesive joints from a finite difference calculation in a uniform adhesive medium used previously, to a finite element model of a complex diffusion space. The open source program Gmsh is used to generate the diffusion space from a set of input parameters. The calculations of concentration profiles and diffusion fluxes of volatile species at the void interface are made using the open source finite element program elmer. As done previously, the position of the void interface is updated by integrating the product of time and flux of diffusing species over the area of the interface. The internal pressure of the void is determined by application of the Young-Laplace equation, while Henry’s law is used to estimate the concentration of diffusing species adjacent to the void interface. The calculation proceeds for a time equivalent to the integral of the time temperature product required to achieve a 70% cure state of the adhesive, at which point the void interface is immobile. The experimental approach is the same as used previously, with the filled adhesive sandwiched between glass slides and cured on a hot plate while imaged through a microscope. Images are automatically captured and analyzed by using the open source program imageJ, which allows us to track the evolution of individual voids as well as the time dependent distribution of the void population. We are working to correlate these experimental results with the predictions of our finite element calculations to allow us to make insightful choices of adhesives and optimize our bonding processes.

<p>Samples from different industrial grape cultivars were collected during the vintage season from the vineyard of the winery (the «Shabo» winery Company, located in the Odesa region, Ukraine). The following industrial cultivars of grapes were selected for the research: Chardonnay, Cabernet Sauvignon, Merlot, Sauvignon, Riesling Rhenish, Aligote, Rkatsiteli, Bastardo, Traminer, Telti Kuruk, Grinosh.</p> <p>The grape cultivars were cultivated on the sandy soils in the district located between the Black Sea and the Dnestrovsky estuary. Grape must derived from different grape cultivars was placed into sterile glass flasks to half of the 450ml flask volume. Each flask was carefully closed with a rubber stopper with an injection needle in it. During the fermentation process, it was necessary to remove carbon dioxide, which was present as a result of active anaerobic fermentation processes in the grape must. At the end of grape must fermentation, pure yeast cultures were isolated using traditional microbiological methods by consistent inoculation of a sample into a Petri dish with a few modifications of nutrient selective agar for yeast isolation and cultivation. Primary yeast isolation was carried out using Inhibitory Mold Agar medium (Becton Dickinson Company, USA).</p> <p>The yeast culture morphological properties were analyzed after the primary yeast culture isolation. Yeasts were identified by polymerase chain reaction (PCR) using universal yeast primers. After yeast culture identification, the next step in yeast cultivation was carried out on Wort Agar medium (Becton Dickinson Company, USA). Each isolated, and identified yeast culture was deposited in the Genebank of Japan, MAFF culture Collection, Tsukuba, Ibaraki, Japan and (NCYC) - Yeast Culture Collection (National Collection of Yeast Cultures, Institute of Food Research, Norwich, United Kingdom). Each yeast culture was tested for technological characteristics such as growth resistance to high temperature (+42°C) and low temperature (+6°C), growth at low pH 2.6–3.0 (acid resistance), growth in the presence of 5, 10, and 15% ethanol (ethanol resistance), and growth in the presence of high concentration potassium bisulfite (bisulfite resistance). Hydrosulfide synthesis (H₂S gassing production) was studied in addition.</p> <p>Parameters of cellular metabolism in yeast suspension, such as concentration of nitrogen, protein, triglicerides, enzymatic activity and total sugar (which include glucose, fructose, and galactose) were determined. Macro- and micro-element concentrations in fermented grape must, which contained pure yeast culture was determined and included: potassium, sodium, calcium, phosphorus, magnesium, iron, chlorides. In addition to identifying parameters of macro- and micro- element concentration in grape must during and following fermentation based on a principle of photometric analysis, carried out using a biochemical analyser Respons-920 (DiaSys Diagnostic Systems GmbH, Germany).</p> <p>Laboratory selected <em>Saccharomyces cerevisiae </em>wine yeast showed high enzymatic activity with short lag phase. Since of fermentation started on third day concentration of Triglicerides, Protein (total), Potassium and Sodium increased and then level of Protein (total) on the 5th day of fermentation twice decreased. Trigliceride concentration on the 5th day of fermentation continued to increase. Concentration of Iron on the 5th day of fermentation increase in geometrical progression, concentration increase in 4-5 times. Contrary Chloride concentration on the 5th day of fermentation decreased in 3-4 times. Enzymatic activity on 3rd day of fermentation maximal for Lactate Dehydrogenase, Alanine aminotransferase, Aspartate aminotransferase, Phosphatase. Since of 5th day of fermentation Enzymatic activity for Lactate Dehydrogenase, Alanine aminotransferase, Aspartate aminotransferase 3-4 times. Especially level of Phosphatase activity very decreased in 6-7 times. Comparative assessment between our Laboratory selected <em>Saccharomyces cerevisiae</em> yeast culture and Dry active commercial <em>Saccharomyces cerevisiae</em> yeast culture did not showed any difference in enzymatic activity. Both groups showed high enzymatic activity on the third day from the start of fermentation and decreasing on the fifth day since of fermentation started.</p> <p><em> Key words: wine yeast, enzymatic activity, cellular metabolism</em><em>, </em><em>Saccharomyces cerevisiae</em><em>.</em><em></em></p>

Background: The nanoclay (NC) and glass micro balloons (GMB) based reinforced polymer composites are explored extensively through traditional processing methods. NC shows substantial enhancement in mechanical properties. Polymer composites developed by reinforcing GMB fillers provide a substantial reduction in weight, which is essential in the marine, aerospace, and automotive field. In this study, an attempt is made by developing polymer nano composites by reinforcing NC and GMB particles. Objective: The paper deals with 3 dimensional printing (3DP) of lightweight nanocomposite foam (NF) developed by mixing nanoclay (NC) and glass micro balloons (GMB) in high-density polyethylene (HDPE). The NF blend is prepared by keeping NC at 5 weight %. Subsequently, GMBs are added by volume (20 - 60 %) to NC/HDPE blend to realize lightweight NFs. Methods: The lightweight feedstock filaments are developed by extruding the blends using a single screw extruder. The extruded NF filaments are used as an input in a 3D printer to print NFs. The density of extruded filaments and prints are measured. The printed NFs are subjected to tensile and flexural testing. Conclusion: With an increase in GMB loading the density of both filaments and prints decreases. Compared to neat HDPE, printed NFs show ~30 % weight reducing potential. The tensile, flexural modulus and strength increases with GMB loading. NFs exhibited superior mechanical performance as compared to HDPE and NC/HDPE. Further, the property map reveals that the 3D printed NFs show superior tensile, flexural modulus, and strength in comparison with injection and compression-molded foams.

Introdution: The occlusal surface of the molars are more susceptible to dental caries because of their anatomy, so in some cases, the sealants are indicated. Objective: The objective of this study was to evaluate the efficacy, retention, presence of caries and marginal discoloration of resinous sealants (Fluoroshield and Prevent) in first permanent molars. Methods: Ninety - one children aged 7 to 9 years were selected from a municipal institution Regente Feijó, SP, Brazil, for the application of resinous sealants to first permanent lower first molars. The application of Fluoroshield and Prevent resin sealants was performed according to the manufacturer's recommendations. The evaluation was performed after 6 and 12 months by double-blind examiners and followed the criteria: alpha (total sealant, absence of caries and absence of pigmentation) charlie (partial sealing, superficial caries and light pigmentation) charlie complete sealing, presence of cavitation and pigmentation) after 12 months of application by two previously calibrated examiners. Results: Using Fischer's exact test, no significant difference (p 0.05) was observed between the resin-based sealant groups. In the evaluated criteria, both sealants after three years were similar, and may therefore be suitable materials for sealing grooves and fissures in permanent molars.Descriptors: Pit and Fissure Sealants; Dental Caries; Dentition, Permanent; Oral Health.ReferencesPalma-Dibb RG, Chinelatti MA, Souza-Zaroni WC. Diagnóstico de lesões de cárie. In: Assed S. Odontopediatria: bases científicas para a prática clínica. São Paulo: Artes Médicas; 2005.Sheiham A, James WP. Diet and Dental Caries: The Pivotal Role of Free Sugars Reemphasized. J Dent Res. 2015;94(10):1341-47.Faleiros Chioca S, Urzúa Araya L, Rodríguez Martínez G, Cabello Ibacache R. Uso de sellantes de fosas y fisuras para La prevención de caries em población infanto-juvenil: Revisión metodológica de ensayos clínicos. Rev Clin Periodoncia Implantol Rehabil Oral. 2013;6(1):14-9.Liu BY, Lo EC, Chu CH, Lin HC. Randomized Trial on Fluorides and Sealants for Fissure Caries Prevention. J Dent Res 2012;91(8):753-58Condò R, Cioffi A, Riccio A, Totino M, Condò SG, Cerroni L. Sealants in dentistry: a systematic review of the literature. Oral Implantol (Rome). 2014;6(3):67-74. Ahovuo-Saloranta A, Forss H, Walsh T, Hiiri A, Nordblad A, Mäkelä M et al. Sealants for preventing dental decay in the permanent teeth. Cochrane Database Syst Rev. 2013;(3):CD001830Moreira KMS,Kantovitz KR,Aguiar JPD, Borges AFS, Pascon FM, Puppin-Rontani RM. Impact of the intermediary layer on sealant retention: a randomized 24-month clinical trial. Clin Oral Investig. 2017;21(5):1435-43.Griffin SO, Gray SK, Malvitz DM, Gooch BF. Caries Risk in Formerly Sealed Teeth. J Am Dent Assoc 2009;140(4):415-23.Splieth CH, Ekstrand KR, Alkilzy M, Clarkson J, Meyer-Lueckel H, Martignon S et al. Sealants in dentistry: outcomes of the ORCA Saturday Afternoon Symposium 2007. Caries Res. 2010;44(1):3-13Sundfeld RH, Briso ALF, Mauro SJ, de Alexandre RS, Sundfeld Neto D, Oliveira FG et al. Twenty years experience with pit and fissure sealants. Int J Clin Dent. 2010;2(4):1-12.Baldini V, Tagliaferro EPS, Ambrosano GMB, Meneghim MC, Pereira AC. Use of occlusal sealant in a community program and caries incidence in high- and low-risk children. J Appl Oral Sci. 2010;19(4):396-402.Provenzano MGA, Rios D, Fracasso MLC, Marchesi A, Honório HM. Clinical Evaluation of a Resin-Modifi ed Glass Ionomer Cement (Vitremer®) Used as Pit-And-Fissure Sealant in Primary Molars. Pesq Bras Odontoped Clin Integr.2010;10(2):233-40.Saito CM, Lima EP, Mello D, Mello FAS. Selante resinoso: tratamento preventivo e minimamente invasivo. Rev Gest Saúde. 2014;11:10-17.Zenkner JE, Alves LS, de Oliveira RS, Bica RH, Wagner MB, Maltz M. Influence of eruption stage and biofilm accumulation on occlusal caries in permanent molars: a generalized estimating equations logistic approach. Caries Res. 2013;47(3):177-82.Delmondes FS, Imparato JCP. Selamento de primeiros molares permanentes em erupção com cimento de ionômero de vidro. J Bras Odontopediatr. Odontol Bebê. 2003;6(33):373-78.Heyduck C, Meller C, Schwahn C, Spliet CH. Effectiveness of Sealants in Adolescents with High and Low Caries Experience. Caries Res. 2006;40(5):375-81.Tagliaferro EPS, Ambrosano GMB, Meneghim MC, Pereira AC. Risk indicators and risk predictors of dental caries in schoolchildren. J Appl Oral Sci. 2008;16(6):408-13.Silva RCSP, Araujo MAM, Rego MA. Avaliação clinica de selantes de fossulas e fissuras: efeitos de materiais e tempo de analise. Rev Odontol UNESP. 1996;25(2):237-45.Beraldo DZ, Pereira KFS, Zafalon EJ, Yoshinari FMS.Análise comparativa entre selante resinoso e selante ionomérico por microscópio eletrônico de varredura. Rev Odontol UNESP. 2015;44(4):239-43.Araújo IT, Cunha MMF, Vasconcelos MG, Vasconcelos, RG. Selantes: uma técnica eficaz na prevenção da cárie. Com ciênc saúde. 2013;24(3):259-66.Moura SK, Lemos LVFM, Myszkovisk S, Provenzano MGA, Balducci I, Myaki SI. Bonding durability of dental sealants to deciduous and permanent teeth. Braz J Oral Sci. 2014; 13(3):198-202.Sundfeld RH, Mauro SJ, Briso ALF, Sundfeld MLMM. Clinical/photographic evaluation of a single application of two sealants after eleven years. Bull Tokyo Dent Coll. 2004;45(2):67-75.Folke BD, Walton JL, Feigal RJ. Occlusal Sealant Success Over Ten Years in a Private Practice: Comparing Longevity of Sealants Placed by Dentists, Hygienists, and Assistants. Pediatr Dent. 2004;26(5):426-32.Sundfeld RH, Croll Theodore P, José MS, Briso ALF, Sversut AR, Sundefeld MLMM. Longitudinal photographic observation of the occurrence of bubbles in pit and fissure sealants. J Appl Oral Sci. 2006;14(1):27-32.Arhakis A, Damianaki S, Toumba KJ. Pit and fissure sealants: types, effectiveness, retention, and fluoride release: a literature review. Balkan J Stomatol. 2007;11(3):151-62.Garbin CAS, Garbin AJI, Santos KT, Pizzato E, Moroso TT. Retention of a pit-and-fissure sealant: comparison of three types of isolation. Pesq Bras Odontoped Clin Integr. 2008;8(2):175-78.Kühnisch J, Mansmannb U, Roswitha HW, Hickel R. Longevity of materials for pit and fissure sealing - results from a meta-analysis. Dent Mater. 2012;28(3):298-303.

In the loss of much of the coronary structure, either through caries or a fracture, it is indicated to perform restorative laboratory techniques in order to re-establish the patient's health, function and aesthetics, through conservative and minimally invasive techniques. The aim of this manuscript is to report on a clinical case of a posterior restoration using a semidirect composite resin onlay restoration. Initially, a direct morphological reconstruction of bulk-fill resin was performed, followed by cavity preparation with diamond tips. Alginate melding and a model of elastomer-based material were performed. The professional made the onlay piece in micro-hybrid composite resin in the model incrementally. Cementation was performed with dual resin cement following manufacturer's recommendations. Finally, the occlusal adjustment was performed in the maximum habitual intercuspal position and during eccentric mandible movements. We conclude that the semidirect restorative technique in composite resin is as effective as direct and indirect restorations; however, the correct indication of these restorative procedures will define the clinical prognosis.Descriptors: Dental Restoration; Permanent; Molar. Rehabilitation.ReferencesAngeletaki F, Gkogkos A, Papazoglou E, Kloukos D. Direct versus indirect inlay/onlay composite restorations in posterior teeth. A systematic review and meta-analysis. J Dent. 2016;53:12-21.Morimoto S, Rebello de Sampaio FB, Braga MM, Sesma N, Özcan M. Survival Rate of Resin and Ceramic Inlays, Onlays, and Overlays: A Systematic Review and Meta-analysis. J Dent Res. 2016;95:985-94.Spreafico RC, Krejci I, Dietschi D. Clinical performance and marginal adaptation of class II direct and semidirect composite restorations over 3.5 years in vivo. J Dent. 2005;33:499-507.Lins R, Vinagre A, Alberto N, Domingues MF, Messias A, Martins LR, Nogueira R, Ramos JC. Polymerization Shrinkage Evaluation of Restorative Resin-Based Composites Using Fiber Bragg Grating Sensors. Polymers (Basel). 2019a;11;E859.Lins RBE, Aristilde S, Osório JH, Cordeiro CMB, Yanikian CRF, Bicalho AA, Stape THS, Soares CJ, Martins LRM. Biomechanical behaviour of bulk-fill resin composites in class II restorations. J Mech Behav Biomed Mater. 2019b;2:255-261.Opdam NJM, Roeters FJM, Feilzer AJ, Verdonschot EH. Marginal integrity and postoperative sensitivity in Class 2 resin composite restorations in vivo. J. Dent. 1998;26: 555-62.Bicalho AA, Valdívia AD, Barreto BC, Tantbirojn D, Versluis A, Soares CJ. Incremental filling technique and composite material–part II: shrinkage and shrinkage stresses. Operat. Dent. 2014;39:E83–E92.Soares CJ, Faria-E-Silva AL, Rodrigues MP, Vilela ABF, Pfeifer CS, Tantbirojn D, Versluis A. Polymerization shrinkage stress of composite resins and resin cements - What do we need to know? Braz Oral Res. 2017;28:e62.van Dijken JW. A 6-year evaluation of a direct composite resin inlay/onlay system and glass ionomer cement-composite resin sandwich restorations. Acta Odontol Scand. 1994;52:368-76.Ferracane JL, Stansbury JW, Burke FJ. Self-adhesive resin cements - chemistry, properties and clinical considerations. J Oral Rehabil. 2011;38:295-314.Bacelar-Sá R, Sauro S, Abuna G, Vitti R, Nikaido T, Tagami J, Ambrosano GMB, Giannini M. Adhesion Evaluation of Dentin Sealing, Micropermeability, and Bond Strength of Current HEMA-free Adhesives to Dentin. J Adhes Dent. 2017;19:357-364.Alharbi A, Rocca GT, Dietschi D, Krejci I. Semidirect composite onlay with cavity sealing: a review of clinical procedures. J Esthet Restor Dent. 2014;26:97-106.Hirata R, Kabbach W, de Andrade OS, Bonfante EA, Giannini M, Coelho PG. Bulk Fill Composites: An Anatomic Sculpting Technique. J Esthet Restor Dent. 2015;27:335-43.Fron Chabouis H, Prot C, Fonteneau C, Nasr K, Chabreron O, Cazier S, Moussally C, Gaucher A, Khabthani Ben Jaballah I, Boyer R, Leforestier JF, Caumont-Prim A, Chemla F, Maman L, Nabet C, Attal JP. Efficacy of composite versus ceramic inlays and onlays: study protocol for the CECOIA randomized controlled trial. Trials. 2013;3:278.Torres CRG, Zanatta RF, Huhtala MFRL, Borges AB. Semidirect posterior composite restorations with a flexible die technique: A case series. J Am Dent Assoc. 2017;148:671-676.Marcondes M, Souza N, Manfroi FB, Burnett LH Jr, Spohr AM. Clinical Evaluation of Indirect Composite Resin Restorations Cemented with Different Resin Cements. J Adhes Dent. 2016;18:59-67.Liu X, Fok A, Li H. Influence of restorative material and proximal cavity design on the fracture resistance of MOD inlay restoration. Dent Mater. 2014;30:327-33.Fruits TJ, Knapp JA, Khajotia SS. Microleakage in the proximal walls of direct and indirect posterior resin slot restorations. Oper Dent. 2006;31:719-27.

Introdução: O maior foco das pesquisas odontológicas nos últimos 60 anos tem sido a adesão e suas técnicas. Mais de 7000 artigos já foram publicados a este respeito. O desenvolvimento dos materiais odontológicos adesivos e as técnicas a eles relacionadas possuem uma história interessante, onde descobertas do passado ainda são usadas de alguma forma no presente. Objetivo: expor, através de uma revisão de literatura, um breve histórico sobre materiais e técnicas restauradoras, bem como o estágio atual da odontologia adesiva, com ênfase na tradução de evidências baseadas em pesquisas laboratoriais para a prática clínica. Materiais e Métodos: Foram selecionados livros de preferência do autor para a introdução de conceitos clássicos e artigos de revisão publicados nos últimos 10 anos, utilizando as cinco palavras-chave: “Dental Bonding” AND “Dental Cements” AND “Resin Cements” AND “Adhesives” AND “Ceramics”, sorteados pela melhor combinação na plataforma Pub/Med/MEDLINE. Resultados: Duzentos e um artigos, foram encontrados, sendo utilizados para análise qualitativa e quantitativa aqueles pertinentes ao direcionamento do autor, de acordo com o tema. Conclusão: Considerando as limitações do estudo, concluiu-se que a odontologia adesiva é uma área que segue em constante desenvolvimento, fundamental para a realização de restaurações minimamente invasivas e estéticas. Onde para que seja possível consequentemente longevidade clínica, os materiais utilizados e substrato dentário requerem conhecimento do profissional e fidelidade na execução de um correto pré-tratamento das superfícies, respeitando suas naturezas e composições.Descritores: Colagem Dentária; Cimentos Dentários; Cimentos de Resina; Adesivos; Cerâmica.ReferênciasVan Meerbeek B, De Munck J, Yoshida Y, Inoue S, Vargas M, Vijay P, et al. Buonocore memorial lecture. Adhesion to enamel and dentin: current status and future challenges. Oper Dent. 2003;28:215-35.Miyashita E, Fonseca AS. 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Background: Reperfusion following ischemia can lead to more injuries than ischemia itself especially in diabetic patients. The aim of this study was to evaluate the effect of dexmedetomidine on ischemia-reperfusion injury (IRI) in rats with have hepatic IRI and diabetes mellitus. Methodology: Twenty-eight Wistar Albino rats were randomised into four groups as control (C), diabetic (DC), diabetic with hepatic ischemia-reperfusion injury (DIR), and diabetic but administered dexmedetomidine followed by hepatic IRI (DIRD) groups. Hepatic tissue samples were evaluated histopathologically by semiquantitative methods. Malondialdehyde (MDA), superoxide dismutase (SOD), glutathion s-transpherase (GST), and catalase (CAT) enzyme levels were investigated in liver and kidney tissues as oxidative state parameters. Results: In Group DIR; hepatocyte degeneration, sinusoidal dilatation, pycnotic nucleus, and necrotic cells were found to be more in rat hepatic tissue; while mononuclear cell infiltration was higher in the parenchyme. MDA levels were significantly lower; but SOD levels were significantly higher in Group DIRD with regard to Group DIR. In the IRI induced diabetic rats’ hepatic and nephrotic tissues MDA levels, showing oxidative injury, were found to be lower. SOD levels, showing early antioxidant activity, were higher. Conclusion: The enzymatic findings of our study together with the hepatic histopathology indicate that dexmedetomidine has a potential role to decrease IRI. Key words: Hepatic ischemia reperfusion injury; Diabetes mellitus; Dexmedetomidine; Rat; MDA; SOD Citation: Sezen SC, Işık B, Bilge M, Arslan M, Çomu FM, Öztürk L, Kesimci E, Kavutçu M. Effect of dexmedetomidine on ischemia-reperfusion injury of liver and kidney tissues in experimental diabetes and hepatic ischemia-reperfusion injury induced rats. Anaesth Pain & Intensive Care 2016;20(2):143-149 Received: 21 November 2015; Reviewed: 10, 24 December 2015, 9, 10 June 2016; Corrected: 12 December 2015; Accepted: 10 June 2016 INTRODUCTİON Perioperative acute tissue injury induced by ischemia-reperfusion is a comman clinical event caused by reduced blood supply to the tissue being compromised during major surgery. Ischemia leads to cellular injury by depleting cellular energy deposits and resulting in accumulation of toxic metabolites. The reperfusion of tissues that have remained in ischemic conditions causes even more damage.1 Furthermore hepatic ischemia-reperfusion injury (IRI) demonstrates a strong relationship with peri-operative acute kidney injury.2 The etiology of diabetic complications is strongly associated with increased oxidative stress (OS). Diabetic patients are known to have a high risk of developing OS or IRI which results with tissue failure.3 The most important role in ischemia and reperfusion is played by free oxygen radicals.1 In diabetes, characterized by hyperglycemia, even more free oxygen radicals are produced due to oxidation of glucose and glycosylation of proteins.3 The structures which are most sensitive to free oxygen radicals in the cells are membrane lipids, proteins, nucleic acids and deoxyribonucleic acids.1 It has been reported that endogenous antioxidant enzymes [superoxide dismutase (SOD), glutathion s-transpherase (GST), catalase (CAT)] play an important role to alleviate IRI.4-8 Also some pharmacological agents have certain effects on IRI.1 The anesthetic agents influence endogenous antioxidant systems and free oxygen radical formation.9-12 Dexmedetomidine is a selective α-2 adrenoceptor agonist agent. It has been described as a useful and safe adjunct in many clinical applications. It has been found that it may increase urine output by considerably redistributing cardiac output, inhibiting vasopressin secretion and maintaining renal blood flow and glomerular filtration. Previous studies demonstrated that dexmedetomidine provides protection against renal, focal cerebral, cardiac, testicular, and tourniquet-induced IRI.13-18 Arslan et al observed that dexmedetomidine protected against lipid peroxidation and cellular membrane alterations in hepatic IRI, when given before induction of ischemia.17 Si et al18 demonstrated that dexmedetomidine treatment results in a partial but significant attenuation of renal demage induced by IRI through the inactivation of JAK/STAT signaling pathway in an in vivo model. The efficacy of the dexmedetomidine for IRI in diabetic patient is not resarched yet. The purpose of this experimental study was to evaluate the biochemical and histological effects of dexmedetomidine on hepatic IRI in diabetic rat’s hepatic and renal tissue. METHODOLOGY Animals and Experimental Protocol: This study was conducted in the Physiology Laboratory of Kirikkale University upon the consent of the Experimental Animals Ethics Committee of Kirikkale University. All of the procedures were performed according to the accepted standards of the Guide for the Care and Use of Laboratory Animals. In the study, 28 male Wistar Albino rats, weighing between 250 and 300 g, raised under the same environmental conditions, were used. The rats were kept under 20-21 oC at cycles of 12-hour daylight and 12-hour darkness and had free access to food until 2 hours before the anesthesia procedure. The animals were randomly separated into four groups, each containing 7 rats. Diabetes was induced by a single intraperitoneal injection of streptozotocin (Sigma Chemical, St. Louis, MO, USA) at a dose of 65 mg/kg body weight. The blood glucose levels were measured at 72 hrs following this injection. Rats were classified as diabetic if their fasting blood glucose (FBG) levels exceeded 250 mg/dl, and only animals with FBGs of > 250 mg/dl were included in the diabetic groups (dia­betes only, diabetes plus ischemia-reperfusion and diabetes plus dexmedetomidine-ischemia-reperfusion). The rats were kept alive 4 weeks after streptozotocin injection to allow development of chronic dia­betes before they were exposed to ischemia-reperfusion.(19) The rats were weighed before the study. Rats were anesthetized with intraperitoneal ketamine 100 mg/kg. The chest and abdomen were shaved and each animal was fixed in a supine position on the operating table. The abdomen was cleaned with 1% polyvinyl iodine and when dry, the operating field was covered with a sterile drape and median laparotomy was performed. There were four experimental groups (Group C (sham-control; n = 7), (Group DC (diabetes-sham-control; n = 7), Group DIR (diabetes-ischemia-reperfusion; n = 7), and Group DIRD (diabetes-ischemia-reperfusion-dexmedetomidine; n = 7). Sham operation was performed on the rats in Group C and Group DC. The sham operation consisted of mobilization of the hepatic pedicle only. The rats in this group were sacrificed 90 min after the procedure. Hepatic I/R injury was induced in Groups DIR and DIRD respectively with hepatic pedicle clamping using a vascular clamp as in the previous study of Arslan et al.(17) After an ischemic period of 45 min, the vascular clamp was removed. A reperfusion period was maintained for 45 min. In Group DIRD, dexmedetomidine hydrochloride 100 μg/kg, (Precedex 100 μg/2 ml, Abbott®, Abbott Laboratory, North Chicago, Illinois, USA) was administrated via intraperitoneal route 30 minutes before surgery. All the rats were given ketamine 100 mg/kg intraperitoneally and intracardiac blood samples were obtained. Preserving the tissue integrity by avoiding trauma, liver and renal biopsy samples were obtained. Biochemical Analysis: The liver and renal tissues were first washed with cold deionized water to discard blood contamination and then homogenized in a homogenizer. Measurements on cell contest require an initial preparation of the tissues. The preparation procedure may involve grinding of the tissue in a ground glass tissue blender using a rotor driven by a simple electric motor. The homogenizer as a tissue blender similar to the typical kitchen blender is used to emulsify and pulverize the tissue (Heidolph Instruments GMBH & CO KGDiax 900 Germany®) at 1000 U for about 3 min. After centrifugation at 10,000 g for about 60 min, the upper clear layer was taken. MDA levels were determined using the method of Van Ye et al,(20) based on the reaction of MDA with thiobarbituric acid (TBA). In the TBA test reaction, MDA and TBA react in acid pH to form a pink pigment with an absorption maximum at 532 nm. Arbitrary values obtained were compared with a series of standard solutions (1,1,3,3-tetraethoxypropane). Results were expressed as nmol/mg.protein. Part of the homogenate was extracted in ethanol/chloroform mixture (5/3 v/v) to discard the lipid fraction, which caused interferences in the activity measurements of T-SOD, CAT and GST activities. After centrifugation at 10.000 x g for 60 min, the upper clear layer was removed and used for the T-SOD, CAT, GST enzyme activity measurement by methods as described by Durak et al21, Aebi22 and Habig et al23 respectively. One unit of SOD activity was defined as the enzyme protein amount causing 50% inhibition in NBTH2 reduction rate and result were expressed in U/mg protein. The CAT activity method is based on the measurement of absorbance decrease due to H2O2 consumption at 240 nm. The GST activity method is based on the measurement of absorbance changes at 340 nm due to formation of GSH-CDNB complex. Histological determinations: Semiquantitative evaluation technique used by Abdel-Wahhab et al(24) was applied for interpreting the structural changes investigated in hepatic tissues of control and research groups. According to this, (-) (negative point) represents no structural change, while (+) (one positive point) represents mild, (++) (two positive points) medium and (+++) (three positive points) represents severe structural changes. Statistical analysis: The Statistical Package for the Social Sciences (SPSS, Chicago, IL, USA) 20.0 softwre was used for the statistical analysis. Variations in oxidative state parameters, and histopathological examination between study groups were assessed using the Kruskal-Wallis test. The Bonferroni-adjusted Mann-Whitney U-test was used after significant Kruskal-Wallis to determine which groups differed from the others. Results were expressed as mean ± standard deviation (Mean ± SD). Statistical significance was set at a p value < 0.05 for all analyses. RESULTS There was statistically significant difference observed between the groups with respect to findings from the histological changes in the rat liver tissue (hepatocyte degeneration, sinüsoidal dilatation, pycnotic nucleus, prenecrotic cell) determined by light microscopy according to semiquantitative evaluation techniques (p < 0.0001). In Group DIR, hepatocyte degeneration was significantly high compared to Group C, Group DC and Group DIRD (p < 0.0001, p < 0.0001, p = 0.002, respectively), (Table 1, Figure 1-4). Similarly, sinüsoidal dilatation was significantly higher in Group DIR (p < 0.0001, p = 0.004, p = 0.015, respectively). Although, pcynotic nucleus was decreased in Group DIRD, it did not make a significant difference in comparison to Group DIR (p = 0.053), (Table 1, Figure 1-4). The prenecrotic cells were significantly increased in Group DIR, with respect to Group C, Group DC and Group DIRD (p < 0.0001, p = 0.004, p < 0.0001, respectively), (Table 1, Figure 1-4). Table 1. The comparison of histological changes in rat hepatic tissue [Mean ± SD)] p**: Statistical significance was set at a p value < 0.05 for Kruskal-Wallis test *p < 0.05: When compared with Group DIR Figure 1: Light microscopic view of hepatic tissue of Group C (control). VC: vena centralis, *: sinusoids. ®: hepatocytes, k: Kupffer cells, G: glycogen granules, mc: minimal cellular changes, Hematoxilen & Eosin x 40 Figure 2: Light-microscopic view of hepatic tissue of Group DC (diabetes mellitus control) (G: Glycogen granules increased in number, (VC: vena centralis, *:sinusoids. ®:hepatocytes, k:Kupffer cells, G: glycogen granules, mc: minimal cellular changes; Hematoxylin & Eosin x 40) Figure 3: Light-microscopic view of hepatic tissue of Group DIR (Diabetes Mellitus and ischemia-reperfusion) (VC: vena centralis, (H) degenerative and hydrophic hepatocytes, (dej) vena centralis degeneration (centrolobar injury) (*): sinusoid dilatation. (←) pycnotic and hyperchromatic nuclei, MNL: mononuclear cell infiltration, (¯) congestion, K: Kupffer cell hyperplasia, (­) vacuolar degeneration (Hematoxylin & Eosin x 40) Figure 4: Light-microscopic view of hepatic tissue of Group DIRD (Diabetes Mellitus and ischemia-reperfusion together with dexmedetomidine applied group) (VC: vena centralis, (MNL) mononuclear cell infiltration, (dej) hydrophilic degeneration in hepatocytes around vena centralis, (conj) congestion, G: glycogen granules, (←) pycnotic and hyperchromatic nuclei, sinusoid dilatation (*) (Hematoxylin & Eosin x 40) Besides, in liver tissue parenchyma, MN cellular infiltration was a light microscopic finding; and showed significant changes among the groups (p < 0.0001). This was significantly higher in Group DIR, compared to Group C, DC, and DIRD (p < 0.0001, p=0.007, p = 0.007, respectively), (Table 1, Figure 1-4). The enzymatic activity of MDA, SOD and GST in hepatic tissues showed significant differences among the groups [(p = 0.019), (p = 0.034). (p = 0.008) respectively]. MDA enzyme activity was significantly incresed in Group DIR, according to Group C and Group DIRD (p = 0.011, p = 0.016, respectively), (Table 2). In Group DIR SOD enzyme activity was lower with respect to Group C and Group DIRD (p = 0.010, p = 0.038, respectively), (Table 2). The GST enzyme activity was significantly higher in Group DIR, when compared to Group C, DC and DIRD (p = 0.007, p = 0.038, p = 0.039, respectively), (Table 2). Table 2. Oxidative state parameters in rat hepatic tissue [Mean ± SD] p**: Statistical significance was set at a p value < 0.05 for Kruskal-Wallis test *p < 0.05: When compared with Group DIR The enzymatic activity of MDA, SOD in renal tissues, showed significant differences among the groups [(p < 0.0001), (p = 0.008) respectively ]. MDA enzyme activity was significantly incresed in Group DIR, according to Group C and Group DIRD (p < 0.0001, p < 0.0001, respectively). Also MDA enzyme activity level was significantly increased in Group DC, in comparison to Group C and Group DIRD (p = 0.003, p = 0.001, respectively), (Table 3). In Group DIR SOD enzyme activity was lower with respect to Group C and Group DIRD (p = 0.032, p = 0.013, respectively), (Table 3). The GST enzyme activity was significantly higher in Group DIR than the other three groups, however; CAT levels were similar among the groups (Table 3). Table 3: Oxidative state parameters in rat nephrotic tissue [Mean ± SD)] p**: Statistical significance was set at a p value < 0.05 for Kruskal-Wallis test *p < 0.05: When compared with Group DIR DISCUSSION In this study, we have reported the protective effect of dexmedetomidine in experimental hepatic and renal IRI model in the rat by investigating the MDA and SOD levels biochemically. Besides, hepatic histopathological findings also supported our report. Ischemic damage may occur with trauma, hemorrhagic shock, and some surgical interventions, mainly hepatic and renal resections. Reperfusion following ischemia results in even more injury than ischemia itself. IRI is an inflammatory response accompanied by free radical formation, leucocyte migration and activation, sinusoidal endothelial cellular damage, deteoriated microcirculation and coagulation and complement system activation.1 We also detected injury in hepatic and renal tissue caused by reperfusion following ischemia in liver. Experimental and clinical evidence indicates that OS is involved in both the pathogenesis and the complications of diabetes mellitus.25,26 Diabetes mellitus is a serious risk factor for the development of renal and cardiovascular disease. It is also related to fatty changes in the liver.27 Diabetes-related organ damage seems to be the result of multiple mechanisms. Diabetes has been associated with increased free radical reactions and oxidant tissue damage in STZ-induced diabetic rats and also in patients.26Oxidative stress has been implicated in the destruction of pancreatic β-cells28 and could largely contribute to the oxidant tissue damage associated with chronic hyperglycemia.29 A number of reports have shown that antioxidants can attenuate the complications of diabetes in patients30 and in experimental models.28,31 This study demonstrated that diabetes causes a tendency to increase the IRI. There is a lot of investigations related to the pharmacological agents or food supplements applied for decreasing OS and IRI. Antioxidant agents paly an important role in IRI by effecting antioxidant system or lessening the formation of ROS. It has been reported that anesthetic agents too, are effective in oxidative stress.1 During surgical interventions, it seems rational to get benefit from anesthetic agents in prevention of OS caused by IRI instead of using other agents. It has been declared that; dexmedetomidine; as an α-2 agonist with sedative, hypnotic properties; is important in prevention of renal, focal, cerebral, cardiac, testicular and tourniquet-induced IRI.13-18 On the other hand Bostankolu et al. concluded that dexmedetomidine did not have an additional protective role for tournique induced IRI during routine general anesthesia.32 In this study; we have shown that dexmedetomidine has a reducing effect in IRI in diabetic rats. Some biochemical tests and histopathological evaluations are applied for bringing up oxidative stress and IRI in the tissues. Reactive oxygen species (ROS) that appear with reperfusion injury damage cellular structures through the process of the lipid peroxidation of cellular membranes and yield toxic metabolites such as MDA.33 As an important intermidiate product in lipid peroxidation, MDA is used as a sensitive marker of IRI.34 ROS-induced tissue injury is triggered by various defense mechanisms.35 The first defence mechanisms include the antioxidant enzymes of SOD, CAT, and GPx. These endogenous antioxidants are the first lines of defence against oxidative stres and act by scavenging potentially damaging free radical moieties.36 There is a balance between ROS and the scavenging capacity of antioxidant enzymes.1-8 In this study, for evaluation of oxidative damage and antioxidant activity, MDS, SOD, GST and CAT levels were determined in liver and kidney tissues. MDA levels in hepatic and renal tissues were higher in Group DIR compared to Group C and Group DIRD. GST levels were higher in Group DIR compared to all the other three groups. When the groups were arranged from highest to lowest order, with respect to CAT levels, the order was; Group DIR, Group DIRD, Group DC and Group C. However, the difference was not significant. The acute phase reactant MDA, as a marker of OS, was found to be high in Group DIR and low in Group DIRD. This could be interpreted as the presence of protective effect of dexmedetomidine in IRI. IRI developing in splanchnic area causes injury also in the other organs.35 Leithead et al showed that clinically significant hepatic IRI demonstrates a strong relationship with peri-operative acute kidney injury.2 In our experimental research that showed correlation to that of research by Leithead et al. After hepatic IRI in diabetic rats renal OS marker MDA levels were significantly more in Group DIR than Group DIRD. In our study, we observed histopathological changes in the ischemic liver tissue and alterations in the level of MDA, SOD, GST and CAT levels which are OS markers. Histopathological changes of the liver tissues are hepatocyt degeneration, sinusoidal dilatation, nuclear picnosis, celluler necrosis, mononuclear cell infiltrationat paranchimal tissue. These histopathological injury scores were significantly lower in the Group DIRD than those in group DIR. LIMITATION Study limitation is there was no negative control group, as this type of surgical intervention is not possible in rats without anesthesia. CONCLUSION The enzymatic findings of our study together with the hepatic histopathology indicate that dexmedetomidine has a potential role to decrease ischemia-reperfusion injury. Conflict of interest and funding: The authors have not received any funding or benefits from industry or elsewhere to conduct this study. 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