Budlein A methylacrylate demonstrates potent activity against triple-negative breast cancer by targeting IκBα kinase and exportin-1.

Triple-negative breast cancer (TNBC) remains the most challenging breast cancer subtype to treat because there are no targeted therapies. Currently, chemotherapy is the only clinical option for TNBC despite development of resistance. New therapeutic agents with unique mechanisms of action are urgently needed; therefore, this study investigated the potential anti-TNBC effects of budlein A methylacrylate (BAM), a natural sesquiterpene lactone isolated from plants of the Helianthus genus. We discovered that BAM selectively suppressed and induced apoptosis TNBC cell growth versus other breast cancer or normal mammary epithelial cells. Mechanistically, BAM co-inhibited inhibitor of nuclear factor κBα (IκBα) kinase subunit ß (IKKß) and exportin-1 (XPO-1; chromosome region maintenance 1, CRM1), which are two dysregulated onco-related proteins in TNBC cells, by covalently modifying key functional cysteine residues (Cys179 of IKKß, Cys528 of XPO-1). Dual inhibition led to the stabilization and nuclear retention of IκBα, impairment of NF-κB transcriptional activity, and consequent induction of TNBC cell apoptosis. In conclusion, this study provides evidence that co-inhibition of IKKß and XPO-1 by BAM was effective against TNBC, demonstrating it as a representative new generation inhibitor with potential for TNBC treatment.

Dimethylaminododecyl methacrylate inhibits Candida albicans and oropharyngeal candidiasis in a pH-dependent manner.

The prevalence of stomatitis, especially that caused by Candida albicans, has highlighted the need for new antifungal agents. We previously found that a type of quaternary ammonium salts, dimethylaminododecyl methacrylate (DMADDM), incorporated in dental materials inhibited the growth and hyphal development of C. albicans. However, how the quaternary ammonium salts inhibited the fungal pathogens and whether the oral condition, such as salivary pH variation under different diseases, can affect the antimicrobial capacity of quaternary ammonium salts is unknown. This study evaluated the antifungal effects of DMADDM at different pH in vitro and in vivo. A pH-dependent antifungal effect of DMADDM was observed in planktonic and biofilm growth. DMADDM enhanced antifungal activity at alkaline pH. Two pH-regulated genes (PHR1/PHR2) of C. albicans were correlated with the pH-dependent antifungal effects of DMADDM. The PHR1/PHR2 genes and pH values regulated the zeta potential of C. albicans, which then influenced the binding between C. albicans cells and DMADDM. The pH-dependent antifungal activity of DMADDM was then substantiated in a murine oropharyngeal candidiasis model. We directly demonstrated that the antifungal abilities of quaternary ammonium salts relied on the cell zeta potential which affected the binding between fungal cells and quaternary ammonium salts. These findings suggest a new antifungal mechanism of quaternary ammonium under different pH and that DMADDM can be a potential antifungal agent applied in dental materials and stomatitis therapy.Key Points • DMADDM has stronger antifungal activity in alkaline than in acidic pH conditions. • The pH values and pH-regulated genes can affect the zeta potential of fungal cells. • Zeta potential of fungal cells directly affect the binding between DMADDM and cells. Graphical abstract Schematic diagram of the antifungal activities of DMADDM at different pH values.

The effect of adipose-derived stem cells on enthesis healing after repair of acute and chronic massive rotator cuff tears in rats.

BACKGROUND: Chronic massive rotator cuff tears heal poorly and often retear. This study investigated the effect of adipose-derived stem cells (ADSCs) and transforming growth factor-ß3 (TGF-ß3) delivered in 1 of 2 hydrogels (fibrin or gelatin methacrylate [GelMA]) on enthesis healing after repair of acute or chronic massive rotator cuff tears in rats. METHODS: Adult male Lewis rats underwent bilateral transection of the supraspinatus and infraspinatus tendons with intramuscular injection of botulinum toxin A (n = 48 rats). After 8 weeks, animals received 1 of 8 interventions (n = 12 shoulders/group): (1) no repair, (2) repair only, or repair augmented with (3) fibrin, (4) GelMA, (5) fibrin + ADSCs, (6) GelMA + ADSCs, (7) fibrin + ADSCs + TGF-ß3, or (8) GelMA + ADSCs + TGF-ß3. An equal number of animals underwent acute tendon transection and immediate application of 1 of 8 interventions. Enthesis healing was evaluated 4 weeks after the repair by microcomputed tomography, histology, and mechanical testing. RESULTS: Increased bone loss and reduced structural properties were seen in chronic compared with acute tears. Bone mineral density of the proximal humerus was higher in repairs of chronic tears augmented with fibrin + ADSCs and GelMA + ADSCs than in unrepaired chronic tears. Similar improvement was not seen in acute tears. No intervention enhanced histologic appearance or structural properties in acute or chronic tears. CONCLUSIONS: Surgical repair augmented with ADSCs may provide more benefit in chronic tears compared with acute tears, although there was no added benefit to supplementing ADSCs with TGF-ß3.

Efficiency of Lasers and a Desensitizer Agent on Dentin Hypersensitivity Treatment: A Clinical Study.

AIM: The aim of this clinical study was to determine and compare the efficiency of the glutaraldehyde-containing agent (GCA), Nd:YAG, Er,Cr:YSGG lasers, and the combination of them on the dentin hypersensitivity (DH) treatment. SUBJECTS AND METHODS: This study was performed with the participation of 17 healthy adult patients having 100 teeth with DH; the patients were randomly divided into five groups according to the treatment protocol: (1) application of GCA on sensitive teeth, (2) Nd:YAG laser (1 W/cm2, 10 Hz) irradiation on sensitive teeth, (3) application of GCA on sensitive teeth and then Nd:YAG laser irradiation, (4) Er,Cr:YSGG laser (0.25 W/cm2, 20 Hz) irradiation on sensitive teeth, (5) application of GCA on sensitive teeth and then Er,Cr:YSGG laser irradiation. Sensitivity levels were assessed by the Yeaple probe on the buccal surfaces of the teeth at a force setting of 10 g. Measurements were performed for 30 min, after 7, 90, and 180 days of the therapy to assess the effects of desensitization. The evaluations were analyzed using the one-way analysis of variance and repeated measurement test (P < 0.05). RESULTS: After sessions, DH was significantly reduced in all groups at each measurement point. The Er,Cr:YSGG laser with or without GCA application were the most effective ones in DH treatment (P < 0.05). Comparison of the treatment regimens demonstrated that the scores achieved with the Yeaple probe were not significantly higher for the Nd:YAG laser groups than the GCA alone group. CONCLUSIONS: This clinical study shows that the Er,Cr:YSGG laser have promising potential for the treatment of DH.

Multifunctional hetero-nanostructures of hydroxyl-rich polycation wrapped cellulose-gold hybrids for combined cancer therapy.

The development of new hetero-nanostructures for multifunctional applications in cancer therapy has attracted widespread attention. In this work, we put forward a facile approach to synthesize multifunctional hetero-nanostructures of cellulose nanocrystal (CNC)-gold nanoparticle hybrids wrapped with low-toxic hydroxyl-rich polycations to integrate versatile functions for effective cancer therapy. Biocompatible CNCs with the superior rod-like morphology for high cellular uptake were employed as substrates to flexibly load spherical gold nanoparticles (Au NPs) or gold nanorods (Au NRs) through gold-thiolate bonds, producing hetero-layered nanohybrids of CNC-Au NPs or CNC-Au NRs. Profound hydroxyl-rich cationic gene carrier, CD-PGEA (comprising ß-cyclodextrin cores and ethanolamine-functionalized poly(glycidyl methacrylate) arms), was then assembled onto the surface of CNC-Au nanohybrids through host-guest interaction and gold-thiolate bonds, where PEG was employed as the intermediate and spacer. The resultant CNC-Au-PGEA hetero-nanostructures exhibited excellent performances as gene carriers. Furthermore, CNC-Au NR-PGEA comprising Au NRs demonstrated favorable optical absorption properties and were validated for photoacoustic imaging and combined photothermal/gene therapy with considerable antitumor effects. The present work provided a flexible strategy for the construction of new multifunctional hetero-nanostructures with high antitumor efficacy.

Evaluation of different treatment protocols for dentin hypersensitivity: an 18-month randomized clinical trial.

This randomized and longitudinal in vivo study aimed to assess different protocols for the treatment of dentin hypersensitivity with low-power laser (with different doses), high-power laser, and a desensitizing agent, for a period of 12 and 18 months. The lesions from 32 patients (117 lesions), who were submitted to the inclusion and exclusion criteria, were divided into nine groups (n = 13): G1: Gluma Desensitizer (Heraeus Kulzer), G2: low-power laser with low dose (three points of irradiation in vestibular portion and an apical point 30 mW, 10 J/cm2, 9 s per point with the wavelength of 810 nm, with three sessions with an interval of 72 h), G3: low-power laser with high dose (one point in the cervical area, and one apical point 100 mW, 40 J/cm2, 11 s per point with the wavelength of 810 nm in three sessions with an interval of 72 h), G4: low-power laser with low dose + Gluma Desensitizer, G5: low-power laser with high dose + Gluma Desensitizer, G6: Nd:YAG laser (Power Laser™ ST6, Research® in contact 1.0 W, 10 Hz and 100 mJ, ≈85 J/cm2, with the wavelength of 1064 nm), G7: Nd:YAG laser + Gluma Desensitizer, G8: low-power laser with low dose + Nd:YAG laser, and G9: low-power laser with high dose + Nd:YAG laser. The level of sensitivity of each volunteer was assessed by visual analog scale of pain (VAS) with the aid of air from the triple syringe and exploration probe, 12 and 18 months after treatment. All analyses were performed separately for air and probe stimulus. The level of significance was considered for values of p < 0.05. After statistical analysis, all treatments were shown to be effective in reducing dentinal hypersensitivity, and the results were considered not statistically different from those at 12 months. Therefore, until the 18-month evaluation, it could be said that no statistical differences were observed in the sensitivity levels for all treatments.

Evaluation of the bond strengths of 3 endodontic cements via push-out test.

In this study, the push-out method was used to evaluate the bond strengths of 3 types of endodontic cements according to their composite base: methacrylate, epoxy resin, and an experimental copaiba oil resin. The study hypothesis was that the methacrylate-based and experimental cements would have bond strengths equal to or greater than that of the epoxy resin-based cement. Thirty bovine tooth roots, 18 mm long, were divided into 3 groups (n = 10) based on the chosen cement treatment. After treatment, the specimens were sectioned and submitted to a push-out test. Results showed that there was no statistically significant difference (P < 0.05) between the cements used or between the middle and apical thirds of the roots. It could be concluded that the tested cements had satisfactory and similar bond strengths to dentin.

In vitro and in vivo evaluation of the effectiveness of three dentin desensitizing treatment regimens.

PURPOSE: To evaluate the in vitro and in vivo effects of three treatment regimens on dentin permeability and reduction of dentin hypersensitivity (DH). METHODS: The desensitization treatments were: Gluma Desensitizer PowerGel (GLU), MS Coat One (MSC), and dentin burnishing with fiber-resin burs (STB). A split-chamber device was used to determine the permeability of dentin slices cut from human molars in vitro. Fluid flow through dentin was recorded with a photochemical method after EDTA cleaning, albumin soaking and desensitization treatment (n = 10). 61 study participants with three severely hypersensitive teeth each were enrolled. Sensitivity was determined with an air stimulus before, immediately after treatment, and after 1, 3 and 6 months, using a verbal rating scale. RESULTS: From the 61 study participants enrolled, 52 completed the trial. Permeability at baseline and after albumin soaking was not significantly different. All treatments produced reduced fluid flow through dentin (P > 0.05). All treatments reduced DH significantly (no or moderate sensitivity). Statistical results revealed significant differences among the treatments (P = 0.03). Mann-Whitney comparisons showed GLU, STB < MSC.

Bacterial leakage in root canals filled with AH Plus and dentine bonding agents.

OBJECTIVE: The aim of this study was to compare the efficacy of different dentine adhesives in delaying the coronal bacterial leakage of Enterococcus faecalis in filled root canals. Materials and methods. Ninety-five lower incisors of patients >65 years of age were instrumented using the ProTaper system and were irrigated with 1 mL of 2.5% sodium hypochlorite (NaOCl) alternated with 1 mL 17% EDTA between each file change. Final irrigation was performed with 5 mL of 17% EDTA and then flushed with 5 mL of distilled water. The teeth were randomly divided into five experimental groups (n = 15/group) and one of the following dentine adhesives was applied: (1) AdheSE; (2) Excite DSC; (3) Clearfil Protect Bond; (4) One Coat 7.0; or (5) Control group without adhesive. After filling the root canals, the samples were mounted on a double chamber device to evaluate the bacterial filtration of E. faecalis during a period of 240 days. The results underwent non-parametric Kaplan-Meier survival analysis and comparisons among groups were done using the Log-Rank test. RESULTS: At 240 days, E. faecalis was detected in samples of all groups in the lower chamber. The highest survival value was obtained by One Coat 7.0, giving statistically significant differences from the other groups, whereas Clearfil Protect Bond, AdheSE and Excite DSC showed similar behaviours, likewise similar to the Control group. CONCLUSIONS: One Coat 7.0 adhesive system provides the longest survival value to delay E. faecalis coronal leakage in filled root canals.

Effect of different irrigation protocols on the radicular dentin interface and bond strength with a metacrylate-based endodontic sealer.

This study assessed the influence of different endodontic chemical substances on the adhesion of the Epiphany SE/Resilon system (with and without resinous solvent) to radicular dentin walls, using the push-out test and scanning electron microscopy (SEM). Forty-eight root canals of human canines were prepared biomechanically with ProTaper rotary files (crown-down technique) and the radicular dentin was treated with either 17% EDTA, 2% chlorhexidine gel (CHX) or 2.5% NaOCl (control). The root canals were filled with Resilon cones and Epiphany SE sealer with and without resinous solvent. Six groups of eight canals each had their roots sectioned transversally to obtain 1-mm thick slices. Data were subjected to statistical analysis by ANOVA and Tukey's tests. The specimens treated with 17% EDTA (1.59 ± 0.91) presented higher bond strength (P < 0.05) than those treated with 2.5% NaOCl (0.93 ± 0.27) and 2% CHX (0.92 ± 0.22). Significantly higher bond strength (P < 0.05) was observed when the Epiphany SE was prepared with (1.37 ± 0.78) than without (0.92 ± 0.33) solvent. Adhesive failures were predominant in all groups. SEM analysis showed greater homogeneity of the filling mass when the solvent was added to the sealer. Treatment of root canal walls with 17% EDTA, and addition of a resinous solvent to Epiphany SE produced the highest adhesion to radicular dentin.

Percentage exposure of root dentin collagen after application of two irrigation protocols with manual or rotary instrumentation and two methacrylate resin-based sealers.

PURPOSE: To compare the percentage of collagen exposed in dentin root thirds after two irrigation protocols with manual or rotary instrumentation using two methacrylate resin-based sealers. MATERIALS AND METHODS: Forty-eight single-root human teeth were prepared with manual (n = 24) or nickeltitanium ProFile rotary (n = 24) instrumentation, using 5% NaOCl between instruments and 5 ml 17% EDTA as final irrigant or 20% citric acid + 2% chlorhexidine (CHX) between instruments and as the final irrigant. RealSeal or EndoREZ were used as filling materials. One 1-mm slice per third was abraded and stained with Masson's trichrome method. Mean exposed collagen values were obtained in four areas from each section (at 60X magnification) and a complete factorial ANOVA was used to analyze the influence of the study variables. Non-parametric Mann-Whitney's test was used to compare groups. Differences with p < 0.05 were considered significant. RESULTS: A significantly higher percentage of collagen was exposed in all thirds with the use of the 20% citric acid + 2% CHX protocol with rotary vs manual instrumentation, but percent collagen exposed did not differ as a function of the filling material. After the 5% NaOCl + 17% EDTA protocol, the percentage of collagen exposed did not differ between rotary and manual instrumentation but was higher with the use of RealSeal. CONCLUSION: The highest percentage exposure of collagen was with 20% citric acid + 2% CHX using rotary instrumentation, regardless of the filling material.

Resistance to vertical root fracture of endodontically treated teeth with MetaSEAL.

INTRODUCTION: The purpose of this in vitro study was to assess the influence of MetaSEAL and AH Plus on the resistance to vertical root fracture of endodontically treated teeth when either the matched-taper single-cone or lateral condensation technique was used. METHODS: Ninety extracted single-canal mandibular premolar teeth were sectioned, leaving a standard root length of 13 mm. The buccolingual and mesiodistal diameters were measured, and the teeth were randomly divided into 6 groups (n = 15). There were no statistically significant differences between the groups in terms of the diameters. In group 1, no instrumentation or obturation was performed. The rest of the roots were chemomechanically prepared with nickel-titanium ProTaper rotary instruments up to size F3 at the working length. Group 2 was left unobturated. Groups 3 and 4 were obturated with AH Plus used with the matched-taper single-cone and lateral condensation techniques, respectively. In groups 5 and 6, MetaSEAL was used instead of AH Plus. All of the roots were mounted vertically in self-curing acrylic resin blocks that exposed 8 mm of the coronal part. Then the roots were subjected to a vertical loading force (1 mm/min). The force required to produce a fracture was recorded in newtons. The data were analyzed by using Kruskal-Wallis and post hoc Dunn multiple comparison tests (P < .05). RESULTS: Although we did not detect statistical significance, there was a substantial difference between the fracture resistance values of the intact and instrumented but not obturated roots. The groups in which AH Plus and MetaSEAL were used with the matched-taper single-cone technique showed significantly higher fracture resistance values than the instrumented but not obturated roots (P < .05). There were no significant differences between the groups submitted to the matched-taper single-cone technique. The force required to fracture the roots in the group treated with AH Plus and the lateral condensation technique was similar to that required to fracture intact roots, whereas the group treated with MetaSEAL and the lateral condensation technique revealed comparable values to the instrumented but not obturated roots. CONCLUSIONS: When used with the matched-taper single-cone technique, MetaSEAL and AH Plus have the potential to reinforce endodontically treated teeth.

Preclinical effectiveness of a novel pulp capping material.

INTRODUCTION: The purpose of this study was to evaluate the direct pulp capping response to a novel resin-based calcium phosphate cement (RCPC). METHODS: The RCPC was placed in contact with the exposed healthy pulps of dog teeth and in a follow-up study on the healthy or inflamed pulps of ferret teeth. The inflamed ferret teeth had reversible pulpitis induced with Salmonella typhimurium lipopolysaccharides. After direct pulp capping with RCPC or visible light-curing resin-modified calcium hydroxide material (VLCCH) as a control, the restorations were bonded using a composite resin. The pulp responses and dentin repair were evaluated histologically in dog teeth after 7, 28, or 90 days and in ferret teeth after 45 days. RESULTS: Most of the RCPC-treated healthy pulps and 75% of the RCPC-treated inflamed ferret teeth had dentin healing and repair, whereas those teeth treated with VLCCH had minimal healing and dentin repair. CONCLUSIONS: The direct pulp capping of ferret and dog teeth with RCPC was associated with superior healing in comparison to VLCCH.

Evaluation of dentinal tubule penetration after the use of dentin bonding agent as a root canal sealer.

INTRODUCTION: The purpose of this study was to compare the effectiveness of Excite DSC (Ivoclar Vivadent, Schaan, Liechtenstein), a dentin bonding agent, with AH-26 (Dentsply, Detrey, Germany) as a root canal sealer by evaluating the penetration depth into the dentinal tubules and the tag density of the two compounds. METHODS: Forty-two extracted, single-rooted premolars were prepared and randomly obturated with either Excite DSC (n = 20) or AH-26 (n = 20). Two teeth were filled without sealer and used as controls. Randomly, one half of the specimens in each group (n = 10) was sectioned 3 days after obturation (short-term), and the other half (n = 10) was sectioned after 3 months (long-term). The specimens were sectioned perpendicular to the long axis in two regions and prepared for observation using scanning electron microscopy. RESULTS: In the short-term evaluation, the mean penetration depth of AH-26 in the apical sections (520.48 micromol/L) was significantly higher than that of Excite DSC (0.00 micromol/L). In the long-term evaluation, AH-26 exhibited a significantly greater depth of penetration in both the apical (797.74 micromol/L) and middle sections (1162.11 micromol/L) than Excite DSC (321.43 micromol/L and 657.72 micromol/L, respectively). CONCLUSION: AH-26 showed more dentinal tubule penetration depth than Excite DSC in both evaluation periods.

Retinal artery embolization during carotid angioplasty and carotid artery stenting: case report.

A 69-year-old man presented with a rare case of retinal artery embolization, which occurred as a complication of carotid angioplasty and carotid artery stenting performed for recurrent cerebral infarction. Magnetic resonance imaging and angiography showed right internal carotid artery stenosis with ulceration. Carotid angioplasty and carotid artery stenting were performed using the distal protection system with the PercuSurge GuardWire. However, just after dilation, the patient complained of ocular pain and blurred vision on the right, which was subsequently diagnosed as retinal artery embolization. Heparin was given for 15 hours after stenting, and aspirin and ticlopidine medication were continued. The patient received hyperbaric oxygen therapy for 1 week. The patient's blurred vision gradually improved, but visual field defect remained. Debris was probably flushed into the external carotid artery, and passed through an anastomosis into the ophthalmic artery, resulting in retinal artery embolization.

High modulus nanopowder reinforced dimethacrylate matrix composites for dental cement applications.

Results from the study of a novel, high modulus nanopowder filled resin composite are presented. This composite is developed to serve (1) as a high stiffness support to all-ceramic crowns and (2) as a means of joining independently fabricated crown core and veneer layers. Nanosized Al(2)O(3) (average particle size 47 nm) reinforcement provides stiffness across joins. Two systems are examined: Al(2)O(3) with 50:50 bis-GMA:TEGDMA monomers (ALBT) and Al(2)O(3) with pure TEGDMA (ALT). To obtain higher filler levels, surfactant is used to aid mixing and increase maximum weight percent of nanopowder filler from 72 to 80. The loading level of Al(2)O(3) has significant effects on composite properties. The elastic modulus for cured ALBT systems increases from 4.6 GPa (0 wt % filler) to 29.2 GPa (80 wt % filler). The elastic modulus for cured ALT systems increases from 3.0 GPa (0 wt % filler) to 22.9 GPa (80 wt % filler). Similarly, ALBT hardness increases from 200 MPa (0% filler) to 949 MPa (80 wt % filler), and ALT hardness increases from 93 MPa (0% filler) to 760 MPa (80 wt % filler). Our results indicate that with a generally monodispersed nanosized high modulus filler relatively high elastic modulus resin based composite cements are possible.

Effect of placement of calcium sulphate when used for the repair of furcation perforations on the seal produced by a resin-based material.

AIM: To evaluate the sealing ability of calcium sulphate when used under composite resin for the repair of furcation perforations having different diameters. METHODOLOGY: Perforations of different diameter were created in the floors of pulp chambers in 60 extracted human molar teeth with either a number 3 (1 mm diameter) or 5 (1.5 mm diameter) round bur. The specimens of each group were divided into four sub-groups which were repaired with composite resin either alone or in combination with calcium sulphate that created an artificial floor (15 teeth group(-1)). Eight teeth without furcation perforations served as negative controls. In the leakage detection device, 1 mol L(-1) glucose solution was forced under a pressure of 1.5 KPa from the crown towards the pulp chamber floor. The concentration of leaked glucose was measured at 1, 2, 4, 7, 10, 15 and 20 days using a glucose oxidase method and the data evaluated using the rank sum test. RESULTS: The specimens with larger perforations repaired with composite resin alone had significantly more leakage (P < 0.05). Using calcium sulphate as an artificial floor significantly decreased leakage of smaller perforations (P < 0.05). In groups repaired with calcium sulphate under composite resin, leakage in smaller perforations was markedly lower than that in larger ones (P < 0.05). No significant difference was found between the specimens with 1 or 1.5 mm perforations repaired with resin alone (P > 0.05). CONCLUSIONS: Calcium sulphate significantly improved the sealing ability of 1 mm perforations repaired with composite resin but not for 1.5 mm perforations.

Design, synthesis, and in vivo evaluation of oxamniquine methacrylate and acrylamide prodrugs.

Oxamniquine is an antiparasitic agent commonly used in therapeutics against Schistosoma mansoni. Although it is well tolerated, some adverse effects justify the search for new compounds with prolonged biological action, so that monomeric and polymeric oxamniquine prodrugs were designed. Synthetic results assisted by molecular modeling study showed the possibility to obtain the corresponding monomeric forms of the oxamniquine methacrylate (1) and oxamniquine acrylamide (2). Successful copolymerization procedure only occurred on the methacrylic compound, generating the oxamniquine methacrylate copolymer (3). Submitted to a preliminary in vivo biological evaluation, a similar oxamniquine profile was observed to the monomeric forms although an inadequate drug release may be responsible for the methacrylic copolymer failure.

The evaluation of trifloxystrobin in protection of Calendula officinalis (Pot marigold) against Erysiphe cichoracearum DC.

The aim of the two-years field's examinations was the evaluation of the fungicide Zato 50 WG (biologically active substances BAS--trifloxystrobin 50%) in protection of Calendula officinalis (Pot marigold) against Erysiphe cichoracearum. Mentioned fungicide was applied at three concentrations: 0.1, 0.15 and 0.2%. As the standard fungicide Amistar 250 SC (biologically active substances BAS - azoxystrobin 250 g/dm3) was used. In every year of research work the four protective treatments were carried out. The estimation of infestation degree of Calendula officinalis leafs by the Erysiphe cichoracearum was made 5 times. Before each treatment four analysis were done, whereas the last analysis--the fifth one was executed after 10 days from the last protective spraying. According to the results, it was found that investigated preparations significant reduced the mean infestation degree of Calendula officinalis leafs by the Erysiphe cichoracearum compared to the control. The results pointed, that in protection of the mentioned plant by the powdery mildew the 0.2% dose of Zato 50WG showed the best suitability.

Scanning electron microscopy examination of 3 different adhesive systems.

OBJECTIVES: The aim of this study was to compare the interaction of dentin with 2 different self-etch resin bonding systems, as well as with a total-etch resin bonding system. METHOD AND MATERIALS: Nine recently extracted, unerupted third molars, roots, and occlusal thirds were used. A standardized smear layer was produced on the occlusal dentin surface exposed. The specimens were split into 3 groups of 3 specimens each, 1 group for each bonding agent: Clearfil Liner Bond 2, Prime & Bond 2.1, and Scotchbond Multipurpose (control group). After the tooth was briefly sprayed with an air/water mixture, 1 of the experimental adhesive systems was applied on the dentin surface. A 2-mm layer of composite was applied over the adhesive system layer. After 7 days in distilled water at 37 degrees C, the specimens were cross-sectioned perpendicular to the resin-dentin interface. The crosssections were mounted on aluminum stubs, etched with 2% hydrochloridric acid, and studied using scanning electron microscopy. A descriptive analysis of the images of the interdiffusion zone characteristics was done first. Afterwards, statistical analyses of the measurements of the interdiffusion zone structures-hybrid layer thickness, resin tags penetration, and adhesive layer thickness using analysis of variance, followed by "post hoc" test-were carried out to compare the bonding systems' interactions. RESULTS: The descriptive analysis of the self-etch bonding systems studied showed a good interlocking of Clearfil Liner Bond 2 with dentin, similar to Scotchbond Multipurpose and better than Prime & Bond 2.1. The analysis of variance, followed by the "post hoc" test, identified statistical differences just for the adhesive layer thickness that was thicker for Scotchbond than for Prime & Bond (P = .020). The "post hoc" test also showed a strong tendency to identify differences between the Scotchbond and the Prime & Bond groups (P = .062), and the Clearfil and the Prime & Bond groups (P = .069). CONCLUSION: Within the limitations of this study, Clearfil Liner Bond 2 produced the thickest hybrid layer with deepest tag formation and good interlocking with dentin, similar to the control. Statistical differences among the interdiffusion zone of the 3 bonding systems studied were identified just for the adhesive layer thickness, which was thicker for Scotchbond than for Prime & Bond.