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Rock art sites containing petroglyphs are found throughout the Negev Desert of southern Israel. Recently, as more sites have been revealed, there has been an increasing awareness of their importance as a cultural heritage resource. However, the rocks on which the petroglyphs were engraved are exposed to natural and anthropogenic weathering processes. In order to characterize the bacterial communities that may play a role in the weathering of rock surfaces and petroglyphs panels, we undertook culture-independent (Next Generation Sequencing technologies) and culture-dependent methods to identify the bacterial communities on these rock surfaces. The Results reveal that the most common bacterial components at two petroglyphs sites studied were Actinobacteria (33%), Cyanobacteria (30%), Proteobacteria (15%) and Bacteriodetes (7%). Further study and isolation revealed several Cyanobacteria strains related to the Oscillatoriales and Synecococcales orders. This study provides an important first step in understanding the bacterial community structure that may be associated with the weathering of petroglyphs in this region. • Petroglyphs are exposed to natural and anthropogenic weathering processes. • NGS technologies was used to analyze the rock of petroglyph's sites. • Four major phyla were found to be the most common including cyanobacteria. [ABSTRACT FROM AUTHOR]

Organosolv lignin (OL) extracted from pine wood was self-assembled into uniform nanocolloidal spheres (OLCS) in acetone/water and blended with varnish for better UV-blocking and antioxidant performance. The UV transmittance of the varnish with 1% OL was lower than that of a commercial varnish containing synthetic UVA and UVB blocker. Samples coated with OL-based varnish and UV irradiated for 100 h showed 84 and 69% less color change, respectively, compared to that of pure and commercial varnishes. Due to the higher surface area and better compatibility, the varnish blended with 1% OLCS showed better UV-blocking and photostability than those based on 1% OL additive. The color change of varnish was not perceptible. The lignin-based additives significantly enhanced the hardness and adhesion performance of the varnish and had little influence on the esthetic appearance of the samples. The hardness and modulus of elasticity of varnish increased by 61 and 36%, respectively, in the presence of 1% OLCS. The possible enhancement mechanism was explained by molecular interaction forces. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rock varnish is a thin coating enriched with manganese (Mn) and iron (Fe) oxides. The mineral composition and formation of rock varnish elicit considerable attention from geologists and microbiologists. However, limited research has been devoted to the semiconducting properties of these Fe/Mn oxides in varnish and relatively little attention is paid to the mineral–microbe interaction under sunlight. In this study, the mineral composition and the bacterial communities on varnish from the Gobi Desert in Xinjiang, China were analyzed. Results of principal components analysis and t -test indicated that more electroactive genera such as Acinetobacter , Staphylococcus , Dietzia , and Pseudomonas gathered on varnish bacterial communities than on substrate rock and surrounding soils. We then explored the culture of varnish, substrate and soil samples in media and the extracellular electron transfer (EET) between bacterial communities and mineral electrodes under light/dark conditions for the first time. Orthogonal electrochemical experiments demonstrated that the most remarkable photocurrent density of 6.1 ± 0.4 μA/cm2 was observed between varnish electrode and varnish microflora. Finally, based on Raman and 16S rRNA gene–sequencing results, coculture system of birnessite and Pseudomonas (the major Mn oxide and a common electroactive bacterium in varnish) was established to study underlying mechanism. A steadily growing photocurrent (205 μA at 100 h) under light was observed with a stable birnessite after 110 h. However, only 47 μA was generated in the dark control and birnessite was reduced to Mn2+ in 13 h, suggesting that birnessite helped deliver electrons instead of serving as an electron acceptor under light. Our study demonstrated that electroactive bacterial communities were positively correlated with Fe/Mn semiconducting minerals in varnish, and diversified EET process occurred on varnish under sunlight. Overall, these phenomena may influence bacterial–community structure in natural environments over time. [ABSTRACT FROM AUTHOR]

The use of varnishes as a final coat in graphic work fulfills an aesthetic and protective function. Over time, or due to adverse conditions, these varnishes undergo a series of degradations in their color that can distort the original appearance of the underlying work. Knowing the chromatic variations of these materials is essential for their selection as a conservation varnish. This work collects the results obtained from the colorimetric study carried out on a series of samples of paper with varnish exposing to different physical-chemical tests (humidity, immersion in water, dry heat and accelerated aging) tests that recreate adverse conditions to which this type of woks may be exposed as a consequence of its natural aging, the action of certain degradation factors or the restorative action. For this purpose, Somerset 100% cotton paper has been selected, which has been applied different varnishes of traditional use in graphic works: shellac, gum arabic, egg white, rosin and dammar. The color of these samples has been studied following the CIEL*a*b* 1976 system, calculating the colorimetric differences from the comparison between the reference samples and the samples after the physical-chemical tests. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nativa is the property of Revista Nativa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Highlights • Thermal compression – alternative method of the preparation of the wood substrate. • Adhesion strength of compressed and varnished samples is higher than of control samples. • The lacquer performed well on thermally compressed wood surfaces. Abstract The objectives of this work was to evaluate the adhesion strength of thermally compressed and varnished veneer used as overlay on medium density fibreboard (MDF) panels. Rotary cut birch veneer sheets were compressed at temperature levels of 150 °C, 180 °C and 210 °C before they were bonded MDF substrate. The varnish was applied to the surface of the samples at various layers and spread rates. Based on the findings of this study compression temperature significantly influences overall adhesion strength of the samples. Since thermal compression process resulted in uniform surface quality of both loose and tight sides no significant difference between them regarding their adhesion strength characteristics was determined. It was also determined that adhesion strength values of compressed and varnished samples had higher values than those of control samples. [ABSTRACT FROM AUTHOR]

Copyright of Acta Stomatologica Croatica is the property of Acta Stomatologica Croatica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to evaluate the fluoride release from differently formulated 5% NaF varnishes into unstimulated whole saliva in vivo. The fluoride concentration in unstimulated whole saliva was determined after the application of 3 different 5% NaF varnishes (5% NaF, 5% NaF + tricalcium phosphate [TCP], and 5% NaF + amorphous calcium phosphate [ACP]) or a placebo. Fifteen subjects were recruited and enrolled following Institutional Review Board approval based upon the inclusion/exclusion criteria of this study. A cross-over study design was used for the application of either one of the 5% NaF varnishes or a placebo. Unstimulated whole saliva was collected at baseline and at 1, 4, 6, 26, and 50 h following application and analyzed for supernatant ionic fluoride and whole fluoride by microdiffusion. Linear mixed-effects models (5% significance level) were used to determine the effects of varnish and time on the salivary fluoride concentration. The highest amount of fluoride in saliva was found 1 h after application of the fluoride varnishes, with no significant differences among the treatment varnishes with respect to whole fluoride but with lower levels for 5% NaF + ACP in the saliva supernatant. Salivary fluoride levels at 4, 6, and 26 h decreased at each time point and were generally significantly higher for 5% NaF and 5% NaF + TCP. After 50 h, fluoride levels in saliva for all groups were at or below baseline levels. In conclusion, the formulation of other ingredients in fluoride varnishes can affect the fluoride concentration in saliva. The reasons for this phenomenon warrant further investigation since it might affect efficacy of the treatment. This trial is registered at ClinicalTrials.gov (NCT01629290). [ABSTRACT FROM AUTHOR]

The tintype, a wet collodion photograph on a japanned metal support, was a popular type of photographic image in mid-nineteenth-century United States. Tintype plates consisting of a metal sheet with a protective varnish on the verso and a dark colored japanning layer on the recto were commercially available in different colors and surface textures. Although millions of plates were produced, there is little information regarding the materials used to create them. To address this lacuna, the metal supports, japanning layers, and protective verso varnishes of 226 historic tintypes were analyzed to identify the support metal, binders, and pigments. The predominant component of the japanning layers is drying oil, or drying oil with Pinaceae resin; shellac, sandarac, and camphor also occur. The verso varnishes are primarily drying oil and Pinaceae resin, and the presence of these two materials permits comparison of relative extent of oxidation and illustrates that factors other than age impact these metrics. Carbonaceous blacks and iron oxide pigments are common japanning layer pigments, but asphaltum was minimally used. Cross-sections reveal that some japanning layers are a single layer, while others contain multiple coats indicating a complex manufacturing process. The materials used and manner of coating applications differ from the contemporaneous literature and may be manufacturer dependent. [ABSTRACT FROM AUTHOR]

The in vitro study objectives were to investigate the effect of arginine (Arg) incorporation in a 5% sodium fluoride (NaF) varnish on its physical and chemical properties including F/Arg release. Six experimental formulations were prepared with L-arginine (L-Arg) and L-arginine monohydrochloride at 2%, 4%, and 8% w/v in a 5% NaF varnish, which served as a control. The varnishes were subjected to assessments for adhesion, viscosity, and NaF extraction. Molecular dynamics were simulated to identify post-dynamics total energy for NaF=Arg/Arg>NaF/Argp < 0.001). L-Arg in NaF varnish institutes the Arg-F complex. Molecular dynamics suggests that NaF>Arg concentration denotes the stabilized environment compared to NaFp < 0.001). The 2% Arg-NaF exhibits periodic perennial Arg/F release and shows significantly higher integrated mean F release than NaF (p < 0.001). Incorporating 2% L-arginine in 5% NaF varnish improves its physical properties and renders a stable matrix with enduring higher F/Arg release than control.

New amphiphilic cationic copolymers based on poly((methacryloyloxy) ethyl trimethylammonium chloride) (PMETAC) and bio-based poly(thymol methacrylate) (PTMA) were prepared by atom transfer radical polymerization (ATRP) methods, using low concentration of metal catalyst and a bio-based eutectic mixture (EM), composed of L-menthol and thymol. The antimicrobial activity of the polymers was evaluated against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) bacteria. The results in solution showed that increasing the terpenic segment (PTMA) in the copolymers resulted in lower antimicrobial activity against S. aureus (as the MIC increases from 3.1 to 100 μM) and higher activity against E. coli (as the MIC decreases from 400 to 200 μM). Scanning electron microscopy (SEM) analysis suggests that polymers affected the bacterial viability by damaging the cell structure. The synthesized biocidal polymers were used as additives in polyurethane-based varnish formulations to produce bioactive coated surfaces that were found to be more active against E. coli. Coatings containing either PTMA or PMETAC homopolymers were more efficient than those containing PMETAC- co -PTMA copolymers. A dramatic improvement in the antimicrobial activity of PMETAC-containing varnish against both S. aureus (3 orders of magnitude) and E. coli (4 orders of magnitude) was observed when an aqueous solution of the homopolymer was applied to the dried varnish instead of being incorporated into the varnish formulation. The strategy presented here is simple and opens the door for the preparation of customized bioactive surfaces to prevent bacterial infections. [Display omitted] • The presence of PTMA in copolymers led to a decrease of the antimicrobial activity for S. aures and an increase for E. coli. • The polymers synthesized not only inhibit the bacterial growth but also kill them since the MIC and MBC were the same. • Varnishes containing PMETAC homopolymer or PTMA homopolymer were more efficient than the ones with PMETAC- co -PTMA copolymers. • PTMA with the lowest MW gave a significative reduction in the number of CFU in comparison with homopolymers with higher MW. • PMETAC activity was enhanced by applying the polymer on top of the varnish layer instead of mixed in the varnish formulation. [ABSTRACT FROM AUTHOR]

Prepared test specimens were surface treated and coated with synthetic and water-based outdoor varnishes after being chemically impregnated. The test specimens were left outdoors to determine the effects of impregnation and treatment on the wood during each of the four seasons. Caucasian spruce (Picea orientalis L.) test specimens were prepared and combustion analyses were performed. As a result of the combustion test, weight loss results, as compared with the control, were 89% lower in the spring specimens, 90% lower with impregnation, and 90% lower with the synthetic varnish coating. Furthermore, the O2 amount during combustion was found to be the highest in combustion with a flame source in the winter specimens (21%). The CO2 amount was the highest in combustion without a flame source for full-year specimens (20%). The CO amount was the highest in combustion without a flame source of full-year specimens (31,787 ppm), and the NO amount was the highest during glowing of full-year specimens (55 ppm). Final results showed impregnation with Tanalith-E and water-based varnish coating to be the most effective fire protective treatments.

Mohamed A Hendaus,1,2 Hibaq A Jama,1 Faisal J Siddiqui,1,3 Sohair A Elsiddig,1 Ahmed H Alhammadi1,2 1Department of Pediatrics, General Academic Pediatrics Section, Hamad Medical Corporation, Doha, 2Department of Clinical Pediatrics, Weill Cornell Medical College, 3Pediatric Residency Program, Hamad Medical Corporation, Doha, Qatar Objective: The objective of this study was to investigate parental preference for fluoride varnish in a country where the average percentage of dental caries in young children is up to ~73%. Consequently, the aim of this study, despite being a pilot, was to create a nationwide project in the State of Qatar to promote oral health in children. Methods: A cross-sectional perspective study was conducted at Hamad Medical Corporation in Qatar. Parents of children aged ≤5 years were offered an interview survey. A total of 200 questionnaires were completed (response rate =100%). The study was conducted between December 1, 2014 and March 30, 2015, and included all children aged >1 year and 90% of families were aware that dental health affects the health of the whole body. The study showed that ~70% of parents were not aware of the existence of fluoride varnish, but would allow a health provider to apply fluoride varnish. Furthermore, ~80% of parents would not stop brushing their child’s teeth and would not skip dentist appointments if varnish was to be applied. Approximately 40% of parents conveyed some concerns regarding the safety of fluoride varnish, despite being considered as a new concept. The main concern was that the child might swallow some of the fluoride. Another important concern expressed by parents was the availability of the fluoride varnish in all clinics. Conclusion: The robust positive attitude of parents in this sample suggests that introducing fluoride varnish is feasible and acceptable in our community. Actions to augment fluoride varnish acceptability in the developing world, such as focusing on safety, could be important in the disseminated implementation of fluoride varnish. Keywords: fluoride, parents, varnish, Qatar

Aim: The aim of the present study was to evaluate the short-term clinical and microbiological effect of chlorhexidine varnish when used as an adjuvant to scaling and root planing in the treatment of chronic periodontitis. Materials and Methods: A split-mouth design was conducted in 11 patients suffering from chronic periodontitis. The control site underwent scaling and root planing, and the experimental site was additionally treated with chlorhexidine varnish application. Clinical parameters, namely, gingival index (GI), plaque index (PI), bleeding on probing (BoP), probing pocket depth (PPD), and clinical attachment level were recorded at baseline, 1 month, and 3 months postoperatively. Furthermore, microbial examination of the plaque samples was done at baseline, 1 month, and 3 months. Results: Both treatment strategies showed significant improvement in GI, PI, BoP, PPD, and clinical attachment level, at both follow-up visits by comparison with baseline levels. At study termination, chlorhexidine varnish implemented treatment strategy resulted in additional improvement in the clinical parameters, and more reduction in the total anaerobic count at 1 month and 3 months. Conclusions: These findings suggest that a chlorhexidine varnish implemented treatment strategy along with scaling and root planing may improve the clinical outcome for the treatment of chronic periodontitis in comparison to scaling and root planing alone.

Introduction: Dental caries occurs as a result of demineralization-remineralization phases occurring alternately at the tooth surface. Fluoride varnishes have a caries-inhibiting effect on teeth through remineralization. The resulting enamel is resistant to acid dissolution. Aim: The aim of this study is to assess enamel surface microhardness (SMH) following varnish application with different fluoride concentrations. Materials and Methods: Ninety freshly extracted, caries-free premolar teeth were used. Teeth were sectioned to obtain enamel blocks from the buccal surface of crown. The blocks were serially polished and flattened, embedded in acrylic blocks and smoothened to achieve a flat surface. The samples were divided into three groups, namely, A, B, and C consisting of 30 enamel blocks each. In Group A, Fluor Protector® varnish and in Group B, Bi-Fluorid 10® varnish was applied. Group C served as controls. All samples were subjected to a demineralization-remineralization cycle for 7 days. The SMH of enamel was measured. Data obtained was subjected to statistical analysis using the Student's t-test and one-way ANOVA. Results: The mean values of enamel SMH of Groups A and B were 496.99 ± 4.81 and 449.47 ± 7.37 Vickers Hardness Number, respectively. Conclusion: Fluor Protector varnish showed significantly higher enamel SMH than that of the other two groups (P < 0.05).

Treating wood with impregnating materials in order to improve resistance to burning is a commonly employed safety measure. In this study, chestnut (Castanea sativa Mill.) wood samples were impregnated using either Tanalith-E or Wolmanit-CB according to ASTM-D 1413-76 and surface-treated using water-based or synthetic varnish according to ASTM-D 3023. These samples were used to investigate the combustion characteristics of samples left outdoors for one year as detailed in ASTM-E 160-50. The combustion temperatures of the samples left outdoors were similar upon impregnation with either Tanalith-E or Wolmanit-CB. However, the combustion temperature of the samples treated with synthetic varnish was lower than those that were treated with water-based varnish. The time to collapse and the total duration of combustion of the samples left outdoors were shorter for those impregnated with Wolmanit-CB. Weight loss of the samples left outdoors was higher for those that were impregnated with Tanalith-E and treated with water-based varnish. Gas analysis of the samples that were left outdoors indicated that the O2 content of flue gas from samples that were impregnated with Wolmanit-CB and treated with synthetic varnish was high and the CO content of flue gas from the same samples was low.

Abstract Titanium tetrafluoride (TiF4) is known for interacting with enamel reducing demineralization. However, no information is available about its potential antimicrobial effect. Objectives This study evaluated the antimicrobial and anti-caries potential of TiF4 varnish compared to NaF varnish, chlorhexidine gel (positive control), placebo varnish and untreated (negative controls) using a dental microcosm biofilm model. Material and Methods A microcosm biofilm was produced on bovine enamel previously treated with the varnishes, using inoculum from human saliva mixed with McBain saliva, under 0.2% sucrose exposure, for 14 days. All experiments were performed in biological triplicate (n=4/group in each experiment). Factors evaluated were: bacterial viability (% dead and live bacteria); CFU counting (log10 CFU/mL); and enamel demineralization (transverse microradiography – TMR). Data were analysed using ANOVA/Tukey's test or Kruskal-Wallis/Dunn's test (p

Under severe bearing conditions, deposits form on the loaded part of bearing pads and if this happens excessively, it could lead to unacceptable rises in temperature and vibration. Deposits are mainly organic compounds, formed as oxidation by-products, which are insoluble in lubricating oil and can be the precursor to deposits. In this study, the deposit precursor in lubricating oil was investigated in detail and the deposit production mechanism was demonstrated. Furthermore, the difference of oil type effects and the dependence of conditions on deposit formation are also considered.

Copyright of Acta Musei Brukenthal is the property of Brukenthal National Museum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An effect of SiO 2 nanoparticles modification on spectra and integral absorption coefficient of silicon-organic varnish KO-859 before and after 30 keV electron and 100 keV proton exposure has been investigated. An increase in reflectance in UV, visible, and near-IR ranges and radiation stability of varnish modified with nanoparticles in comparison to unmodified have been established. [ABSTRACT FROM AUTHOR]

In the Cultural Heritage field, stratigraphic analysis is commonly carried out by applying microscopic and micro-analytical techniques to cross-sections of micro-samples taken from artwork. This methodology provides the most comprehensive information on the object's physical structure, but necessarily implies the loss of precious or unique fragments. For this reason, sampling is rarely feasible on musical instruments having such a historical and commercial value as Stradivari or Guarneri violins. Having been played over the centuries, these masterpieces have undergone different kinds of degradation and wear, and subsequent invasive restorations. Varnish layers have therefore been thinned or even removed from the surface and other materials could have been added overlaying the original ones, with consequent variations in coating thickness and composition over time. In the present work, a novel non-destructive and non-invasive methodology combined UV-Induced Fluorescence (UVIFL) photography and reflection FT-IR spectroscopy to investigate how and to what extent varnish thicknesses vary on the surface of historical violins as well as to reconstruct the stratigraphic layer order and chemical composition. Firstly, UV-induced variations and IR diagnostic bands were identified on numerous model samples reproducing musical instrument stratigraphy. Then the methodology was applied to the study of several Stradivari and Guarneri violins and its limitations and strengths were showed in three representative case studies. [ABSTRACT FROM AUTHOR]

Abstract: Varnish layers applied to paintings often discolor as they age, upsetting the original colour relationships intended by the artist. The removal of aged varnish layers using physical and chemical means is a highly skilled and often time‐consuming operation, which is not lightly undertaken. There are many aspects under consideration before embarking upon such treatment, including the visual result inferred by spot cleaning tests. In this article, we develop a technique for digital removal of discolored varnish that can help to envisage how a painting will look following cleaning treatment. The digital technique was applied to Vincent van Gogh's painting Field with Irises near Arles (May 1888), in parallel to the painting actually being cleaned, which allowed direct validation of the method developed. In the new method, we utilized not only hyperspectral data from parts of the painting with and without the varnish, but also experts' identification of spots on the painting where unmixed white pigment has been applied. The physical model that we use is based on Kubelka‐Munk two‐constant theory, commonly used to model the optical properties of paint. We show that with this model it is possible to determine the transmittance and reflectance of the varnish layer as function of wavelength. Results from previous studies confirm the calculated values. With the new method, we created a high‐resolution digital image of the painting, as it would look after varnish removal, at a moment when the actual varnish was still present on the painting. The new method may help conservators and others involved in decisions made regarding issues of varnish removal from paintings, or may help to visualize the colors of a painting without discolored varnish in cases where its physical removal cannot be safely accomplished and so is not an option. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the caries-preventive effect of different fluoride varnishes on sound dentin as well as on artificial dentin caries-like lesions. Bovine dentin specimens (n = 220) with one sound surface (ST) and one artificial caries lesion (DT) were prepared and randomly allocated to 11 groups. The interventions before pH cycling were as follows: application of a varnish containing NaF (22,600 ppm F-; Duraphat [NaF0/NaF1]), NaF plus tricalcium phosphate (22,600 ppm F-; Clinpro White Varnish Mint [TCP0/TCP1]), NaF plus casein phosphopeptide-stabilized amorphous calcium phosphate complexes (CPP-ACP; 22,600 ppm F-; MI Varnish [CPP0/CPP1]), or silver diamine fluoride (SDF; 35,400 ppm F-; Cariestop 30% [SDF0/SDF1]) and no intervention (NNB/N0/N1). During pH cycling (14 days, 6 × 120 min demineralization/day) half of the specimens in each group were brushed (10 s; 2 times/day) with either fluoride-free ("0"; e.g., TCP0) or 1,100 ppm F- ("1"; e.g., TCP1) dentifrice slurry. In another subgroup, the specimens were pH cycled but not brushed (NNB). Differences in integrated mineral loss (ΔΔZ), lesion depth (ΔLD), and colorimetric values (ΔΔE) were calculated between the values after initial demineralization and those after pH cycling, using transversal microradiography and photographic images. After pH cycling, no discoloration could be observed. Furthermore, NNB, N0, and N1 showed significantly increased ΔZDT/LDDT and ΔZST/LDST values, indicating further demineralization. In contrast, CPP0, CPP1, SDF0, and SDF1 showed significantly decreased ΔZDT/LDDT values, indicating remineralization (p ≤ 0.004; paired t test). CPP0, CPP1, SDF0, and SDF1 showed significantly higher changes in ΔΔZDT/ΔLDDT and ΔΔZST/ΔLDST than NNB, N0, and N1 (p < 0.001; Bonferroni post hoc test). In conclusion, under the conditions chosen, all fluoride varnishes prevented further demineralization. However, only NaF plus CPP-ACP and SDF could remineralize artificial dentin caries-like lesions under net-demineralizing conditions, thereby indicating that NaF plus CPP-ACP and SDF may be helpful to high-caries-risk patients. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: The total body of evidence finds fluoride varnish effective to prevent caries. However, most trials were conducted in high‐risk populations, with more recent trials on low‐risk groups finding a lower efficacy. We aimed to assess the cost‐effectiveness of fluoride varnish application in clinic setting in populations with different caries risk. Methods: A mixed public‐private‐payer perspective in the context of German health care was performed using a lifetime Markov model. Effectiveness data were derived from an update of the most recent systematic Cochrane review and synthesized in three different risk groups according to control group caries increment via random‐effects meta‐analysis. Varnish was assumed to be applied twice yearly between age 6 and 18 years. Teeth with carious defects would be treated restoratively and could experience further follow‐up treatments. Costs were deduced from German fee item catalogues. Monte Carlo microsimulations were used for to analyse lifetime treatment costs and caries increment (Euro/Decayed, Missing, Filled Teeth (DMFT)). Results: In low‐risk groups, fluoride varnish was nearly twice as costly and minimally more effective (293 Euro, 8.1 DMFT) than no varnish (163 Euro, 8.5 DMFT). The incremental cost‐effectiveness ratio (ICER) was 343 Euro spent per avoided DMFT. The ICER was lower in medium‐risk (ICER 93 Euro/DMFT) and high‐risk groups (8 Euro/DMFT). Conclusions: Application of fluoride varnish in the clinic setting is unlikely to be cost‐effective in low‐risk populations. There is the need to either target high‐risk groups or to provide fluoride varnish at lower costs, possibly in nonclinic settings. [ABSTRACT FROM AUTHOR]

Catheter-associated urinary tract infections are difficult to eradicate or prevent, due to their biofilm-related nature. Chlorhexidine, a widely used antiseptic, was previously found to be effective against catheter-related biofilms. For the present study, we developed sustained-release chlorhexidine varnishes for catheter coating and evaluated their antibiofilm properties and chlorhexidine-dissolution kinetics under various conditions. The varnishes were based on ethylcellulose or ammonio methacrylate copolymer type A (Eudragit® RL). Chlorhexidine was released by diffusion from a heterogeneous matrix in the case of the ethylcellulose-based formulation, and from a homogeneous matrix in the case of Eudragit® RL. This dictated the release pattern of chlorhexidine under testing conditions: from film specimens, and from coated catheters in a static or flow-through system. Momentary saturation was observed with the flow-through system in Eudragit® RL-based coatings, an effect that might be present in vivo with other formulations as well. The coatings were retained on the catheters for at least 2 weeks, and showed prolonged activity in a biological medium, including an antibiofilm effect against Pseudomonas aeruginosa . The current study demonstrates the potential of catheter coatings with sustained release of chlorhexidine in the prevention of catheter-associated urinary tract infections. [ABSTRACT FROM AUTHOR]