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Sample records for pit and fissure sealants

  1. Pit and fissure sealants or fluoride varnishes?

    Science.gov (United States)

    Paglia, L

    2016-09-01

    Despite the general advances in dental care, dental caries is still a global health problem affecting many children. Occlusal surfaces of first permanent molars are the most susceptible sites in the developing permanent dentition. Dentists should use sealants or fluoride varnish - as well as other means - to limit the onset of tooth decay. Application of sealants is a recommended procedure to prevent or control caries. Sealing occlusal surfaces of newly erupted permanent molars in children and teenagers delays caries onset up to 48 months compared with unsealed teeth. However longer follow-ups shows a reduction of the preventive effect [Tikhonova et al., 2015]. A review of 2013 pointed out how sealants are effective in high risk children, however information about the benefits of sealing in other conditions is still scant [Ahovuo-Saloranta et al., 2013]. Fluoride varnishes are frequently used to prevent early childhood caries and reduce caries increment in very young children [Weintraub et al., 2006] and in the most vulnerable populations, where the prevalence of caries is higher and specialist visits are occasional [Chu et al., 2010]. Many studies have reported the effectiveness of different types and forms of fluoride agents in preventing dental caries among children and adolescents [Divaris et al., 2013]. A review clarifies that professional application of a 5% sodium fluoride varnish leads to remineralisation of early enamel caries in children. Solutions of 38% silver diamine fluoride are effective in arresting active dentine caries [Gao et al., 2016]. The last systematic review [Ahovuo-Saloranta et al., 2016], comparing pit and fissure sealants with fluoride varnishes explains that the pooled estimate slightly favours resin sealants over fluoride varnishes at two years. At four and nine years, the only comparative study (with high drop-out rates) found more caries on fluoride-varnished occlusal surfaces than on resin-sealed surfaces. There is evidence

  2. Comparative study of resin sealant and resin modified glass ionomer as pit and fissure sealant

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    Shirin Malek

    2017-02-01

    Full Text Available The purpose of the present study was to compare the marginal integrity of resin modified glass ionomer cement with that of resin sealant, in vitro. Forty artificial pit and fissure cavities were prepared in occlusal surface of extracted premolar teeth by using ¼ round carbide bur. Cavities were condensed with artificial organic debris followed by cleaning with prophylaxis pumice brush and paste and then separated into two treatment groups. In Group A, 15 fissure cavities were sealed by resin sealant and in Group B, 15 fissure cavities were sealed by resin modified glass ionomer sealant. These specimens were subjected to thermo-cycling followed by dye penetration test. The remaining 5 cavities from each group were analyzed for debris score by the SEM. The results of the microleakage test showed that the efficacy of preventing microleakage of samples sealed by resin modified glass ionomer sealant was higher than the samples sealed by resin sealant. However, no significant differences were found. It can be concluded that use of resin modified glass ionomer sealant is a good alternative for sealing pits and fissures.

  3. The Effect of Fluoride Varnish on Enamel Shear Bond Strength of Pit and Fissure Sealants.

    Science.gov (United States)

    Frazer, Rebecca A; Platt, Jeffrey A; Sanders, Brian J; Yepes, Juan F; Jones, James E

    2017-03-15

    The purpose of this study was to determine the effects of fluoride varnish on the enamel shear bond strength of pit and fissure sealants. Ninety-six teeth were divided into three duplicated test groups: sealant (S)/sealant thermocycle (ST) received Clinpro Sealant only; varnish sealant (VS)/varnish sealant thermocycle (VST) received five percent sodium fluoride (NaF) varnish plus sealant (VPS); and VPS/VPS thermocycle (VPST) received NaF, polish with Clinpro Prophy Paste, plus sealant. One set of each group (ST, VST, VPST) was thermocycled to represent aging, and one set (S, VS, PVS) was not. The shear bond strengths for the thermocycled groups and nonthermocycled groups were determined, and two-way analysis of variance tested the effects of thermocycling and varnish. Thermocycling did not have a significant effect on the peak stresses of the groups (P=0.0552), so sets were combined. The peak stress for S/ST was significantly higher than for VS/VST (PFluoride varnish applied immediately before pit and fissure sealant placement negatively affected the shear bond strength of the sealant. Mechanically cleaning a fluoride varnish-coated tooth with prophy paste did not provide pit and fissure sealant enamel shear bond strengths comparable to those of untreated enamel.

  4. Effect of LED curing on the marginal leakage of a pit and fissure sealant

    OpenAIRE

    Pineda Mejia, Martha Elena; Magister en Estomatología. Profesor Principal. UNMSM. Dpto. Estomatología Rehabilitadora. Facultad Odontología. UNMSM.; Gloria Zevallos, Waldo; Dpto. Estomatología Rehabilitadora. Facultad Odontología. UNMSM.; Abuhadba Hoyos, Tulio; Dpto. Estomatología Rehabilitadora. Facultad Odontología. UNMSM.

    2014-01-01

    The purpose of this study was to evaluate in vitro the curing effect of a light-emitting diode LED unit and conventional halogen light on the marginal leakage of a pit and fissure sealant. We used 40 caries-free permanent premolars recently extracted, which were randomly divided into two groups (n = 20), sealed with a resin based fissure sealant, Helioseal F (Ivoclar Vivadent), according to the manufacturer patterns, then photopolymerized using either L.E.D. light or conventional halogen ligh...

  5. Effect of an Antibacterial Monomer on the Antibacterial Activity of a Pit-and-Fissure Sealant

    Science.gov (United States)

    Dong, Yan; Zhang, Ling; Sun, Xiang; Liu, Zhengya; Guo, Huihui; Huang, Li; Chen, Jihua

    2016-01-01

    Resin-based pit-and-fissure sealants are often used to form a barrier on the occlusal surface of molars to treat caries lesions; however, bacteria can remain in the pit and fissures without detection, increasing the risk of secondary caries. Sealants with antimicrobial properties or microbial repellent actions might be advantageous. The aim of this study was to assess the inhibitory effect of a 2-methacryloxylethyl dodecyl methyl ammonium bromide (MAE-DB)-incorporated sealant against Streptococcus mutans. MAE-DB (4% wt) was incorporated into a commercially available sealant, Eco-S resin-based pit-and-fissure sealant (Vericom Co., Ltd., Korea); a sealant without MAE-DB served as a negative control, and Clinpro™ Sealant (3M™ ESPE™), a fluoride-releasing resin, was used as a commercial control. The effects of the cured sealants and their eluents on the growth of S. mutans were determined according to colony-forming unit counts and metabolic tests. The effects of the cured sealants on the adherence and membrane integrity of S. mutans were investigated using confocal laser-scanning microscopy (CLSM) in conjunction with fluorescent indicators. Compared with the negative control and commercial control, the cured MAE-DB-incorporated pit-and-fissure sealant exhibited a significant inhibitory effect on the growth of S. mutans (P < 0.05), whereas the eluents did not show any detectable antibacterial activity. The commercial control also showed no detectable bactericidal activity. Moreover, the aged experimental material retained its property of contact inhibition of biofilm formation. The fluorescence analysis of CLSM images demonstrated that the cured MAE-DB-incorporated sealant could hamper the adherence of S. mutans and exert a detrimental effect on bacterial membrane integrity. The incorporation of MAE-DB can render a pit-and-fissure sealant with contact antibacterial activity after polymerization via influencing the growth, adherence, and membrane integrity of S

  6. [Clinical evaluation of fluor protector and glass-ionomer cement used as pit and fissure sealant for preventing pit and fissure caries in children].

    Science.gov (United States)

    Ji, Pei-hong; Xu, Quan-lin; Ba, Yong

    2007-08-01

    To study the clinical effect of the fluor protector and glass-ionomer cement used as pit and fissure sealant for preventing pit and fissure caries in children. 622 health permanent teeth in 6-8 years old children were divided into three groups. Children in the experimental group A (n=207,335 teeth) underwent fluor protector every six months, experimental group B(n=205, 327 teeth) with glass-ionomer cement used as pit and fissure sealant and children in the control group(n=210, 354 teeth) underwent no treatment. The incidence of caries were compared among the three groups using SPSS10.0 software package after 3 years. After 3 years, the incidence of caries in A and B experimental groups were lower than in the control group, the difference was significant (P0.05). Fluor protector and glass-ionomer cement used as pit and fissure sealant also have good clinical effect in preventing caries.

  7. The Effects of Opaque and Clear Pit and Fissure Sealants on Infrared Laser Fluorescence Measurements

    Science.gov (United States)

    Bahrololoomi, Z.; Khodabakhsh, M.; Khaksar, Y.

    2014-01-01

    Statement of the Problem: The purpose of placing sealants is to inhibit caries by physical closure of the pits and fissures of teeth. A device named DIAGNOdent is useful in detecting occlusal caries by employing laser fluorescence (LF). However, there are contradictory results in the influence of sealants on LF measurements. Purpose: The aim of this study is to investigate the effects of two different types of fissure sealants on LF measurements. Materials and Method: In this in vitro study, 86 extracted permanent third molars were divided randomly into two groups and clear or opaque sealant was applied on the occlusal surfaces. Two examiners performed pre- and post-seal fluorescence measurements twice with one week interval by employing DIAGNOdent device. Finally, measured values were evaluated through the statistical paired t-test by means of SPSS 17 software. Results: The mean value of LF measurements increased significantly due to the application of clear sealant (p= 0.001) while the statistical changes in this measurement was negligible after applying opaque sealant (p= 0.311). Conclusion: Clear sealants increase the LF measured values but opaque sealants cause almost no changes. Therefore, DIAGNOdent device is not reliable for detecting caries beneath the clear sealant. PMID:24883342

  8. The Effects of Opaque and Clear Pit and Fissure Sealants on Infrared Laser Fluorescence Measurements

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    Bahrololoomi Z.

    2013-10-01

    Full Text Available Statement of the Problem: The purpose of placing sealants is to inhibit caries by physical closure of the pits and fissures of teeth. A device named DIAGNOdent is useful in detecting occlusal caries by employing laser fluorescence (LF. However, there are contradictory results in the influence of sealants on LF measurements. Purpose: The aim of this study is to investigate the effects of two different types of fissure sealants on LF measurements. Materials and Method: In this in vitro study, 86 extracted permanent third molars were divided randomly into two groups and clear or opaque sealant was applied on the occlusal surfaces. Two examiners performed pre and post-seal fluorescence measurements twice with one week interval by employing DIAGNOdent device. Finally, measured values were evaluated through the statistical paired t-test by means of SPSS 17 software. Results: The mean value of LF measurements increased significantly due to the application of clear sealant (p= 0.001 while the statistical changes in this measurement is negligible after applying opaque sealant (p= 0.311. Conclusion: Clear sealants increase the LF measured values but opaque sealants cause almost no changes. Therefore DIAGNOdent device is not reliable for detecting caries beneath the clear sealant.

  9. In vitro evaluation of shear bond strength and microleakage of different pit and fissure sealants

    Science.gov (United States)

    Babaji, Prashant; Vaid, Shivali; Deep, S.; Mishra, Samvit; Srivastava, Madhulika; Manjooran, Thomas

    2016-01-01

    Aim and Objectives: Fissure caries is most common in children due to deep pit and fissures. Pit and fissure areas on the occlusal surface of the teeth make them susceptible to dental caries, which need to be prevented or restored. Fissures sealant reduces the risk of occlusal caries. The present study was done to evaluate microleakage and shear bond strength of various fissure sealants. Materials and Methods: Thirty-six extracted molars were randomly allocated equally (n = 12) into three groups with three different sealants to evaluate shear bond strength and microleakage at sealant space. The shear bond strengths was evaluated with one-way analysis of variance and microleakage by Kruskal-Wallis nonparametric test using the Statistical Package for the Social Sciences version 18.0 (Chicago: SPSS Inc, 2009). Results: Tetric flow (16.8 MPa) recorded the highest shear bond strength and the difference was statistically significant with enamel loc (12.8 MPa). There was no statistically significant difference in relation to microleakage (P > 0.05) in the tested groups. Conclusions: Tetric flow recorded the highest shear bond strength and the difference was statistically significant with enamel loc. However, there was no statistically significant difference among the groups regarding microleakage. PMID:27652241

  10. A comparison between three different pit and fissure sealants with regard to marginal integrity

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    Kristlee Sabrin Fernandes

    2012-01-01

    Full Text Available Aim: The aim of this study is to compare the occurrence of enamel fractures, sealant fractures and marginal fissures after placement of three sealants: Helioseal F, Conseal F and Clinpro. Materials and Methods: Thirty individuals between 13 and 15 years of age, diagnosed with pit and fissure caries by visual and DIAGNOdent examination, were chosen for sealant placement on their mandibular molars. The sealants were placed at random, after which, impressions were made with polyvinyl siloxane and casts were fabricated. Dies were prepared, each of which were sputter coated with gold in order to be examined under a scanning electron microscope. The following morphologies were analyzed from dies from each of the sealant groups: Continuous margins, sealant fractures, marginal fissures and enamel fractures. After six months, they were recalled for impression making. Dies were prepared and microscopically analyzed as mentioned. Based on the time of evaluation, there were two groups: Initial group (soon after placement and final group (after six months. Statistical analysis was done using the paired ′t′ test and One-way analysis of variance (ANOVA. Results and Conclusions: Clinpro had the greatest fracture resistance, followed by Conseal F and Helioseal F. The occurrence of marginal fissure was found to be least with Clinpro.

  11. A comparison between three different pit and fissure sealants with regard to marginal integrity

    Science.gov (United States)

    Fernandes, Kristlee Sabrin; Chalakkal, Paul; de Ataide, Ida de Noronha; Pavaskar, Rajdeep; Fernandes, Precylia Philo; Soni, Harleen

    2012-01-01

    Aim: The aim of this study is to compare the occurrence of enamel fractures, sealant fractures and marginal fissures after placement of three sealants: Helioseal F, Conseal F and Clinpro. Materials and Methods: Thirty individuals between 13 and 15 years of age, diagnosed with pit and fissure caries by visual and DIAGNOdent examination, were chosen for sealant placement on their mandibular molars. The sealants were placed at random, after which, impressions were made with polyvinyl siloxane and casts were fabricated. Dies were prepared, each of which were sputter coated with gold in order to be examined under a scanning electron microscope. The following morphologies were analyzed from dies from each of the sealant groups: Continuous margins, sealant fractures, marginal fissures and enamel fractures. After six months, they were recalled for impression making. Dies were prepared and microscopically analyzed as mentioned. Based on the time of evaluation, there were two groups: Initial group (soon after placement) and final group (after six months). Statistical analysis was done using the paired ‘t’ test and One-way analysis of variance (ANOVA). Results and Conclusions: Clinpro had the greatest fracture resistance, followed by Conseal F and Helioseal F. The occurrence of marginal fissure was found to be least with Clinpro. PMID:22557813

  12. An evaluation of nanocomposites as pit and fissure sealants in child patients

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    S Singh

    2011-01-01

    Full Text Available Background: Dental caries affects populations of all ages in all the regions of the world, with the child patient being at the highest risk. Fifty percent of the permanent molars are decayed by the age of 12, due to lack of information about protection and occlusal morphology. Pit and fissure sealing undoubtedly plays a fundamental role in preventing occlusal caries. The most common approach to assess the sealing ability of pit and fissure sealants of tooth/restoration is the measurement of dye penetration along the interface. Aims and Objectives: The present study aims to evaluate the microleakage and penetration depth of three different types of dental materials, namely (A Conventional pit and fissure sealant, (B Flowable composite, (C Flowable nanocomposite. Study Design: This in-vitro comparative study comprised of extracted human posterior teeth mounted as blocks. Materials and Methods: In the present study, microleakage and penetration depths of conventional sealants/flowable composite and nanocomposite were measured with the help of a dye under stereomicroscope. Statistical Analysis: A student′t′ test and Analysis of variance (ANOVA tests were performed to compare the mean microleakage and penetration depth. Results: Microleakage was found to be highest for the flowable composites, and least for the conventional sealant. The nanocomposite values were intermediate. Penetration depth was highest for nanocomposite and least for flowable composite. Conclusions: According to the results, the nanocomposite was found to be an excellent dental material for penetration in deep pits and fissures, though it exhibits mild microleakage. Hence, it can be recommended for use in pediatric dental patients, as a pit and fissure sealing agent.

  13. In Vitro Comparison of Microleakage of Two Materials Used as Pit and Fissure Sealants

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    Zahra Bahrololoomi

    2011-09-01

    Full Text Available Background and aims. Marginal seal of the material is extremely important in fissure sealant therapy. The aim of this study was to investigate microleakage of flowable composite resins and conventional fissure sealants with or without dentin bonding agent. Materials and methods. The occlusal surface of 60 intact extracted human premolars, divided into four groups, were cleaned with pumice/slurry, etched with 37% phosphoric acid for 15 seconds, rinsed and dried. Groups were treated differently: Excite bonding agent followed by Helioseal F fissure sealant in group1; Helioseal F alone in group 2; Excite bonding agent followed by Tetric Flow in group 3; and Tetric Flow alone in group 4. Light-curing was done after each application. After thermocycling, the whole surface of each specimen was coated with nail varnish except for one millimeter around the fissure sealant. The teeth were immersed in 2% basic fuchsin for 24 hours and then sectioned buccolingually. The sections were analyzed for leakage under a stereomicroscope. Data was analyzed by Kruskal-Wallis and Mann-Whitney tests at a significance level of P 0.05, except for groups 2 and 4 (P = 0.002 and groups 3 and 4 (P = 0.033. Conclusion. Use of a flowable composite with bonding agent is a good alternative for sealing pits and fissures; however, further in vitro and in vivo studies are necessary.

  14. Effect of Silver Nanoparticle-Added Pit and Fissure Sealant in the Prevention of Dental Caries in Children.

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    Salas-López, Enid Karina; Pierdant-Pérez, Mauricio; Hernández-Sierra, Juan Francisco; Ruíz, Facundo; Mandeville, Peter; Pozos-Guillén, Amaury J

    The objective of this study was to evaluate the effects of pit and fissure sealant mixed with silver nanoparticles on dental caries, by means of monthly measurement of fluorescence with DIAGNOdent over six months. This study was divided in two phases: experimental and clinical. In the experimental phase, the adhesion and microleakage of the pit and fissure sealant experiment were evaluated. Two groups of 10 teeth, without serious carious lesions, were included. Conventional (group A) and silver nanoparticles (group B) were added to the pit and fissure sealant. For the clinical phase, a split-mouth study was performed on 40 children aged 6-10 years old with healthy, erupted permanent first molars. A conventional pit and fissure sealant or a silver nanoparticle-mixed sealant was randomly placed. Repeated measures analysis was performed. Conventional sealant presented an average microleakage of 30.6%, and the silver nanoparticle-mixed sealant showed 33.6% (P=NS). A three times greater reduction in fluorescence was found in the silver nanoparticles group compared to the conventional group (P<0.05). No sex- or age-based associations were found. The silver nanoparticle-mixed sealant reduced tooth demineralization significantly and likely increased remineralization, compared to the conventional sealant.

  15. Pit and fissure sealants in dental public health – application criteria and general policy in Finland

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    Meurman Jukka H

    2009-02-01

    Full Text Available Abstract Background Pit and fissure sealants (sealants are widely used as a non-operative preventive method in public dental health in Finland. Most children under 19 years of age attend the community-organized dental health services free of charge. The aims of this study were to find out to what extent sealants were applied, what the attitudes of dental professionals towards sealant application were, and whether any existing sealant policies could be detected among the health centres or among the respondents in general. The study evaluated changes that had taken place in the policies used during a ten year period (1991–2001. Methods A questionnaire was mailed to each chief dental officer (CDO of the 265 public dental health centres in Finland, and to a group of general dentists (GDP applying sealants in these health centres, giving a total of 434 questionnaires with 22 questions. The response rate was 80% (N = 342. Results A majority of the respondents reported to application of sealants on a systematic basis for children with increased caries risk. The criteria for applying sealants and the actual strategies seemed to vary locally between the dentists within the health centres and between the health centres nationwide. The majority of respondents believed sealants had short- and long-term effects. The overall use of sealants decreased towards the end of the ten year period. The health centres (N = 28 choosing criteria to seal over detected or suspected enamel caries lesion had a DMFT value of 1.0 (SD ± 0.49 at age 12 (year 2000 compared to a value of 1.2 (SD ± 0.47 for those health centres (N = 177 applying sealants by alternative criteria (t-test, p Conclusion There seems to be a need for defined guidelines for sealant application criteria and policy both locally and nationwide. Occlusal caries management may be improved by shifting the sealant policy from the traditional approach of prevention to interception, i.e. applying the sealants

  16. Quality Assessment of Information About Pit and Fissure Sealants in Persian Websites in 2012

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    Firoozeh Nilchian Nilchian

    2016-08-01

    Full Text Available Objectives: Despite the increasing use of Internet, there is no supervision over the accuracy and quality of the information provided in the web. To deal with this problem, health specialists should take part in planning, publishing and supervision of online health-related information. The aim of this study was to evaluate the quality of information related to pit and fissure sealants in Persian websites.Materials and Methods: In this cross-sectional study, Persian websites providing information about fissure sealants were found using Google search engine. The searched keywords according to the MeSH database were "patient education" and "fissure sealant". After applying the exclusion criteria, 37 websites out of 500 initial links remained in the study. These websites were evaluated based on a researcher-made checklist. The validity and reliability of the checklist were evaluated and confirmed. Descriptive analysis was applied to report the results of our study using SPSS version 11.5.Results: The average score for the quality of information was 22.46 out of 38. The minimum scores were 16 and 30 and belonged to Pezeshkanemrooz.com and Asa85.blogfa.com, respectively. The results showed that 62.2% of the answers were scored 2-4 and 37.8% were scored 1; therefore, the overall quality of the published content was rated to be moderate for 62.2% and low for 37.8% of the websites.Conclusions: Overall, the quality of information related to fissure sealant provided in Persian websites was good; however, the information given was mostly incomplete and could be improved. The main problems were doubtful credibility and outdated information.

  17. Enamel Surface with Pit and Fissure Sealant Containing 45S5 Bioactive Glass.

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    Yang, S-Y; Kwon, J-S; Kim, K-N; Kim, K-M

    2016-05-01

    Enamel demineralization adjacent to pit and fissure sealants leads to the formation of marginal caries, which can necessitate the replacement of existing sealants. Dental materials with bioactive glass, which releases ions that inhibit dental caries, have been studied. The purpose of this study was to evaluate the enamel surface adjacent to sealants containing 45S5 bioactive glass (BAG) under simulated microleakage between the material and the tooth in a cariogenic environment. Sealants containing 45S5BAG filler were prepared as follows: 0% 45S5BAG + 50.0% glass (BAG0 group), 12.5% 45S5BAG + 37.5% glass (BAG12.5 group), 25.0% 45S5BAG + 25.0% glass (BAG25.0 group), 37.5% 45S5BAG + 12.5% glass (BAG37.5 group), and 50.0% 45S5BAG + 0% glass (BAG50.0 group). A cured sealant disk was placed over a flat bovine enamel disk, separated by a 60-µm gap, and immersed in lactic acid solution (pH 4.0) at 37 °C for 15, 30, and 45 d. After the storage period, each enamel disk was separated from the cured sealant disk, and the enamel surface was examined with optical 3-dimensional surface profilometer, microhardness tester, and scanning electron microscopy. The results showed a significant increase in roughness and a decrease in microhardness of the enamel surface as the proportion of 45S5BAG decreased (Penamel surfaces with BAG50.0 showed a smooth surface, similar to those in the control group with distilled water, even after prolonged acid storage. Additionally, an etched pattern was observed on the surface of the demineralized enamel with a decreasing proportion of 45S5BAG. Increasing the 45S5BAG filler contents of the sealants had a significant impact in preventing the demineralization of the enamel surface within microgaps between the material and the tooth when exposed to a cariogenic environment. Therefore, despite some marginal leakage, these novel sealants may be effective preventive dental materials for inhibiting secondary caries at the margins.

  18. Comparison of different methods of cleaning and preparing occlusal fissure surface before placement of pit and fissure sealants: An in vivo study

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    Rahul J Hegde

    2016-01-01

    Full Text Available Aim: To evaluate an individual method of cleaning and preparing occlusal fissure surface before placement of pit and fissure sealant and to determine a method for better retention of the sealant. Materials and Methods: The present study consisted of 100 young permanent molar teeth divided into four equal groups: Group 1-Brushing only, Group 2-Application of pumice slurry, Group 3-Surface conditioning, and Group 4-Control (without any preparation. Subsequent to fissure preparation, the fissures were etched using 37% phosphoric acid except for Group 3, which was etched using 10% maleic acid for 30 s. The samples were then rinsed for 10 s using air water spray of the three-way syringe and dried using oil-free compressed air with a hand pump air pressure syringe. After ensuring a frosted appearance of the enamel at the fissure entrance, pit and fissure sealants were applied on the surface according to manufacturer′s instructions. All the cases were clinically evaluated for retention after 3 months, 6 months, and 12 months of application and the retention rate was assessed based on the criteria proposed by Simonsen. Results: The pumice slurry group and surface conditioning group showed results with 100%, 96%, and 92% complete retention seen at 3 months, 6 months, and 12 months, respectively. Conclusion: The pumice slurry group and surface conditioning group showed a significantly higher retention when compared to the brushing group, whereas the control group (without any preparation showed the least retention when compared to all the other groups.

  19. Effectiveness of pit and fissure sealants bonded with different adhesive systems: a prospective randomized controlled trial.

    Science.gov (United States)

    Erbas Unverdi, Gizem; Atac, Stephan Atilla; Cehreli, Zafer Cavit

    2016-11-30

    To evaluate and compare the clinical retention of a resin-based fissure sealant placed with an intermediate layer of etch-and-rinse (ER) or self-etch (SE) adhesives. Two hundred twenty-eight sealants were placed in 57 children with previously unsealed, caries-free permanent first molars, employing a split-mouth design. The teeth were randomized into four groups (n = 57 teeth/groups) according to the adhesive system placed under the tested sealant (Delton FS+; Dentsply). Group 1 (control): no bonding agent (conventional acid-etch sealant); group 2: prior enamel etch + ER adhesive (XP Bond; Dentsply); group 3: SE adhesive (Clearfil SE Bond; Kuraray) without prior etching; and group 4: prior enamel etch + SE adhesive (Clearfil SE Bond). Clinical assessments were performed according to modified USPHS criteria at 1, 3, 6, 12, 18, and 24 months. The data were analyzed statistically using Fisher's Exact test, the Kaplan-Meier analysis, and the Log-rank test. At 24 months, sealants bonded with XP Bond and Clearfil SE Bond with prior enamel etching showed similar retention rates (p > 0.05), and these rates were significantly better than the rates of the conventional sealant and Clearfil-SE groups (p  0.05). The cumulative survival rates on palatal/buccal surfaces showed similar outcomes as with occlusal surfaces: XP Bond (94%), Clearfil SE Bond + acid-etch (94%), conventional sealant (52%), and Clearfil SE Bond only (37%). Application of the tested ER adhesive and the SE adhesive with enamel etching significantly improved the clinical retention of Delton-FS over the 24-month period. The use of a resin-based fissure sealant placed with ER or SE adhesive with prior acid-etching yielded better retention than the conventional sealant over the 24-month period.

  20. Comparison of antibacterial properties of two fluoride-releasing and a nonfluoride-releasing pit and fissure sealants

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    Menon Preetha V

    2007-09-01

    Full Text Available Occlusal pits and fissures are the most susceptible sites for the development of dental caries and prevention is difficult in the areas of occurrence. Although only 12.5% of all the tooth surfaces are occlusal, these surfaces develop more than two-thirds of total caries experienced by children. The fate of the bacteria is of significance when they are inadvertently sealed by a dental sealant. This study aimed in examining the antibacterial properties of three commercially available sealants, viz., Teethmate-F, Helioseal-F and Helioseal. Antibacterial testing was done by disc diffusion method. Selective agars were used to grow Streptococcus mutans and Lactobacillus acidophilus, which are implicated in the pathogenesis of dental caries. Statistical analysis was carried out using student′s t test. The study proved that Helioseal-F and Helioseal did not possess antibacterial properties and Teethmate-F was the only sealant that showed antibacterial properties.

  1. Comparative study of fluoride released and recharged from conventional pit and fissure sealants versus surface prereacted glass ionomer technology

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    Elias Nahum Salmerón-Valdés

    2016-01-01

    Full Text Available Context: The fluoride release of sealants in vitro shows a marked decrease. Giomers are distinguishable from manufactured resin-based sealants and contain prereacted glass-ionomer particles (PRG. Aims: To compare the amounts of fluoride released from the main pit and fissure of a resin-based sealant with that from a Giomer and to assess the abilities of the sealant and the Giomer to recharge when exposed to regular use of fluoride rinse. Materials and Methods: The readings for the fluoride concentration were carried out for 60 days using a fluoride ion-specific electrode. After this period, the samples were recharged using a fluoride mouth rinse. The amount of fluoride released after this recharge was determined for 5 days. The data were analyzed using Student′s t- and analysis of variance tests. Results: In general, all materials presented higher fluoride release in the first 24 h; G1 and G4 showed a higher fluoride release in this period. On the other hand, G3 and G1 presented the most constant fluoride release until the 8 th day, wherein all the sealants considerably decreased in the amount of fluoride released. Conclusion: G1 and G3 released higher concentrations of fluoride, although no significant differences were found. Giomers recharged in the first 24 h after polymerization presented an improved and sustained fluoride release.

  2. Evaluation of retention of pit and fissure sealants placed with and without air abrasion pretreatment in 6-8 year old children – An in vivo study

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    Goswami, Mridula

    2017-01-01

    Background The success of pit and fissure sealants is directly related to their retention. The purpose of this study was to assess and compare the retention of pit and fissure sealants placed using acid etch alone and a combination of air abrasion and acid etch techniques. Material and Methods 50 subjects aged 6-8 years were included in the study. Primary second molars and permanent first molars were sealed in all four quadrants using split mouth design. The right maxillary and mandibular molars (Group A) were treated by acid etching alone while the left maxillary and mandibular molars (Group B) were pretreated with air abrasion followed by acid etching before application of pit and fissure sealant. Retention of sealants was checked using Simonsen’s criteria of sealant retention after three and six months of sealant application. Results There was no significant difference in retention of sealants in Group A and Group B (p0.05). Maxillary molars showed superior retention compared to mandibular molars, which was statistically significant at both three and six months (p<0.05). Conclusions Combining air abrasion pretreatment with subsequent acid etching did not result in statistically significant difference in sealant retention compared to acid etching alone in both primary and permanent molars after 3 and 6 months follow up. An additional air abrasion pretreatment step can be avoided in pediatric patients when placing sealants and the procedure can be completed faster with better behavior management using acid etching alone. Key words:Pit and fissure sealant, acid etching, air abrasion. PMID:28210438

  3. Comparative evaluation of the length of resin tags, viscosity and microleakage of pit and fissure sealants - an in vitro scanning electron microscope study

    Directory of Open Access Journals (Sweden)

    A R Prabhakar

    2011-01-01

    Full Text Available Introduction : In this era of preventive dentistry, many techniques are available for prevention of caries, such as plaque control, use of systemic and local fluorides and pit and fissure sealants. The rationale of pit and fissure sealants is that, when they are applied into the caries prone fissures, they penetrate and seal them from the oral environment. This study aims to correlate the relationship between the viscosity of the sealant, resin tag length and microleakage. Materials and Methods : 30 third molars were selected for study. The teeth were randomly divided into 3 groups. Group E: Embrace wetbond, H: Helioseal, G: Guardian seal. Teeth were cleaned with pumice prophylaxis and pretreated with acid etching and bonding agent. The respective pit and fissure sealants were applied. Teeth were placed in 1% methylene blue dye and sectioned mesio-distally into two halves. These were used to assess the microleakage using stereomicroscope and resin tag length using SEM. Viscosity was assessed using Brooke′s field viscometer. Results : Viscosity was lowest for Embrace wetbond and highest for Guardian seal. Microleakage scores were highest with Guardian seal and lowest with Embrace wetbond. Resin tag lengths were longer with Embrace wetbond as compared to other groups. There is a definite negative correlation between viscosity, resin tag length and microleakage. Lower the viscosity, the longer were the resin tags and the microleakage decreased. Embrace wetbond pit and fissure sealant had lowest viscosity, longest resin tag length and lowest microleakage scores. Conclusion : Embrace wetbond appears to be compatible with residual moisture and ideal for use in children, where isolation is a problem.

  4. Pit and fissure sealants versus fluoride varnishes for preventing dental decay in children and adolescents

    DEFF Research Database (Denmark)

    Hiiri, Anne; Ahovuo-Saloranta, Anneli; Nordblad, Anne

    2010-01-01

    ; sealants versus fluoride varnish or sealants and fluoride varnish combination versus fluoride varnish alone; and subjects under 20 years of age. The primary outcome of interest was the increment in the numbers of carious occlusal surfaces of permanent premolars and molars. DATA COLLECTION AND ANALYSIS: Two...... review authors independently screened search results, extracted data and assessed the risk of bias of trials. Risk ratios (RR) were calculated for differences between intervention and control groups and in split-mouth studies for differences of paired tooth surfaces being carious or not. No data could...

  5. Pit and fissure sealants for preventing dental decay in the permanent teeth of children and adolescents

    DEFF Research Database (Denmark)

    Ahovuo-Saloranta, Anneli; Hiiri, Anne; Nordblad, Anne

    2008-01-01

    was the increment in the numbers of carious occlusal surfaces of premolars and molars. DATA COLLECTION AND ANALYSIS: Two review authors independently screened search results, extracted data and quality assessed trials. Risk ratios (RR) were calculated for differences between intervention and control groups...... and in split-mouth studies for differences of paired tooth surfaces being carious or not. The meta-analyses were conducted using a random-effects model. MAIN RESULTS: Sixteen studies were included in the review; 7 studies provided data for comparison of sealant versus control without sealant and 10 studies...

  6. Pit and fissure sealants versus fluoride varnishes for preventing dental decay in the permanent teeth of children and adolescents.

    Science.gov (United States)

    Ahovuo-Saloranta, Anneli; Forss, Helena; Hiiri, Anne; Nordblad, Anne; Mäkelä, Marjukka

    2016-01-18

    Most of the detected increment in dental caries among children and adolescents is confined to occlusal surfaces of posterior permanent molars. Dental sealants and fluoride varnishes are much used preventive options for caries. Although the effectiveness of sealants and fluoride varnishes for controlling caries as compared with no intervention has been demonstrated in clinical trials and summarised in systematic reviews, the relative effectiveness of these two interventions remains unclear. This review is an update of one first published in 2006 and last updated in 2010. Primary objective • To evaluate the relative effectiveness of fissure sealants compared with fluoride varnishes, or fissure sealants together with fluoride varnishes compared with fluoride varnishes alone, for preventing dental caries in the occlusal surfaces of permanent teeth of children and adolescents. Secondary objectives • To evaluate whether effectiveness is influenced by sealant material type and length of follow-up.• To document and report on data concerning adverse events associated with sealants and fluoride varnishes. We searched the following electronic databases: the Cochrane Oral Health Group Trials Register (to 18 December 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 11), MEDLINE via Ovid (1946 to 18 December 2015) and EMBASE via Ovid (1980 to 18 December 2015). We also searched the US National Institutes of Health Trials Register (http://clinicaltrials.gov) and the World Health Organization (WHO) Clinical Trials Registry Platform for ongoing trials. We placed no restrictions on language or date of publication when searching electronic databases. We screened the reference lists of identified trials and review articles for additional relevant studies. We included randomised controlled trials with at least 12 months of follow-up comparing fissure sealants, or fissure sealants together with fluoride varnishes, versus fluoride varnishes for

  7. Comparative evaluation of Shear bond strength of different Pit and fissure Sealants in Primary and Permanent teeth - An In-Vitro Study

    OpenAIRE

    Pushpalatha, H M; Ravichandra, K S; Srikanth, Koya; G. Divya; Done, Vasanthi; Krishna, K Bala; Patil, Vishwanath

    2014-01-01

    Background: Dental caries among children is one of the greatest challenges faced by dentists globally; especially that of susceptible surfaces like the Pit and fissures. Dental sealants have proved to be an effective way to prevent caries development. The Clinical success of any material depends upon its adhesion to tooth structure, resistance to wear and ability to withstand the masticatory or occlusal forces. Hence it is important to evaluate the shear bond strength ...

  8. Synthesized mesoporous silica and calcium aluminate cement fillers increased the fluoride recharge and lactic acid neutralizing ability of a resin-based pit and fissure sealant.

    Science.gov (United States)

    Surintanasarn, Atikom; Siralertmukul, Krisana; Thamrongananskul, Niyom

    2017-07-12

    This study evaluated the effect of different types of filler in a resin-based pit and fissure sealant on fluoride release, recharge, and lactic acid neutralization. Resin-based sealant was incorporated with 5% w/w of the following fillers: calcium aluminate cement (CAC), synthesized mesoporous silica (SI), a CAC and SI mixture (CAC+SI), glass-ionomer powder (GIC), and acetic acid-treated GIC (GICA). Sealant without filler served as control. The samples were immersed in deionized water or a lactic acid solution and the concentration of fluoride in the water, before and after fluoride recharge, and the lactic acid pH change, respectively, were determined. The CAC+SI group demonstrated the highest fluoride release after being recharged with fluoride gel. The CAC+SI group also demonstrated increased lactic acid pH. These findings suggest that a resin-based sealant containing synthesized mesoporous silica and calcium aluminate cement may enhance remineralization due to fluoride release and higher pH.

  9. Pit and fissure sealants in the prevention of dental caries in children and adolescents: a systematic review

    National Research Council Canada - National Science Library

    Azarpazhooh, Amir; Main, Patricia A

    2008-01-01

    To investigate the evidence for sealants as a means to prevent caries in children and adolescents and, in the presence of suitable supporting evidence, to develop a protocol for the application of sealants...

  10. Flow characteristics and sealing ability of fissure sealants.

    Science.gov (United States)

    Barnes, D M; Kihn, P; von Fraunhofer, J A; Elsabach, A

    2000-01-01

    This study evaluated the relationship between fissure sealant viscosity, leakage prevention and the incidence of void formation of five commercially available pit-and-fissure sealants. Seventy-two intact, caries free human pre-molars and molars were divided into six test groups of 12 teeth each. All teeth were cleaned with a flour of pumice prophylaxis followed by etching for 60 seconds with 37% H3PO4, rinsing for 30 seconds and drying with oil-free air. Five commercial, light-cured fissure sealants and an unfilled version of one sealant were applied following manufacturers' instructions. Teeth were thermal cycled for 5000 cycles from 5-50 degrees C with a one-minute dwell time at each temperature. Silver nitrate staining followed by mesiodistal sectioning was performed. Leakage and void formation were evaluated at X50 optical magnification. Viscosity was assessed by syringing the fissure sealants into short pipettes, allowing free flow for 30 seconds and then light curing for one minute. The length of unfilled capillary was measured with a Vernier gauge. All experimental data was subjected to a one-way ANOVA, and where differences were detected, they were identified by a post hoc Tukey hsd test at a priori alpha = 0.05. Based on the conditions of the study, viscosity and flow characteristics had no effect on sealing ability or void formation.

  11. Effect of occlusal calculus utilized as a potential "biological sealant" in special needs patients with gastric feeding tubes: a qualitative in vitro contrast to pit and fissure sealant restorations.

    Science.gov (United States)

    Owens, Barry M; Sharp, Harry K; Fourmy, Emily E; Phebus, Jeffrey G

    2016-01-01

    The aim of this case report and in vitro investigation was to evaluate the marginal microleakage of intact occlusal calculus of primary molars extracted from a special needs patient who received nutrition via a gastric feeding tube. An adolescent with a history of developmental disturbance presented for routine dental care in a hospital facility. Prophylaxis was performed, and 2 mandibular permanent molars were restored. Five primary molars were extracted due to mobility and delayed retention. Heavy deposits of intact calculus were present on the occlusal surfaces of the primary teeth. The extracted teeth were immersed in methylene blue dye solution, invested in acrylic resin, sectioned into blocks, and photographed at 20× and 40× magnification. Previously photographed calculus-free molars with pit and fissure sealants were reviewed and served as contrasting "restorations." The occlusal calculus on the primary teeth extracted from the patient absorbed the dye, while the comparison teeth containing pit and fissure sealants exhibited varying degrees of marginal dye penetration (microleakage). No marginal microleakage was noted in the calculus specimens, indicating that this substrate may serve as a "natural" occlusal surface sealant and that its removal from occlusal surfaces during routine oral prophylaxis may be unnecessary.

  12. Comparison of short-term in vitro fluoride release and recharge from four different types of pit-and-fissure sealants.

    Science.gov (United States)

    Koga, Hiroshi; Kameyama, Atsushi; Matsukubo, Takashi; Hirai, Yoshito; Takaesu, Yoshinori

    2004-08-01

    The purpose of this in vitro study was to assess the effects of four commercial fluoride-containing pit-and-fissure sealants on caries prevention. Four sealants containing fluoride, Fuji III, Fuji III LC (GC Co., Tokyo), Teethmate F-1 (Kuraray Medical Co., Osaka) and Helioseal F (Vivadent Co., Liechtenstein) were used to investigate fluoride release and recharge. Disk-shaped specimens prepared from each material were immersed in distilled water at a temperature of 37 degrees C. After seven days, acidulated phosphate fluoride solution (APF) was applied to each specimen, and it was then again immersed in distilled water for 14 days. We then determined how much fluoride had been released into the immersing water. Fuji III LC was used with APF solution to investigate the fluoride uptake. Fuji III had the highest fluoride release, and Fuji III LC had the highest fluoride recharge. Helioseal F and Teethmate F-1 had almost no fluoride recharge. Fuji III LC/APF had a higher fluoride uptake to enamel than Fuji III LC. These results suggest that GIC-sealants in the oral cavity can serve as a fluoride reservoir and contribute to retaining a low fluoride level in oral fluids, thereby preventing caries.

  13. An in vitro comparison of microleakage of two self-etched adhesive and the one-bottle adhesive used in pit and fissure sealant with or without saliva contamination.

    Science.gov (United States)

    Bassir, Leila; Khanehmasjedi, Mashaallah; Nasr, Ehsan; Kaviani, Azita

    2012-01-01

    To minimize the deleterious effects of contaminated enamel on bonding, some authors have advocated the use of adhesive systems under the sealant. The aim of this study was to compare the microleakage of two self-etch and the one-bottle adhesive used in pit and fissure sealant with or without saliva contamination. Sixty extracted premolar teeth were assigned to the six groups. Group 1: Acid +saliva +single bond +sealant, Group 2: Acid +single bond +sealant, Group 3: Saliva +S (3) bond +sealant, Group 4: S (3) bond +sealant, Group 5: Saliva +protect bond +sealant, Group 6: Protect bond +sealant. The teeth were thermocycled and immersed in 2% basic fuchsine dye for 24 h, then sectioned and examined with a stereomicroscope under ×40 magnification. The results were evaluated with Kruskal-Wallis and Dunn tests. Group 2 has the lower microleakage scores than Groups 4 and 6. Also, Group 6 has the lower microleakage scores than Group 4, and generally an increase in microleakage was observed in each group related to contamination. The best technique of sealant therapy in saliva contaminated and non- contaminated condition is the use of acid-etching and bonding agent.

  14. KEBERHASILAN PENETRASI BAHAN PIT & FISSURE SEALANT KE DALAM FISURA MENGGUNAKAN SYRINGE BLUE MICRO TIPS DAN SYRINGE WHITE MINI BRUSH TIPS (LAPORAN PENELITIAN)

    OpenAIRE

    2015-01-01

    The aim of this study was to know the success and differences of pit & fissure sealant materal penetration of composite resin type (UltraSeal XT Plus) into fissure by using syringe blue micro tips and syringe white mini brush tips in fissure closure efforts for caries prevention of permanent teeth. The study was conducted to 30 maxillary first premolar, using syring blue micro tips, and 30 maxilary first premolar using syringw white mini brush tips. The samples, then, were made smears and...

  15. Pit and Fissure Sealants with Different Materials: Resin Based x Glass Ionomer Cement – Results after Six Months

    Directory of Open Access Journals (Sweden)

    Priscilla Santana Pinto Gonçalves

    2016-01-01

    Full Text Available Objective: To compare the retention and superficial characteristics between a new resin-modified glass ionomer sealant and resin sealant. In addition, the teeth sealed were compared to partially erupted first molars (control group without sealing in relation to the incidence of dental caries. Material and Methods: Initially, 31 children aged 6-8 years participated in this study. The study children showed caries history, but had at least two healthy first molars. A total of 114 teeth were randomly divided into three groups: Clinpro (n=36, Fluroshield (n=38, and control (n=40. The two sealants were applied under relative isolation after previous prophylaxis and enamel etching with phosphoric acid 35% (15s. Clinical evaluation was performed by two calibrated examiners. They evaluated the retention and surface characteristics of the occlusal surface. Results: Fluroshield® showed significantly greater retention than ClinproTM Varnish® XT (p=0.002. However, the performance analysis of the success and failure of retention presented no significant difference between the materials (p=0.141. Concerning to the surface characteristics, Fluroshield performed better than Clinpro after analyzing the marginal deterioration, marginal discoloration, and superficial discoloration (p<0.05. The surface texture of the materials under study was similar (p=0.071. Sealed groups (Clinpro=Fluroshield showed similar performance in the prevention of dental caries, which was significantly lower than that of control group (p=0.001. Conclusion: Both sealants, Fluroshield® and Clinpro TM Varnish® XT were effective in preventing caries lesion within 6 months, although Fluroshield sealant showed better clinical retention.

  16. Protocol for “Seal or Varnish?” (SoV) trial: a randomised controlled trial to measure the relative cost and effectiveness of pit and fissure sealants and fluoride varnish in preventing dental decay

    OpenAIRE

    Chestnutt, Ivor Gordon; Chadwick, Barbara Lesley; Hutchings, Simon; Playle, Rebecca Anne; Pickles, Timothy E.; Lisles, Catherine; Kirkby, Nigel; Morgan, Maria Zeta; Hunter, Margaret Lindsay; Hodell, Ceri; Withers, Beverely; Murphy, Simon; Morgan-Trimmer, Sarah; Fitzsimmons, Deborah; Phillips, Ceri

    2012-01-01

    Abstract Background Dental caries remains a significant public health problem, prevalence being linked to social and economic deprivation. Occlusal surfaces of first permanent molars are the most susceptible site in the developing permanent dentition. Cochrane reviews have shown pit and fissure sealants (PFS) and fluoride varnish (FV) to be effective over no intervention in preventing caries. However, the comparative cost and effectiveness of these treatments is uncertain. The primary aim of ...

  17. Pit and Fissure Sealants in Young Adults: An Evaluation of Placement Time and Retention Rate Using Two Isolation Techniques.

    Science.gov (United States)

    1983-01-01

    described as "the single most important anatomical feature leading to the development of occlusal caries" (13). 4 Recent state and national surveys have...was caused due to placement of the sealant. One patient returned after five days and stated he was still having temporomandibular joint dysfunction...longitudinal study of caries development in initially caries-free naval recruits, J Dent Res 61:1405-1407, 1982. 15. Miller, N. D.: Preventive treatment of teeth

  18. Clinical Evaluation of Helioseal F Pit and Fissure Sealant in Preventive Resin Restoration%Helioseal F窝沟封闭剂应用于预防性树脂充填术的临床疗效评价

    Institute of Scientific and Technical Information of China (English)

    雷志红; 任辉

    2011-01-01

    Objective To evaluate the clinical effects of Helioseal F pit and fissure sealant on preventive resin restoration. Methods Two hundred and six permanent molars with small carious lesions in pits and fissures were enrolled in the study and randomly divided into two groups. After cavities preparation, Heliomolar composite resin was used to restore the lesions, then covered with Helioseal F pit and fissure sealant (trial group) or Helioseal pit and fissure sealant ( control group) respectively. Effects of treatment were evaluated with modified United States Public Health Service evaluation eriterion, when patients were recalled 3, 6, 12, 18 and 24 months after therapy. Results During two years' follow-up, in regard to retention, marginal sealing, and marginal staining, there were no significant differences between two groups ( P > 0. 05 ), but there was significant statistical differences in occurrence of secondary caries between two groups (P < 0. 05). Conclusion The result indicats that Helioseal F pit and fissure sealant could get satisfied clinical effect when used in preventive resin restoration. It is much better than traditional pit and fissure sealant in preventing secondary caries.%目的 评价Helioseal F窝沟封闭剂应用于预防性树脂充填术的临床疗效.方法 206颗窝沟龋患牙,随机分为2组,试验组102颗,预防性树脂充填后应用Helioseal F窝沟封闭剂;对照组104颗,预防性树脂充填后应用Helioseal窝沟封闭剂.术后3、6、12、18、24个月复查,采用改良的美国公共卫生署评价标准进行疗效评估.结果 随访的2年内,2组固位情况、边缘密合性、边缘着色方面的差异均无统计学意义(P>0.05),术后2年的继发龋发生率差异有统计学意义(χ2=6.572,P=0.010).结论 Helioseal F窝沟封闭剂应用于预防性树脂充填术2年临床疗效肯定,在预防继发龋方面效果优于传统窝沟封闭剂.

  19. Retention and penetration of a conventional resin-based sealant and a photochromatic flowable composite resin placed on occlusal pits and fissures

    Directory of Open Access Journals (Sweden)

    Aguilar F

    2007-01-01

    Full Text Available This study compares the retention and penetration of a conventional resin-based sealant (Fluroshield and a photochromatic flowable composite resin (Tetric Flow Chroma placed on occlusal pits and fissures and submitted to thermal or chemical cycling regimens. Penetration assessment - ten premolars were sealed with each material, isolated (except for the sealed surface and immersed in 0.2% Rhodamine B. The teeth were serially sectioned in a mesiodistal direction. The images of the sections were digitized and analyzed (ImageLab. The distance between the most superficial and the deepest points on the occlusal central groove was calculated to determine the groove′s total depth. The length of the central groove filled with the sealant was divided by its total depth to obtain the percentage of sealing of the occlusal groove. Retention assessment - 30 premolars were sealed, their occlusal surfaces were photographed and the area occupied by the sealing materials was demarcated (ImageLab. The teeth were submitted to different treatments: thermocycled, stored in artificial saliva and immersed in acetic acid and saliva (10 cycles/day protocol for 30 days. New photographs were taken to assess the final area occupied by the materials. The difference between the final and initial area was calculated to obtain the material loss. The data was analyzed (two-way anova and Tukey′s test P < 0.05. Both materials presented similar penetration of the occlusal central groove. After thermal and chemical cycling, the materials did not differ with respect to retention, except for immersion in acetic acid. In this case, Tetric Flow Chroma presented greater retention than Fluoroshield.

  20. Marginal Microleakage of Conventional Fissure Sealants and Self-Adhering Flowable Composite as Fissure Sealant in Permanent Teeth

    OpenAIRE

    Sara Rahimian-Imam; Nahid Ramazani; Mohammad Reza Fayazi

    2015-01-01

    Objectives: Application of sealants is a safe and effective way to prevent occlusal caries in the posterior teeth. A successful sealant therapy depends on good isolation. Decreased steps of adhesive application may enable proper isolation and use of self-adhering flowable composites for sealant therapy. This study sought to compare the marginal microleakage of fissure sealants and self-adhering flowable composites in permanent teeth.Materials and Methods: This in vitro, experimental study was...

  1. Evaluation of pit and fissure sealant intervation recall mode of children' s oral health in Zunyi%儿童窝沟封闭综合干预项目4种召回模式评价

    Institute of Scientific and Technical Information of China (English)

    周丽俐; 王胜; 张绍伟; 刘君武; 李炳红

    2013-01-01

    目的 对遵义市7~9岁儿童进行窝沟封闭综合干预所采用的4种召回模式进行分析评价,探讨窝沟封闭综合干预的经验与模式.方法 采用标准流程、电话召回、学校群体召回、学校现场封闭4种模式组织召回7~9岁符合窝沟封闭适应证的儿童进行第一恒磨牙窝沟封闭综合干预,对不同召回模式效果进行评价,在6个月和12个月后进行回访,检测窝沟封闭的完好率.对不同模式召回的儿童进行口腔健康干预,并在6个月后对他们进行口腔健康知识问卷调查.结果 学校现场封闭组口腔卫生知识和刷牙知识的知晓率分别为89.56%和78.39%,高于其他3个组,差异有统计学意义(P<0.05).群体召回模式的学校群体召回组、学校现场封闭组窝沟封闭召回实施率分别为95.66%、92.82%,好于零散召回模式的标准流程组和电话召回组,差异有统计学意义(P<0.05).四手操作窝沟封闭后6个月和12个月封闭物完好率分别为96.63%和85.14%.结论 7~9岁儿童窝沟封闭召回方式尽量采用群体召回尤其是进入学校现场窝沟封闭的模式.%Objective To evaluate 4 recalling modes for pit and fissure sealant in 7 -9 years old children in Zunyi and summarize the intervention experience of Zunyi in the pit and fissure sealant. Methods Recalled 7-9 years old children whose first permanent molars mel the pit and fissure sealant indications in groups or scattered, to execute pit and fissure sealant intervention, and evaluated the results of different recall modes. Children were followed up after 6 months and 12 months to check the sealant retention rate. Questionnaire survey of oral health knowledge and oral health behavior was done before and after oral health intervention. Results The oral health awareness of the group which were conducted during oral health classes reached 89.56%. The different effects of pit and fissure sealant project varied while recall models

  2. in vitro evaluation of marginal leakage using invasive and noninvasive technique of light cure glass ionomer and flowable polyacid modified composite resin used as pit and fissure sealant

    Directory of Open Access Journals (Sweden)

    Anshu Singla

    2011-01-01

    Full Text Available Aim: This study compared the microleakage of light cure glass ionomer and flowable compomer as pit and fissure sealant, with and without tooth preparation. Materials and Methods: One hundred premolars that were extracted for orthodontic purpose were used. After adequate storage and surface debridement, the teeth were randomly divided into four groups. In Group I and III, the occlusal surfaces were left intact, while in Group II and Group IV, tooth surfaces were prepared. Teeth in Group I and Group II were sealed with Light cure glass ionomer, whereas flowable compomer was used to seal teeth in Group III and IV. The sealed teeth were then immersed in dye. Subsequently, buccolingual sections were made and each section was examined under stereomicroscope for microleakage followed by scoring. Results: In group I, microleakage score ranged from 2 to 4 with mean of 3.64 (±0.757, while in group II the range was observed to be 1-4 with mean of 2.88 (±1.236. Group III recorded a range of 0-4 with the mean of 2.20 (±1.443 while 0-2 and 0.60 (±0.707 being the range and mean observed, respectively, for group IV. Conclusion: Flowable compomer placed after tooth preparation showed better penetration and less marginal leakage than the light cure glass ionomer.

  3. KEBERHASILAN PENETRASI BAHAN PIT & FISSURE SEALANT KE DALAM FISURA MENGGUNAKAN SYRINGE BLUE MICRO TIPS DAN SYRINGE WHITE MINI BRUSH TIPS (LAPORAN PENELITIAN

    Directory of Open Access Journals (Sweden)

    Avy Permata Sari

    2015-07-01

    Full Text Available The aim of this study was to know the success and differences of pit & fissure sealant materal penetration of composite resin type (UltraSeal XT Plus into fissure by using syringe blue micro tips and syringe white mini brush tips in fissure closure efforts for caries prevention of permanent teeth. The study was conducted to 30 maxillary first premolar, using syring blue micro tips, and 30 maxilary first premolar using syringw white mini brush tips. The samples, then, were made smears and observed by optic microscope with 300 times magnification. The result of this stuy showed that mean of pit & fissure sealant material penetration of composite resin type into fissure by using blue micro tips was (67.93 ± 13.09%. By using syringe white mini brush tips was (92.96 ± 6.18%. With t-test, it showed a significant difference (t = 9.84, p<0,01.

  4. Marginal Microleakage of Conventional Fissure Sealants and Self-Adhering Flowable Composite as Fissure Sealant in Permanent Teeth

    Directory of Open Access Journals (Sweden)

    Sara Rahimian-Imam

    2015-11-01

    Full Text Available Objectives: Application of sealants is a safe and effective way to prevent occlusal caries in the posterior teeth. A successful sealant therapy depends on good isolation. Decreased steps of adhesive application may enable proper isolation and use of self-adhering flowable composites for sealant therapy. This study sought to compare the marginal microleakage of fissure sealants and self-adhering flowable composites in permanent teeth.Materials and Methods: This in vitro, experimental study was conducted on 60 extracted human premolar teeth. The teeth were divided randomly into two groups of 30. In the first group, fissure sealant (Clinpro, 3M ESPE, USA was placed on the teeth. In the second group, self-adhering flowable composite (Vertise Flow, Kerr, USA was applied as the sealant. Then, both groups were immersed in 0.5% fuchsin dye solution for 24 hours. Sectioned samples were observed with a stereomicroscope for the extent of dye penetration. Data were analyzed using SPSS 21 and the Mann-Whitney test (P<0.05.Results: Microleakage in the fissure sealant group was significantly higher than that in the self-adhering flowable composite group (P<0.001.Conclusion: Microleakage was less using self-adhering flowable composite compared to conventional fissure sealant; therefore, self-adhering flowable composite can be used as a suitable fissure sealant in permanent teeth.

  5. Clinical evaluation of pit and fissure sealant with light-cured flowable resin and light-cured pit and fissure sealants%光固化封闭剂与光固化流体树脂窝沟封闭临床效果评价

    Institute of Scientific and Technical Information of China (English)

    曹慧珍; 束陈斌; 汪隼; 黄伟

    2011-01-01

    目的:比较光固化流体树脂与光固化封闭剂在实施窝沟封闭方面防龋成本及保留率的差异.方法:选择上海市7~10岁儿童256名,口腔内至少有1对第一恒磨牙无龋.每名儿童一侧的恒磨牙用光固化流体树脂进行窝沟封闭,另一侧用传统光固化封闭剂进行窝沟封闭,使用便携式牙科椅吸取唾液,并用棉卷隔湿.使用2种方法操作时记录每个牙封闭所用去的棉卷数和操作时间.1a后,检查2种材料在牙面上的保留情况.所有操作均在学校内施行,检查由2名医师用镰形探针进行,采用SPSS 10.0软件包对数据进行统计学分析.结果:使用传统光固化封闭剂进行窝沟封闭操作时间每牙需3.53min,而光固化流体树脂组需3.32min(P<0.05).在封闭剂的保留率方面,光固化流体树脂组显著高于传统的窝沟封闭组(P<0.05).结论:应用光固化流体树脂进行窝沟封闭,能用较短操作时间达到防龋目的,适合在学校推广应用.%PURPOSE: To evaluate the difference between light-cured flowable resin and light-cured pit and fissure sealant in the cost and retention rate of pit and fissure sealant treatment. METHODS: Two hundred and fifty six children aged from 7 to 10 years were selected in this study. Each of them had at least two caries-free first molars. One first molar was sealed with light-cured flowable resin and the other one was sealed with traditional light-cured sealant. The portable dental chair were used to absorb saliva and cotton rolls were applied for moisture control. The operation time and number of cotton rolls used were recorded. After one year, the reservation of material was checked by two dentists using explorer. All the procedures were undertaken in schools.The data were analyzed using SPSS 10.0 software package. RESULTS: It took 3.53 minutes for one tooth to be sealed with traditional light-cured sealant and 3.32 minutes with light-cured flowable resin (P<0.05). The retention

  6. Curative effects of pit and fissure sealant and fluor protector on preventing caries%窝沟封闭和氟保护漆预防学生恒牙龋的疗效观察

    Institute of Scientific and Technical Information of China (English)

    蔡蔚; 高祯; 王奕; 霍东婷

    2016-01-01

    Objective To compare the caries⁃preventive effect between pit and fissure sealant and fluor protector on first permanent molars pit and fissure caries. Methods The first permanent molars of 300 children were treated respectively with light cured pit and fissure sealant (left side) and fluor protector (right side), and incidence of caries was examined respectively after 0.5, 1.0 and 2.0 years. Results No significant differences of incidence of caries were detected after 0.5, 1.0 and 2.0 years. Conclusion Both pit and fissure sealant and fluor protector have good clinical effect on preventing caries.%目的:比较窝沟封闭和氟保护漆预防学生年轻第一恒磨牙窝沟龋的效果。方法应用两种材料对300名小学生进行上下颌第一恒磨牙同体对照封闭试验,左侧使用光固化窝沟封闭剂,右侧使用氟保护漆,于0.5、1.0、2.0年观察3次龋病发生情况。结果0.5、1.0、2.0年左右侧第一恒磨牙龋齿发生率均无统计学意义。结论窝沟封闭和氟保护漆均有良好的防龋效果。

  7. A 12-month clinical evaluation of pit-and-fissure sealants placed with and without etch-and-rinse and self-etch adhesive systems in newly-erupted teeth

    Directory of Open Access Journals (Sweden)

    Maryam Karami Nogourani

    2012-06-01

    Full Text Available OBJECTIVES: The objective of this one-year clinical study was to investigate the effect of two adhesive systems (Adper Single Bond, a two-step etch-and-rinse and Clearfil SE Bond, a two-step self-etch system on pit-and-fissure sealant retention in newly-erupted teeth. This study compared the success of the sealants in mesial and distopalatal grooves with and without these two adhesive systems. MATERIAL AND METHODS: In a clinical trial, 35 children aged 6-8 years undergoing sealant placement were recruited. This one-year clinical study scored 70 mesial and 70 distopalatal sealants of newly-erupted permanent maxillary first molar, with a split-mouth design. All children received sealant alone in one permanent maxillary molar tooth. Children were randomized into two groups. One group received Self-etch (Se bond plus sealant and the other group received Single Bond plus sealant in another permanent maxillary molar tooth. Clinical evaluation at 3, 6 and 12 months was performed and the retention was studied in terms of the success and failure. RESULTS: The success rate of sealant in the distopalatal groove, using SeB at 3, 6 and 12 months was 93.3% (95% CI: 68.0, 99.8, 73.3% (95% CI: 44.9, 92.2 and 66.7% (95% CI: 38.4, 88.2, respectively. It was greater than that of the distopalatal groove in SB group with a success rate of 62.5% (95% CI: 35.4, 84.8, 31.3% (95% CI: 11.8, 58.7 and 31.3% (95% CI: 11.8, 58.7, at the three evaluation periods. The success rate of sealant in the mesial groove using SeB was 86.6% (95% CI: 59.5, 98.3, 53.3% (95% CI: 26.6, 78.7 and 53.3% (95% CI: 26.6, 78.7, while this was 100% (95% CI: 79.4, 100.0, 81.3% (95% CI: 54.4, 96.0 and 81.3% (95% CI: 54.4, 96.0 using SB, at 3, 6 and 12-month evaluation periods. CONCLUSIONS: These results support the use of these two bonding agents in pit-and-fissure sealants under both isolated and contaminated conditions. Further, Se bond seemed to be less sensitive to moisture contamination.

  8. In vitro Microleakage Comparison of Two Fissure Sealants and two Flowable Composite Resins

    Directory of Open Access Journals (Sweden)

    Ahmadi M.

    2012-02-01

    Full Text Available Statement of Problem: Nowadays, fissure sealants are commonly used for sealing the occlusal pit and fissures. However, flowable composites which are more resistance to wear and have a lower amount of shrinkage might be a good substitute for sealants.Purpose: The aim of this study was to compare the amount of micro-leakage between two types of fissure sealants, clinpro and embrace, and two kinds of flowable composites, Filtek flow and Flows-Rite.Materials and Method: 60 intact extracted maxillary permolars were selected and divided into 4 groups. In each group, occlusal fissures of the samples were sealed with fissures sealants (clinpro or Embrace or flowable composites (Filtek flow or Flows-Rite. The apex and furcation of all the teeth were sealed by sealing wax and then the root and crown of the samples were covered by two layers of nail varnish to 1 mm next to the sealant margin. The teeth were immersed in 0.5% fuchsine for 24 hours; then, the teeth were washed and cut off parallel to the linear axis. The microleakage of the samples was studied under the stereomicroscope with a magnification of 16x. Finally, data were analyzed using the Kruskal-Wallis test.Results: There was no significant difference between the amount of microleakage of fissure sealants (clinpro and embrace and flowable composites (filtek flow and Flows-Rite. Conclusion: Under the circumstances of this study and with respect to the clinical situation, it seems that both flowable composite and fissure sealants are suitable materials for pit and fissure sealing.

  9. 窝沟封闭术联合氟保护漆在预防儿童龋齿中的疗效观察%Effects of pit and fissure sealant joint fluor protector on the prevention of childhood caries

    Institute of Scientific and Technical Information of China (English)

    张晓蓉; 王小燕; 闫亮

    2013-01-01

    目的 探讨窝沟封闭术联合氟保护漆对预防儿童龋齿的效果.方法 选取2010年1月至2011年1月在该院进行健康体检的96例儿童(5~8岁)为研究对象,随机将其分为A组、B组及对照组3组,每组各32名儿童.A组儿童采用窝沟封闭术进行预防治疗,B组儿童采用窝沟封闭术联合0.5%高露洁的多乐氟(Duraphat)进行预防治疗,对照组儿童单纯行日常刷牙口腔护理.对3组儿童进行为期2年的随访,观察龋齿发生率以及A、B两组儿童封闭剂脱落情况.结果 A、B组儿童龋齿发生率显著低于对照组儿童,差异有统计学意义(P<0.05).与A组比较,B组儿童龋齿发生率较低,B组儿童窝沟封闭剂治疗后保留的情况较好,差异均有统计学意义(P<0.05).结论 对学龄儿童采用窝沟封闭术联合氟保护漆预防龋齿的临床效果理想,氟保护漆能起到保护窝沟封闭剂的作用,防止封闭剂脱落,从而能有效预防儿童龋齿.%Objective To investigate the effect of pit and fissure sealant joint fluor protector on the prevention of childhood caries. Methods 96 healthy children(5-8 years old) were divided into three groups ( group A, group B, and the control group ),there were 32 children in each group. A group of children preventive treatment pit and fissure sealant pit and fissure sealant joint 0. 5% Colgate Dole fluorine was used in groud A. Pit and fissure sealant was used in (Duraphat), B-group children. Preventive treatment of Preventive treatment was used in children in tthe control group a simple line of oral care of daily brushing, Three groups of children was follow up two year. The incidence of dental caries was observed in two groud. Results Child caries incidence of group A and group B was significantly lower than children in the control group, the difference was statistically significant (P<0. 05 ). Group B children caries incidence was lower than the A group, the difference was statistically significant (P

  10. Application of glass ionomer and light-cured resin sealant to the pit and fissure of deciduous teeth%玻璃离子与光固化树脂封闭剂封闭乳牙窝沟

    Institute of Scientific and Technical Information of China (English)

    任飞; 刘建平; 黄少宏; 李艳容; 范卫华; 陈晓春; 陈清

    2011-01-01

    背景:传统方法玻璃离子作为封闭剂耐磨性能差,抗折强度低,位于合面的封闭剂很容易脱落,很难取代树脂封闭剂.目的:观察光固化树脂封闭剂和非创伤性充填技术玻璃离子窝沟封闭幼儿乳牙的效果.方法:按同人半口随机比较的方法,对89名3岁幼儿的左或右半口符合窝沟封闭条件的乳磨牙在非创伤性充填技术下行玻璃离子窝沟封闭,对侧半口符合窝沟封闭条件的乳磨牙进行树脂封闭.结果与结论:窝沟封闭后6,18个月玻璃离子组封闭物脱落率均低于树脂材料组(P < 0.05).玻璃离子材料最易脱落的牙位是下颌第二乳磨牙;树脂材料最易脱落的牙位是上颌第二乳磨牙.封闭后6个月,玻璃离子组封闭的乳牙患龋率低于树脂材料组,18个月时两组间差异无显著性意义.说明非创伤性充填技术玻璃离子窝沟封闭幼儿乳牙的脱落率低,操作简单,防龋效果肯定,且成本低,在经济学上可行性优于树脂封闭.%BACKGROUND: Traditional glass ion sealant has a poor abradability and a low rupture strength. The sealant on the occlusal surfaces easily fell off, and is difficult to replace resin sealant. OBJECTIVE: To observe the effects of traditional resin sealant and atraumatic restorative treatment (ART) glass ionomer-based pit and fissure sealant for the young children. METHODS: Randomized comparison method was used to compare ART glass ionomer-based pit on molars of one side with resin sealant on the opposite side in 89 3-year-old children. RESULTS AND CONCLUSION: The retention rates of ART glass ionomer sealant after 6 and 18 months were significantly lower than those of resin sealant (P < 0.05). The caducous position of ART gliass ionomer sealant was the second deciduous molar of the lower mandible, but the caducous position of resin sealant was the second deciduous molar of the upper mandible. The secondary caries rate of ART glass ionomer sealant was significantly

  11. 窝沟封闭术在儿童口腔临床中的应用和防龋效能%The efficiency and application of pit and fissure sealant technique in clinical pediatric dentistry

    Institute of Scientific and Technical Information of China (English)

    吴幸晨; 束陈斌

    2013-01-01

      Dental fissure in children has unique anatomical and physiological features, which provide a micro-e-cological environment for the growth of bacteria colonization and plaque accumulation, and then will result in dem-ineralization of teeth surfaces and occurrence of caries, and pit and fissure caries accounts for the vast majority of them. The pit and fissure sealant technique has become one of the most effective prevention methods. At present, the clinical dentists usually use enameloplasty sealant technique(EST), or conventional sealant technique(CST) to prevent caries happening. The application of EST can be preferred to CST for improving adhesion, adaptation, pen-etration and the remaining rate of the sealant within the fissure system, and also has less microleakage. Thus enameloplasty has been implicated in the successful application of pit and fissure sealants. The following words will discuss about the research progress in efficiency and application of the pit and fissure sealant, in order to ap-ply reference to the operation in children.%  儿童乳磨牙和年轻恒磨牙窝沟以其独特的解剖和生理特点,为细菌的生长定植,菌斑的集聚提供了一个微生态环境,从而导致牙面脱矿和龋的发生,其中又以窝沟龋占绝大多数。窝沟封闭术是儿童窝沟龋最有效的预防方法之一,临床上常用的窝沟封闭术有常规窝沟封闭术(CST)和釉质窝沟封闭术(EST)。 EST的应用明显地提高了封闭剂的黏结面积,增强了封闭剂在牙面上的黏结性、渗透性和密合性,既提高了窝沟封闭剂的保留率和防龋效果,还可及时地发现窝沟早期龋和隐匿龋,明显地提高了窝沟封闭剂的保留率,其防龋效果优于CST。本文就窝沟封闭术的临床应用和窝沟封闭术的防龋效能等研究进展作一综述,旨在为儿童窝沟封闭术的操作提供部分参考。

  12. Microleakage, adaptation ability and clinical efficacy of two fluoride releasing fissure sealants

    Directory of Open Access Journals (Sweden)

    Marković Dejan

    2012-01-01

    Full Text Available Background/Aim. Retention of fissure sealants and good adaptation to enamel are essential for their success. Fluoride releasing resin-based materials are widely accepted for pit and fissure sealing, but newly designed glass ionomers can serve as a good alternative. The aim of this study was to evaluate microleakage and sealing ability in vitro, and to clinically assess two fluoride releasing fissure sealants. Methods. The sample for experimental study consisted of 20 freshly extracted intact human third molars, divided in two experimental groups according to the sealing material: fluoride releasing resin-based (Heliosel F and glass ionomer (Fuji Triage material. Digital images and scanning electron microscope were used to assess microleakage and adaptation ability. Sample for clinical study consisted of 60 children, aged 6-8 years, with high caries risk, divided in two groups according to the sealant material. Fissure sealant was applied to all erupted, caries-free first permanent molars. Sealants were evaluated after 3, 6 and 12 months using modified Ryge criteria for retention, marginal adaptation, colour match, surface smoothness and caries. Results. Microleakage was detected in more than half of the specimen, without significant differences between the two groups (p > 0.05. Both materials exhibited acceptable sealing ability. Complete retention at the end of the observation period was 81.8% for resin-based, and 21.1% for glass-ionomer fissure sealant (p < 0.001. The presence of caries in sealed molars has been detected in one patient in both groups. During the 12-month observation period, Helioseal F demonstrated better retention, marginal adaptation and surface smoothness (p < 0.001. There were no differences between the two materials regarding caries and color match (p > 0.05. Conclusion. Both tested materials demonstrate satisfactory clinical and caries prophylactic characteristics that justify their use in contemporary preventive

  13. 东莞市小学生窝沟封闭术预防儿童窝沟龋齿的临床效果分析%Clinical Analysis of Dongguan Primary Pit and Fissure Sealant Pit and Fissure Caries Prevention

    Institute of Scientific and Technical Information of China (English)

    项琳怡; 彭冲

    2014-01-01

    Objective:By comparing the use of pit and fissure sealant(PFS) for three consecutive years child retained its caries pit and fissure sealants,to explore the application of PFS after clinical efficacy in the prevention of dental caries. Method:From January 2009 to June 2010 in our hospital for treatment of 700 cases of PFS children as the subject of this observation,its first and second permanent treatment given PFS were closed 810 set it as the treatment group;The right to choose their namesake healthy teeth 810 as a control group,treatment group compared with two blocking agent retained caries situation. Result:The treatment group three years after the pit and fissure sealant retention rate was 77.90%,dental caries rate of was 3.14%;Control group after 3 years was 9.75%in treatment group than in control of dental caries incidence was significantly lower(P<0.05). Conclusion:PFS in permanent teeth and the oral environment created a barrier between the clinical indications and ensure sealant attention to its rigor,and adhere to regular review,obvious effect on the effective prevention of dental caries.%目的:通过对比采用窝沟封闭术(PFS)儿童连续3年窝沟封闭剂留存及其龋齿情况,探讨应用PFS后对预防龋齿的临床疗效。方法:将2009年1月-2010年6月来笔者所在医院进行PFS处理的700名儿童作为本次观察主体,将其第一、二恒牙给予PFS处理,共封闭810颗设其为治疗组;选择其右侧同名健康牙810颗作为对照组,对比治疗组封闭剂留存与两组龋齿情况。结果:治疗组3年后窝沟封闭剂留存率为77.90%,龋齿率为3.14%;对照组3年后龋齿率为9.75%,治疗组龋齿发生率明显较对照组低(P<0.05)。结论:PFS是在恒牙与口腔环境间建立的一道屏障,临床注意其适应证和确保窝沟封闭的严密性,并坚持定期复查,对有效预防龋齿效果明显。

  14. Prevalence of dental caries and fissure sealants in a Portuguese sample of adolescents.

    Directory of Open Access Journals (Sweden)

    Nélio J Veiga

    Full Text Available The aims of this study were to assess the prevalence of dental caries and the DMFT index, as well as the distribution pattern of pit and fissure sealants on permanent teeth in a Portuguese sample of adolescents, and to assess whether the existing usage of sealants and socio-demographic factors are correlated to caries prevalence on the examined sample.A cross-sectional study was designed with a sample of 447 adolescents aged 12 to 18 years old, attending a public school in Sátão, Portugal. A self-administered questionnaire with questions about oral health behaviours and socio-economic status was answered by adolescents in the classroom. Clinical examination of oral health status and assessment of fissure sealants were accomplished by only one trained member of the research team.We obtained a DMFT index of 3.32 (2.92, which indicates a moderate level of prevalence of dental caries. When considering a DMFT = 0, we found significant statistical differences between the parents' level of education (≤ 4th grade = 26.3 vs 5th-12th grade = 18.8 vs <12th grade = 43.3, p = 0.001, gender (male = 27.3 vs female = 19.6, p = 0.04, age (≤ 15 years = 27.1 vs <15 years = 18.5, p = 0.02, presence of fissure sealants (yes = 30.6 vs no = 13.5, p = 0.001 and experience of dental pain (no = 25.4 vs yes = 16.8, p = 0.02. When analyzing the prevalence of fissure sealants, we verified that 58.8% of adolescents had at least one fissure sealant applied. Significant statistical differences were found when analyzing the presence of fissure sealants related with parents' educational level (<9th grade, OR = 1.56 CI95% = 1.05-2.54, gender (female, OR = 1.86 CI95% = 1.19-2.98, experience of dental pain (yes, OR = 0.62 CI95% = 0.39-0.97 and presence of dental caries (yes, OR = 0.35 CI95% = 0.19-0.65.The moderate level of caries prevalence reveals the need of improvement of primary prevention interventions among Portuguese adolescents. The establishment of a more targeted

  15. Antibacterial effects of a pit and fissure sealant incorporating a quaternary ammonium monomer%季铵盐单体改性窝沟封闭剂的抗菌性能研究

    Institute of Scientific and Technical Information of China (English)

    李锋; 陈吉华; 吴丹; 李芳; 高婧; 方明

    2011-01-01

    AIM: To incorporate an antihacterial monomer, methacryloxylethyl cetyl dimethyl ammonium chloride ( DMAE-CB) , into a pit and fissure sealant, and to evaluate the antibaccerial activity of this DMAE-CB-incorporated sealant against Streptococcus mutans.METHODS : DMAE-CB was incorporated into a clinically used sealant, Helioseal.Helioseal without DMAE-CB served as a negative control.Helioseal F, containing a fluoride-releasing resin, was used as a positive control.The effects of the cured sealants on the growth and adherence of S.mutans were determined by film contact test and absorbance measurement, respectively.The influence of aging treatment on the antibacterial efficiency of the modified sealant was evaluated.Moreover, the bacterial grwrh in the eluents of three different sealants was investigated.RESULTS: The cured DMAE-CB - incorporated sealant exhibjted inhibitory effect on the growth and atiherence of S.mutans ( P < 0.05) ; whereas its eluent didnt show detectable antibacterial activity.Moreover, after aging treatment, the DMAE-CB-incorporated sealant could still inhibit the growth and adherence of S.mutans significantly ( P <0.05).CONCLUSION: The DMAE-CB-incorporated sealam after polymerization showed a contact antibacterial effect against S.mutans, which could inhibit the haccerial growth and biofilm accumulation.The antibacterial activity could be maintained after aging process.%目的:将季铵盐抗菌单体甲基丙烯酰氧乙基一正十六烷基一二甲基氯化铵(DMAE-CB)添加到窝沟封闭剂中获得改性封闭剂,评价改性封闭剂对细菌生长、黏附的影响.方法:将DMAE-CB添加到商品窝沟封闭剂Helioseal中获得DMAE-CB改性封闭剂作为实验组;未添加抗菌单体的Helioseal则作为阴性对照,具备氟释放功能的窝沟封闭剂Helioseal F作为阳性对照,采用接触抑菌实验和黏附实验评价改性封闭剂的固化表面对变异链球菌生长和黏附的影响;研究老化处理对改性材

  16. Effects of aging on surface properties and adhesion of Streptococcus mutans on various fissure sealants.

    Science.gov (United States)

    Bürgers, Ralf; Cariaga, Tashiana; Müller, Rainer; Rosentritt, Martin; Reischl, Udo; Handel, Gerhard; Hahnel, Sebastian

    2009-12-01

    The aim of the present study was the quantification of Streptococcus mutans adhesion on ten widely used pit and fissure sealant materials and the correlation of these findings to surface roughness (R(a)) and surface free energy (SFE). Additionally, changes in streptococcal adhesion and surface parameters after water immersion and artificial aging have been investigated. Circular specimens of ten fissure sealants (seven resin-based composites, two glass ionomers, and one compomer) were made and polished. Surface roughness was determined by perthometer and SFE by goniometer measurements. Sealant materials were incubated with S. mutans suspension (2.5 h, 37 degrees C), and adhering bacteria were quantified by using a biofluorescence assay in combination with an automated plate reader. Surface properties and S. mutans adhesion were measured prior to and after water immersion after 1 and 6 months and after additional thermocycling (5,000 cycles; 5 degrees C/55 degrees C). The tested sealants showed significant differences in S. mutans adhesion prior to and after the applied aging procedures. Aging resulted in slight increases (mostly <0.2 microm) in surface roughness, as well as in significant decreases in SFE and in significantly lower quantities of adhering bacteria. Ketac Bond and UltraSeal XT plus revealed the lowest adhesion potential after artificial aging. In general, the amount of adhering S. mutans was reduced after aging, which may be related to the decline in SFEs.

  17. Effects Observation of Pit and Fissure Sealant Combined with Fluor Protector Against Dental Caries on Children%儿童窝沟封闭联合氟保护漆防龋的效果观察

    Institute of Scientific and Technical Information of China (English)

    刘艳; 陈晖; 陆蓓; 田琦; 彭艳; 张焱

    2012-01-01

    Objective: To evaluate the effects pit and fissure sealant combined with fluor protector against dental caries on children, to provide interventions for the prevention of dental caries in children. Methods: 120 cases of 3—4-year-old children were selected from department of stomatology and children's dental clinic from Dec.2009 to May.2010. According to the random number table, they were divided into observation group and control group with 60 cases in each group. The control group used fluor protector painting, on this basis the observation group used pit and fissure sealant on the point gap ditch split of deciduous molars crown surface. The incidence of caries and caries of 6 months ,12 months, 24 months of two groups were compared. Results: The incidence of caries and caries at 6 months showed no statistically significant differences between the two groups (P>0.05); the incidence of caries at 12 months compared, the differences were not statistically significant (P>0.05), but the caries of observation group were significantly lower than the control group at 12 months (P<0.05); The incidence of caries and caries of observation group at 24 months were both significantly lower than that of control group, and the differences were statistically significant (P <0.05). Conclusion: Compared with a single prevention mode, the application of pit and fissure sealant and fluor protector against dental caries on children can effectively reduce the incidence of caries, greatly reduce the destruction of dental caries on children's teeth. It is of clinical application.%目的:对儿童窝沟封闭联合氟保护漆的防龋效果进行评价,为儿童龋齿的预防提供干预措施.方法:选择我所预防科于2009年12月~2010年5月检查的3~4岁幼儿120例,按随机数字表法分为观察组和对照组,每组各60例.对照组进行氟保护漆涂布,观察组在此基础上对乳磨牙冠表面点隙沟裂进行窝沟封闭.比较两组6个月、12

  18. Clinical procedure in sealing pit and fissure using technological aids: VistaCam iX Proof and Combi

    Directory of Open Access Journals (Sweden)

    Fabrizio Guerra

    2016-03-01

    Full Text Available The effectiveness of sealants in preventing pits and fissures decay is currently assessed by retention as principal clinical evaluation criteria. Among the determinants for sealant retention, an incomplete removal of plaque debris can cause lack of adhesion at the sealant-enamel interface. Therefore, in order to optimize the caries prevention outcome, clinical procedures of biofilm detection and cleansing are crucial. Technological aids can help clinicians in these critical phases. A clinical procedure is described of sealant application using VistaCam iX Proof fluorescence camera for quantitative assessment of surface demineralization and Combi air polishing unit for plaque removal. Pre and post air polishing intraoral VistaCam iX Proof images show the effectiveness of glycine airpolish technology in plaque removal. The results encourage technological aided clinical procedures in enhancing sealant application for pit and fissures caries prevention. Further clinical research is needed to validate our preliminary outcomes.

  19. Application of pit and fissure sealant in prevention of dental caries in villages and towns%窝沟封闭预防龋齿在乡镇农村的推广应用

    Institute of Scientific and Technical Information of China (English)

    彭建民; 邝丽萍; 陈淑贤

    2015-01-01

    Objective To compare the influence of different ways of oral hygiene instruction, in preservation rate of pit and fissure sealant and explore suitable methods of oral health education in rural villages and towns. Methods 315 children from 6 to 8 years old were selected to accept 3 different oral hygiene instruction ( outpatient service group, school group, health station group) . The preservation rate and intact rate were carefully detected. Results The initial rate of outpatient service group was 96. 70%, compared 92. 30% of school groups and 61. 92% of health station group, which has a significant difference. After 3, 6 months follow-up, the preservation rate of Sealants was 98. 37% and 98. 37%, the intact rate of sealants was 90. 88% and 88. 23%. Conclusion Oral hygiene instruction should be encouraged in dai-ly work. Schools should be organized on a regular basis for oral hygiene instruction. Effective and easily to be accepted, pit and fissure sealant is worth spreading and applying in rural grass roots.%目的:比较不同宣教方式对窝沟封闭率的影响,探讨乡镇农村适宜的口腔卫生宣教方法。方法选择符合纳入标准的6~8岁儿童315名,将其分为门诊组(96名)、学校组(156名)、卫生站组(63名),各组针对窝沟封闭分别采用不同的口腔卫生宣教方法,比较各组封闭率,分析封闭剂保留率与完好率。结果门诊组、学校组、卫生站组封闭率分别为96.70%、92.30%和61.92%。3组封闭后3个月、6个月后复查,封闭剂保留率分别为98.37%和97.23%,封闭剂完好率分别为90.88%和88.23%。结论口腔医师日常工作中开展口腔卫生宣教、学校有组织的进行群体性口腔卫生宣教,能有效推广窝沟封闭的开展,有助于预防龋齿,值得在乡镇农村等基层地区推广应用。

  20. Conversion degree, microhardness, microleakage and fluoride release of different fissure sealants.

    Science.gov (United States)

    Kuşgöz, Adem; Tüzüner, Tamer; Ulker, Mustafa; Kemer, Bariş; Saray, Onur

    2010-11-01

    The purpose of this study was to determine the degree of conversion (DC), microhardness, microleakage and fluoride release of a nano-filled resin based fissure sealant (Grandio Seal, GS) and compare it with an un-filled resin based fissure sealant (Clinpro, CL) and a glass-ionomer based fissure sealant (Fuji Triage, FT). Disk shaped specimens were prepared from tested fissure sealants to determine the DC, Vicker hardness (VHN) and fluoride release (FR). The DC and VHN of each material was evaluated after 24 h. The cumulative fluoride concentrations were evaluated at 1 h, 6 h, 12 h, 1, 7, 15 and 30 days. For microleakage evaluation, fissure sealants were applied to the etched and dried enamel surfaces of sound third molar teeth according to the manufacturer's instructions (n=10). After the thermocycling and mechanical loading procedures, microleakage assessments were carried out. Data were analyzed using one-way ANOVA followed by a post hoc Tukey test, the Kruskal Wallis and Mann-Whitney U test (p GS (55.02%) > CL (%51.10) (p FT > CL (p<0.05). FT exhibited significantly higher microleakage scores compared to the CL and GS sealants (p<0.05). The FR of FT was significantly greater than CL and GS (p<0.05). Nano-filled resin based sealant can be used as an alternative to other fissure sealant materials because of its superior hardness results and feasible sealing ability.

  1. Randomized trial on fluorides and sealants for fissure caries prevention

    OpenAIRE

    Lin, HC; Liu, BY; Lo, ECM; Chu, CH

    2012-01-01

    To investigate the effectiveness of topical fluorides in preventing fissure caries, we conducted a randomized controlled trial with parallel groups. In total, 501 children (1,539 molars, 3,078 sites), mean age 9.1 years, who had at least one sound permanent first molar with deep fissures or fissures with signs of early caries were recruited. They were randomly allocated among four groups: (1) resin sealant, single placement; (2) 5% NaF varnish, semi-annual application; (3) 38% silver diamine ...

  2. Effect evaluation of phosphoric acid etching combined with flowable composite resin in pit and fissure sealant of young per-manent molars%磷酸酸蚀结合流动树脂对年轻恒牙窝沟封闭的疗效分析

    Institute of Scientific and Technical Information of China (English)

    谢妮娜; 宋文婷; 魏路明; 刘宗响

    2015-01-01

    Objective After the teeth were etched with 35%phosphoric acid,the first permanent molars were sealed by 3M flowable composite resin and common pit and fissure sealant so as to compare the retention rate and caries prevalence rate of dental caries by the two kinds of sealing material.Methods 240 permanent mandibular first molars with deep fissures and with no caries among 120 chil-dren of 7-9 years old were selected.The self export control method was used.According to the result of coin tossing,one side was cho-sen as the phosphoric acid +3M flowable resin group,and the other side the phosphoric acid etching +3M pit and fissure sealant group.After 3 months,6 months,12 months,and 24 months,pit and fissure sealant retention and caries rates were respectively exam-ined.Results In the 3rd and 6th months,pit and fissure sealant retention,and caries decrease rate between two groups were different with no statistical significance (P>0.05).In the 12th and 24th months,retention and caries decrease rates in the flowable composite resin group were higher than those in the pit and fissure sealant group,while caries incidence rate was lower than that in the pit and fis-sure sealant group.The differences were statistically significant (P<0.05).Conclusions The clinical effect of the phosphoric acid etching combined with flowable composite resin is better than that of phosphoric acid etching combined with pit and fissure sealant.The former method can increase retention rate of sealing materials,thus lowering prevalence rate of dental caries.%目的:比较3M流动树脂和3M窝沟封闭剂为第一恒磨牙行窝沟封闭术,2种材料窝沟封闭的保留率及龋病发生率情况。方法选择7~9岁120例240颗窝沟较深无龋的下颌第一恒磨牙,采用自身半口对照方法,掷币法随机选择一侧为3M流动树脂组,另一侧则为3M窝沟封闭剂组。于术后3、6、12、24个月复查,检查两组窝沟封闭材料的保留率和封闭后牙

  3. Prevalence of Dental Caries and Fissure Sealants in a Portuguese Sample of Adolescents

    Science.gov (United States)

    Veiga, Nélio J.; Pereira, Carlos M.; Ferreira, Paula C.; Correia, Ilidio J.

    2015-01-01

    Introduction The aims of this study were to assess the prevalence of dental caries and the DMFT index, as well as the distribution pattern of pit and fissure sealants on permanent teeth in a Portuguese sample of adolescents, and to assess whether the existing usage of sealants and socio-demographic factors are correlated to caries prevalence on the examined sample. Materials and Methods A cross-sectional study was designed with a sample of 447 adolescents aged 12 to 18 years old, attending a public school in Sátão, Portugal. A self-administered questionnaire with questions about oral health behaviours and socio-economic status was answered by adolescents in the classroom. Clinical examination of oral health status and assessment of fissure sealants were accomplished by only one trained member of the research team. Results We obtained a DMFT index of 3.32 (2.92), which indicates a moderate level of prevalence of dental caries. When considering a DMFT = 0, we found significant statistical differences between the parents´ level of education (≤ 4th grade = 26.3 vs 5th–12th grade = 18.8 vs Portuguese adolescents. The establishment of a more targeted preventive program with better and more effective oral health education is essential, having into account socio-demographic aspects. PMID:25803849

  4. Comparison of various concentrations of tricalcium phosphate nanoparticles on mechanical properties and remineralization of fissure sealants.

    Directory of Open Access Journals (Sweden)

    Sara Tavassoli-Hojjati

    2014-08-01

    Full Text Available The aim of this study was to investigate the mechanical properties (flexural strength, micro-shear bond strength and remineralizing potential of fissure sealants by adding various concentrations of β-tricalcium phosphate nanoparticles.This in-vitro study consisted of five experimental groups containing prepared nano-fisssure sealants (1-5 wt.% β-TCP nanoparticles and two control groups containing a prepared and a commercial fissure sealant. Flexural/micro-shear bond strength values were measured using Zwick test machine. Cavities on sixty healthy premolar teeth were filled with the fissure sealants containing 0-5 wt.% of nano β-TCP. The samples were assessed for remineralization under scanning electron microscopy (SEM and EDAX. Kolmogorov-Smirnov test, One-way ANOVA and Tukey's Post Hoc analysis/HSD were used to analyze the data.There was no significant difference between the flexural strengths/elastic modulus of the 0-5 wt.% nano β-TCP groups (p>0.05. The average flexural strength/elastic modulus of the prepared fissure sealant group (0% was significantly higher than the commercial fissure sealant group (Clinpro (p0.05. Examining the samples under SEM showed a significant increase in thickness of the intermediate layer with increasing concentrations of β-TCP nanoparticles (p<0.05.Addition of 1-5 wt.% β-TCP nanoparticles to the fissure sealants significantly increased the remineralization potential without affecting the mechanical properties.

  5. Uso de sellantes de fosas y fisuras para la prevención de caries en población infanto-juvenil: Methodological review of clinical trials Use of pit and fissure sealants for preventing caries in child population

    Directory of Open Access Journals (Sweden)

    S Faleiros Chioca

    2013-04-01

    using complementary methods for its control. Pit and fissures sealants represent one of the most effective preventive interventions in dentistry, being considered as a contribution to the public health interventions. Nevertheless, there are no consistent evidences about their true effectiveness and impact in the prevention of caries. These inconsistencies could be due to the presence of bias or the heterogeneity of the studies available in literature. Thus, we propose to make a review with the aim to evaluate the methodological quality of clinical trials using pit and fissure sealants. A search of studies between 1990 and 2012 was conducted and 18 clinical trials that fulfilled the inclusion and exclusion criteria were found. The studies included were obtained and evaluated by a single reviewer. This review concludes that the evidence that guarantees the use of this intervention is methodologically poor. These findings may stimulate the professionals to clarify the truth referring to the effectiveness of sealants, before applying it indiscriminately. The accomplishment of new clinical trials executed with an appropriate methodological design and statistical analysis is recommended, generating reliable results for the decision making that guides the Public Health Policies.

  6. 正畸中加用自酸蚀窝沟封闭术的临床观察%A Comparison Study on Pit and Fissure Sealant Effects of Self-etching Adhesive in Orthdontic Treatment Patients

    Institute of Scientific and Technical Information of China (English)

    廖珩

    2014-01-01

    目的:探究正畸磨牙进行窝沟封闭术中加用自酸蚀剂后流体树脂的保留率和龋齿预防情况。方法选择78例年龄在10~15岁的正畸患者,共150颗健康下颌第一或第二恒磨牙,采用自身半口对照方法。随机选择一侧为试验组,磷酸酸蚀法加用自酸蚀粘接剂处理牙面后以流体树脂进行窝沟封闭;另一侧为对照组,单纯磷酸酸蚀法以流体树脂进行窝沟封闭。定期比较两种牙面窝沟处理方法封闭剂的保留率和龋病发生率,应用 SPSS12.0统计软件包对数据进行卡方检验。结果3个月复查时,经过统计学处理3个月时2组患牙的总脱落率差异无统计学意义(P >0.05);6、12个月时2组患牙的总脱落率差异均有统计学意义(P <0.05)。结论在窝沟封闭中加用自酸蚀粘结剂可提高窝沟封闭剂的封闭效果,提高材料保留率,能有效预防年轻恒牙窝沟龋的发生。%Objective To evaluate the clinical effect of pit and fissure sealant on molar following orthdontic treatment with self-etching adhesive and phosphoric acid. Methods 150 health mandible the first or second molar in 78 orthdontic treatment patients aged from 10 to 15 years were divided into two groups:A and B. The split-mouth design was used in this study. Self-etching adhesive was used only in group A,and orthophosphoric acid was used in the two groups. The rate of the sealant reservation and the caries decreased were compared in two groups,and used SPSS 12. 0 software package for Chi-square test. Results The two group no statistical difference after 3 month. At 6,12 months,the retention rate of self-etching adhesive group was statistically lower than that of phosphoric acid group(P <0. 05). Conclusion Self-etching adhesive can improve the retention rate of pit and fissure sealant.

  7. 不同酸蚀粘接系统对流动树脂行窝沟封闭的影响%The influence of different etching adhesive systems on flowable resin used as pit and fissure sealant

    Institute of Scientific and Technical Information of China (English)

    李洁; 谷建琦; 王琳; 于雪; 董青

    2015-01-01

    Objective:To evaluate the effects of the flowable resin used as pit and fissure sealant using different etching adhesive systems.Methods:60 caries-free extracted human premolars were randomly divided into 4 groups(n =1 5)and treated by Gluma, NT and 3M-Z350 flowable resin(group A);Clearifil SE Bond adhesive and 3M-Z350 flowable resin(group B),phosphoric acid etching,3M-Z350 flowable resin and phosphoric acid etching(group C)and 3Mconcise sealant(group D)respectively.After pro-cessing the tooth surface the pit and fissue of 1 0 sample in each group were sealed.The microleakage was measured by 1 % methyl-ene blue staining(n =8).The material-enamel interface was observed by SEM(n =2).The shear bond strength of the column-shaped samples with the diameter and the height of 3 mm(n =5)on the mesial or dental surface was examined by a test machine. The sealant cartridges and flowable resin cartridges with the diameter and height of 4 mm were used for the crushing strength exami-nation(n =1 0).Results:There was no significant difference in the microleakage among the 4 groups.SEMobservation showed that the resin tags of group A were long and dense and the resin tags of group B were short and sparse,bubbles and cracks were found on the local site in group A and B.The resin tags of group C were long and thin,but combined with tooth tightly;the resin tags of group D were short and dense;the penetration was poor at the bottom of the fissures in the 4 groups.The shear bond strength of Group A was the highest(P 0.05).The compressive strength of flowable resin groups was higher than that of fissure seal-ant group(P <0.05).Conclusion:The shear bond strength and compressive strength of all-etching bonding system combined with flowable resin is superior to that of self-etching bonding system combined with flowable resin and the traditional sealant.Using Prime&Bond NT bond after acid etching may improve the shear bonding strength.%目的:探讨不同酸蚀粘接系统对流动树脂

  8. Protocol for “Seal or Varnish?” (SoV trial: a randomised controlled trial to measure the relative cost and effectiveness of pit and fissure sealants and fluoride varnish in preventing dental decay

    Directory of Open Access Journals (Sweden)

    Chestnutt Ivor Gordon

    2012-11-01

    Full Text Available Abstract Background Dental caries remains a significant public health problem, prevalence being linked to social and economic deprivation. Occlusal surfaces of first permanent molars are the most susceptible site in the developing permanent dentition. Cochrane reviews have shown pit and fissure sealants (PFS and fluoride varnish (FV to be effective over no intervention in preventing caries. However, the comparative cost and effectiveness of these treatments is uncertain. The primary aim of the trial described in this protocol is to compare the clinical effectiveness of PFS and FV in preventing dental caries in first permanent molars in 6-7 year-olds. Secondary aims include: establishing the costs and the relative cost-effectiveness of PFS and FV delivered in a community/school setting; examining the impact of PFS and FV on children and their parents/carers in terms of quality of life/treatment acceptability measures; and examining the implementation of treatment in a community setting. Methods/design The trial design comprises a randomised, assessor-blinded, two-arm, parallel group trial in 6–7 year old schoolchildren. Clinical procedures and assessments will be performed at 66 primary schools, in deprived areas in South Wales. Treatments will be delivered via a mobile dental clinic. In total, 920 children will be recruited (460 per trial arm. At baseline and annually for 36 months dental caries will be recorded using the International Caries Detection and Assessment System (ICDAS by trained and calibrated dentists. PFS and FV will be applied by trained dental hygienists. The FV will be applied at baseline, 6, 12, 18, 24 and 30 months. The PFS will be applied at baseline and re-examined at 6, 12, 18, 24, and 30 months, and will be re-applied if the existing sealant has become detached/is insufficient. The economic analysis will estimate the costs of providing the PFS versus FV. The process evaluation will assess implementation and

  9. Adhesive systems under fissure sealants: yes or no?: A systematic review and meta-analysis.

    Science.gov (United States)

    Bagherian, Ali; Sarraf Shirazi, Alireza; Sadeghi, Ramin

    2016-06-01

    The authors of this systematic review and meta-analysis had 2 aims: to evaluate fissure sealant retention with and without the use of an adhesive system and to compare fissure sealant retention using etch-and-rinse adhesive systems versus self-etching adhesive systems. The authors conducted a literature search (all articles published through November 1, 2015) to identify studies for inclusion in this systematic review. They assessed the quality of the evidence provided using the modified Jadad scale and performed meta-analyses using a random-effects model. The authors considered 12 studies that met the inclusion criteria for the systematic review. In addition, they used 5 of 9 studies related to the first part of the study and 3 of 4 studies related to the second part of the study that met the inclusion criteria for meta-analysis. In the analysis of the first part of the systematic review, the authors found that adhesive systems had a significant positive effect on fissure sealant (odds ratio, 3.294; 95% confidence interval, 1.292-8.401; P = .013). In the analysis of the second part of the systematic review, the authors found that etch-and-rinse adhesives were superior to self-etching adhesives in the fissure sealant procedure (odds ratio, 14.569; 95% confidence interval, 2.616-81.131; P = .002). The use of adhesive systems beneath fissure sealants can increase the retention of fissure sealants. Also, when adhesive systems are used with fissure sealants, etch-and-rinse systems are preferable. Copyright © 2016 American Dental Association. Published by Elsevier Inc. All rights reserved.

  10. New diagnostic technology and hidden pits and fissures caries

    Directory of Open Access Journals (Sweden)

    Fabrizio Guerra

    2015-10-01

    Full Text Available The accuracy in pits and fissures caries detection is of paramount importance in dental caries primary and secondary prevention. A combination of visual examination and probing is currently the mainstay of occlusal caries diagnosis. Unfortunately, these types of inspection alone may leave a certain number of pit and fissure caries undetected. The Vista Cam iX fluorescence camera (Durr Dental, Bietigheim-Bissingen, Germany is a novel dental diagnostic tool for quantitative assessment of dental caries with high specificity for carious lesions detection. In the presented cases photographic images, representing the visual diagnostic approach, are applied as integration to VistaCam iX Proof images. A step-by-step sequence of inspection and assessment of operative treatment need is presented in a case of hidden pit and fissure caries on a permanent molar. Based on the reported case, it could be observed that VistaCam iX Proof shows promising results in hidden pits and fissures caries detection and could be considered a non-invasive examination method that facilitate the detection of early lesions and a potential diagnostic aid.

  11. A One-Year Evaluation of a Free Fissure Sealant Program.

    Science.gov (United States)

    M, Bakhtiar; N, Azadi; A, Golkari

    2016-12-01

    Pit and fissure sealant therapy has been approved as an effective measure in the prevention of occlusal dental caries. Resin based materials are the most common materials used worldwide. A variety of resin based fissure sealants are produced and used. Most of them have been presented with ideal results in research environment. However, their effectiveness in the real life, especially in a mass application program such as Iran's oral health reform plan is not clear. To evaluate the longevity of different fissure sealant applied in Iran's oral health reform plan in Fars Province (south of Iran) after one year. Seven counties were selected. One hundred 6- to 8-year-old school children who had undergone fissure sealant therapy in spring 2015 were randomly selected from each county. Their first molars were examined to evaluate the status of the fissure sealants which were applied one year ago. Data on the type/brand of fissure sealant materials, type and experience of clinicians who applied them, existence of a chair-side assistant, and whether the children were caries-free at the time of fissure sealant application were collected from the existing reports. Data of 1974 teeth from 598 children were used for the final analysis. The effects of type/brand of the material was significant on the final results and remained significant (p a chair-side assistant, and child's gender, age, and being caries-free. Many factors affect the success rate of a fissure sealant therapy program. The type/brand of the material remained significantly related to the success rate of the fissure sealant even after adjustments for other influencing factors. In this study, ClinproTM Sealant (3M/ESPE, USA) showed better longevity after one year of application.

  12. Relationship between DIAGNOdent values and sealant penetration depth on occlusal fissures.

    Science.gov (United States)

    Rodrigues, Jonas A; Diniz, Michele B; Hug, Isabel; Cordeiro, Rita C L; Lussi, Adrian

    2010-12-01

    The aim of this in vitro study was to evaluate the relationship between laser fluorescence values and sealant penetration depth on occlusal fissures. One hundred and sixty-six permanent molars were selected and divided into four groups, which were each treated using a different sealant (two clear and two opaque). The teeth were independently measured twice by two experienced dentists using two laser fluorescence devices-DIAGNOdent (LF and LFpen)-before and after sealing, and then thermoclycled. After measuring, the teeth were histologically prepared and assessed for caries extension. Digital photographs of the cut sealed sites were assessed, and the sealant penetration depth was measured. All 166 sites were measured by one of the examiners taking as limits the outer and inner surface of the sealant into the fissure. For each device (LF and LFpen) and each group, the difference between the values at baseline and after sealing was plotted against the sealant penetration depth and scatter plots were provided. It could be observed that most of the points were concentrated around the zero line, for both LF and LFpen in the four groups. In conclusion, there is no relation between changes in DIAGNOdent values and increasing of depth sealant penetration within the occlusal fissures.

  13. Evaluation on effect of oral cavity health study, pit and fissure sealant, defending periodontal disease and dental caries in schools in Jiufo%九佛开展小学生口腔健康教育及窝沟封闭预防龋病和牙周病效果评价

    Institute of Scientific and Technical Information of China (English)

    刘爱容; 陈佩祥; 曾雪红; 彭建民

    2014-01-01

    Objective To evaluate the effects of carrying out oral cavity health study, pit and fissure sealant, defending periodontal disease and dental caries in schools. Methods 390 six-year teeth’s pit and fissure sealant students will be divided into two groups, one comparison group and two experiment groups. Due to various reasons, 78 students who lack systematical health education of oral cavity and whose parents don’t agree to make six-year teeth pit and fissure sealant operations will be the comparison group. The rest of 312 students will be automatically divided into two groups. The first group are the students who have systematical health education and meanwhile have an operation of six-year teeth pit and fissure sealant. The second group were students who just need to realize the importance of pit and fissure sealant and can’t get systematical oral cavity health education. After half a year of one year, all the students’oral cavity health knowledge, health behaviors, periodontal and dental caries’s condition will be checked. Results The results showed that the first experiment group have improved more than the first experiment group in the oral cavity health knowledge, behaviors and dental caries’s condition(P<0.05). After having an operation of pit and fissure sealant, both experiment groups don’t suffer from dental caries. Conclusion Carrying out study of oral cavity and operation of pit and fissure sealant based on schools is of great importance to defend periodontal disease and dental caries.%目的:评价在学校开展口腔健康教育及窝沟封闭预防牙周病和龋病的效果。方法将应行六龄齿窝沟封闭的390名学生进行分组,一组对照组及两组实验组。由于各种原因家长不同意实施六龄齿窝沟封闭术,也无系统的开展口腔健康教育活动的78名学生为对照组。把余下的312名学生随机分为两组实验组。实验组一为系统的开展健康教育活动及行六龄齿窝

  14. Glass ionomer with atraumatic restorative treatment and light-cured resin sealant to the pit and fissure of deciduous teeth%玻璃离子非创伤性充填技术与光固化树脂封闭乳牙窝沟的效果观察

    Institute of Scientific and Technical Information of China (English)

    任飞; 刘建平; 黄少宏; 章锦才; 范卫华; 陈清

    2012-01-01

    目的 比较玻璃离子联合非创伤性充填技术(atraumatic restorative treatment,ART)进行窝沟封闭和光固化树脂窝沟封闭两种方法应用于幼儿乳牙的效果.方法 按自身半口随机对照的方法,采用于预试验对89名3岁幼儿左或右半口符合条件的乳磨牙进行玻璃离子联合ART窝沟封闭(ART玻璃离子组),对侧半口符合封闭条件的乳磨牙进行树脂窝沟封闭(树脂组).ART玻璃离子组共188颗牙齿,树脂组共168颗牙齿.术后记录两组的术中不适发生情况.封闭后6个月、18个月检查窝沟封闭剂的保留情况和新发龋齿情况.对结果进行统计学分析.结果 术中不适ART玻璃离子组1例,树脂组8例,两组比较差异无统计学意义(P =0.160).封闭后6个月、18个月,ART玻璃离子组的封闭物脱落率分别为5.85%、21.81%,树脂组的封闭物脱落率分别为21.43%、38.10%,6个月及18个月时,两组差异均有统计学意义(P<0.05).6个月、18个月时复查患龋率,ART玻璃离子组分别为1.60%、3.19%,树脂组分别为5.95%、5.95%.6个月时两组差异有统计学意义(P=0.029),18个月时差异无统计学意义(P =0.209).结论 玻璃离子联合ART窝沟封闭应用于幼儿乳牙时,封闭物脱落率低,术中不适少,防龋效果肯定,可在低龄幼儿防龋工作中推广.%Objective To observe the effects of traditional resin sealant and atraumatic restorative treatment (ART) , glass ionomer-based pit and fissure sealant by interference experiments for primary molars. Methods Randomized comparison method was used to compare ART glass ionomer-based pit on primary molars of one side with resin sealant on the opposite side. Results Defulvium rates; The defulvium rates of ART glass ionomer sealant after 6 and 18 months were significantly lower than those of resin sealant ( P < 0.05 ). Caries rates: The caries rate of ART glass ionomer sealant was significantly lower than that of resin sealant (P =0

  15. A 1-year clinical evaluation of fissure sealants on permanent first molars

    Directory of Open Access Journals (Sweden)

    Nupur Ninawe

    2012-01-01

    Full Text Available Objective : To evaluate and compare the retention, marginal discoloration, surface texture and anatomical form of pit and fissure sealants. Materials and Methods : Thirty children between the ages of 6 and 10 years, who were attending the school health program regularly, had participated in the study. A split-mouth design was used in which the two fissure sealants (Helioseal-F and Glass ionomer Fuji VII were randomly placed in 60 matched contralateral pairs of permanent molar teeth. Sealants were rated by a single trained and calibrated examiner using mouth mirrors and probes following the US Public Health Service criteria. The sealants were evaluated at 3 months, 6 months and 1 year intervals. Results : The data obtained for retention, marginal discoloration, surface texture and anatomical form of pit and fissure sealants were tabulated and compared statistically using the Chi-square test of significance. Conclusion : The Helioseal-F sealant was better than the Glass ionomer Fuji VII sealant with respect to retention, anatomical form and surface texture. Both the materials showed similar results with respect to marginal discoloration.

  16. Characterisation and microleakage of a new hydrophilic fissure sealant - UltraSeal XT® hydro™

    Science.gov (United States)

    GÜÇLÜ, Zeynep A.; DÖNMEZ, Nazmiye; HURT, Andrew P.; COLEMAN, Nichola J.

    2016-01-01

    ABSTRACT Objectives The aim of this study was to characterise the new hydrophilic fissure sealant, UltraSeal XT® hydro™ (Ultradent Products, USA), and to investigate its in vitro resistance to microleakage after placement on conventionally acid etched and sequentially lased and acid etched molars. Material and Methods The sealant was characterised by Fourier transform infra-red spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and Vickers indentation test. Occlusal surfaces of extracted human molars were either conventionally acid etched (n=10), or sequentially acid etched and laser irradiated (n=10). UltraSeal XT® hydro™ was applied to both groups of teeth which were then subjected to 2,500 thermocycles between 5 and 55°C prior to microleakage assessment by fuchsin dye penetration. Results UltraSeal XT® hydro™ is an acrylate-based sealant that achieved a degree of conversion of 50.6±2.2% and a Vickers microhardness of 24.2±1.5 under standard light curing (1,000 mWcm-2 for 20 s). Fluoride ion release is negligible within a 14-day period. SEM and EDX analyses indicated that the sealant comprises irregular submicron and nano-sized silicon-, barium-, and aluminium-bearing filler phases embedded in a ductile matrix. Laser preconditioning was found to significantly reduce microleakage (Mann-Whitney U test, proughness on a 50 to 100 μm scale that caused the segregation and concentration of the filler particles at the enamel-sealant interface. Conclusion Laser preconditioning significantly decreased microleakage and increased enamel surface roughness, which caused zoning of the filler particles at the enamel-sealant interface. PMID:27556205

  17. Fissure sealant materials: Wear resistance of flowable composite resins.

    Science.gov (United States)

    Asefi, Sohrab; Eskandarion, Solmaz; Hamidiaval, Shadi

    2016-01-01

    Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists). A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm(2) and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm(2)of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics.

  18. Fissure sealant materials: Wear resistance of flowable composite resins

    Directory of Open Access Journals (Sweden)

    Sohrab Asefi

    2016-08-01

    Full Text Available Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow, Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists. A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm2 and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm2of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics.

  19. Fissure sealant materials: Wear resistance of flowable composite resins

    Science.gov (United States)

    Asefi, Sohrab; Eskandarion, Solmaz; Hamidiaval, Shadi

    2016-01-01

    Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists). A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm2 and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm2of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics. PMID:27651887

  20. The Problem of Occlusal Surface Pit and Fissure Dental Caries in Naval Recruits.

    Science.gov (United States)

    1980-06-01

    been little attention devoted to oclusal surface pit and fissure dental caries. There is so= evidence that tooth morphology is related to susceptibility...AD-A0CM 755 NAVAL DENTAL RESEARCH INST GREAT LAKES IL F/S 6/5 THE PROBLEM OF OCCLUSAL SURFACE PIT AND FISSURE DENTAL CARIES I--ETC(U) JUN 80 M R...THE PROBLEM OF OCCLUSAL SURFACE PIT AND FISSURE DENTAL CARIES IN NAVAL RECRUITS M. R. WIRTHLIN 1. L. SHKLAIR R. G. WALTER J. C. CECIL 0 M. E. COHEN

  1. 4种不同含氟窝沟封闭剂氟离子释放和回收的体外研究%In vitro fluoride release and recharge from 4 different types of fluoride-containing pit and fissure sealants

    Institute of Scientific and Technical Information of China (English)

    王金华; 邓锋; 林居红

    2011-01-01

    目的 检测4种不同含氟窝沟封闭剂的氟离子释放和回收能力.方法 采用4种不同的含氟窝沟封闭剂,包括Fuji VⅡ、FujiⅡLC、Fissurit F 以及Teethmate F-1.将各种材料制备成圆盘状样本,储存在含有5 ml去离子水的聚乙烯试管中,21 d后,用1.23%酸性磷酸氟(APF)凝胶处理每个样本,用氟离子选择性电极检测1~7、14、21、22、28、35 d和42 d的氟释放量.结果 玻璃离子封闭剂Fuji VⅡ氟离子释放量最高;树脂加强型玻璃离子封闭剂FujiⅡLC氟离子回收能力最强;Fissurit F氟离子回收能力最差.在整个检测时间段内,玻璃离子类封闭剂比其他封闭剂有更高的氟离子释放(P<0.05);4种封闭剂在APF凝胶处理后氟离子释放均有显著性增高(P<0.05).结论 在6周的短期研究中,玻璃离子为基础的封闭剂Fuji VⅡ和FujiⅡLC与其他封闭剂比较显示了较高的氟离子释放及回收能力.%Objective To determine the fluoride release and recharge of 4 different types of fluoridecontaining pit and fissure sealants in vitro. Methods Fuji Ⅴ Ⅱ, Fuji Ⅱ LC, Fissurit F and Teethmate F-1 were used to investigate fluoride release and recharge. Disk-shaped specimens were prepared from each material.Specimens were stored in a polyethylene test tube containing 5.0 ml ultrapure water. On day 21, specimens were exposed to 1.23% APF gel. Fluoride release was measured using a fluoride-specific ion electrode at days 1 to 7, 14, 21, 22, 28, 35 and 42 respectively. Results The glass-ionomer sealants Fuji Ⅴ Ⅱ had the highest fluoride release, and resin-modified glass-ionormer cement Fuji Ⅱ LC had the highest fluoride recharge,but Fissurit F had the lowest recharge. The glass-ionomer based sealants had significantly higher fluoride release than the other materials at all times tested ( P < 0.05 ). Fluoride release of all materials tested was increased following exposure to 1.23% APF gel (P < 0. 05 ). Conclusion In this

  2. Fissure sealants: in vitro evaluation of abrasion wear and superficial roughness

    Directory of Open Access Journals (Sweden)

    Vanessa Pardi

    2008-06-01

    Full Text Available The aim of this study was to compare the in vitro wear and superficial roughness of four materials (Delton Dyract Flow, Dentsply; Filtek Flow, Vitremer, 3M ESPE used as fissure sealant in 32 extracted human molars divided in four groups (n = 8 after abrasion with toothbrush/dentifrice. Impressions of each occlusal surface were made to analyze wear and circular specimens were prepared to analyze the roughness. Teeth and specimens were mounted in a toothbrushing machine. The replicas were observed using a SEM to determine the superficial wear. Wear: there were no statistically significant differences either between Delton and Filtek Flow or between Dyract Flow and Vitremer. Roughness: there were no statistical differences between Filtek Flow and Dyract Flow, Dyract Flow and Vitremer, Vitremer and Delton., Considering the clinical practice, if caries activity is present the use of Vitremer is suggested not only for its well known fluoride release, but it presented good roughness results.

  3. A comparative study to evaluate the effect of fluoride releasing sealant cured by visible light, argon laers, and light emitting diode curing units: An in vitro study

    OpenAIRE

    Das U; Prashanth S

    2009-01-01

    In Pediatric Dentistry, the use of pit and fissure sealant is one of the essential forms of prevention. Pit and fissure caries may be substantially decreased by obliteration of these developmental defects in occlusal, buccal and lingual surfaces with resin based dental sealants. Visible light-curing units, or LCUs, are an integral part of modern adhesive dentistry" They are used to cure resin based composite restoration materials, resin modified glass-ionomer and pit and fissure sealants, as ...

  4. Micro-leakage of a Fissure Sealant Cured Using Quartz-tungsten-halogen and Plasma Arc Light Curing Units.

    Science.gov (United States)

    Bahrololoomi, Zahra; Soleimani, Ali Asghar; Jafari, Najmeh; Varkesh, Bentolhoda

    2014-01-01

    Background and aims. Newer curing units such as plasma arc can polymerize the sealants in much shorter curing times. The aim of this study was to compare the effect of two different curing units on the micro-leakage of a fissure sealant material. Materials and methods. Sixty two extracted premolars without caries were randomly divided into two groups of 31 samples. Occlusal surfaces of all teeth were cleansed. Then, teeth surfaces were etched by 37% phosphoric acid. After rinsing and drying, occlusal surfaces of teeth were sealed by a fissure sealant. The sealant was then cured using either a halogen light curing unit or a plasma arc curing light. After sealing, the teeth were thermocycled for 500 cycles. The teeth were then sectioned and examined for micro-leakage. Statistical analyses were performed with Mann-Whitney test. Results. There was no significant difference between two groups regarding micro-leakage (P = 0.42). Conclusion. Results showed that there was no significant difference between two different curing units. Therefore, plasma arc unit might be a useful alternative for sealant polymerization.

  5. The use of holmium-yttrium aluminum garnet laser as pit and fissure cleaner

    Directory of Open Access Journals (Sweden)

    Armasastra Bahar

    2009-09-01

    Full Text Available Background: The prevention and management of pit and fissure caries has become relatively more important in recent times. There is a need for an effective preventive measure against pit and fissure caries. Purpose: The purpose of this study was to investigate the effect of laser beam as a cleaning method of pits and fissures. Methods: Ho-YAG laser which has a wavelength of 2.1 µm was used in this experiment. The specimens were extracted human teeth. The effect of three cleaning methods was examined comparatively by scoring the cleaned area of fissure, namely laser irradiation with Ho-YAG laser, chemico-mechanical with combination of 10% NaOCl and ultrasonic scaler and mechanical with ultrasonic scaler. Vertico-bucco-lingual serial ground sections of each tooth were observed under light microscopy. Scoring the depth of cleaned area was performed by comparing the depth of fissure. result: Progressive result was obtained on the cleaning effect of three methods laser irradiation methods which was the most effective compared to other methods but statistically was not significant. Cleaned area of laser irradiation method was 48.91%, chemico-mechanical method was 41.77% and mechanical method was 36.78%. Conclusion: Holmium -yttrium aluminum garner laser is a relatively new method for pit and fissure cleaning even though the effectivity is not yet maximal. More research is needed to maximize the use of this laser.

  6. The Effectiveness of Fissure Sealant Therapy Placed by Professional Complementary to Dentistry Compared with Dentists

    Directory of Open Access Journals (Sweden)

    F Nilchian

    2005-10-01

    Full Text Available Background: Dental caries is a process that may take place on any tooth surface in the oral cavity where a microbial biofilm (dental plaque is allowed to develop over a period. From the public health perspective, the prevention of caries is still a major challenge. The development of dental caries within the mouth follows a fixed hierarchy indicating that tooth surfaces vary in caries susceptibility. The most susceptible surfaces are the buccal pits and occlusal-fissured surfaces of the first molar teeth. Since the 1960`s many trials have investigated the effectiveness of using sealants on pit and fissure surfaces. However, the cost effectiveness of sealants is an important issue considered by many studies noted that cost-effectiveness of sealants would be enhanced by using trained auxiliaries to apply them. The changes in dentistry and oral health reveal a need to review the roles of dental auxiliaries in order to deliver quality care cost-effectively. There were number of studies conducted on the effectiveness of dental auxiliaries around the world. According to the purpose of this project, studies evaluated the effectiveness of Professional complementary to dentistry (PCDs and different type of dental auxiliaries in carrying out complete restorations and in the preventive therapies, fissure sealants, traumatic restorative treatment were evaluated in literature review. The aim of the present study is to review the literature and assess whether PCDs can perform pit and fissure sealants as effectively as dentist through investigation of the caries preventive effect of sealant placed by dentist relative to sealant placed by PCDs. Method: Electronic databases were searched till January 2005. The databases which were used are: Medline via Ovid, Cochrane databases of systematic review , DARE (Database of Abstracts of Reviews of Effectiveness, CCTR (Clinical Controlled Trials Register Cochrane Library, Dissertation Abstracts International database

  7. Removal of organic debris with Er:YAG laser irradiation and microleakage of fissures sealants in vitro.

    Science.gov (United States)

    Hossain, Mozammal; Yamada, Yoshishige; Masuda-Murakami, Yoshiko; Nakamura, Yukio

    2012-09-01

    The current study was conducted to improve fissure sealing by pre-treatment with Er:YAG laser irradiation in order to remove organic debris. The surface morphology, surface roughness of fissure cavities, and the degree of microleakage after laser treatment were compared with those after bristle brush treatment in vitro. Sixty extracted human teeth were used in this study. The teeth were randomly divided into two groups of 30 each. Artificial fissures were prepared in all teeth into which artificial organic debris was placed. The debris in 30 teeth of one group was removed by means of Er:YAG laser system and the remaining 30 teeth were cleaned using a bristle brush with prophylaxis paste. Surface morphology and surface roughness of were analyzed in ten samples from each group by color laser three-dimensional (3D) microscopy and by scanning electron microscopic examination. The remaining samples were then filled with sealant and subjected to a microleakage test under thermocycling. Statistical analysis was performed using the Mann-Whitney U test; a value of p Er:YAG laser treatment, whereas some fissures were not cleaned by bristle brush. However, microleakage test of both laser and etched brush methods showed similar results. Laser technique might facilitate good adaptation of resin sealant to enamel, because of an increase in surface roughness and favorable surface characteristics.

  8. In vitro study of microleakage of different techniques of surface preparation used in pits and fissures

    Directory of Open Access Journals (Sweden)

    Shahrzad Javadi Nejad

    2012-01-01

    Full Text Available Objective : The purpose of this in vitro study was to evaluate the effect of different techniques of surface preparation on the microleakage of a sealant applied with traditional acid etching and self-etched bonding agent. Study Design : A total of 60 extracted third molars were randomly assigned into six groups (n = 10/each. The occlusal surfaces were sealed with a sealant (Clinpro after one of the following pretreatments: (1 phosphoric acid etching; (2 Prompt L-Pop; (3 laser + etching; (4 laser + Prompt L-Pop; (5 air abrasion + etching; (6 air abrasion + Prompt L-Pop. The specimens were immersed in a 0.5% basic fuchsin solution. Buccolingual cuts parallel to the long axis of the tooth were made. The surfaces were scored 0--2 for extent of microleakage using a microscope and the data were analyzed statistically. Results : The poorest results were obtained with laser + Prompt L-Pop which showed a greater number of specimens with microleakage (80%. Air abrasion surface preparation + phosphoric acid etching showed less microleakage than the other groups (40%. Kruskal--Wallis and t-tests revealed no significant difference in microleakage between six groups. Conclusion : The self-etching adhesive studied seems an attractive alternative to the acid-etch technique for sealant application in young children where simplifications in the clinical procedure are warranted. No significant difference was noted between the different types of enamel preparation before fissure sealant.

  9. [Prevalence of caries, fissure sealants and filling materials among German children and children of migrants].

    Science.gov (United States)

    van Steenkiste, M; Becher, A; Banschbach, R; Gaa, S; Kreckel, S; Pocanschi, C

    2004-11-01

    The aim of this study was to collect information on dental health and dental care of German children and children of migrants for planning oral health promotion in the Rems-Murr-district. To meet this aim all first and fourth degree children in primary and special schools were examined. The dmft- and DMFT-Index, the number of fissure sealants, the filling material used and the children's nationality were recorded. The dmft of 6- and 7-year-olds was 1.50 among Germans, 4.61 among German migrants from Russia, 4.02 among Turks, 4.05 among children from former Yugoslavia, 2.35 among Italians, 1.95 among Greeks and 3.76 among children of other nationalities. At the age of 9 to 10 years Germans had an average of 0.31, German migrants from Russia 0.77, Turks 1.19, children from former Yugoslavia 1.32, Italians 0.64, Greeks 0.69 and children of other nationalities 0.57 DMF-teeth. In both age groups the proportion of caries-free children was highest among Germans and lowest among Turks. Also, more migrants than Germans were referred to a dentist for caries treatment. Compared to the Germans fewer migrants had at least one tooth sealed. The proportion of amalgam fillings to the total number of fillings was higher among 9- and 10-year-olds of Turkish, Italian or Yugoslavian origin than among other nationalities. The results of this study show that further development of oral health promotion programmes for children and parents with Turkish and Russian cultural background has the top-most priority.

  10. Comparison of Caries Prevention With Glass Ionomer and Composite Resin Fissure Sealants

    Directory of Open Access Journals (Sweden)

    Aylin Akbay Oba

    2009-11-01

    Conclusion: Under field conditions in which moisture control was not effective, a high-viscosity and less technique-sensitive glass ionomer material can be used as an effective sealant material, rather than resin.

  11. 光固化流体树脂与非创伤性充填窝沟封闭成本效果评价%Cost-effectiveness evaluation of pit and fissure sealant with light-cured flowable resin and ART

    Institute of Scientific and Technical Information of China (English)

    曹慧珍; 束陈斌; 汪隼

    2011-01-01

    Objective To compare the difference of the cost and retention rate between pit and fissure sealants light-cured flowable resin and ART. Methods 267 children aged 7 ~ 10 from two primary schools were selected for this study. Each of them had at least two caries-free and deep fissure first molars. One first molar was sealed with ART techniques and the other molar were sealed with light-cured flowable resin. The portable dental chair was used to absorb saliva and cotton rolls were applied for moisture control. The number of cotton rolls and time cost in the operation were recorded. One year later, the retention rates of the two materials were checked by two dentists using explorer. All procedures were performed in primary schools. Results It took 3. 18 minutes for one tooth to be sealed with ART and 3.32 minutes with flowable resin ( P 0.05 ). The retention rate of the light-cured flowable resin group was higher compared to ART group (P < 0.01). Conclusions Both flowable resin composites and ART can prevent caries. They're recommended to be performed in schools.%目的 比较光固化流体树脂与非创伤性充填(ART)封闭技术在实施窝沟封闭方面防龋成本及保留率的差异.方法 选择上海市两所小学7~10岁儿童267名,口腔内至少有2个第一恒磨牙无龋及有较深窝沟.随机选择每名儿童第一恒磨牙一侧用ART技术进行窝沟封闭,其它的第一恒磨牙用光固化流体树脂进行窝沟封闭,使用便携式牙科椅吸取唾液,并用棉卷隔湿.两种方法在操作时记录每个牙封闭所用去的棉卷数和操作时间.1年后检查两种材料在牙面上的保留情况.所有操作均在学校内施行,检查由两名医师使用镰形探针进行检查.结果 使用ART封闭技术进行窝沟封闭操作时间每牙需3.18 min,而光固化流体树脂组需3.32 min(P<0.01),所用棉花卷数和重复次数无差异(P>0.05).在封闭剂的保留率方面,光固化流体树脂

  12. Comparison of Clinical Success of Applying a Kind of Fissure Sealant on the Lower Permanent Molar Teeth in Dry and Wet Conditions

    Directory of Open Access Journals (Sweden)

    Tahereh Eskandarian

    2015-09-01

    Full Text Available Statement of the Problem: Fissure sealant therapy is among the most effective methods of preventing dental caries. However, it is lengthy and isolation of the teeth is difficult in this procedure especially in young children. Using new hydrophilic fissure sealant may reduce such problems. Purpose: This study aimed to evaluate the clinical success of a hydrophilic fissure sealant on the lower permanent mo-lar teeth in dry and wet conditions. Materials and Method: This clinical trial assessed 31 patients (mean age 8.13±1.77 years who needed fissure sealant therapy on their first or second mandibular permanent molar. Having performed dental prophylaxis, the teeth were etched and rinsed. Then one of the two was randomly selected and sealed with smartseal & loc in isolated and dry con-ditions; while, the other was wetted on the etched enamel by using a saliva-contaminated micro brush, and was then sealed with the same fissure as the first tooth. Six and 12 months later, two independent observers examined the clinical success of sealant through checking the marginal integrity, marginal discoloration, and anatomical form. Data were analyzed by using SPSS software, version 16. The bivariate Chi-square and Exact Fisher tests were used to compare the clinical success of the two treatment methods. Results: There was a high interpersonal reliability between the two examiners (K= 0.713. After 12 months, 90.3% clinical success was observed in dry conditions and 83.9% in wet conditions for smartseal & loc; however, the differ-ence was not statistically significant (p= 0.0707. Conclusion: According to the results of this study, it seems that using new hydrophilic fissure sealant can reduce tech-nical sensitivities and consequently decreases the apprehensions on saliva contamination of etched enamel during treatment procedures.

  13. Comparison of the Effect of Topical Acidulated Phosphate Fluoride Application on Surface Roughness of Two Fissure Sealants and One Flowable Composite

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    Leila Pishevar

    Full Text Available Introduction: fluoride application and fissure sealant therapy have an important cariostatic effect in pediatric dentistry. Investigations are indicative for effects of topical fluoride specially APF (Acidulated Phosphate Fluoride gel on the restorative materials. The purpose of this study was to assess the effect of repeated application of APF (1. 23% gel on the surface roughness of two fissure sealants and one flowable composite. Materials & Methods: In this experimental study, 81 specimens of two fissure sealants and one flowable composite were prepared, using special polymer mold in three groups of 27 including: unfilled resin sealant (Fissurite F, Voco, filled resin sealant (Fissurit FX, Voco and one flowable composite (Arabesk Flow, Voco. Then, these three groups were divided into three sub groups of 9 as follows: Group 1, 4, 7 (control: No treatment. Group 2, 5, 8: Single application of APF gel. Group 3, 6, 9: Six times application of APF gel. The APF gel was applied on the surface of specimens each time for 4 minutes. Then, the specimens were stored in the distilled water. Finally, the surface roughness of the sealants was measured by Profilometer. The statistical analysis was performed by 2-Way ANOVA & One-Way ANOVA. Results: The results of the study showed a significant statistical different between the surface roughness according to the type of material (P0.05. Conclusion: All three materials were resistant to the destructive effects of APF gel and no significant surface roughness was detected on them.

  14. Enamel pretreatment with Er:YAG laser: effects on the microleakage of fissure sealant in fluorosed teeth

    Directory of Open Access Journals (Sweden)

    Mahtab Memarpour,

    2014-08-01

    Full Text Available Objectives The purpose of this in vitro study was to evaluate the microleakage and penetration of fissure sealant in permanent molar teeth with fluorosis after pretreatment of the occlusal surface. Materials and Methods A total of 120 third molars with mild dental fluorosis were randomly divided into 6 groups (n = 20. The tooth surfaces were sealed with an unfilled resin fissure sealant (FS material. The experimental groups included: 1 phosphoric acid etching (AE + FS (control; 2 AE + One-Step Plus (OS, Bisco + FS; 3 bur + AE + FS; 4 bur + AE + OS + FS; 5 Er:YAG laser + AE + FS; and 6 Er:YAG laser + AE + OS + FS. After thermocycling, the teeth were immersed in 0.5% fuchsin and sectioned. Proportions of mircoleakage (PM and unfilled area (PUA were measured by digital microscope. Results Overall, there were significant differences among all groups in the PM (p = 0.00. Group 3 showed the greatest PM, and was significantly different from groups 2 to 6 (p < 0.05. Group 6 showed the lowest PM. Pretreatment with Er:YAG with or without adhesive led to less PM than bur pretreatment. There were no significant differences among groups in PUA. Conclusions Conventional acid etching provided a similar degree of occlusal seal in teeth with fluorosis compared to those pretreated with a bur or Er:YAG laser. Pretreatment of pits and fissures with Er:YAG in teeth with fluorosis may be an alternative method before fissure sealant application.

  15. Long-term performance of resin based fissure sealants placed in a general dental practice.

    NARCIS (Netherlands)

    Hevinga, M.; Opdam, N.J.M.; Bronkhorst, E.M.; Truin, G.J.; Huysmans, M.C.D.N.J.M.

    2010-01-01

    OBJECTIVES: The aim of the present retrospective study was to evaluate the long-term performance of resin based fissure sealants applied in a general dental practice. METHODS: Regularly attending patients visiting the practice between July 2006 until November 2007 and who had received sealants befor

  16. Coseismic Pit Crater, Normal Fault, and Extensional Fissure Formation in Unconsolidated Sediment and Basalt in Northern Iceland

    Science.gov (United States)

    Ferrill, D. A.; Wyrick, D. Y.; Smart, K. J.

    2008-12-01

    Two rifting-related seismic events in 1975 and 1978 along the Mid-Atlantic Ridge near the northern coast of Iceland produced an array of surface deformation features in Holocene basalt flows and overlying unconsolidated sediments. New field mapping and aerial photograph interpretation is coupled with analysis of maps of seismic activity and level-line survey results to constrain the timing, style, and magnitude of this deformation. Fault scarps and fissures in basalts can be traced laterally down a gentle northward dip projecting into unconsolidated braided stream deposits, providing an impressive view of the deformation style in the two contrasting mechanical layers. We report on detailed field mapping of two of these laterally traceable structures conducted in the summer of 2008 and analysis of a suite of aerial photographs from 1958 to 1998. Map-scale structures in the basalts with little or no sedimentary cover include (i) fault scarps, (ii) fissures, and (iii) locally-developed gentle dip away from the related normal fault. Dilation of faults and extension fractures in the basalt has led to rock toppling and rock fall causing widening of fissures. Wedging of toppled rock blocks at the tops of fissures has locally produced keystone arches and bridges across the tops of open fissures. Different stages in the progression of fissure formation and collapse, including (i) fissure, (ii) widened fissure with cavern, (iii) localized collapse pit, and (iv) elongate collapsed fissure, can be observed over along-strike distances of 10's of meters. Where unconsolidated sand and gravel deposits >3 m thick cover the basalts (200 m to the north along strike) structural geomorphologic features are dominated by (i) grabens, (ii) pit craters, and (iii) elongate troughs. Graben-bounding normal faults cutting the sedimentary cover in many cases have displacements >1 m. Pit craters have cone to bowl shapes, commonly occur within grabens, and have depths up to 2.8 m. The mapped

  17. Retention of fissure sealants in young permanent molars affected by dental fluorosis: a 12-month clinical study.

    Science.gov (United States)

    Hasanuddin, S; Reddy, E R; Manjula, M; Srilaxmi, N; Rani, S T; Rajesh, A

    2014-10-01

    To evaluate and compare retention and caries occurance following placement of Clinpro and FUJI VII fissure sealants, by two different techniques simultaneously in unsealed, contralateral young permanent molars of 7- to 10-year-old children affected by mild to moderate dental fluorosis at various recall intervals of 1 week, 1, 3, 6 and 12 months. 80 schoolchildren with mild to moderate dental fluorosis were assigned to Group A and Group B with 40 children in each group. In Group A Clinpro fissure sealant and in Group B Fuji VII fissure sealant was used. In both the groups fissure sealants were applied by conventional fissure sealant technique (CST) on one side and enameloplasty sealant technique (EST) on the other side of the same arch. The applied fissure sealants were evaluated clinically for retention and caries incidence. Clinpro fissure sealant showed a retention rate of 95% when compared with Fuji VII (57.5%) at the end of 12 months, which was statistically significant. Regarding techniques, EST showed better results than CST in both the groups. Comparison of groups with respect to retention and techniques at different time periods was performed using Mann-Whitney U test (p < 0.05). Comparison of different time periods with respect to retention and technique in all the groups was performed using Wilcoxon matched pairs test by ranks (p < 0.05). Clinpro fissure sealant showed better retention at all treatment intervals, when compared with Fuji VII. Further follow-up is required to study the efficacy of the fissure sealant placement techniques.

  18. Effect of the application of a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste and adhesive systems on bond durability of a fissure sealant.

    Science.gov (United States)

    Borges, Boniek Castillo Dutra; Catelan, Anderson; Sasaki, Robson Tetsuo; Ambrosano, Gláucia Maria Bovi; Reis, André Figueiredo; Aguiar, Flávio Henrique Baggio

    2013-01-01

    This study aimed to evaluate the effect of the previous application of a casein phosphopeptide-amorphous calcium phosphate paste (MI Paste, MI) and adhesive systems on the bond durability of a fissure sealant. Ninety-eight enamel blocks were obtained from proximal surfaces of erupted third molars. Specimens were divided into 14 groups (n = 7) according to the previous application of MI (with and without) and the adhesive systems used (no adhesive system; hydrophobic resin of a three-step etch-and-rinse adhesive system; etch-and-rinse single-bottle adhesive system; all-in-one adhesive system; two-step self-etching adhesive system; additional phosphoric acid conditioning and all-in-one adhesive system; additional phosphoric acid conditioning and two-step self-etching adhesive system). A fissure sealant (Fluroshield) was applied and photoactivated for 20 s. Beams (~0.7 mm(2)) were prepared for the microtensile bond strength test, which was executed after 24 h or 6 months of water storage. Fractured specimens were analyzed by scanning electronic microscopy. Data were analyzed by two-way ANOVA with repeated measures/Tukey's test (P adhesive systems presented higher means than those groups where MI was not applied. Higher frequency of cohesive failures was observed for groups with MI. Applying a CPP-ACP containing paste on enamel before adhesive systems was an effective method to increase bond durability of the sealant tested.

  19. Genetic Susceptibility to Dental Caries on Pit and Fissure and Smooth Surfaces

    Science.gov (United States)

    Shaffer, J.R.; Wang, X.; DeSensi, R.S.; Wendell, S.; Weyant, R.J.; Cuenco, K.T.; Crout, R.; McNeil, D.W.; Marazita, M.L.

    2012-01-01

    Carious lesions are distributed nonuniformly across tooth surfaces of the complete dentition, suggesting that the effects of risk factors may be surface-specific. Whether genes differentially affect caries risk across tooth surfaces is unknown. We investigated the role of genetics on two classes of tooth surfaces, pit and fissure surfaces (PFS) and smooth surfaces (SMS), in more than 2,600 subjects from 740 families. Participants were examined for surface-level evidence of dental caries, and caries scores for permanent and/or primary teeth were generated separately for PFS and SMS. Heritability estimates (h2, i.e. the proportion of trait variation due to genes) of PFS and SMS caries scores were obtained using likelihood methods. The genetic correlations between PFS and SMS caries scores were calculated to assess the degree to which traits covary due to common genetic effects. Overall, the heritability of caries scores was similar for PFS (h2 = 19–53%; p caries scores for both PFS and SMS in the primary dentition was greater than in the permanent dentition and total dentition. With one exception, the genetic correlation between PFS and SMS caries scores was not significantly different from 100%, indicating that (mostly) common genes are involved in the risk of caries for both surface types. Genetic correlation for the primary dentition dfs (decay + filled surfaces) was significantly less than 100% (p caries risk in PFS versus SMS in the primary dentition. PMID:22286298

  20. Do light cured ART conventional high-viscosity glass-ionomer sealants perform better than resin-composite sealants: a 4-year randomized clinical trial

    NARCIS (Netherlands)

    Zhang, W.; Chen, X.; Fan, M.W.; Mulder, J.; Huysmans, M.C.D.N.J.M.; Frencken, J.E.F.M.

    2014-01-01

    OBJECTIVE: The hypotheses tested were: the cumulative survival rates of dentin caries lesion-free pits and fissures of ART conventional high-viscosity glass-ionomer sealants with light-curing (high-intensity LED) and glass-carbomer sealants are higher than those of conventional ART sealants and resi

  1. Retention and Effectiveness of Dental Sealant After Twelve Months in Iranian Children

    Directory of Open Access Journals (Sweden)

    Rafatjou

    2013-12-01

    Full Text Available Background Pit-and-fissure sealants are safe and effective ways to prevent dental caries and are considered as a part of an overall caries-preventive strategy. Dental caries are a public health problem and the most common intraoral disease affecting mankind. It is an infectious transmissible disease, with the child patient being at the highest risk. Objectives The purpose of this study was to evaluate the retention rates and effectiveness of occlusal sealants in children in Hamadan, Iran. Materials and Methods A total of 118 sealed first permanent molar teeth in 52 students (mean age, 8 years;male, 48% were evaluated for fissure sealant retention and occlusal caries status. All teeth were examined 12 months after application of sealants. Data were collected and evaluated by survival analyses methods for age at placement, patient sex, decayed/missing/filled teeth (DMFT index, fluoride history, toothbrush, tooth position in arch, and refer to dentistry. Results The overall success rate with pit-and-fissure sealant was 68.6%; in addition, 38.9% of the seals were completely retained, 38.9% partially lost, and 10.2% completely lost. There were no signs of carious lesions in 69.6% of the teeth. The factors associated with an increased risk of failure included female sex (P = 0.001 and no history of fluoride use (P < 0.01. There were no significant association between the results and patient age, tooth position in the arch, DMFT index, toothbrush, and refer to dentistry. Conclusions Although pit-and-fissure sealants are effective methods for preventing tooth caries, the low success rate of fissure sealants in current study indicated that dental sealant need to be implemented more carefully and follow-up programs are advisable.

  2. Observation of pit and fissure sealing efficacy for 1113 cases of mandibular first molars%1113例下颌第一恒磨牙窝沟封闭疗效观察

    Institute of Scientific and Technical Information of China (English)

    宋洁文; 姚科; 蔡华雄

    2013-01-01

    目的评价使用自酸蚀粘结剂及Primaflow树脂增强玻璃离子作为窝沟封闭剂的临床效果。方法对1113例6~8岁小学生采取自身双侧对照研究方法,随机选择一侧第一恒磨牙采用Contax粘结剂+Primaflow进行窝沟封闭;对侧同名牙作为对照组,采用FUJI VII传统玻璃离子窝沟封闭剂,在第1、2年进行临床观察比较。结果窝沟封闭后2年,Primaflow树脂增强玻璃离子与FUJI VII玻璃离子窝沟封闭剂的保留率分别为70.80%和49.05%,龋齿发生率分别为6.56%和22.46%。两组封闭剂保留率及患龋率差异均有统计学意义(P<0.05)。结论使用自酸蚀粘结剂及Primaflow流动复合体能有效地预防窝沟龋的发生,其保留率及防龋能力均优于FUJI VII窝沟封闭剂。%Objective To evaluate the clinical effect of self-etching adhesives and Primaflow resin reinforced glass ionomer as the pit and fissure sealants. Methods 1113 6-8 year-old pupils were selected and the self bilateral control study method was used. The first molar of one side was randomly selected to receive Contax binder + Primaflow for pit and fissure sealing. The first molar on the other side served as the control and received FUJI VII traditional glass ionomer for pit and fissure sealing. The clinical results were observed and compared in the 1st and 2nd years. Results Two years after the pit and fissure sealing, the retention rates of the Primaflow resin reinforced glass ionomer and FUJI VII glass ionomer pit and fissure sealants were 70.80% and 49.05% respectively. The retention rates and the caries incidence rates of the two groups were significantly different (P < 0.05). Conclusion Self-etching adhesives and Primaflow flow compound can effectively prevent the occurrence of pit and fissure caries and both its retention rate and caries prevention ability are superior to those of FUJI VII pit and fissure sealants.

  3. Present and future value of dental composite materials and sealants.

    Science.gov (United States)

    Dogon, I L

    1990-01-01

    This article reviews the development, composition, chemistry, recent technological advances, and extent of use of composite resin restorative materials, adhesives, and pit and fissure sealants. The problems related to the clinical behavior of these materials in the oral environment are dealt with, and methods of minimizing their present deficiencies are suggested. Future directions that might be taken to improve these materials and solve some of the inadequacies that these materials exhibit are also discussed.

  4. 流动纳米树脂预防性窝沟龋充填%Flowable nano-resin in preventive pit and fissure caries restoration

    Institute of Scientific and Technical Information of China (English)

    谢富强; 颉伟博; 刘国华; 孙健; 胡朝昶

    2011-01-01

    背景:预防性树脂充填术由于不采用传统的预防性扩展,只去除少量的龋坏组织后即用复合树脂或玻璃离子材料充填龋洞,而未患龋的窝沟使用封闭剂保护.目的:通过应用美国3M公司生产的Filtek Z350流动纳米树脂对窝沟可疑龋、初龋磨除后进行预防性充填,观察并评价其临床效果,探索预防性充填治疗早期窝沟龋的新方法.方法:对196例6~25岁患者磨牙的牙合面窝沟龋在去除龋坏的牙体组织后,采用Eadper prompt自酸蚀粘结技术,用Filtek Z350流动纳米树脂对整个牙面进行预防性充填术,并采用对侧同名牙或邻牙也有窝沟龋者用同一公司生产的ClinproTM可见光固化变色窝沟封闭剂充填作对照研究.结果与结论:随治4年后发现该方法涂膜保留率高,能有效阻止龋病的进一步发展.实验组与对照组在术后1,2年时的涂膜保留率差异无显著性意义,而在第3,4年时差异有显著性意义(P < 0.01、P < 0.05).龋病发生率在1,2年时差异无显著性意义,而在3,4年时差异有显著性意义(P < 0.05).提示Filtek Z350流动纳米树脂预防性窝沟充填是一种有效阻止窝沟早期龋进一步发展的方法.%BACKGROUND: Without use of traditional precautionary expansion, preventive resin restorations only remove a small amount of decayed tissue and immediately fill caries with composite resin or glass ionomer materials, while the pit and fissure without caries are prevented using a sealant.OBJECTIVE: To evaluate the clinical effect of Filtek Z350 flowable nano-composite resin (3M, USA) in molar occlusal pit and fissure caries, and to explore a new preventive restoration for pit and fissure caries.METHODS: A total of 350 permanent molars with occlusal pit and fissure caries in 196 patients aged from 6 to 25 years were treated with Filtek 2350 flowable nano-composite resin after the cariated tissue had been removed. The opposite or adjacent teeth also with similar

  5. 3种窝沟封闭剂微渗漏的实验研究%Experimental Study on Microleakage of Three Different Fissure Sealants

    Institute of Scientific and Technical Information of China (English)

    张海亮; 赵玉宏; 欧晓艳

    2011-01-01

    Objective: To provide experimental evidence by study on microleakage of three different fissure sealants. Methods: Forty human maxillary premolars,caries -free for orthodontic reasons were collected and randomly divided into five groups. Fissures were respectively sealed with conventional pit and fissure sealant (Helioseal F) ? Glass ionomer cement(GC Fuji VII), GC Fuji VII plus saliva contamination, wetbond sealant(Embrace WetBond), Embrace WetBond plus saliva contamination. Six teeth in each group were stained with 50% silver nitrate for 2 hours, then were sectioned for evaluation of microleakage. Two other teeth in each group were used to observe the marginal adaptability of fissure sealants and interface condition by scanning electronic microscope. Results: Without saliva contamination, there were significantly differences concerning the microleakage results among three different sealants. Helioseal F was fully penetrated into the bottom of the fissure by SEM, together with the enamel completely. While with saliva contamination, GC Fuji VII and Embrace WetBond had a poor sealing ability, the interface between sealants and enamel appeared significant micro-gap. Conclusion: The pit and fissure sealant Helioseal F had a excellent marginal adaptation. The new glass ionomer sealant GC Fuji VII and wet -bond sealant Embrace WetBond only needed a technology with lower difficulty, and could achieve a acceptable marginal adaptation, their sealing abilities needed further clinical trials.%目的:比较3种窝沟封闭剂的微渗漏情况,为选择操作技术难度低且具良好边缘密合性的窝沟封闭剂提供实验依据.方法:收集正畸减数的上颌前磨牙40颗,随机分为5组,每组8颗.即:Helioseal F组、GC Fuji Ⅶ组、GC Fuji Ⅶ+唾液污染组、Embrace WetBond组、Embrace WetBond+唾液污染组,每组中6颗用50%硝酸银染料浸润2h,切片于体视显微镜下观察微渗漏情况,余下2颗用扫描电镜观察窝沟封闭剂与牙

  6. Sealants in dentistry: outcomes of the ORCA Saturday Afternoon Symposium 2007

    DEFF Research Database (Denmark)

    Splieth, C H; Ekstrand, K R; Alkilzy, M

    2009-01-01

    . Evidence for effectiveness of sealants in controlling caries in posterior teeth implies that sealants should be an integrated part of management of pit and fissure caries. Still, the indication for occlusal sealants seems to be shifting from primary prevention to a therapeutic decision for caries...... are as complex to apply and time-consuming as approximal fillings. The article proposes guidelines for teaching on the use of sealants....

  7. Evaluation of a sealant intervention program among Taiwanese aboriginal schoolchildren

    Directory of Open Access Journals (Sweden)

    Hui-Ju Hsieh

    2014-06-01

    Conclusion: The application of pit-and-fissure sealants was 94.54% effective in preventing caries on newly erupted permanent molars among Taiwanese aboriginal schoolchildren. Complete sealant failure demonstrated a high risk for caries, and such teeth should immediately be resealed.

  8. Selective ablation of pit and fissure caries from occlusal surfaces using λ=355-nm laser pulses and air-abrasion demonstrated using PS-OCT and near-IR imaging

    Science.gov (United States)

    Ross, Steven T.; Fan, Kenneth; Fried, Daniel

    2006-02-01

    Several past studies have suggested that lasers with and without added chromophores can be used for the selective removal of dental caries from stained pit and fissures in preparation for composite sealant placement with minimal damage to sound, unstained tooth structure. Polarization sensitive optical coherence tomography (PS-OCT) is a new nondestructive imaging technology that can be used to acquire images of caries lesions in occlusal surfaces. PSOCT is ideally suited to measure the caries depth and severity before and after selective removal from occlusal surfaces. In this study, λ=355-nm laser pulses of 5-ns duration at irradiation intensities ranging from 0.5-1.3 J/cm2 were scanned across tooth surfaces to selectively remove decayed enamel with and without the addition of India ink. PS-OCT images were acquired before and after removal. The laser removal was also compared to air abrasion in order to compare selectivity of these two conservative caries removal technologies.

  9. Flowable resin used as a sealant in molars using conventional, enameloplasty and fissurotomy techniques: An in vitro study

    Directory of Open Access Journals (Sweden)

    Chaitra T

    2010-09-01

    Full Text Available Background and Objective: Preventive procedures using pit and fissure sealants are one of the most important aspects of pediatric dental practice. The objectives of this in vitro study were to comparatively evaluate microleakage of a flowable resin used as a sealant on molars after preparation with conventional, enameloplasty and fissurotomy techniques. Materials and Methods: A total of 24 teeth were divided into three groups of eight samples each. Pits and fissures were prepared with conventional sealant technique (CST (Group A, enameloplasty sealant technique (EST (Group B and fissurotomy technique (FT (Group C. Following sealant placement, thermocycling and sectioning of samples of Groups A, B and C were performed and microleakage was assessed under a stereomicroscope after methylene blue dye immersion. Results: There was significantly lesser microleakage in EST when compared with CST and FT, which showed more microleakage. No statistical significance between CST and FT was found. Interpretation and Conclusion: EST has proven to be an excellent method of preparation of pits and fissures when flowable composite is used as a sealant because of its lesser microleakage.

  10. Effect of Adhesive Application on Sealant Success: A Clinical Study of Fifth and Seventh Generation Adhesive Systems

    Directory of Open Access Journals (Sweden)

    Vaibhav Tandon

    2016-03-01

    Full Text Available Objectives: The aim of the study was to compare the effect of fifth and seventh generation bonding agent on sealant success.Materials and Methods: Sixty-four school children aged six to nine years received sealants in four permanent molars in a split mouth design, such that each patient received sealant in the first permanent molar with fifth generation bonding agent in one arch and seventh generation bonding agent in the other arch; contra-lateral molars were sealed with sealant alone. The evaluation was carried out at baseline, three months, six months and 12 months, according to the criteria by Feigal et al, in 2000. Chi- square test was used to analyze data at P<0.05 level of significance.Results: Statistically significant differences were found for sealant retention between fifth generation and sealant group, and fifth generation and seventh generation groups; whereas, no significant difference was found for sealant retention between seventh generation and sealant group at three, six and 12 months.Conclusion: As separate etch and rinse steps are not required for seventh generation bonding agents, and almost similar results were obtained for both sealant and seventh generation groups, it can be concluded that application of sealant along with a seventh generation bonding agent may enhance sealant success and can be used for caries prevention in preventive programs.Key words:  Pit and Fissure Sealants; Dental Caries; Adhesives

  11. 光固化流体树脂窝沟封闭防龋疗效的评价%Clinical evaluation of light-cured flowable resin in preventing pit and fissure caries

    Institute of Scientific and Technical Information of China (English)

    韩静; 于洪波; 焦菲菲

    2016-01-01

    目的:比较光固化流体树脂与光固化窝沟封闭剂在儿童新生恒牙窝沟封闭预防龋坏的临床效果。方法临床选取150名7~10岁,双侧下颌第一恒磨牙无龋坏的儿童。每个儿童随机选取一侧作为试验组,用光固化流体树脂进行窝沟封闭,另一侧为对照组,用传统光固化窝沟封闭剂进行封闭。封闭治疗后6、12、24个月复查,检查封闭剂在牙面的保留率及龋病发生率,并进行统计学分析。结果2年后试验组光固化流体树脂脱落率和龋病发生率分别为7.80%和2.13%,对照组传统窝沟封闭剂的脱落率和龋病发生率分别为21.43%和7.09%,两组封闭剂脱落率和龋病发生率均有显著性差异(P<0.05)。结论光固化流体树脂在窝沟封闭预防龋坏治疗效果确切,值得临床推广。%Objective To compare the clinical effect of light-cured flowable resin and traditional light-cured pit and fissure sealant in preventing pit and fissure caries. Methods 150 children aged from 7 to 10 years with healthy permanent mandibular first molars were enrolled in this study. One side of permanent mandibular first molar was selected randomly as experimental group, which was sealed with light-cured flowable resin. The other side, as control group, was treated with traditional light-cured pit and fissure sealant. Pa-tients were followed up 6, 12 and 24 months later. The rate of resin loss and incidence of dental caries between two groups were com-pared by χ2 test. Results After two years, the rate of sealant loss and the incidence of caries of experimental group ( 7. 80%;2. 13%) were significantly lower than those of the control group(21. 43%;7. 09%) (P<0. 05). Conclusions Light-cured flowable resin is an effectively anticarious and reliable pit and fissure sealant.

  12. Retention of a Flowable Composite Resin in Comparison to a Conventional Resin-Based Sealant: One-year Follow-up

    OpenAIRE

    N. Tadayon; B. Malekafzali; M.Jafarzadeh; Fallahi, S.

    2010-01-01

    Objective: Long-term retention of pit and fissure sealants is crucial for their success. This clinical study evaluated the retention rate of a flowable composite resin (Filtek Supreme XT Flowable Restorative) compared to a conventional resin-based sealant (Concise Light Cure White Sealant) over 12 months. Materials and Methods: Forty subjects aged 6 to 9 years were included in the study. Using a half-mouth design, a total of 80 first permanent molars were sealed with conventional fissure seal...

  13. 4种窝沟封闭剂微渗漏及抗压强度的比较实验%Comparative study on microleakage and compressive strength of four fissure sealants

    Institute of Scientific and Technical Information of China (English)

    蔡雅; 沈家平

    2013-01-01

    目的:比较4种窝沟封闭剂的微渗漏及抗压强度,为临床选择使用提供实验室依据.方法:收集12 ~16周岁志愿者因正畸治疗需要而新鲜拔除的前磨牙28个,并将其随机分为A、B、C、D4组(n=7),分别用Helioseal F、VOCO Fissurit F、AscentTM和ClinproTM封闭(牙合)面及颊、舌侧窝沟;冷热循环100次后,分别从每组中各随机抽取5个用20 mg/L的亚甲蓝染色检查微渗漏;所余2个用扫描电镜观察窝沟封闭剂与牙体组织结合界面及两者之间的密合度.取4种窝沟封闭剂分别制作直径4 mm,厚4 mm的盘状标本各9个,置于生理盐水中37℃下浸泡.分别于浸泡后ld、28 d、63 d后测定各标本的抗压强度(n=3).结果:4种封闭剂之间微渗漏评分均无显著性差异(P>0.05);扫描电镜观察显示,VOCO Fissurit F与牙釉质完全结合在一起,并渗透到窝沟底部,Helioseal F、AscentTM、ClinproTM虽与釉质结合较紧密但窝沟底部的封闭剂中有气泡或断裂.4种封闭剂中AscentTM组3个时间点的抗压强度均高于其他3组(P<0.05),而另3组各时间点内两两相比均无统计学差异(P>0.05).结论:VOCO Fissurit F的边缘密合性相对较好;AscentTM的抗压强度较高.%AIM:To evaluate the microleakage and compressive strength of 4 fissure sealants.METHODS:28 caries-free premolars extracted for orthodontic reasons from 12-16 years old volunteers were collected and randomly divided into 4 groups(n =7).Fissures were respectively sealed with Helioseal F,VOCO Fissurit F,AscentMT,and ClinproMT pit and fissure sealant.Then the teeth were thermocyclinged for 100 times.5 teeth in each group were stained with 20 mg/L methylene blue for 24 hours,and then were sectioned for the evaluation of microleakage.The remaining 2 teeth in each group were used for the observation of marginal adaptability of fissure sealants with tooth interface by SEM.9 disc-like specimens (with the thickness on 4mm diameter on 4mm) were prepared

  14. The effect of different enamel surface treatments on microleakage of fissure sealants

    Directory of Open Access Journals (Sweden)

    Asli Topaloglu-Ak

    2013-11-01

    Full Text Available Objective. The aim of this study was to evaluate the effects of different techniques of surface treatment on the microleakage of fissure sealants in permanent molar teeth in vitro. Materials and methods. 96 extracted impacted human third molars were randomly divided into 8 surface treatment groups (n=12/group as 1. Er: YAG laser; (Fidelis II, Fotona, Ljubljana, Slovenia (125 mj, 20Hz. 2. Er: YAG laser + 37% H3PO4 (15s; 3. ER: AG laser + 37% H3PO4+Prime&Bond NT; 4. Er: YAG laser + G Bond; 5. Er: YAG laser + Prime&Bond NT; 6. 37% H3PO4; 7. 37% H3PO4 + Prime &Bond NT; 8. G Bond. Sealant material (Clinpro, 3M ESPE, Seefeld, Germany, was applied into the fissures and light-cured for 20s with LED (Bluephase C5, Ivoclar-Vivadent, Schaan, Liechtenstein. Specimens were subjected to thermocycling (1000×, 5-55°C, dwell time: 15s and immersed in 0.5% basic fuchsin solution for 24h at 37°C. The samples were sectioned and scored on a 3 point rating scale using a light microscope with a magnification of ×20. One-way analysis of variance was used to analyze data. Multiple comparisons were analyzed using Bonferroni test (p=0.05. Results. Er:YAG laser showed the highest microleakage scores whereas Er YAG laser + 37% H3PO4 showed the lowest. Although 37% H3PO4 group showed higher scores than Er:YAG laser + 37% H3PO4, the difference was not statistically significant. Conclusion. Etching fissures with phosphoric acid is sufficient prior to fissure sealant application.

  15. Clinical assessment of two types of adhesive (fifth & sixth generation on fissure sealant of saliva contaminated enamel

    Directory of Open Access Journals (Sweden)

    Karami Nogourani M.

    2009-08-01

    Full Text Available "nBackground and Aim: Since the clinical studies conducted to explore the effect of bonding agents on the success of fissure sealant are limited in number, the present study was conducted to compare the effects of two bonding agents on the success of fissure sealant of the saliva- contaminated teeth. "nMaterials and Methods: In this study, 63 teeth of 35 students aged 6-8 with healthy and newly-erupted upper jaw molar teeth, were selected and divided into two groups. In one group, single-bond and In the other, SE bond were used. As the teeth were newly erupted and the distopalatal area being in contact with the gingival sulcus and this fact that, this area was impossible to isolate, the distal sulcus of the contaminated teeth and the mesial area capable of adequate isolation were assumed isolated. For each group, after etching, the teeth on one side were treated with a sealant and the teeth on the other side were first bonded and then treated with the sealant. Hence, four groups were formed: bonded/isolated, bonded/contaminated, controlled/isolated and controlled/contaminated for any bonding agent. The results of the treatment were assessed in terms of the success and failure and then analyzed using Mc Nemar, and Chi-square tests and Cochran. "nResults: The results of the study indicated that:1. Saliva contamination caused a significant increase in sealant failures(p<0.05.2. Use of the two bonding agents significantly increased the success of the sealant(p<0.05.3. Use of the two bonding agents significantly increased the success of the fissure sealant on the saliva-contaminated teeth, even more than when the teeth had been isolated and with only fissure sealant(p<0.05. 4. For the contaminated enamel, the results of SE bond were better than those of the single bond (p<0.05. However, in isolated condition the results of using single bond were better (p<0.05. "nConclusion: The results of the study supported the use of these two bonding agents in

  16. Sealants in dentistry: outcomes of the ORCA saturday afternoon symposium 2007

    NARCIS (Netherlands)

    Splieth, C.H.; Ekstrand, K.R.; Alkilzy, M.; Clarkson, J.; Meyer-Lueckel, H.; Martignon, S.; Paris, S.; Pitts, N.B.; Rickets, D.N.; van Loveren, C.

    2010-01-01

    Sealants are a successful tool in caries prevention, but their role in preventive strategies after the caries decline has to be discussed. A survey of paediatric departments across Europe revealed that indications for pit and fissure sealants vary considerably, both nationally and internationally. E

  17. An in vitro comparison between laser fluorescence and visual examination for detection of demineralization in occlusal pits and fissures.

    Science.gov (United States)

    Ferreira Zandoná, A G; Analoui, M; Beiswanger, B B; Isaacs, R L; Kafrawy, A H; Eckert, G J; Stookey, G K

    1998-01-01

    It has been demonstrated that when excited by laser light carious enamel appears dark compared to luminescent sound enamel. The aim of this study was to compare the sensitivity and specificity of visual exams (V), laser fluorescence (LF) and dye-enhanced LF (DELF) for detecting demineralization in occlusal pits and fissures. The actual presence of lesions was determined by subsequent confocal laser microscopy (CM), which was compared to histology (H). Independent clinical examiners visually graded three sites on occlusal surfaces of extracted, human premolars as sound or carious and also rated the color of each graded site as: 0 = same as surrounding enamel; 1 = white; 2 = light brown, or 3 = brown/dark brown. An argon laser was used to illuminate the teeth for LF and DELF; the images were captured with a CCD camera and then analyzed. DELF images were captured after the teeth had been exposed to 0.075% sodium fluorescein. Sections were then cut from each specimen and analyzed by CM and H for the presence or absence of caries. Results showed that DELF (0.72) was significantly more sensitive (pDELF 0.60). When color was used as an indication of caries in V (VC, sensitivity 0.47; specificity 0.70), V exams were not different from LF. The area under the ROC curve, using H as the gold standard and CM as the test, was 0.78. Results indicated that DELF was the best diagnostic tool and that VC and LF were equally effective as diagnostic methods, when color of fissures was included as an indication of demineralization in the visual exam.

  18. Chitosan whiskers from shrimp shells incorporated into dimethacrylate-based dental resin sealant.

    Science.gov (United States)

    Mahapoka, Ekamon; Arirachakaran, Pratanporn; Watthanaphanit, Anyarat; Rujiravanit, Ratana; Poolthong, Suchit

    2012-01-01

    A resin-based sealant containing chitosan whiskers was developed for use as a pit and fissure sealer. Chitosan whiskers were synthesized and then characterized using Fourier transform infrared spectrometry and transmission electron microscopy. The whiskers were next incorporated into dimethacrylate monomer at various ratios by weight and subsequently analyzed for their antimicrobial and physical properties. The dimethacrylate-based sealant containing chitosan whiskers had a greater antimicrobial activity than control sealant and they were comparable with antimicrobial commercial resin sealants. The inclusion of the whiskers did not reduce the curing depth or degree of double bond conversion and the reduction in hardness was minimal. In conclusion, a resin-based sealant containing chitosan whiskers can be considered an effective antimicrobial pit and fissure sealant.

  19. Dental depth profilometric diagnosis of pit & fissure caries using frequency-domain infrared photothermal radiometry and modulated laser luminescence

    Science.gov (United States)

    Jeon, R. J.; Mandelis, A.; Sanchez, V.; Abrams, S. H.

    2005-06-01

    Non-intrusive, non-contacting frequency-domain photothermal radiometry (FD-PTR or PTR) and frequency-domain luminescence (FD-LUM or LUM) have been used with 659- nm and 830-nm laser sources to detect artificial and natural sub-surface defects in human teeth. Fifty-two human teeth were examined with simultaneous measurements of PTR and LUM and compared to conventional diagnostic methods including continuous (dc) luminescence (DIAGNOdent), visual inspection and radiographs by calculating sensitivities and specificities. With the combined criteria of four PTR and LUM signals (two amplitudes and two phases), it was found that the sensitivity of this method was much higher than any of the other methods used in this study, whereas the specificity was comparable to that of dc luminescence diagnostics. Therefore, PTR and LUM, used together as a combined technique, have the potential to be a reliable tool to diagnose early pit and fissure caries and could provide detailed information about deep lesions with its depth profilometric character. Also, from experiments with natural or artificial defects, some depth profilometric characteristics were confirmed.

  20. A comparative study to evaluate the effect of fluoride releasing sealant cured by visible light, argon laers, and light emitting diode curing units: An in vitro study

    Directory of Open Access Journals (Sweden)

    Das U

    2009-09-01

    Full Text Available In Pediatric Dentistry, the use of pit and fissure sealant is one of the essential forms of prevention. Pit and fissure caries may be substantially decreased by obliteration of these developmental defects in occlusal, buccal and lingual surfaces with resin based dental sealants. Visible light-curing units, or LCUs, are an integral part of modern adhesive dentistry" They are used to cure resin based composite restoration materials, resin modified glass-ionomer and pit and fissure sealants, as well as to bond orthodontic teeth. Most recently, the argon laser has been approved for initiating the setting reaction with visible light cured-resins. Argon curing of resin materials has been show to enhance the physical properties and degree of polymerization of the resin, while reducing the polymerization time by 75 percent. The study is undertaken considering the inadequate research reports of regarding the comparison of curing ability using argon laser. LEDs and visible light as well as the resistant towards caries activity of the preventive fluoride releasing pit and fissure sealant cured by above mentioned curing units.

  1. Dental depth profilometric diagnosis of pit and fissure caries using frequency-domain infrared photothermal radiometry and modulated laser luminescence

    Science.gov (United States)

    Jeon, Raymond J.; Mandelis, Andreas; Sanchez, Victor; Abrams, Stephen H.

    2004-07-01

    Non-intrusive, non-contacting frequency-domain photothermal radiometry (FD-PTR or PTR) and frequency-domain luminescence (FD-LUM or LUM) have been used with 659-nm and 830-nm laser sources to detect artificial and natural sub-surface defects in human teeth. Fifty-two human teeth were examined with simultaneous measurements of PTR and LUM with the 659-nm laser and compared to conventional diagnostic methods including continuous (dc) luminescence (DIAGNOdent), visual inspection and radiographs. To compare each method, sensitivities and specificities were calculated by using histological observations as the gold standard. With the combined criteria of four PTR and LUM signals (two amplitudes and two phases), it was found that the sensitivity of this method was much higher than any of the other methods used in this study, whereas the specificity was comparable to that of dc luminescence diagnostics. Therefore, PTR and LUM, as a combined technique, has the potential to be a reliable tool to diagnose early pit and fissure caries and could provide detailed information about deep lesions with its depth profilometric character. Also, from the experiments with the teeth having natural or aritficial defect, some depth profilometric characteristics were confirmed. The major findings are (i) PTR is sensitive to very deep (>5 mm) defects at low modulation frequencies (5 Hz). Both PTR and LUM amplitudes exhibit a peak at tooth thicknesses ca. 1.4 - 2.7 mm. Furthermore the LUM amplitude exhibits a small trough at ca. 2.5~3.5 mm; (ii) PTR is sensitive to various defects such as a deep carious lesion, a demineralized area, and a crack while LUM exhibits low sensitivity and spatial resolution.

  2. Validation of micro-CT against the section method regarding the assessment of marginal leakage of sealants.

    NARCIS (Netherlands)

    Chen, X.; Cuijpers, V.M.J.I.; Fan, M.W.; Frencken, J.E.F.M.

    2012-01-01

    BACKGROUND: The aim of this study was to validate the micro-CT and related software against the section method using the stereomicroscope for marginal leakage assessment along the sealant-enamel interface. METHODS: Pits and fissures of the occlusal surface of 10 teeth were sealed with a resin-fissur

  3. Assessment of gingival condition and cytokine content in gingival crevicular fluid after elastic fiber combined with flowable resin repair of pit and fissure caries

    Institute of Scientific and Technical Information of China (English)

    Zhao-Ran Fu

    2016-01-01

    Objective:To study the gingival condition and cytokine content in gingival crevicular fluid after elastic fiber combined with flowable resin repair of pit and fissure caries.Methods:A total of 68 patients with pit and fissure caries who received elastic fiber combined with flowable resin repair treatment in our hospital between May 2013 and August 2015 were selected as the research subjects and randomly divided into two groups, group A received elastic fiber combined with reinforced flowable resin material for repair and group B received elastic fiber combined with normal flowable resin material for repair. Four weeks after repair, gingival bleeding index was assessed, and gingival crevicular fluid was collected to determine the content of interleukins and protease molecules as well as the expression levels of autophagy genes.Results: Four weeks after treatment, the gingival bleeding index of group A was significantly lower than that of group B; IL-8, IL-17, IL-18, IL-21, IL-23, IL-35, MMP1, MMP2, MMP3 and MMP9 content as well asAtg3, Atg5, Atg7, Atg12 andLC-3II expression levels in gingival crevicular fluid of group A were significantly lower than those of control group while TIMP1 and TIMP2 content were significantly higher than those of group B. Conclusions: The gingival condition is more ideal after elastic fiber combined with reinforced flowable resin repair of pit and fissure caries, and reinforced flowable resin can alleviate the tissue injury mediated by interleukins, matrix metalloproteinases and autophagy.

  4. [The observation of the contained fluoride sealant on caries prevention for 3 years

    Science.gov (United States)

    Feng, X P; Li, G L; Dogon, L

    1997-06-01

    Pit and fissure sealant is an effective method for preventing pit and fissure caries,though it has less effect in smooth surface teeth.But the contained sealant is effective on caries prevention both in pit and fissure area and in smooth surface.The aim of the present search was observing the clinic results of the contained fluoride sealant on caries prevention.786 children aged 6-8 years old were divided into four groups.The first permanent molars in group 1 were sealed by the contained fluoride sealant and those in group 2 were used the conventional sealant.The same molars in group 3 were used the conventional sealant plus the APFI gel and those in group 4 were only used the APFI gel.APFI gel was used one time per half year.The results showed the caries preventive effect of the contained fluoride sealant was significant higher than the conventional sealant or the APFI gel in first molars which had been sealed for three years.The caries incidence of the unsealed teeth in group 1 was lower than that in the other groups.The results also indicated the caries preventive effect of all above methods was less in female than in male.

  5. Retention of a Flowable Composite Resin in Comparison to a Conventional Resin-Based Sealant: One-year Follow-up

    Directory of Open Access Journals (Sweden)

    N. Tadayon

    2010-03-01

    Full Text Available Objective: Long-term retention of pit and fissure sealants is crucial for their success. This clinical study evaluated the retention rate of a flowable composite resin (Filtek SupremeXT Flowable Restorative compared to a conventional resin-based sealant (Concise Light Cure White Sealant over 12 months.Materials and Methods: Forty subjects aged 6 to 9 years were included in the study. Using a half-mouth design, a total of 80 first permanent molars were sealed with conventional fissure sealant on one side of the mouth and flowable composite on the contralateralside. Clinical evaluation was performed at 3, 6, and 12 months by a single blind examiner and the retention was classified as complete retention, partial loss, or total loss.Results: For both materials, there was no total loss of sealants over 12 months. Partial loss of both materials was observed in one sealant after 3 months. After 6 months, 36 teeth sealed with conventional fissure sealant were intact compared with 37 sealed with a flowable composite, and after 12 months, 33 teeth sealed with conventional fissure sealant were intact compared with 35 that were sealed with a flowable composite. There were no statistically significant difference (P>0.05 between the two materials regarding the retention rate at each follow-up period.Conclusion: As flowable composite resulted in comparable sealant retention rates, this material could be a good choice for fissure sealant.

  6. Retention of fissure sealants using two different methods of application in teeth with hypomineralised molars (MIH): a 4 year clinical study.

    Science.gov (United States)

    Lygidakis, N A; Dimou, G; Stamataki, E

    2009-12-01

    This was to evaluate the retention rate of fissure sealants applied to MIH molars with occlusal enamel opacities, using two different application methods after 4 years. 54 children exhibiting molars with MIH aged 6-7 years, participated in the study. presence of at least 2 fully erupted caries-free maxillary or mandibular first permanent molars in the opposite sides of the mouth, both with occlusal enamel opacities without breakdown. Following parental consent, sealants were applied using a half-mouth experimental design. Group A: On a randomly assigned first molar on one side of the mouth sealants Fissurit were placed using a single bottle adhesive system (One-step prior to sealant application. Group B: Sealants were applied on the contra-lateral molar using the conventional etch and seal technique. Children were seen biannually when a preventive program was applied, without replacing any lost sealant. After 4 years, 47 sets of molars (94 teeth) were available for blind evaluation. Teeth in Group A presented a better retention rate; 70.2% were fully sealed, 29.7% partly sealed and none unsealed (lost sealant). Group B revealed 25.5% fully sealed, 44.6% partly sealed and 29.7% unsealed teeth. Differences between groups A and B were statistically significant (p0.01). In hypomineralised molars with occlusal opacities sealants appear to have greater retention when applied using 5th generation adhesive systems prior to sealant.

  7. Evaluation of the effects of enameloplasty and air abrasion on sealant micro-leakage.

    Directory of Open Access Journals (Sweden)

    Aliasghar Soleymani

    2014-12-01

    Full Text Available Micro-leakage, one of the major reasons for recurrent decays, may lead to uncontrollable flow of liquids, pulp inflammation and peri-apical pathology. The purpose of this in vitro study was to evaluate micro-leakage of pit and fissure sealants after using three different pit and fissure preparation techniques: 1 acid etching, 2 fissure enameloplasty and acid etching, and 3 air abrasion and acid etching.Sixty-nine extracted sound molars and premolars were randomly divided into three groups (23 samples in each group. Teeth were prepared using one of three occlusal surface treatments. Then the sealant was applied on the occlusal fissures of all teeth. The teeth were thermocycled and stored in normal saline. All teeth were sealed apically and coated with nail varnish and then were immersed in a 2% solution of methylen blue. Two buccolingual sections were made. The surfaces were scored 0 to 3 for the extent of micro-leakage using a stereomicroscope. Data were analyzed by Kruskal- wallis and Dunn procedure.Enameloplasty and acid etching were significantly different regarding micro-leakage (P= 0.016, but no significant difference in micro-leakage was observed between air abrasion and the other methods.Enameloplasty followed by acid etching produced significantly less micro-leakage than the acid etching technique. Air abrasion acid etching was better than the acid etching technique in reducing micro-leakage too.

  8. The state-of-the-art of ART sealants

    NARCIS (Netherlands)

    Frencken, J.E.F.M.

    2014-01-01

    Sealing caries-prone pits and fissure systems is an effective caries-preventive measure. There are basically two types of sealant materials: glass-ionomer and resin-based materials. Low- and medium-viscosity glass-ionomers were initially used and showed a low level of retention. With the advent of t

  9. GC FujiⅦ玻璃离子应用于乳牙窝沟封闭疗效评价%Evaluation of curative effect of GC Fuji Ⅶ glass ionomer used for pit and fissure sealing of deciduous teeth

    Institute of Scientific and Technical Information of China (English)

    欧晓丽; 施春梅; 周嫣; 罗菊芬; 李民冬; 梁群

    2013-01-01

    Objective: To explore the curative effect of GC Fuji Ⅶ glass ionomer used for pit and fissure sealing of deciduous teeth, and improve clinical effect of pit and fissure sealing for preventing dental caries in children. Methods: Forty - five 2 - 5 - year - old children were randomly selected from June 2009 to June 2010, a ;self - control study was performed; 80 teeth were treated with pit and fissure sealing of deciduous teeth by GC Fuji Ⅶ glass ionomer; and 80 teeth were treated with pit and fissure sealing of deciduous teeth by light curing fissure sealant. The one - year and two - year conservative successful rates in the two groups were evaluated. The operation times of every tooth in the two groups were analyzed statistically. Results: After follow -up for two years, the successful rate of GC Fuji Ⅶ glass ionomer used for pit and fissure sealing of deciduous teeth was 90.0% , and the successful rate in light curing group was 73. 7% , there was statistically significant difference between the two groups ( P < 0. 05 ) . At two years after treatment, the morbidities of secondary dental decay in Fuji Ⅵ group and light curing group were 1. 2% , and 9. 2% , respectively. The mean operation times of every tooth in Fuji Ⅶ group and light curing group were (4. 0 ±0. 5) minutes and (5. 2 ±0. 7) minutes, there was statistically significant difference between the two groups (t =9. 664, P = 0. 000) . Conclusion: The clinical efficacy of GC Fuji VI for preventing pit and fissure caries of deciduous teeth is better than that of light curing, and the operation time of the former is shortened, the efficacy of medical workers is improved, so the method is worthy ro be popularized.%目的:探讨GC FujiⅦ玻璃离子体应用于乳牙窝沟封闭的疗效,提高窝沟封闭对预防儿童龋齿的临床效果.方法:随机选择2009年6月~2010年6月45例2~5岁患儿,采用自身半口对照的方法.80颗牙应用GC FujiⅦ玻璃离子体

  10. Er:YAG激光预备窝沟充填的微渗漏研究%Study on the microleakage of Er: YAG laser reserve pit and fissure filling

    Institute of Scientific and Technical Information of China (English)

    耿涛

    2013-01-01

    <0.05),55% of D group(χ2 =7.21,P <0.05) and 87% of E group (χ2 =11.65,P < 0.05).The efficiency of C group was 87%,which was significandy higher than 43% of A group (χ2 =3.97,P < 0.05) and 61% of B group (χ2 =8.35,P < 0.05).The efficiency of B group was 61%,which was significantly higher than 43% of A group (χ2 =6.25,P < 0.05).Conclusion Er:YAG laser with fluid resin filling is the most effective way for the clinical treatment of pit and fissure deep narrow,already susPicious pit and fissure caries pit and fissure sealant failed teeth.

  11. Selective removal of composite sealants with near-ultraviolet laser pulses of nanosecond duration.

    Science.gov (United States)

    Louie, Tiffany M; Jones, Robert S; Sarma, Anupama V; Fried, Daniel

    2005-01-01

    It is often necessary to replace pit and fissure sealants and composite restorations. This task is complicated by the necessity for complete removal of the remaining composite to enable suitable adhesion of new composite. Previous studies have shown that 355-nm laser pulses from a frequency-tripled Nd:YAG laser can selectively remove residual composite after orthodontic bracket removal on enamel surfaces. Our objective is to determine if such laser pulses are suitable for selective removal of composite pit and fissure sealants and restorations. Optical coherence tomography is used to acquire optical cross sections of the occlusal topography nondestructively before sealant application, after sealant application, and after sealant removal. Thermocouples are used to monitor the temperature in the pulp chamber during composite removal under clinically relevant ablation rates, i.e., 30 Hz and 30 mJ/pulse. At an irradiation intensity of 1.3 J/cm2, pit and fissure sealants are completely removed without visible damage to the underlying enamel. At intensities above 1.5 J/cm2, incident laser pulses remove the resin layer while at the same time preferentially etching the surface of the enamel. Temperature excursions in the pulp chamber of extracted teeth are limited to less than 5 degrees C if air-cooling is used during the rapid removal (1 to 2 min) of sealants, water-cooling is not necessary. Selective removal of composite restorative materials is possible without damage to the underlying sound tooth structure.

  12. Dental sealant knowledge, opinion, values and practice of Spanish dentists

    Directory of Open Access Journals (Sweden)

    San Martin Laura

    2013-02-01

    Full Text Available Abstract Background Multiple guidelines and systematic reviews recommend sealant use to reduce caries risk. Yet, multiple reports also indicate that sealants are significantly underutilized. This study examined the knowledge, opinions, values, and practice (KOVP of dentists concerning sealant use in the southwest region of Andalusia, Spain. This is a prelude to the generation of a regional plan for improving children’s oral health in Andalusia. Methods The survey’s target population was dentists working in western Andalusia, equally distributed in the provinces of Seville, Cadiz, and Huelva (N=2,047. A convenience sample of meeting participants and meeting participant email lists (N=400 were solicited from the annual course on Community and Pediatric Dentistry. This course is required for all public health sector dentists, and is open to all private sector dentists. Information on the dentist’s KOVP of sealants was collected using four-part questionnaire with 31, 5-point Likert-scaled questions. Results The survey population demographics included 190 men (48% and 206 women (52% with an average clinical experience of 10.6 (± 8.4 years and 9.3 (± 7.5 years, respectively. A significant sex difference was observed in the distribution of place of work (urban/suburb (p=0.001, but no sex differences between working sector (public/private. The mean ± SD values for each of the four KOVP sections for pit and fissure sealants were: knowledge = 3.57 ± 0.47; opinion = 2.48 ± 0.47; value = 2.74 ± 0.52; and practice = 3.48 ± 0.50. No sex differences were found in KOVP (all p >0.4. Independent of sex: knowledge statistically differed by years of experience and place of work; opinion statistically differed by years of experience and sector; and practice statistically differed by years of experience and sector. Less experienced dentists tended to have slightly higher scores (~0.25 on a Likert 1–5 scale. Statistically significant correlations were

  13. Impact of extended radiant exposure time on polymerization depth of fluoride-containing fissure sealer materials.

    Science.gov (United States)

    Borges, Boniek C D; Souza-Junior, Eduardo J; Catelan, Anderson; Ambrosano, Gláucia M B; Paulillo, Luís A M S; Aguiar, Flávio H B

    2011-01-01

    Physical properties such as surface hardness of dental materials are directly linked to their clinical behavior. The aim of this study was to investigate the influence of extended curing time on the polymerization depth offluoride-containing materials used as pit and fissure sealants. Conventional and extended exposure times (20 and 60 seconds) were used to photoactivate a gold-standard pit and fissure sealant (Fluroshield, Dentsply) and a flowable composite (PermaFlo, Ultradent). Twenty square-shaped samples (n=5) were prepared using a LED device (Bluephase 16i, Ivoclar). The Knoop Hardness Number (KHN) was calculated for the top and bottom surface of each sample 24 hours after polymerization. Bottom/top hardness ratio (B/T KHN) was than calculated. Averages were analyzed by two-way ANOVA and Tukey test (alpha=0.05). The flowable composite had higher KHN than conventional pit and fissure sealant for all experimental conditions (p<0.05). The 60-second photoactivation time increased KHN at the bottom surface and B/T KHN only of composite specimens. The flowable composite had better physical properties than the pit and fissure sealant, and they were improved by extended curing time.

  14. Effect of irradiation times on the polymerization depth of contemporary fissure sealants with different opacities

    Directory of Open Access Journals (Sweden)

    Boniek Castillo Dutra Borges

    2011-04-01

    Full Text Available The aim of this study was to evaluate the depth of curing of 10 contemporary blue light-activated dental flowable materials at several opacities, influenced by different irradiation times using FT-IR spectroscopy. Fifty-five specimens (n = 5 with a 5-mm diameter and 1-mm thickness of translucent (Opallis Flow T, yellowed (Master Flow A2; Opallis Flow A2; Natural Flow A2; Fluroshield Yellowed, and opaque materials (Master Flow OA2; Natural Flow O; Opallis Flow OA3.5; Opallis Flow OP; Fluroshield White were obtained at six curing times (10s, 20s, 30s, 40s, 50s, and 60s using a high-intensity LED (Coltolux, Coltène/Whaledent. The degree of conversion (DC (% was obtained using the Nexus 470 FTIR Spectrometer (Nicolet Instruments, USA. The FTIR-ATR spectra for uncured and cured samples were analyzed using a ZnSe crystal. The top and bottom surfaces of the cured specimens were analyzed to obtain the depth of curing. Two-way ANOVA was used to analyze the data. The highest curing depth was obtained by Natural Flow OA2, while the lowest was shown by Master Flow OA2. The shortest curing time generated similar depths of cure in comparison with the most extensive for Opallis Flow A2 and Fluroshield Yellowed. Therefore, depth of curing, influenced by the irradiation time, was dependent on the materials. Using the Natural Flow OA2 opaque sealant and the 10-s curing time for Opallis Flow A2 and Fluroshield Yellowed may represent alternative approaches to sealing tooth fissures.

  15. Applying psychological theories to evidence-based clinical practice: identifying factors predictive of placing preventive fissure sealants

    Directory of Open Access Journals (Sweden)

    Maclennan Graeme

    2010-04-01

    Full Text Available Abstract Background Psychological models are used to understand and predict behaviour in a wide range of settings, but have not been consistently applied to health professional behaviours, and the contribution of differing theories is not clear. This study explored the usefulness of a range of models to predict an evidence-based behaviour -- the placing of fissure sealants. Methods Measures were collected by postal questionnaire from a random sample of general dental practitioners (GDPs in Scotland. Outcomes were behavioural simulation (scenario decision-making, and behavioural intention. Predictor variables were from the Theory of Planned Behaviour (TPB, Social Cognitive Theory (SCT, Common Sense Self-regulation Model (CS-SRM, Operant Learning Theory (OLT, Implementation Intention (II, Stage Model, and knowledge (a non-theoretical construct. Multiple regression analysis was used to examine the predictive value of each theoretical model individually. Significant constructs from all theories were then entered into a 'cross theory' stepwise regression analysis to investigate their combined predictive value Results Behavioural simulation - theory level variance explained was: TPB 31%; SCT 29%; II 7%; OLT 30%. Neither CS-SRM nor stage explained significant variance. In the cross theory analysis, habit (OLT, timeline acute (CS-SRM, and outcome expectancy (SCT entered the equation, together explaining 38% of the variance. Behavioural intention - theory level variance explained was: TPB 30%; SCT 24%; OLT 58%, CS-SRM 27%. GDPs in the action stage had significantly higher intention to place fissure sealants. In the cross theory analysis, habit (OLT and attitude (TPB entered the equation, together explaining 68% of the variance in intention. Summary The study provides evidence that psychological models can be useful in understanding and predicting clinical behaviour. Taking a theory-based approach enables the creation of a replicable methodology for

  16. Applying psychological theories to evidence-based clinical practice: identifying factors predictive of placing preventive fissure sealants.

    Science.gov (United States)

    Bonetti, Debbie; Johnston, Marie; Clarkson, Jan E; Grimshaw, Jeremy; Pitts, Nigel B; Eccles, Martin; Steen, Nick; Thomas, Ruth; Maclennan, Graeme; Glidewell, Liz; Walker, Anne

    2010-04-08

    Psychological models are used to understand and predict behaviour in a wide range of settings, but have not been consistently applied to health professional behaviours, and the contribution of differing theories is not clear. This study explored the usefulness of a range of models to predict an evidence-based behaviour -- the placing of fissure sealants. Measures were collected by postal questionnaire from a random sample of general dental practitioners (GDPs) in Scotland. Outcomes were behavioural simulation (scenario decision-making), and behavioural intention. Predictor variables were from the Theory of Planned Behaviour (TPB), Social Cognitive Theory (SCT), Common Sense Self-regulation Model (CS-SRM), Operant Learning Theory (OLT), Implementation Intention (II), Stage Model, and knowledge (a non-theoretical construct). Multiple regression analysis was used to examine the predictive value of each theoretical model individually. Significant constructs from all theories were then entered into a 'cross theory' stepwise regression analysis to investigate their combined predictive value. Behavioural simulation - theory level variance explained was: TPB 31%; SCT 29%; II 7%; OLT 30%. Neither CS-SRM nor stage explained significant variance. In the cross theory analysis, habit (OLT), timeline acute (CS-SRM), and outcome expectancy (SCT) entered the equation, together explaining 38% of the variance. Behavioural intention - theory level variance explained was: TPB 30%; SCT 24%; OLT 58%, CS-SRM 27%. GDPs in the action stage had significantly higher intention to place fissure sealants. In the cross theory analysis, habit (OLT) and attitude (TPB) entered the equation, together explaining 68% of the variance in intention. The study provides evidence that psychological models can be useful in understanding and predicting clinical behaviour. Taking a theory-based approach enables the creation of a replicable methodology for identifying factors that may predict clinical behaviour

  17. Prevalence of sealants in relation to dental caries on the permanent molars of 12 and 15-year-old Greek adolescents. A national pathfinder survey

    Directory of Open Access Journals (Sweden)

    Mamai-Homata Eleni

    2011-02-01

    Full Text Available Abstract Background The use of sealants as an effective measure for the prevention of pit and fissure caries in children has been well documented by several studies; either they are used on an individual or on a public health basis. In order to plan and establish a national preventive program with sealants in a community, it is mandatory to know the epidemiological pattern of caries along with other variables influencing their use and effectiveness. Aims: To assess the utilization and distribution pattern of pit and fissure sealants on the first and second permanent molars of Greek adolescents and to evaluate whether the existing usage of sealants and some socio-demographic factors are correlated to caries prevalence on the population examined Methods A stratified cluster sample of 2481 Greek adolescents was selected according to WHO guidelines (1224 twelve and 1,257 fifteen-year-old, living in urban and rural areas in 11 districts within the country. Five calibrated examiners carried out clinical examinations, recording caries experience at the dentine threshold (BASCD criteria and presence or absence of sealants along with Socio-demographic indicators associated with oral health. Mann Whitney and Pearson's chi-square non parametric tests were utilized for assessing the data. The level of significance was p Results Sealants utilization varied considerably within the different districts, with 8,3% of the 12 and 8,0% of the 15-year-old adolescents having at least one sealed molar. Sealants reduced DMFS scores by 11% in the 12-year-olds and by 24% in the 15-year-olds, while 15-year-old adolescents from rural areas had a statistically significant (p = 0.002 less chance of having sealants (71% compared to children from urban areas. Girls had higher chance to receive sealants in both age groups (26% for the 12 and 19% for the 15-year-old as well as patients that visited the dentist for prevention compared to those visiting the dentist because they

  18. Selective removal of composite sealants with near-UV laser pulses

    Science.gov (United States)

    Louie, Tiffany M.; Jones, Robert S.; Sarma, Anupama V.; Fried, Daniel

    2004-05-01

    It is often necessary to replace pit and fissure sealants and composite restorations. This task is complicated by the necessity for complete removal of the remaining composite to enable suitable adhesion of new composite. Previous studies have shown that lasers pulses from a frequency-tripled Nd:YAG laser (355-nm) can selectively remove residual composite after orthodontic bracket removal on enamel surfaces. UV laser light is preferentially absorbed by polymeric resins and the organic content of the tooth enamel. The objective of this study was to determine if such laser pulses are suitable for selective removal of the old composite from pit and fissure sealants and restorations without damaging surrounding sound tissues. Optical coherence tomography was used to acquire optical cross sections of the occlusal topography and peripheral tooth structure non-destructively before application of the sealants, after sealant application, and after sealant removal with 355-nm laser pulses with intensities ranging from 0-10 J/cm2. Thermocouples were used to monitor the temperature in the pulp chamber during composite removal under clinically relevant ablation rates, i.e., 30 Hz and 30 mJ per laser pulse. At an irradiation intensity of 1.3 J/cm2 pit and fissure sealants were completely removed without visible damage to the underlying enamel. At intensities above 1.5 J/cm2, the laser removes the resin layer while at the same time preferentially etching the surface of the enamel. Temperature excursions in the pulp chamber of extracted teeth was limited to less than 5°C if air-cooling was used during the rapid removal (1-2 min) of sealants, water-cooling was not needed. This is the first presentation of a method for the selective removal of composite restorative materials without damage to the underlying sound tooth structure.

  19. Feasibility Study on a Process for Electroless Metal Deposition in Pits and Fissures of Teeth for Use in Preventive Dentistry.

    Science.gov (United States)

    1980-08-01

    and demineralized water. The specimen is put in a sample holder and attached with double- stick tape to a scale, Hanson Dietetic Scale Model 1440. The... fiber brush PS: Power supply V: Potential meter +: Anode -: Cathode Figure 1 17 * Figure 2 18 Figure3 .a- 19 TABLE I EFFECT OF C.D. AND AgF

  20. The electronic diagnosis of caries in pits and fissures: site-specific stable conductance readings or cumulative resistance readings?

    Science.gov (United States)

    Ricketts, D N; Kidd, E A; Wilson, R F

    1997-01-01

    A prototype electronic caries meter (ECM II; LODE, Groningen. The Netherlands) was designed to deliver a conductance reading when the reading had remained stable for 3 consecutive seconds. The aim of this study was to determine whether this type of stable conductance reading was optimal for caries diagnosis. The ECM II was connected to a graphic recorder which enabled the continuous resistance to be recorded. The graphic recording was calibrated using a standard, variable resistance box. Stable conductance readings were taken for 76 sites on 32 extracted teeth with no visible sign of cavitation at an airflow of 7.5 l/min. Simultaneous graphic recording of resistance was continued for 10 s and cumulative resistance measurements were calculated by adding the resistance values at 1-second intervals. Histological validation of caries status was carried out on macroradiographs of sections cut to include sample sites. The histological picture was compared with the stable conductance reading and the cumulative resistance value for each site. Sensitivity and specificity values were calculated by randomly choosing stable conductance and cumulative resistance values to differentiate sound and carious sites. The results were presented as a series of receiver operating characteristics (ROC) curves and the optimum sensitivity and specificity values determined. 33% of sites had enamel caries and 32% had enamel and dentine caries. Results showed that both stable conductance readings and cumulative resistance measurements gave high and comparable sensitivity and specificity values for the diagnosis of dentine caries (sens. 92%, spec. 87% and sens. 88%, spec. 81%, respectively). However, when intra-examiner reproducibility was checked, stable conductance readings were more repeatable and achieved in shorter clinical time. In conclusion, stable conductance readings appear to be the most suitable for occlusal caries diagnosis.

  1. Influence of stains on lesion contrast in the pits and fissures of tooth occlusal surfaces from 800-1600-nm

    Science.gov (United States)

    Almaz, Elias C.; Simon, Jacob C.; Fried, Daniel; Darling, Cynthia L.

    2016-02-01

    For over one hundred years, x-rays have served as a cornerstone of dentistry. Dental radiographic imaging technologies have constantly improved, however, detecting occlusal lesions remains as one of the greatest challenges due to the low sensitivity of radiographs and the overlap of enamel. Once detected, occlusal lesions have penetrated far into the dentin, necessitating invasive restorative treatment. The adoption of near-infrared (NIR) systems in dentistry introduces the potential for early detection of occlusal lesions. Commercially available NIR systems for intra-oral applications currently operate near 800-nm; however, extrinsic stains may interfere with the detection of demineralization of the underlying enamel surface. Higher wavelengths such as 1300-nm render stains nearly transparent and enhances the contrast of sound enamel to demineralized enamel. This novel finding promotes minimally invasive dentistry and allows oral health professionals the ability to detect, image, track, and monitor early lesions without repeated exposure to ionizing radiation nor invasive treatment.

  2. Impact of adhesive and photoactivation method on sealant integrity and polymer network formation

    Directory of Open Access Journals (Sweden)

    Boniek Castillo Dutra Borges

    2012-06-01

    Full Text Available We evaluated the influence of photoactivation method and hydrophobic resin (HR application on the marginal and internal adaptation, hardness (KHN, and crosslink density (CLD of a resin-based fissure sealant. Model fissures were created in bovine enamel fragments (n = 10 and sealed using one of the following protocols: no adhesive system + photoactivation of the sealant using continuous light (CL, no adhesive system + photoactivation of the sealant using the soft-start method (SS, HR + CL, or HR + SS. Marginal and internal gaps and KHN were assessed after storage in water for 24 h. The CLD was indirectly assessed by repeating the KHN measurement after 24 h of immersion in 100% ethanol. There was no difference among the samples with regard to marginal or internal adaptation. The KHN and CLD were similar for samples cured using either photoactivation method. Use of a hydrophobic resin prior to placement of fissure sealants and curing the sealant using the soft-start method may not provide any positive influence on integrity or crosslink density.

  3. [Perianal fistula and anal fissure].

    Science.gov (United States)

    Heitland, W

    2012-12-01

    CRYPTOGLANDULAR ANAL FISTULA: Perianal abscesses are caused by cryptoglandular infections. Not every abscess will end in a fistula. The formation of a fistula is determined by the anatomy of the anal sphincter and perianal fistulas will not heal on their own. The therapy of a fistula is oriented between a more aggressive approach (operation) and a conservative treatment with fibrin glue or a plug. Definitive healing and the development of incontinence are the most important key points. ANAL FISSURES: Acute anal fissures should be treated conservatively by topical ointments, consisting of nitrates, calcium channel blockers and if all else fails by botulinum toxin. Treatment of chronic fissures will start conservatively but operative options are necessary in many cases. Operation of first choice is fissurectomy, including excision of fibrotic margins, curettage of the base and excision of the sentinel pile and anal polyps. Lateral internal sphincterotomy is associated with a certain degree of incontinence and needs critical long-term observation.

  4. Effect of Acidulated Phosphate Fluoride (APF on the Mcroleakage of Composite Flow and Fssure Sealant Restorations

    Directory of Open Access Journals (Sweden)

    Arash Poorsattar Bejeh Mir

    2012-09-01

    Full Text Available Background and Aims: A large number of investigations have revealed that physical and chemical alterations and weight loss could occur in composite materials exposed to acidic phosphate fluoride (APF gel. The purpose of this study was to assess the microleakage of a fissure sealant and a flow composite exposed to acidulated phosphate fluoride (APF gel. Materials and Methods: In this in vitro study, 60 intact human extracted premolar teeth were used. After preparing the occlusal groove, the teeth were divided into two groups (n=30. Teeth were filled with either Helioseal fissure sealant (Vivadent, Germany or Tetric flow composite (Vivadent, Germany. After that, each group was divided into two subgroups (n=15: 1.23% APF gel (Sultan, U.S.A was applied in the case subgroups, while control subgroups were preserved in normal saline solution. All of teeth were covered with 2 layers of nail varnish except for the filling zone and 1mm around the border of filling. After submerging in 0.5% fushin solution, specimens were sectioned bucco-lingually. Then dye penetration through the filling and fissure sealant was assessed by means of a stereo-microscope. The depth of dye penetration was scored. The data were analyzed using One-way ANOVA and Levene test. Results: The mean values of dye penetration were 1.26±1.09, 1.4±1.05, 1.2±1.37, and 1.4±1.35 for fissure sealant+gel, composite+gel, composite+normal saline, and normal saline groups, respectively. No significant difference was found in inter-groups (P=0.96. Conclusion: Considering the result of the present research, APF gel had no significant effect on the microleakage of Tetric flow composite filling and Helioseal fissure sealant and thus, it can be applied for routine usage.

  5. Clinical Study on Enameloplasty Sealant Technique to Prevent Dental Caries%窝沟釉质成形封闭术预防龋齿的临床研究

    Institute of Scientific and Technical Information of China (English)

    张学彬

    2016-01-01

    Objective To investigate the preventive effect of enameloplasty sealant on children first molars caries. Methods 120 cases in May 2012 to 2013 may in our hospital of pit and fissure sealant of children, were randomly divided into ordinary pit and fissure for the closed group (Group C), nest fissure enamel plasty sealant group (Group E) observed the clinical curative effect of the two groups. Results after 1 year, 2 years group E sealant preservation rate was 94.9%, 92.2% were significantly higher than those in group C sealant retention rate was 82.8%, 78.9% respectively, P< 0.05, the difference is significant; treatment after 1 year, 2 years group E caries rate was 1.7%, 3.4% respectively, compared with C group, the dental caries rate was 1.7%, 3.4% were significantly lower (P< 0.05), the difference is significant. Conclusion the pit and fissure enamel forming closed surgery compared to conventional pit and fissure sealant, sealant can be more easily stored, anti caries effect is better, so children’s teeth once they meet the pit and fissure sealant indications should be timely implementation of pit and fissure enamel plasty sealant technique can improve children’s oral health level, preventing pit and fissure caries.%目的:探讨窝沟釉质成形封闭术对儿童第一恒磨牙龋病的预防效果。方法选取120例于2012年5月至2013年5月期间在我院行窝沟封闭术的儿童,随机分为普通窝沟封闭组(C 组)、窝沟釉质成形封闭术组(E 组),观察两组临床疗效。结果术后1年、2年 E 组封闭剂保存率分别为94.9%、92.2%,均显著高于 C 组的封闭剂保存率分别为82.8%、78.9%,P<0.05,差异具有显著性;治疗后1年、2年 E 组龋病率分别为1.7%、3.4%,较 C 组的龋病率分别为1.7%、3.4%,均显著要低(P<0.05),差异具有显著性。结论窝沟釉质成形封闭术相比于常规窝沟封闭术,封闭剂更容易保存,防龋效果更好,因此儿童牙

  6. Caries detection methods : Can they aid decision making for invasive sealant treatment?

    NARCIS (Netherlands)

    Pereira, AC; Verdonschot, EH; Huysmans, MCDNJM

    2001-01-01

    The decision to place sealants is a difficult one, and it has been suggested that in a low risk population it may be efficient to wait until caries is detected in the fissure. An invasive sealant technique with fissure preparation may then be indicated. The diagnostic method used in the indication o

  7. Evidence-based Practice of Pit and Fissure Sealants%窝沟封闭剂防治龋病的循证病案讨论

    Institute of Scientific and Technical Information of China (English)

    阙克华; 郭斌

    2006-01-01

    为评价窝沟封闭剂防治牙齿窝沟点隙龋病的临床效果,作者检索了从1991~2005年的OVID-EBM Reviews(包括 ACP journal club、Cochrane图书馆)和MEDLINE的随机对照试验、Meta 分析和系统评价.结果发现,窝沟封闭剂防龋有效,并且两种不同窝沟封闭剂的疗效略有区别,树脂型窝沟封闭剂具有明显防龋效果,且流动型复合树脂保存率较理想,而玻璃离子窝沟封闭剂防龋效果还有待确认.临床中应用酸蚀技术有助于减少产生微渗漏和提高保存率;机械空气喷磨结合酸蚀技术有可能会获得最好的边缘封闭;而其它的技术如Er:YAG laser激光、牙钻预备和粘接技术等临床效果还不能肯定,还需要更进一步临床研究.据以上证据,我们对患者制定了治疗方案,尚未获得随访资料.

  8. 加强流动树脂在乳牙窝沟龋防治中的作用%The Efficacy of the Strengthening flowable Composite in Preventing and Curing The Pit and Fissure Caries of Decid-uous Teeth

    Institute of Scientific and Technical Information of China (English)

    王莉

    2016-01-01

    Objective The aim of this clinical study was to evaluate the pit and fissure caries-prevention and cure effect of the strengthening flowable composite, thus find a more valid method. Methods 157 patients with total 418 teeth, diagnosed with deciduous teeth caries with deep pit and fissure, were randomly assigned to the A or B group. Both groups were received seal-ing and restoring treatment simultaneously. 81 patients in group A were treated by the flowable composite and 76 patients in group B were treated by the GISRR. The amount of the teeth receiving treatment was 215 and 203 respectively. Each group was received statistical analysis in terms of the intact rate of the filler and the morbidity of the secondary caries after 6 months and 12 months re-spectively. Results The 6-month and 12-month intact rate of group A was higher than group B(P<0. 05). The 12-month mor-bidity of group B was higher than group A(P<0. 05). Conclusion The better efficacy of the composite compared to GISRR indi-cated that the composite was worth popularizing.%目的:观察加强流动树脂在防治乳牙窝沟龋中的疗效,为乳牙窝沟龋的防治寻找简便的方法。方法将157例418颗伴深窝沟的乳牙中龋病例随机分为A、B两组,两组同时行窝沟封闭及龋洞充填。 A观察组81例以加强流动树脂治疗215颗,B对照组76例以银粉加强型玻璃离子治疗203颗。观察治疗后6个月、12个月两组充填物的完整率、继发龋的发病率、并进行统计学分析。结果 A组在治疗后6月,12月充填物完整率均高于B组,差异有统计学意义。 A组在治疗后12月继发龋发病率低于B组,差异有统计学意义(P<0.05)。结论加强流动树脂在乳牙窝沟龋防治上的疗效优于银粉加强型玻璃离子,值得推广。

  9. Morphology of sealant/enamel interface after surface treatment with bioactive glass.

    Science.gov (United States)

    Panzeri Pires-de-Souza, Fernanda de Carvalho; Silveira, Renata Espíndola; Abuna, Gabriel; Chinelatti, Michelle Alexandra; Alandia-Román, Carla Cecilia; Sinhoreti, Mario Alexandre Coelho

    2015-12-01

    The purpose of this study was to analyze, by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM), the morphology of sealant/enamel interface after surface treatment with Biosilicate. Before pits and fissures sealing, the occlusal surfaces of 10 sound human molars were sectioned perpendicularly at the fissures in order to obtain three slices for each tooth. Slices were randomly assigned into three groups (n = 10) according to sealing protocol: Group 1- Acid etching + Biosilicate + glass ionomer-based sealant (Clinpro XT Varnish, 3M ESPE); Group 2- Acid etching + glass ionomer-based sealant (Clinpro XT Varnish, 3M ESPE); Group 3- No sealing. All slices were subjected to thermal cycling (5,000 cycles; 5-55°C; dwell time: 30s). Half of the slices from each group (n = 5) were analyzed by CLSM and the other half by SEM. Groups 1 and 2 were also submitted to EDS analysis and their data were evaluated by Two-Way ANOVA e Tukey's test (α=5%). EDS data analysis showed higher amounts of silicon (Si) ions than calcium (Ca) ions in Group 1 (P glass ionomer-based sealant/enamel interfaces.

  10. Marginal microleakage between fluoride-containing resin sealant and glass ionomer sealant in vitro%含氟树脂封闭剂与玻璃离子封闭剂边缘微渗漏的体外研究

    Institute of Scientific and Technical Information of China (English)

    刘桥; 林居红; 陈丹; 张红梅; 马文竹; 许小辉

    2013-01-01

    Objective:To observe and compare the state of marginal mieroleakage between fluoride-containing resin sealant and glass ionomer sealant in vitro. Methods:Totally 30 newly extracted noncarious human the third molars were randomly divided into three groups with 10 samples in each group. The occlusional surfaces of the specimens were sealed with ClinproTMSealant,Fuji IX GP and Concise, respectively. After 125 cycles of thermo-cycling, all specimens were immersed in 1% solution of methylene blue dye for 48 h then the microleakage of each specimen was measured under stereomicroscope. Results; Results of dye penetration revealed that there was no significant difference in microleakage among two test groups and control group(P>0.05) and there was no significant difference between two test groups(P>0.05),either. Conclusions : All three types of pit and fissure sealants showed lower microleakage. The tooth surface fitness of glass ionomer cement(Fuji IX GP) is comparatively similar to resin sealants,with satisfactory sealing ability. It's worth promoting glass ionomer material as pit and fissure sealant in clinics.%目的:观察和比较含氟树脂封闭剂与玻璃离子封闭剂的边缘微渗漏情况.方法:将30个无龋新鲜拔出的人类第3磨牙随机分为3组,每组10个标本,分别用含氟树脂封闭剂(ClinproTM Sealant),玻璃离子封闭剂(Fuji Ⅸ GP)和传统树脂封闭剂(Concise)对牙齿(牙合)面进行窝沟封闭,经125次热循环处理后,将所有标本浸泡于1%亚甲基蓝溶液中48 h,采用体视显微镜观察封闭剂边缘微渗漏情况.结果:染料渗透结果显示两实验组(ClinproTM Sealant组、FujiⅨGP组)与对照组(Concise组)材料边缘微渗漏比较,差异均无统计学意义(P>0.05);两实验组比较,差异也无统计学意义(P>0.05).结论:3种窝沟封闭材料均显示出较低的边缘微渗漏,并且玻璃离子水门汀FujiⅨGP具有与树脂类封闭剂相似的牙面密合度,封闭性能良

  11. Avaliação in vitro da microinfiltração na interface selante/esmalte sob a influência de contaminação, emprego de "primer" e tipo de selante In vitro evaluation of sealant microleakage under the influence of contamination, use of primer and type of sealant

    Directory of Open Access Journals (Sweden)

    Ana Lídia CIAMPONI

    1998-04-01

    Full Text Available Este estudo avaliou, in vitro, a microinfiltração na interface selante/esmalte sob a influência de contaminação do meio (saliva, emprego de "primer" (Tenure - Den-Mat e tipo de selante (Concise Light Cured White Sealant - 3M; Fluroshield - Caulk/Dentsply. Os resultados foram obtidos a partir de medidas lineares, utilizando um sistema computadorizado de imagens digitalizadas (IMAGE PLUS. Pôde-se concluir que a contaminação salivar e a utilização de "primer" atuaram de maneira diversa nas diferentes etapas do procedimento clínico; os selantes comportaram-se de maneira semelhante quando submetidos às mesmas condições; o emprego do "primer" favoreceu o escoamento do selante Fluroshield (Caulk/Dentsply nos sulcos e pôde ser observado maior número de bolhas com esse material.This in vitro study investigated the effect of different types of sealants (Concise Light Cured White Sealant - 3M; Fluroshield - Caulk/Dentsply and the use of primer (Tenure - Den-Mat on the microleakage of saliva-contaminated enamel. Sealants were placed on 360 surfaces (occlusal, buccal and lingual of extracted teeth free of caries. After being prepared according to each experimental group, they were thermocycled (5 and 55ºC for 500 and 2.000 cycles. Then they were immersed in a silver nitrate solution (50% and cut in longitudinal slices. The results were described in linear measurements (mm by means of a digital-image analysis system. Contamination and use of primer had different influences when subjected to the different experimental conditions. Both sealants had the same influence on microleakage. Flow of Fluroshield into pit and fissures was improved by use of the primer, and a greater amount of bubbles could be observed in this material.

  12. Effect of Saliva Contamination on Microleakage of a Fissure Selant with or without Bonding Agent

    Directory of Open Access Journals (Sweden)

    A Abarghooyi

    2012-10-01

    Full Text Available Introduction: Contamination of etched enamel to saliva before placement of sealant prevents the appropriate bonding and results in microleakage. Using bondings is effective for decreasing the microleakage. This experimental study aimed to evaluate the effect of bonding agent on microleakage of a fissure sealant before or after contamination to saliva. Methods: In this experimental study 40 sound premolar teeth were randomly divided into four groups. The prophylaxis was done and the teeth were etched with 37% phosphoric acid gel, then they were washed and dried. In the first group, Seal-Rite fissure sealant and Dentastic (Pulpdent, USA without saliva contamination, and in the second group sealant with bonding agent after saliva contamination for 10s, were applied and cured for 40s. In the third group, fissure sealant without bonding agent or saliva contamination, and in the fourth group fissure sealant without bonding application was applied after contamination with saliva and then was cured. After thermocycling, the teeth were placed in 50% silver nitrate for 2 hours. The buccolingual sections were applied and microleakage evaluation was made by stereomicroscope at 4X magnifications and results were evaluated with mann-whiteny test. Results: The fissure sealant group without bonding agent showed the most microleakage after contamination to saliva and use of sealant with bonding agent significantly showed decrease of microleakage. Conclusion: Use of bonding agent under fissure sealant in saliva-contamination status is beneficial for decreasing microleakage.

  13. Marginal and internal analysis of preheated dental fissure-sealing materials using optical coherence tomography.

    Science.gov (United States)

    Borges, Boniek Castillo Dutra; de Assunção, Isauremi Vieira; de Aquino, Célia Avani; de Melo Monteiro, Gabriela Queiroz; Gomes, Anderson Stevens Leonidas

    2016-02-01

    This study aimed to evaluate the influence of pre-photoactivation temperature on the marginal and internal integrity (occurrence of voids) of fissure-sealing materials on occlusal fissures using optical coherence tomography (OCT). Occlusal fissures of 40 human third molars were sealed using a resin-based fissure sealant (Fluroshield) and a flowable composite (Permaflo) photoactivated at 68 °C (preheated) or at room temperature (25 °C) (n=10). After sealing, the teeth were subjected to thermocycling (500 cycles, 5-55 °C) and 14 days of pH cycling (demineralisation for 6 hours/day and remineralisation for 18 hours/day). The occlusal surfaces were scanned in a buccolingual direction, and 20 tomographic images parallel to the long axis of each tooth were obtained. Images presenting marginal gaps and internal voids were counted and statistically analysed using analysis of variance and Tukey's test (Pinternal voids than the resin-based sealant. Preheated materials had a lower percentage of gaps and internal voids than the materials at room temperature. Therefore, preheated flowable composite provided the best marginal sealing of fissures, and internal homogeneity of the material. © 2015 FDI World Dental Federation.

  14. A comparative study of clinical effectiveness of fissure sealing with and without bonding systems: 3-year results.

    Science.gov (United States)

    Sakkas, C; Khomenko, L; Trachuk, I

    2013-04-01

    This prospective clinical study evaluated the sealant retention rate and caries-preventive efficacy of two fissure sealing techniques over a 3-year period. Subjects (87) aged between 6.5 and 11.5 years were enrolled into two groups. In Group I (41 subjects), a resin-based fissure sealant (Fissurit FX, VOCO, Germany) was placed on all four sound permanent first molars (FPM-164 teeth) of each subject and in Group II (46 subjects) on 4 caries-free premolars (P1-2 182 teeth),using the following adhesives systems: Optibond FL (Kerr, USA), Optibond Solo plus (Kerr, USA), Prompt-L-Pop (3 M ESPE, USA) or the conventional acid-etch technique. Sealed teeth were evaluated at baseline, 6, 12, 18, 24 and 36-month intervals with regard to retention and new caries development. Sealant retention was scored as: (1) complete retention; (2) partial loss; (3) complete loss of sealant. Wilcoxon-signed rank test was used to analyse the data. The complete retention rate was: Optibond FL/sealant 80.01-82.92 %, Optibond Solo plus/sealant 73.78-74.27 %, Prompt-L-Pop/sealant 42.84-53.65 % versus acid-etch technique 62.86-71.44 % on FPM and P1-2 (p technique 16.66-17.14 % (p adhesive system Prompt-L-Pop and acid-etch technique. It may be concluded that the use of adhesive systems Optibond FL and Optibond Solo plus yielded better fissure sealing performance.

  15. Dental Sealants

    Science.gov (United States)

    ... Dates Electronic Submission of Applications Grants 101 (How to Write a Grant) Questions and Answers Grant Writing Tips ... offers strategies for providing oral care. NIDCR > Data & Statistics > Find Data by Topic > Dental Sealants Dental Sealants ...

  16. Clinical diagnosis of fissure caries with conventional and laser-induced fluorescence techniques

    OpenAIRE

    Chu, C. H.; Lo, E. C. M.; You, D. S. H.

    2010-01-01

    We studied the in vivo validity of dentinal fissure caries diagnosis by visual examination, bitewing radiography, and use of a laser-induced fluorescence device (DIAGNOdent). A total of 144 and second molars with macroscopically intact occlusal surfaces in 41 Chinese young adults were examined visually, by bitewing radiography, and by DIAGNOdent. Visual examination after pit and fissure opening was used as the reference standard. The sensitivity and specificity of detecting caries that had ex...

  17. Anticaries effect of atraumatic restorative treatment with fissure sealants in suburban districts of Turkey

    Directory of Open Access Journals (Sweden)

    Ertuĝrul Ercan

    2009-06-01

    Conclusion: These results clearly show that the ART-GIS procedure can be used as a preventive method in rural and/or suburban areas where other preventive approaches are neither available nor economical.

  18. Filtek Z350流动纳米树脂与Fuji Ⅸ玻璃离子应用于磨牙窝沟浅龋的效果比较%The effect comparison between Filtek Z350 flowable nano-composite resin and FUji Ⅸ glass-ionomer cement in the application of early pit and fissure caries in molars

    Institute of Scientific and Technical Information of China (English)

    申玲; 黄碧杰; 朱燕梅; 安立民; 刘玲

    2013-01-01

    Objective To compare the effects between Filtek Z350 flowable nano-composite resin and FUji IX glass-ionomer cement in the application of early pit and fissure caries in molars in order to explore a more suitable method for prevention and treatment in early pit and fissure caries in molars.Methods Three hundred and fifty-six molars with early pit and fissures caries in 201 patients were selected as the research object and randomly divided into 2 groups,178 molars of 101 patients as the experimental group and 178 molars of 100 patients as the control group.After caries removal,the experimental group with the Filtek Z350 flowable nano-composite resin was restored in caries damage position and preventive resin restoration was sealed in undamaged fissured area.The control group was restored and sealed with FUji IX glass-ionomer cement.The two groups were observed the retention rate and the secondary caries incidence in 4 years.Results The coating retention rate of the experimental group was higher than that of the control group in the second,third and fourth year (P < 0.05).The secondary caries incidences of the two groups were zero in the first 2 years and the differences between the two groups in the third and fourth year were not significant (P > 0.05).Conclusions Filtek Z350 flowable nano-composite resin is a new method for the prevention and treatment of molar pit and fissure caries effectively and is recommended for clinical use.%目的 比较3M ESPE Fihek Z350 Flowable纳米流动树脂(Filtek Z350流动纳米树脂)与而至富士Ⅸ GP玻璃离子水门汀(Fuji Ⅸ玻璃离子)应用于磨牙窝沟浅龋的临床效果,探讨更适合于预防和治疗磨牙窝沟浅龋的方法.方法 选择201例患者的356颗窝沟浅龋的患牙作为研究对象,随机分为两组,实验组101例患者178颗患牙,对照组100例患者178颗患牙,在彻底去除龋坏组织后,实验组用Fihek Z350流动纳米树脂充填龋坏部位并对未龋损的窝沟区域

  19. Fissure seal or fluoride varnish?

    Science.gov (United States)

    Deery, Christopher

    2016-09-01

    Data sourcesCochrane Oral Health Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, the US National Institutes of Health Trials Register and the World Health Organization (WHO) Clinical Trials Registry PlatformStudy selectionRandomised controlled trials (RCTs) with at least 12 months follow-up, in which fissure sealants, or fissure sealants together with fluoride varnishes, were compared with fluoride varnishes alone for preventing caries in occlusal surfaces of permanent teeth of children and adolescents.Data extraction and synthesisTwo reviewers independently screened search results, extracted data and assessed risk of bias of included studies. Studies were grouped and analysed on the basis of sealant material type (resin-based sealant and glass ionomer-based sealant, glass ionomer and resin-modified glass ionomer) and different follow-up periods. Odds ratio were calculated for caries or no caries on occlusal surfaces of permanent molar teeth. Mean differences were calculated for continuous outcomes and data. Evidence quality was assessed using GRADE (Grades of Recommendation, Assessment, Development and Evaluation) methods.ResultsEight RCTs involving a total of 1747 children aged five to ten years of age were included. Three trials compared resin-based fissure sealant versus fluoride varnish. Results from two studies (358 children) after two years were combined. Sealants prevented more caries, pooled odds ratio (OR) = 0.69 (95%CI; 0.50 to 0.94). One trial with follow-up at four and nine years found that the caries-preventive benefit for sealants was maintained, with 26% of sealed teeth and 55.8% of varnished teeth having developed caries at nine years. Evidence for glass-ionomer sealants was of low quality. One split-mouth trial analysing 92 children at two-year follow-up found a significant difference in favour of resin-based fissure sealant together with fluoride varnish compared with fluoride varnish only (OR

  20. Resina fluida autoadhesiva utilizada como sellante de fosas y fisuras: Estudio de microinfiltración Self-adhesive flowable composite-resin as a fissure sealant: A microleakage study

    Directory of Open Access Journals (Sweden)

    D De Nordenflycht

    2013-04-01

    Full Text Available Objetivo: Evaluar la capacidad de sellado de una resina fluida autoadhesiva (Fusio Liquid Dentin, Pentron Clinical utilizada como sellante de fosas y fisuras con distintos acondicionamientos de la superficie de esmalte. Materiales y Métodos: Se seleccionaron 140 terceros molares recientemente extraídos, los que fueron distribuidos aleatoriamente en cuatro grupos (n=35 y recibieron una técnica de acondicionamiento del esmalte y aplicación de un sellante. Se establecieron los siguientes grupos: Grupo 1, grabado ácido y aplicación de sellante (Clinpro, 3M ESPE; Grupo 2, grabado ácido y aplicación de resina autoadhesiva (Fusio Liquid Dentin, Pentron Clinical; Grupo 3, aplicación de resina autoadhesiva; Grupo 4, microarenado del esmalte y aplicación de resina autoadhesiva. Los dientes sellados fueron termociclados (500 ciclos, 5-55°C, y posteriormente sumergidos en solución de nitrato de plata amoniacal por 24 h (pH=14 y luego en revelador radiográfico (GBX, Kodak por 8h. Posteriormente, los dientes fueron cortados para obtener 2 láminas por diente que fueron observadas bajo magnificación (4x y analizadas digitalmente para evaluar la microinfiltración y la penetración en la fisura. Los resultados fueron analizados estadísticamente (ANOVA, Dunnett, pAim: To evaluate the sealing ability of a self-adhesive flowable composite-resin (Fusio Liquid Dentin, Pentron Clinical with different conditioning treatments of the enamel surface used as a fissure sealant. Materials and Method: 140 recently extracted human third molars were selected and randomly divided into four groups (n=35. Each group received an enamel conditioning treatment and a sealant application. The following groups were established: Group 1, acid etching and sealant application (Clinpro, 3M ESPE; Group 2, acid etching and self-adhesive flowable composite-resin (Fusio Liquid Dentin, Pentron Clinical; Group 3, self-adhesive flowable composite-resin; Group 4, sandblasting and

  1. Distribution, morphology, and origins of Martian pit crater chains

    Science.gov (United States)

    Wyrick, Danielle; Ferrill, David A.; Morris, Alan P.; Colton, Shannon L.; Sims, Darrell W.

    2004-06-01

    Pit craters are circular to elliptical depressions found in alignments (chains), which in many cases coalesce into linear troughs. They are common on the surface of Mars and similar to features observed on Earth and other terrestrial bodies. Pit craters lack an elevated rim, ejecta deposits, or lava flows that are associated with impact craters or calderas. It is generally agreed that the pits are formed by collapse into a subsurface cavity or explosive eruption. Hypotheses regarding the formation of pit crater chains require development of a substantial subsurface void to accommodate collapse of the overlying material. Suggested mechanisms of formation include: collapsed lava tubes, dike swarms, collapsed magma chamber, substrate dissolution (analogous to terrestrial karst), fissuring beneath loose material, and dilational faulting. The research described here is intended to constrain current interpretations of pit crater chain formation by analyzing their distribution and morphology. The western hemisphere of Mars was systematically mapped using Mars Orbiter Camera (MOC) images to generate ArcView™ Geographic Information System (GIS) coverages. All visible pit crater chains were mapped, including their orientations and associations with other structures. We found that pit chains commonly occur in areas that show regional extension or local fissuring. There is a strong correlation between pit chains and fault-bounded grabens. Frequently, there are transitions along strike from (1) visible faulting to (2) faults and pits to (3) pits alone. We performed a detailed quantitative analysis of pit crater morphology using MOC narrow angle images, Thermal Emission Imaging System (THEMIS) visual images, and Mars Orbiter Laser Altimeter (MOLA) data. This allowed us to determine a pattern of pit chain evolution and calculate pit depth, slope, and volume. Volumes of approximately 150 pits from five areas were calculated to determine volume size distribution and regional

  2. Anti Streptococcus mutans non fluoride and fluoride containing sealants after adding nano-silver particles

    Directory of Open Access Journals (Sweden)

    Maryam Ghasempour

    2014-04-01

    Full Text Available   Background and Aims: Since recurrent caries are one of the major causes of failure in resin restorations, the production of antibacterial resin composites was always under investigation. The aim of this study was to evaluate the efficacy of fissure sealants containing nanosilver particles against the Streptococcus mutans.   Materials and Methods: In this experimental study, the antibacterial properties of two sealants (with fluoride (Clinpro 3M and without fluoride (Concise 3M was investigated with 0, 0.01, 0.02, 0.03, 0.04, 0.05% w/w after adding nano-silver using direct contact test. Sealants formed on the walls of 500ml micro tube and after curing, they left in contact with bacterial suspension. In periods of 3, 24, 48h, a 10 µl volume of liquid medium was placed in blood agar culture and after 24 h incubation at 37ºC, the number of S.mutans colony was counted by colony counter. Data were analyzed using ANOVA andT-test.   Results: Results reported sealants with fluoride comparing to non fluoride ones had significant effect on inhibition of S.mutans growth (P<0.001. The direct contact test demonstrated that by increasing the amount of nano particles, the bacterial growth was significantly diminished (P<0.001.   Conclusion: While sealants with fluoride demonstrated antibacterial effect, sealants with incorporation of higher weight percentage of nanosilver particles, had stronger and more significant antibacterial effect in direct contact test.

  3. A Review of Bioceramics and Fibrin Sealant

    Directory of Open Access Journals (Sweden)

    Le Guéhennec L.

    2004-09-01

    Full Text Available This review focuses on bone substitute composites made by mixing ceramic biomaterials with fibrin sealants. Different biomaterials such as coral, bone-derived materials, bioactive glass ceramics, and synthetic calcium phosphate have been mixed with fibrin sealant, resulting in a combination of the biological properties of the two components. This type of association has not produced identical results in all studies. In the past for some, the addition of fibrin sealant to the biomaterial failed to produce any significant, positive effect on osteointegration, whereas others found a positive impact on bone colonization. Despite the negative biological effects reported previously, bioceramic-fibrin composites have been widely used in various types of bone surgery because they are easy to manipulate. In particular, the intra-operative preparation of these composites makes it possible to add bone growth factors or autologous osteoprogenitor cells prior to bone reconstruction. The bone growth factors and autologous osteoprogenitor cells associated with the bioceramic-fibrin composites should provide surgeons with tissue engineered grafts with enhanced osteointegrative properties. This review discusses both the advantages and disadvantages, as well as the future perspectives, of using bioceramic-fibrin composites in various clinical indications.

  4. The sealing of second mandibular temporary molar pits and fissure with the laser of Nd: YAG, phosphoric acid and the glass ionomer cement; Selamento de fossulas e fissura de segundo molar deciduo inferior com laser de Nd: YAG, acido fosforico e cimento de ionomero de vidro

    Energy Technology Data Exchange (ETDEWEB)

    Toda, Maria Aparecida

    2003-07-01

    The main of our study was to check the sealing of second mandibular temporary molar pits and fissure, in vitro, with the laser of Nd: YAG, phosphoric acid at 37% and the glass ionomer cement (CIV, Fuji IX GC).The proposal was to check the structural morphologic changes in the laser irradiation upon the enamel surface to watch the pits and fissure sealing with the glass ionomer cement use after the laser irradiation and to verify the efficiency of the 'double conditioning' (phosphoric acid + Nd: YAG). At the same time we watch the evolution of the temperature in the pulp chamber's inside. Our desire was to achieve a therapeutic alternative technic to prevent the dental caries. The Nd: YAG laser parameters were the same: 79 mJ of energy per pulse; frequency of 5 Hz; mean power of 0,4 W; optical fiber on contact of 320 {mu}m diameter; fluency of 99,52 J/ cm{sup 2}, assuming that the only differential was the time of the laser application on the enamel surface. The samples were prepared with this way: Laser Nd: YAG (53 second) + acid + CIV (Fuji IX); Laser Nd: YAG (53 s); Laser Nd: YAG (20 s + 20 s) + acid + CIV; Laser Nd: YAG (20 s + 20 s); Acid + CIV; Control. Through the scanning electron microscopy (MEV) we noticed fusion and resolidification regions due to the laser irradiation and a better adaptation of the glass ionomer cement when we did the 'double conditioning'. Concerning the temperature increase we can conclude that the echeloned period was the best recommended because the temperature was found in a pattern that would not cause any damage to the dental pulp. For future studies we suggest a longer relaxing time between the laser irradiation, a comparative study of this method with other lasers, the use of other sealing materials and the study with the permanent teeth. (author)

  5. Dental Sealants Prevent Cavities

    Science.gov (United States)

    ... MMWR RSS VitalSigns RSS Error processing SSI file Dental Sealants Prevent Cavities Effective protection for children Language: ... more use of sealants and reimbursement of services. Dental care providers can Apply sealants to children at ...

  6. Effect of FiltekTM Z350 flowable nano-composite resin on the repair of early pit and fissure caries with minimally invasive dentistry technique%FiltekTM Z350纳米流动树脂微创修复细小窝沟龋

    Institute of Scientific and Technical Information of China (English)

    顾远平; 秦明群; 毛峻武; 刘莉; 蒋颖泉

    2012-01-01

    背景:传统的细小窝沟龋修复需要按Ⅰ类洞形进行预备,对牙体组织破坏较多.目的:评价流动纳米树脂微创修复细小窝沟龋的临床效果.方法:选择14~30 岁磨牙有窝沟龋且对侧同名牙或邻牙也有窝沟龋患者167 例,在一侧磨牙牙合面窝沟龋去除龋坏牙体组织后,采用Adper Single Bond 2 全酸蚀黏结技术,用Filtek TM Z350 流动纳米树脂充填整个微创窝洞作为实验组,对侧同名牙或邻牙窝沟龋用同一公司生产的Filtek TM Z350 纳米树脂充填作对照.结果与结论:随访2 年后发现实验组Z350 流动纳米树脂填充体保留率高,边缘完整性好,边缘着色率低,树脂保留率、边缘完整性及边缘着色率高于对照组(P<0.05).提示Filtek TM Z350 流动纳米树脂微创窝沟充填可有效修复细小窝沟龋.%BACKGROUND: The traditional treatment for early pit and fissure caries on permanent teeth is to remove caries tissue and prepare the cavity according to class I, but which will cause the excessive loss of tooth substance.OBJECTIVE: To review the clinical effect of flowable nano-composite resin on repairing early pit and fissure caries with minimally invasive dentistry technique.METHODS: A total of 206 permanent molars with occlusal pit and fissure caries in 167 patients who aged from 14 to 30 years were included. After unilateral cariated tissue had been removed, the cavity was treated with Adper Single Bond 2 total-etching adhesive method, and the whole cavity was filled with Filtek ? Z350 flowable nano-composite resin with minimally invasive dentistry technique and as experimental group. The opposite or adjacent teeth with similar caries in the same patients were treated with Filtek ? Z350 nano-resin as control group.RESULTS AND CONCLUSION: All the patients were followed up for 2 years. In the experimental group, the Filtek ? Z350 flowable nano-composite resin exhibited higher retention rate, better marginal integrity and lower

  7. Sealants for preventing dental decay in the permanent teeth

    DEFF Research Database (Denmark)

    Ahovuo-Saloranta, Anneli; Forss, Helena; Walsh, Tanya

    2013-01-01

    in preventing caries in children and adolescents when compared to no sealants. Their effectiveness may be related to the caries prevalence in the population. OBJECTIVES: To compare the effects of different types of fissure sealants in preventing caries in permanent teeth in children and adolescents. SEARCH...... of age. DATA COLLECTION AND ANALYSIS: Two review authors independently screened search results, extracted data and assessed trial quality. We calculated the odds ratio (OR) for caries or no caries on occlusal surfaces of permanent molar teeth. For trials with a split-mouth design, the Becker...... or the baseline caries prevalence.- Resin-based sealant compared with no sealant: Compared to control without sealant, second or third or fourth generation resin-based sealants prevented caries in first permanent molars in children aged 5 to 10 years (at 2 years of follow-up odds ratio (OR) 0.12, 95% confidence...

  8. 高分子树脂与玻璃离子在儿童恒磨牙窝沟封闭中的效果比较%Comparison of Macromolecule Resin and Glass Ionomer in Pit and Fissure Sealing for First Molar of Child

    Institute of Scientific and Technical Information of China (English)

    施乐; 冯希平; 吕进; 李天豪; 吴仲恺

    2012-01-01

    Objective:To compare the operating performance and caries prevention effects of macromolecule resin and glass ionomer in pit and fissure sealing. Methods: A total of 327 children at the age of 8-9 whose first lower molars have emerged on both sides and with no dental caries have been randomly selected. The left and right molars of them underwent pit and fissure sealing using 3M resin and GC glass ionomer respectively,under the same operation conditions. The operating performance of the two types of materials were compared. All the children have been followed up for 2 years. Preserving rate and caries prevention effects were observed at half year,1 year and 2 years after the operation. Results; There were significant difference in the operation time and preserving rate between the two groups,while there were no significant difference in caries prevalence rate between the two groups. Conclusions: Compared with glass ionomer,macromolecule resin has better liquidity,and owing to its injector-type package,it is more convenient.%目的:比较高分子树脂与玻璃离子2种材料在窝沟封闭术中的操作性能与防龋效果.方法:327例8~9岁双侧下颌第一恒磨牙均已萌出且无龋齿的儿童,对其左、右下颌第1恒磨牙分别用3M树脂、GC玻璃离子行窝沟封闭术.分别于半年、1年、2年后复查比较2种材料的保存率与防龋效果.结果:应用2种材料进行窝沟封闭术的操作时间存在显著差异,2组治疗后的保存率存在显著差异,但患龋率无显著差异.结论:与玻璃离子相比,高分子树脂在窝沟封闭治疗中的流动性较好,注射器式使操作治疗更方便,操作时间更短,保存率更高.

  9. Caries-preventive Effect of Supervised Toothbrushing and Sealants.

    Science.gov (United States)

    Hilgert, L A; Leal, S C; Mulder, J; Creugers, N H J; Frencken, J E

    2015-09-01

    To investigate the effectiveness of 3 caries-preventive measures on high- and low-caries risk occlusal surfaces of first permanent molars over 3 y. This cluster-randomized controlled clinical trial covered 242 schoolchildren, 6 to 7 y old, from low socioeconomic areas. At baseline, caries risk was assessed at the tooth surface level, through a combination of ICDAS II (International Caries Detection and Assessment System) and fissure depth codes. High-caries risk occlusal surfaces were treated according to daily supervised toothbrushing (STB) at school and 2 sealants: composite resin (CR) and atraumatic restorative treatment-high-viscosity glass-ionomer cement (ART-GIC). Low-caries risk occlusal surfaces received STB or no intervention. Evaluations were performed after 0.5, 1, 2, and 3 y. A cavitated dentine carious lesion was considered a failure. Data were analyzed according to the proportional hazard rate regression model with frailty correction, Wald test, analysis of variance, and t test, according to the jackknife procedure for calculating standard errors. The cumulative survival rates of cavitated dentine carious lesion-free, high-caries risk occlusal surfaces were 95.6%, 91.4%, and 90.2% for STB, CR, and ART-GIC, respectively, over 3 y, which were not statistically significantly different. For low-caries risk occlusal surfaces, no statistically significant difference was observed between the cumulative survival rate of the STB group (94.8%) and the no-intervention group (92.1%) over 3 y. There was neither a difference among STB, CR, and ART-GIC on school premises in preventing cavitated dentine carious lesions in high-caries risk occlusal surfaces of first permanent molars nor a difference between STB and no intervention for low-caries risk occlusal surfaces of first permanent molars over 3 y.

  10. Incomplete pulmonary fissures evaluated by volumetric thin-section CT: Semi-quantitative evaluation for small fissure gaps identification, description of prevalence and severity of fissural defects

    Energy Technology Data Exchange (ETDEWEB)

    Koenigkam-Santos, Marcel, E-mail: marcelk46@yahoo.com.br [Department of Diagnostic and Interventional Radiology, University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Radiology Department, German Cancer Research Center (Deutsches Krebsforschungszentrum – DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Department of Radiology, University Hospital of the School of Medicine of Ribeirao Preto – University of Sao Paulo, Av. Bandeirantes 3900, Campus Universitario Monte Alegre, 14048900 Ribeirao Preto, SP (Brazil); Paula, Wagner Diniz de, E-mail: wdpaula@unb.br [Department of Diagnostic and Interventional Radiology, University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Department of Radiology, University Hospital of the University of Brasilia, Brasilia, DF (Brazil); Owsijewitsch, Michael, E-mail: michael.owsijewitsch@med.uniheidelberg.de [Department of Diagnostic and Interventional Radiology, University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Radiology Department, German Cancer Research Center (Deutsches Krebsforschungszentrum – DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Wielpütz, Mark Oliver, E-mail: mark.wielpuetz@med.uni-heidelberg.de [Department of Diagnostic and Interventional Radiology, University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Radiology Department, German Cancer Research Center (Deutsches Krebsforschungszentrum – DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Gompelmann, Daniela, E-mail: daniela.gompelmann@thoraxklinik-heidelberg.de [Pneumology and Respiratory Medicine, Chest Clinic (Thoraxklinik) at University of Heidelberg, Amalienstr. 5, 69126 Heidelberg (Germany); Schlemmer, Heinz-Peter, E-mail: h.schlemmer@dkfz-heidelberg.de [Radiology Department, German Cancer Research Center (Deutsches Krebsforschungszentrum – DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); and others

    2013-12-01

    Objective: To assess the interobserver agreement for a semi-quantitative evaluation of the interlobar fissures integrity in volumetric thin-section CT images, looking for more detailed information regarding fissural defects; and describe prevalence and severity of fissural defects between the different functional groups of subjects. Materials and methods: Volumetric scans of 247 individuals exposed to tobacco with different functional status (normal to severe COPD), were retrospectively and independently evaluated by 2 chest radiologists, with a consensual reading additionally with a third reader in disagreement cases. Right oblique (RO), right horizontal (RH) and left oblique fissures (LO) integrity was estimated using a 5% scale. GOLD classification was available for all subjects. Results: Interobserver agreement (weighted Kappa-index) for fissural categorization was 0.76, 0.70 and 0.75, for RO, RH and LO, respectively. Final evaluation found 81%, 89% and 50% of RO, RH and LO to be incomplete, with respective mean integrity of 80%, 58% and 80%. Small fissure gaps (<10%) were present in 30% of patients. Prevalence and severity of fissural defects were not different between the GOLD categories. Conclusions: A substantial agreement between readers was found in the analysis of interlobar fissures integrity. The semi-quantitative method allowed a detailed description of the fissural defects, information that can be important, for example, in endoscopic lung volume reduction therapies for emphysema. Small fissure gaps, overlooked in previous studies, were found in almost a third of the patients. A higher than previously described prevalence of fissural defects was described, but without significant differences among the distinct functional groups.

  11. Hardness testing of some fissure-sealing materials.

    Science.gov (United States)

    Ulvestad, H

    1977-11-01

    The mechanical properties of fissure-sealing materials are of significant importance for their durability, i.e. their wear resistance. One of the methods of evaluating a material's resistance to attrition is to apply a hardness test. In the present investigation, the surface hardness of some fissure-sealing materials was tested. Sealants made from diluted composite materials and with inclusion of inorganic filler particles appeared to have a considerable higher surface hardness than the other sealing materials tested.

  12. 3M Filtek Z350流动树脂与Pekaseal光固化窝沟封闭剂预防儿童龋病的临床效果研究%Comparison of Preventive Effect of 3M Filtek Z350 Flowable Resin and Pekaseal Light-Cured Sealant for Caries in Children

    Institute of Scientific and Technical Information of China (English)

    蒲寒秋; 肖世芳; 勾京东

    2013-01-01

      目的对比观察3M Filtek Z350流动复合树脂与Pekaseal光固化窝沟封闭剂预防儿童恒磨牙龋病的临床效果。方法对2009年1月至2011年6月间本院门诊符合纳入标准的126名6~10岁儿童的315颗恒磨牙随机分为两组,观察组选择3M Filtek Z350流动复合树脂进行窝沟封闭治疗(病例数=63,牙数=136),对照组采用Pekaseal光固化窝沟封闭剂进行窝沟封闭治疗(病例数=63,牙数=179),随访6个月~1年,复查封闭剂保留情况和患龋情况。结果术后6个月观察组和对照组窝沟封闭剂保留率无统计学差异(P>0.05),术后1年观察组封闭剂保留率高于对照组,差异有统计学意义(P<0.05)。术后6个月、1年,观察组患龋率均低于对照组,差异均有统计学意义(P<0.05)。结论采用3M Filtek Z350流动复合树脂进行窝沟封闭预防儿童恒磨牙窝沟龋效果显著,使龋病发生率大大降低,优于传统的窝沟封闭剂,值得临床推广应用。%Objective To compare the preventive effect of 3M Filtek Z350 flowable resin and Pekaseal light-cured pit and fissure sealant for caries in children. Methods One hundred and twenty six children aged 6 to 10 years were selected to perform sealant technique on their first permanent molars. First molars in trial group were sealed with 3M Filtek Z350 flowable resin and in control group were sealed with Pekaseal light-cured sealant. Sealant retention rate and caries prevalence were observed during 1-year follow up. Rusults At 6-month follow up, there were no statistical difference in sealant retention rate between the two groups(P>0.05). At 1 year follow up, the retention rate of flowable resin group was significantly higher than that of light-cured sealant group(P<0.05). However,caries prevalence of flowable resin group was significantly lower than that of light-cured sealant group at both 6-month and 1-year follow up(P<0.05).Conclusion 3M Filtek Z350 flowable

  13. FISSURES AND LOBES OF LUNGS: A MORPHOLOGICAL AND ANATOMICAL STUDY

    Directory of Open Access Journals (Sweden)

    Radha K

    2015-06-01

    Full Text Available Background and Aims: The fissures of the lungs serve as boundaries for the lobes of the lungs. They also acts as barriers to avoid the spread of pathologies .The proposed aim of the study was to study the fissures and lobes of the lungs and their variations and to compare them with previous studies and to find their clinical implications. Methods: Thirty pairs of lungs were used for the study, obtained from formalin-fixed cadavers of south-indian origin. The lung specimens were observed for the patterns of lobes and fissures, variations were noted and specimens were photographed. Results: Five right lungs showed absence of horizontal fissure. Out of thirty, twelve right sided lungs showed incomplete fissures.On the left side, seven specimens showed incomplete oblique fissure. In addition, two right-sided specimens and four left sided specimens showed presence accessory fissure. Conclusion: The results and their comparison with the previous works show that there is a wide range of difference in occurrence of major, minor and accessory fissures between and among different populations. Knowledge of such variations is mandatory for surgeons in pre-operative planning for performing pulmonary lobectomies and for radiologists for interpreting X-rays and CT scans

  14. Dental sealants

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000779.htm Dental sealants To use the sharing features on this ... case a sealant needs to be replaced. How Dental Sealants are Applied Your dentist applies sealants on ...

  15. Non‑Azygos Accessory Fissure in Right Upper Lobe Associated with Superior and Inferior Accessory Fissures in Right Lower Lobe

    Directory of Open Access Journals (Sweden)

    Thomas Jose Eluvathingal Muttikkal

    2012-01-01

    Full Text Available Accessory fissures in the lungs are common congenital variations, usually detected as incidental findings in radiographs or CT scan. Accessory fissures can act as an anatomic barrier to the spread of inflammatory or neoplastic disease, as well as due to the variant anatomy, mimic lesions. It is important to recognize the presence of accessory fissures, as they affect surgical planning of pulmonary lobectomy and segmentectomy. Accessory fissure in the right upper lobe other than due to the anomalous course of azygos vein is very rare. We report a case of non-azygos accessory fissure, between the apical and the anterior segments of right upper lobe, along with superior and inferior accessory fissures in the right lower lobe.

  16. Safety and usability of hemostats, sealants, and adhesives.

    Science.gov (United States)

    Burks, Sandra; Spotnitz, William

    2014-08-01

    Hemostats, sealants, and adhesives are an integral part of surgical patient care. Nurses who have knowledge about these agents can better help ensure safe, efficient surgical patient care. As a caregiver and patient advocate, the perioperative nurse must understand the most current information about these agents and be prepared to facilitate the transfer of this knowledge to all caregivers. Information about these agents, including the contraindications, warnings, and precautions associated with their use as well as their preparation and application, is provided here. Algorithms designed to clarify the best options for using hemostats, sealants, and adhesives are included as well.

  17. Bisphenol A in dental sealants and its estrogen like effect

    Directory of Open Access Journals (Sweden)

    Manu Rathee

    2012-01-01

    Full Text Available Bisphenol A or BPA-based epoxy resins are widely used in the manufacture of commercial products, including dental resins, polycarbonate plastics, and the inner coating of food cans. BPA is a precursor to the resin monomer Bis-GMA. During the manufacturing process of Bis-GMA dental sealants, Bisphenol A (BPA might be present as an impurity or as a degradation product of Bis-DMA through esterases present in saliva. Leaching of these monomers from resins can occur during the initial setting period and in conjunction with fluid sorption and desorption over time and this chemical leach from dental sealants may be bioactive. Researchers found an estrogenic effect with BPA, Bis-DMA, and Bis-GMA because BPA lacks structural specificity as a natural ligand to the estrogen receptor. It generated considerable concern regarding the safety of dental resin materials. This review focuses on the BPA in dental sealants and its estrogen-like effect.

  18. The effect of bonding agents on the microleakage of sealant following contamination with saliva

    Directory of Open Access Journals (Sweden)

    Askarizadeh Nahid

    2008-06-01

    Full Text Available Aims : An issue of concern in dentistry is the inadequacy of adhesion and proper sealing following restoration of a tooth, which can lead to marginal leakage. The aim of this study was to evaluate the effect of a bonding agent on the microleakage of a sealant material following contamination with saliva. Materials and Methods : In this experimental research, 48 sound premolars were divided into two groups. The first group received sealant without bonding and the other group was given sealant with bonding. After prophylaxis, the occlusal surfaces were etched with 37% phosphoric acid gel and the teeth were then placed in fresh human saliva for l0 s. Following this, in the first group fissure sealant (Kerr was applied directly and cured; for the second group sealant was placed and cured after bonding (Single Bond; 3M. All samples were thermocycled (500 cycles; between 5°C and 55°C; dwell time of 30 s. Silver nitrate was used as the leakage tracer. The teeth were sectioned. Microleakage evaluation was made by stereomicroscope at 40x magnification and the results were evaluated with the Mann-Whitney U test. Results : In the group that received sealant without bonding extensive microleakage was seen; placement of sealant with bonding significantly reduced microleakage. Conclusion : In the presence of contamination with saliva, use of bonding under the fissure sealant can reduce microleakage

  19. Wear and superficial roughness of glass ionomer cements used as sealants, after simulated toothbrushing Desgaste e rugosidade superficial de cimentos de ionômero de vidro utilizados como selantes, após escovação simulada

    Directory of Open Access Journals (Sweden)

    Daniela Rios

    2002-12-01

    Full Text Available The purpose of this study was to evaluate, in vitro, the properties (wear and roughness of glass ionomer cements that could influence their indication as pit and fissure sealants. The utilized materials were Fuji Plus, Ketac-Molar and Vitremer (in two different proportions: 1:1 and ¼:1. The resin-based sealant Delton was used as control. By means of an electronic balance (precision of 10-4 g, wear was measured in function of weight loss after simulated toothbrushing. Superficial roughness was determined by means of a surface roughness-measuring apparatus. The results revealed that diluted Vitremer and Fuji Plus were less resistant to toothbrushing abrasion and had the greatest increase in superficial roughness.Although in clinical situations luting or diluted ionomer cements are often utilized as alternatives to resin-based sealants, the resultsof this study revealed that the properties of those cements are worse than those of restorative ionomers, whichpresented results similar to those of the evaluated resin sealant.O presente estudo foi conduzido in vitro com o intuito de constatar as propriedades (desgaste e rugosidade dos CIV, as quais influenciam na sua indicação como material selador de fossas e fissuras. Os materiais empregados foram Fuji Plus, Ketac-Molar e Vitremer (duas proporções: 1:1 e ¼:1. O selante Delton foi controle. A determinação do desgaste foi obtida através da quantidade de massa perdida após a escovação e a rugosidade através da análise quantitativa da superfície. Os resultados mostraram que o Vitremer diluído e o Fuji Plus apresentaram maior grau de desgaste e maior aumento de rugosidade. Apesar de clinicamente se encontrar um maior uso dos ionômeros de vidro cimentantes ou diluídos como forma alternativa para material selador; este trabalho permitiu concluir que estes possuem propriedades bastante inferiores quando comparados aos ionômeros restauradores que, por sua vez, possuem resultados semelhantes

  20. Factors affecting coke size and fissuring during cokemaking part 2

    Energy Technology Data Exchange (ETDEWEB)

    Merrick Mahoney; Jeff Keating; Susan Woodhouse [BHP Billiton Newcastle Technology Centre (Australia)

    2007-12-15

    This work addressed the mechanism of fissuring during metallurgical cokemaking and extends on a previous ACARP project. Considerable progress has been made in understanding the mechanism by an integrated modelling work; experimental program. The work points to opportunities for controlling the carbonisation process to achieve required outcomes in terms of coke lump size and distribution. Key outcomes of the work included: A methodology for determination of the minimum spacing between fissures, and the time at which period doublings (i.e. every second fissure stopping) occur, has been developed and implemented. Implementation of the methodology allows the determination of the complete fissure pattern (at least those perpendicular to the oven walls) for a given coke oven/charge configuration. A plausible mechanistic explanation of the formation of lateral fissures (those that are parallel to the oven walls) has been developed. Knowledge of the fissure pattern, combined with the lateral fissuring explanation, enables the determination of typical size and shape of lumps after stabilisation of the coke.

  1. Fibrin sealant in general surgery. Personal experience and literary review.

    Science.gov (United States)

    Gubitosi, Adelmo; Ruggiero, Roberto; Docimo, Giovanni; Esposito, Alessandro

    2014-01-01

    In consideration of the use of fibrin glue in a general surgery department, authors analyze their last two years series. Operations on liver and biliary ducts, bowel and proctologic surgery, thyroid and breast surgery, abdominal wall hernias, fistulas and difficult wounds are considered with a literary review on fibrin sealant.

  2. The impact of Er:YAG laser enamel conditioning on the microleakage of a new hydrophilic sealant--UltraSeal XT hydro.

    Science.gov (United States)

    Güçlü, Z A; Dönmez, N; Tüzüner, T; Odabaş, M E; Hurt, A P; Coleman, N J

    2016-05-01

    UltraSeal XT hydro is a new hydrophilic, light-cured, methacrylate-based pit and fissure sealant which has been developed by Ultradent Products, USA. The sealant is highly filled with a 53 wt.% mixture of inorganic particles which confer both thixotropy and radiopacity. The principal purpose of this study was to investigate the microleakage of UltraSeal XT hydro as a function of different enamel etching techniques. The occlusal surfaces of sound, extracted human molars were either acid etched, Er:YAG laser irradiated or successively laser irradiated and acid etched. UltraSeal XT hydro was applied to each group of teeth (n = 10) which were subjected to a thermocycling process consisting of 2500 cycles between 5 and 50 °C with a dwell time of 30 s. Microleakage assessments were then carried out using 0.5% fuchsin dye and optical microscopy. The microleakage score data were analysed using the Kruskal-Wallis, Mann-Whitney U test with Bonferroni adjustment. No significant differences in microleakage were noted between the individually acid etched and laser-irradiated groups (p > 0.05); however, teeth treated with a combination of laser irradiation and acid etching demonstrated significantly lower microleakage scores (p Laser etching increases the roughness of the enamel surface which causes a concentrated zoning of the filler particles at the enamel-sealant interface.

  3. Incomplete and accessory fissures of the lung evaluated by high-resolution computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Heřmanová, Zuzana, E-mail: zuzana.hermanova2@fnol.cz; Čtvrtlík, Filip, E-mail: filip.ctvrtlik@fnol.cz; Heřman, Miroslav, E-mail: herman@fnol.cz

    2014-03-15

    Purpose: The aim of our study was to assess incomplete and accessory interlobar fissures using volumetric thin-section high-resolution computed tomography (HRCT). Materials and methods: Retrospective assessment of HRCT examinations of 250 patients was performed. We assessed the localization, extension, and type of the incompleteness of fissures as well as the presence and localization of accessory fissures. We searched for possible correlation among the localization of interlobar fissures, the presence of incompleteness, and accessory fissures. Results: On the left side, an incomplete oblique fissure was found in 24%. The discontinuity was present in the parahilar region and the area of the incompleteness was most frequently between 21% and 40%. The right oblique fissure was incomplete in 35%, mostly parahilarly, with the most frequent discontinuity below 20%. An incomplete horizontal fissure was found in 74%. Accessory fissures were identified in 16% of patients, with the same frequency on both sides. The most frequent finding was accessory horizontal fissure with 8.0% on the left side, superior accessory fissure (7.2%) and inferior accessory fissure (5.2%) on the right side. No correlation was found among the localization of interlobar fissures, the presence of incompleteness, and accessory fissures. Conclusion: Incomplete and accessory fissures are frequent anatomic variations of interlobar fissures.

  4. Toxicity of coal-tar and asphalt sealants to eastern newts, Notophthalmus viridescens.

    Science.gov (United States)

    Bommarito, Thomas; Sparling, Donald W; Halbrook, Richard S

    2010-09-01

    Between 1970 and 2000 the concentration of total polycyclic aromatic hydrocarbons (TPAH) in several lakes across the country increased whereas those of other persistent organic pollutants (POPs) tended to remain stable or declined. Urbanized watersheds experienced greater rises in TPAH concentration compared to non-urban lakes. Sources for urban PAHs include industrial wastes, vehicular exhausts and oil leaks and sealants from pavement surfaces. Both coal-tar and asphalt sealants are used to protect surfaces but runoff from surfaces coated with coal-tar can have mean concentrations of 3500 mg TPAHs kg(-1), much higher than runoff from asphalt-sealed or cement surfaces. Unaltered parent compounds of PAHs can have many lethal and sublethal toxic effects, but oxidation and UV radiation can alter the toxicity of these compounds, sometimes creating degradates that are many times more toxic than parent compounds. The purposes of this study were to determine if coal-tar sealants can be toxic to adult eastern newts (Notophthalmus viridescens) and to compare the toxicity of coal-tar sealant to that of asphalt sealant. Newts were exposed to sediments containing dried sealants ranging from 0 mg kg(-1) to 1500 mg kg(-1) under simultaneous exposure to UV radiation and visible light to determine concentration/response relationships. No significant mortality occurred with any treatment. Significant effects due to sealants included decreased righting ability and diminished liver enzyme activities. Coal-tar sealant was more effective in inducing these changes than was asphalt sealant.

  5. Toxicity of coal-tar and asphalt sealants to eastern newts, Notophthalmus viridescens

    Energy Technology Data Exchange (ETDEWEB)

    Bommarito, T.; Sparling, D.W.; Halbrook, R.S. [South Illinois University, Carbondale, IL (United States). Cooperative Wildlife Research Laboratory

    2010-09-15

    Between 1970 and 2000 the concentration of total polycyclic aromatic hydrocarbons (TPAH) in several lakes across the country increased whereas those of other persistent organic pollutants (POPs) tended to remain stable or declined. Urbanized watersheds experienced greater rises in TPAH concentration compared to non-urban lakes. Sources for urban PAHs include industrial wastes, vehicular exhausts and oil leaks and sealants from pavement surfaces. Both coal-tar and asphalt sealants are used to protect surfaces but runoff from surfaces coated with coal-tar can have mean concentrations of 3500 mg TPAHs kg{sup -1}, much higher than runoff from asphalt-sealed or cement surfaces. Unaltered parent compounds of PAHs can have many lethal and sublethal toxic effects, but oxidation and UV radiation can alter the toxicity of these compounds, sometimes creating degradates that are many times more toxic than parent compounds. The purposes of this study were to determine if coal-tar sealants can be toxic to adult eastern newts (Notophthalmus viridescens) and to compare the toxicity of coal-tar sealant to that of asphalt sealant. Newts were exposed to sediments containing dried sealants ranging from 0 mg kg{sup -1} to 1500 mg kg{sup -1} under simultaneous exposure to UV radiation and visible light to determine concentration/response relationships. No significant mortality occurred with any treatment. Significant effects due to sealants included decreased righting ability and diminished liver enzyme activities. Coal-tar sealant was more effective in inducing these changes than was asphalt sealant.

  6. INTER-TRACHEID AND CROSS-FIELD PITTING IN COMPRESSION AND OPPOSITE WOOD OF

    Directory of Open Access Journals (Sweden)

    Asghar Tarmian

    2009-02-01

    Full Text Available Inter-tracheid and cross-filed pit pairs in compression and opposite wood of Norway spruce (Picea abies were examined. The size, appearance, and frequency of bordered pits on the radial side of axial tracheids and their aperture specification were studied. The type, size, and number of half-bordered pits between the axial tracheids and rays per cross-field were also studied. Several techniques were employed for the measurements: Environmental Scanning Electron Microscope (ESEM, Scanning Electron Microscope (SEM, Light Microscope (LM, and the Frankling method (FM. The structure, size, and frequency of both types of the pits varied between compression and opposite wood. Fewer pits of a smaller size and a smaller aperture diameter were observed in compression wood. The uniseriate arrangement of bordered pit pairs, unpitted tracheid walls, circular- or often slit-like pit aperture, dominantly piceoid but sometimes cupressoid and occasionally taxodioid cross-field pitting, and a number of fissures on the tracheid walls and bordered pits were characteristics of compression wood.

  7. Anal fissure

    Science.gov (United States)

    ... split or tear in the thin moist tissue ( mucosa ) lining the lower rectum (anus). Causes Anal fissures ... Chronic Constipation in infants and children Crohn disease Mucosa Review Date 5/24/2016 Updated by: Mary ...

  8. NIR detection of pits and pit fragments in fresh cherries (abstract)

    Science.gov (United States)

    The feasibility of using near infrared (NIR) diffuse reflectance spectroscopy for the detection of pits and pit fragments in cherries was demonstrated. For detection of whole pits, 300 cherries were obtained locally and pits were removed from half. NIR reflectance spectra were obtained in triplicate...

  9. Monitoring of Sound and Carious Surfaces under Sealants over 44 Months

    Science.gov (United States)

    Fontana, M.; Platt, J.A.; Eckert, G.J.; González-Cabezas, C.; Yoder, K.; Zero, D.T.; Ando, M.; Soto-Rojas, A.E.; Peters, M.C.

    2014-01-01

    Although there is strong evidence for the effectiveness of sealants, one major barrier in sealant utilization is the concern of sealing over active caries lesions. This study evaluated detection and monitoring of caries lesions through a clear sealant over 44 mo. Sixty-four 7- to 10-year-old children with at least 2 permanent molars with International Caries Detection and Assessment System (ICDAS) scores 0-4 (and caries less than halfway through the dentin, radiographically) were examined with ICDAS, DIAGNOdent, and quantitative light-induced fluorescence (QLF) before sealant placement and 1, 12, 24, and 44 mo (except QLF) after. Bitewing radiographs were taken yearly. DIAGNOdent and QLF were able to distinguish between baseline ICDAS before and after sealant placement. There was no significant evidence of ICDAS progression at 12 mo, but there was small evidence of minor increases at 24 and 44 mo (14% and 14%, respectively) with only 2% ICDAS ≥ 5. Additionally, there was little evidence of radiographic progression (at 12 mo = 1%, 24 mo = 3%, and 44 mo = 9%). Sealant retention rates were excellent at 12 mo = 89%, 24 mo = 78%, and 44 mo = 70%. The small risk of sealant repair increased significantly as baseline ICDAS, DIAGNOdent, and QLF values increased. However, regardless of lesion severity, sealants were 100% effective at 12 mo and 98% effective over 44 mo in managing occlusal surfaces at ICDAS 0-4 (i.e., only 4 of 228 teeth progressed to ICDAS ≥ 5 associated with sealants in need of repair and none to halfway or more through the dentin, radiographically). This study suggests that occlusal surfaces without frank cavitation (ICDAS 0-4) that are sealed with a clear sealant can be monitored with ICDAS, QLF, or DIAGNOdent, which may aid in predicting the need for sealant repair. PMID:25248613

  10. Monitoring of sound and carious surfaces under sealants over 44 months.

    Science.gov (United States)

    Fontana, M; Platt, J A; Eckert, G J; González-Cabezas, C; Yoder, K; Zero, D T; Ando, M; Soto-Rojas, A E; Peters, M C

    2014-11-01

    Although there is strong evidence for the effectiveness of sealants, one major barrier in sealant utilization is the concern of sealing over active caries lesions. This study evaluated detection and monitoring of caries lesions through a clear sealant over 44 mo. Sixty-four 7- to 10-year-old children with at least 2 permanent molars with International Caries Detection and Assessment System (ICDAS) scores 0-4 (and caries less than halfway through the dentin, radiographically) were examined with ICDAS, DIAGNOdent, and quantitative light-induced fluorescence (QLF) before sealant placement and 1, 12, 24, and 44 mo (except QLF) after. Bitewing radiographs were taken yearly. DIAGNOdent and QLF were able to distinguish between baseline ICDAS before and after sealant placement. There was no significant evidence of ICDAS progression at 12 mo, but there was small evidence of minor increases at 24 and 44 mo (14% and 14%, respectively) with only 2% ICDAS ≥ 5. Additionally, there was little evidence of radiographic progression (at 12 mo = 1%, 24 mo = 3%, and 44 mo = 9%). Sealant retention rates were excellent at 12 mo = 89%, 24 mo = 78%, and 44 mo = 70%. The small risk of sealant repair increased significantly as baseline ICDAS, DIAGNOdent, and QLF values increased. However, regardless of lesion severity, sealants were 100% effective at 12 mo and 98% effective over 44 mo in managing occlusal surfaces at ICDAS 0-4 (i.e., only 4 of 228 teeth progressed to ICDAS ≥ 5 associated with sealants in need of repair and none to halfway or more through the dentin, radiographically). This study suggests that occlusal surfaces without frank cavitation (ICDAS 0-4) that are sealed with a clear sealant can be monitored with ICDAS, QLF, or DIAGNOdent, which may aid in predicting the need for sealant repair.

  11. Qualification, Demonstration & Validation of Compliant Removers for Aircraft Sealants and Specialty Coatings ESTCP WP-0621

    Science.gov (United States)

    2010-06-01

    materials/ methods to approach sealant removal tasks consistently and effectively, depending upon situation. BUSINESS SENSITIVE 6 TECHNICAL APROACH ...Dem/Val 3 at New River MCAS - V-22 Osprey TECHNICAL APROACH BUSINESS SENSITIVE 5 TECHNICAL APROACH “Toolbox” Approach: Provide end users with...Demonstration Tests (UDRI) - Testing Protocols Parameter Test Test Method Sealant Removal Force Measuring Unit UDRI Proprietary Substrate Damage Potential

  12. Structural Origins of Martian Pit Chains

    Science.gov (United States)

    Wyrick, D.; Ferrill, D. A.; Morris, A. P.; Colton, S. L.; Sims, D. W.

    2003-12-01

    Pit craters are circular to elliptical depressions found in alignments (chains), which in many cases coalesce into linear troughs, and are common on the surface of Mars. Pit craters lack an elevated rim, ejecta deposits, or lava flows that are associated with impact craters or calderas. It is generally agreed that these features are formed by collapse into a subsurface cavity. Hypotheses regarding the formation of pit crater chains require development of a substantial subsurface void to accommodate collapse of the overlying sediments. Suggested mechanisms of formation include: collapsed lava tubes, dike swarms, collapsed magma chamber, karst dissolution, fissuring beneath loose material, and dilational faulting. The research described here is intended to constrain current interpretations of pit crater chain formation by analyzing their distribution and morphology. The western hemisphere of Mars was systematically mapped using Mars Orbiter Camera (MOC) images to generate ArcView Geographic Information System (GIS) coverages. All visible pit crater chains were mapped, including their orientations and associations with other structures. We found that pit chains commonly occur in areas that show regional extension or local fissuring. There is a strong correlation between pit chains and fault-bounded grabens. Frequently, there are transitions along strike from (i) visible faulting to (ii) faults and pits to (iii) pits alone. We performed a detailed quantitative analysis of pit crater morphology using MOC narrow angle images, Thermal Emission Imaging System (THEMIS) visual images and Mars Orbiter Laser Altimeter (MOLA) data. This allowed us to interpret a pattern of pit chain evolution and calculate pit depth, slope, and volume. The information collected in the study was then compared with non-Martian examples of pit chains and physical analog models. We evaluated the various mechanisms for pit chain development based on the data collected and conclude that dilational

  13. Bonding durability of dental sealants to deciduous and permanent teeth

    OpenAIRE

    MOURA, Sandra Kiss; Lemos,Letícia Vargas Freire Martins; Myszkovisk, Suellen; Provenzano, Maria Gisette Arias; Balducci,Ivan; Myaki, Silvio Issao [UNESP

    2014-01-01

    AIM: To evaluate the bonding durability of materials used as sealants on different dentitions. METHODS: Deciduous (D) and permanent (P) molars were divided into four groups (n=5) and sealed with Fluroshield (F) and OptiBond FL (FL). Blocks of composite resin were built, stored in distilled water (24 h/37 °C), sectioned into 0.8 mm2 and tested at tensile (0.5 mm/min) after 24 h and 6 months. The fractures were observed and classified into adhesive, cohesive or mixed types. The data were a...

  14. Fissured Tongue

    Science.gov (United States)

    ... 2020 Annual Meeting Orlando, FL Our Partners Fissured Tongue The term fissured tongue describes the finding of multiple small furrows or grooves on the dorsal (top) surface of the tongue. These fissures can be shallow or deep, single ...

  15. Speed, Acceleration, Chameleons and Cherry Pit Projectiles

    Science.gov (United States)

    Planinsic, Gorazd; Likar, Andrej

    2012-01-01

    The paper describes the mechanics of cherry pit projectiles and ends with showing the similarity between cherry pit launching and chameleon tongue projecting mechanisms. The whole story is written as an investigation, following steps that resemble those typically taken by scientists and can therefore serve as an illustration of scientific…

  16. Effect of Adhesive Application on Sealant Success: A Clinical Study of Fifth and Seventh Generation Adhesive Systems.

    Science.gov (United States)

    Tandon, Vaibhav; Lingesha, Ravishanakar Telgi; Tangade, Pradeep Shankar; Tirth, Amit; Pal, Sumit Kumar; Lingesha, Chaitra Telgi; Arora, Vikram; Yadav, Vipul

    2015-10-01

    The aim of the study was to compare the effect of fifth and seventh generation bonding agent on sealant success. Sixty-four school children aged six to nine years received sealants in four permanent molars in a split mouth design, such that each patient received sealant in the first permanent molar with fifth generation bonding agent in one arch and seventh generation bonding agent in the other arch; contra-lateral molars were sealed with sealant alone. The evaluation was carried out at baseline, three months, six months and 12 months, according to the criteria by Feigal et al, in 2000. Chi- square test was used to analyze data at Pgeneration and sealant group, and fifth generation and seventh generation groups; whereas, no significant difference was found for sealant retention between seventh generation and sealant group at three, six and 12 months. As separate etch and rinse steps are not required for seventh generation bonding agents, and almost similar results were obtained for both sealant and seventh generation groups, it can be concluded that application of sealant along with a seventh generation bonding agent may enhance sealant success and can be used for caries prevention in preventive programs.

  17. Fissured and geographic tongue in Williams-Beuren syndrome

    Directory of Open Access Journals (Sweden)

    Neeta Sharma

    2014-01-01

    Full Text Available Williams-Beuren Syndrome (WBS is a rare, most often sporadic, genetic disease caused by a chromosomal microdeletion at locus 7q11.23 involving 28 genes. It is characterized by congenital heart defects, neonatal hypercalcemia, skeletal and renal abnormalities, cognitive disorder, social personality disorder, and dysmorphic facies. A number of clinical findings has been reported, but none of the studies evaluated this syndrome considering oral cavity. We here report a fissured and geographic tongue in association with WBS.

  18. Modeling plaque fissuring and dissection during balloon angioplasty intervention.

    Science.gov (United States)

    Gasser, T Christian; Holzapfel, Gerhard A

    2007-05-01

    Balloon angioplasty intervention is traumatic to arterial tissue. Fracture mechanisms such as plaque fissuring and/or dissection occur and constitute major contributions to the lumen enlargement. However, these types of mechanically-based traumatization of arterial tissue are also contributing factors to both acute procedural complications and chronic restenosis of the treatment site. We propose physical and finite element models, which are generally useable to trace fissuring and/or dissection in atherosclerotic plaques during balloon angioplasty interventions. The arterial wall is described as an anisotropic, heterogeneous, highly deformable, nearly incompressible body, whereas tissue failure is captured by a strong discontinuity kinematics and a novel cohesive zone model. The numerical implementation is based on the partition of unity finite element method and the interface element method. The later is used to link together meshes of the different tissue components. The balloon angioplasty-based failure mechanisms are numerically studied in 3D by means of an atherosclerotic-prone human external iliac artery, with a type V lesion. Image-based 3D geometry is generated and tissue-specific material properties are considered. Numerical results show that in a primary phase the plaque fissures at both shoulders of the fibrous cap and stops at the lamina elastica interna. In a secondary phase, local dissections between the intima and the media develop at the fibrous cap location with the smallest thickness. The predicted results indicate that plaque fissuring and dissection cause localized mechanical trauma, but prevent the main portion of the stenosis from high stress, and hence from continuous tissue damage.

  19. Is Playing in the Pit Really the Pits?: Pain, Strength, Music Performance Anxiety, and Workplace Satisfaction in Professional Musicians in Stage, Pit, and Combined Stage/Pit Orchestras.

    Science.gov (United States)

    Kenny, Dianna T; Driscoll, Tim; Ackermann, Bronwen J

    2016-03-01

    Typically, Australian orchestral musicians perform on stage, in an orchestra pit, or in a combination of both workplaces. This study explored a range of physical and mental health indicators in musicians who played in these different orchestra types to ascertain whether orchestra environment was a risk factor affecting musician wellbeing. Participants comprised 380 full-time orchestral musicians from the eight major state orchestras in Australia comprised of two dedicated pit orchestras, three stage-only symphonic orchestras, and three mixed stage/pit orchestras. Participants completed a physical assessment and a range of self-report measures assessing performance-related musculoskeletal disorders (PRMD), physical characteristics including strength and perceived exertion, and psychological health, including music performance anxiety (MPA), workplace satisfaction, and bullying. Physical characteristics and performance-related musculoskeletal profiles were similar for most factors on the detailed survey completed by orchestra members. The exceptions were that pit musicians demonstrated greater shoulder and elbow strength, while mixed-workload orchestra musicians had greater flexibility Significantly more exertion was reported by pit musicians when rehearsing and performing. Stage/pit musicians reported less physical exertion when performing in the pit compared with performing on stage. Severity of MPA was significantly greater in pit musicians than mixed orchestra musicians. Pit musicians also reported more frequent bullying and lower job satisfaction compared with stage musicians. There were few differences in the objective physical measures between musicians in the different orchestra types. However, pit musicians appear more psychologically vulnerable and less satisfied with their work than musicians from the other two orchestra types. The physical and psychological characteristics of musicians who perform in different orchestra types have not been adequately

  20. LIQUIDARMOR CM Flashing and Sealant, High Impact Technology Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Hun, Diana E [ORNL; Bhandari, Mahabir S [ORNL

    2016-12-01

    Air leakage is responsible for about 1.1 quads of energy or 6% of the total energy used by commercial buildings in the US. Consequently, infiltration and exfiltration are among the largest envelope-related contributors to the heating, ventilation, and air conditioning loads in commercial buildings. New air sealing technologies have recently emerged that aim to improve the performance of air barrier systems by simplifying their installation procedure. LIQUIDARMORTM CM Flashing and Sealant is an example of these new advanced material technologies. This technology is a spray-applied sealant and liquid flashing and can span gaps that are up to ¼ in. wide without a supporting material. ORNL verified the performance of LIQUIDARMORTM CM with field tests and energy simulations from a building in which LIQUIDARMORTM CM was one of components of the air barrier system. The Homeland Security Training Center (HTC) at the College of DuPage in Glen Ellyn, IL, served as the demonstration site. Blower door test results show the average air leakage rate in the demonstration site to be 0.15 cfm/ft2 at 1.57 psf, or 63% lower than the 0.4 cfm at 1.57 psf specified in the 2015 International Energy Conservation Code (IECC). According to simulation results, HTC lowered its annual heating and cooling cost by about $3,000 or 9% compared to a similar building that lacked an air barrier system. This demonstration project serves as an example of the level of building envelope airtightness that can be achieved by using air barrier materials that are properly installed, and illustrates the energy and financial savings that such an airtight envelope could attain.

  1. Pitted keratolysis, erythromycin, and hyperhidrosis.

    Science.gov (United States)

    Pranteda, Guglielmo; Carlesimo, Marta; Pranteda, Giulia; Abruzzese, Claudia; Grimaldi, Miriam; De Micco, Sabrina; Muscianese, Marta; Bottoni, Ugo

    2014-01-01

    Pitted keratolysis (PK) is a plantar skin disorder mainly caused by coryneform bacteria. A common treatment consists of the topical use of erythromycin. Hyperhidrosis is considered a predisposing factor for bacterial proliferation and, consequently, for the onset of PK. The aim of this study was to evaluate the relationship between PK erythromycin and hyperhidrosis. All patients with PK seen in Sant'Andrea Hospital, between January 2009 and December 2011, were collected. PK was clinically and microscopically diagnosed. All patients underwent only topical treatment with erythromycin 3% gel twice daily. At the beginning of the study and after 5 and 10 days of treatment, a clinical evaluation and a gravimetric measurement of plantar sweating were assessed. A total of 97 patients were diagnosed as PK and were included in the study. Gravimetric measurements showed that in 94 of 97 examined patients (96.90%) at the time of the diagnosis, there was a bilateral excessive sweating occurring specifically in the areas affected by PK. After 10 days of antibiotic therapy, hyperhidrosis regressed together with the clinical manifestations. According to these data, we hypothesize that hyperhidrosis is due to an eccrine sweat gland hyperfunction, probably secondary to bacterial infection.

  2. Relation Between PAHs and Coal-Tar-Based Pavement Sealant in Urban Environments (Invited)

    Science.gov (United States)

    Mahler, B. J.; van Metre, P. C.

    2010-12-01

    Since 2003, coal-tar-based sealant products have come under increased scrutiny as a source of PAHs in urban environments. Sealant (or sealcoat) is the black, shiny substance often applied to asphalt pavement, in particular parking lots and driveways, for esthetic and maintenance purposes. Coal-tar-based sealant, one of the two primary pavement sealant types on the market, typically is 20-35 percent coal-tar pitch, a known carcinogen that is more than 50 percent polycyclic aromatic hydrocarbons (PAHs). The PAH content of the coal-tar-based sealant product is about 1,000 times that of a similar, asphalt-based product, on average. This difference is reflected in regional differences in sealant use and PAH concentrations in pavement dust. In the central and eastern U.S., where the coal-tar-based formulation is prevalent, ΣPAH in mobile particles from sealed pavement have been shown to be about 1,000 times higher than in the western U.S., where the asphalt-based formulation is prevalent (the median ΣPAH concentrations are 2,200 mg/kg in the central and eastern U.S. and 2.1 mg/kg in the western U.S.). Source apportionment modeling indicates that, in the central and eastern U.S., particles from sealed pavement are contributing the majority of the PAHs in recently deposited (post-1990) lake sediment, with implications for ecological health, and that coal-tar-based sealant is the primary cause of upward trends in PAHs in U.S. urban lakes. From the standpoint of human health, research indicates that mobile particles from parking lots with coal-tar-based sealant are tracked indoors, resulting in elevated PAH concentrations in house dust. Coal-tar-based sealcoat being applied to an asphalt parking lot at the University of Texas Pickle Research Center.

  3. Microtensile bond strength of sealant and adhesive systems applied to occlusal primary enamel

    OpenAIRE

    Ramires-Romito, ACD; Reis, A; Loguercio, AD; Hipolito, VD; de Goes, MF; Singer, JD; Grande, RHM

    2007-01-01

    Purpose: To compare the microtensile bond strength (mu TBS) of a self-etch adhesive system (OptiBond Solo Self-Etch Adhesive System), two total etch adhesive system (OptiBond FL; OptiBond Solo), and a conventional sealant (Clinpro) applied to the occlusal surface of primary molars under saliva contamination. Methods: Sealant and adhesive systems were applied under manufacturers' specifications with or without previous saliva contamination. After storage in distilled water at 37 degrees C for ...

  4. Effect of Adhesive Application on Sealant Success: A Clinical Study of Fifth and Seventh Generation Adhesive Systems

    OpenAIRE

    Vaibhav Tandon; Ravishanakar Telgi Lingesha; Pradeep Shankar Tangade; Amit Tirth; Sumit Kumar Pal; Chaitra Telgi Lingesha; Vikram Arora; Vipul Yadav

    2015-01-01

    Objectives: The aim of the study was to compare the effect of fifth and seventh generation bonding agent on sealant success.Materials and Methods: Sixty-four school children aged six to nine years received sealants in four permanent molars in a split mouth design, such that each patient received sealant in the first permanent molar with fifth generation bonding agent in one arch and seventh generation bonding agent in the other arch; contra-lateral molars were sealed with sealant alone. The e...

  5. Adhesion mechanisms of bituminous crack sealant to aggregate and laboratory test development

    Science.gov (United States)

    Hajialiakbari Fini, Elham

    Crack sealing is a common pavement maintenance treatment because it extends pavement service life. However, crack sealant often fails prematurely due to a loss of adhesion. Since current test methods are mostly empirical and only provide a qualitative measure of bond strength, they cannot predict sealant adhesive failure accurately. Hence, there is an urgent need for test methods based on bituminous sealant rheology that can better predict sealant field performance. This study introduces three laboratory tests aimed to assess the bond property of hot-poured crack sealant to pavement crack walls. The three tests are designed to serve the respective needs of producers, engineers, and researchers. The first test implements the principle of surface energy to measure the thermodynamic work of adhesion, which is the energy spent in separating the two materials at the interface. The work of adhesion is reported as a measure of material compatibility at an interface. The second test is a direct adhesion test, a mechanical test which is designed to closely resemble both the installation process and the crack expansion due to thermal loading. This test uses the Direct Tension Test (DTT) device. The principle of the test is to apply a tensile force to detach the sealant from its aggregate counterpart. The maximum load, Pmax, and the energy to separation, E, are calculated and reported to indicate interface bonding. The third test implements the principles of fracture mechanics in a pressurized circular blister test. The apparatus is specifically designed to conduct the test for bituminous crack sealant, asphalt binder, or other bitumen-based materials. In this test, a fluid is injected at a constant rate at the interface between the substrate (aggregate or a standard material) and the adhesive (crack sealant) to create a blister. The fluid pressure and blister height are measured as functions of time; the data is used to calculate Interfacial Fracture Energy (IFE), which is a

  6. EARTHSAWtm IN-SITU CONTAINMENT OF PITS AND TRENCHES

    Energy Technology Data Exchange (ETDEWEB)

    Ernest E. Carter, P.E.

    2002-09-20

    EarthSaw{trademark} is a proposed technology for construction of uniform high quality barriers under and around pits and trenches containing buried radioactive waste without excavating or disturbing the waste. The method works by digging a deep vertical trench around the perimeter of a site, filling that trench with high specific gravity grout sealant, and then cutting a horizontal bottom pathway at the base of the trench with a simple cable saw mechanism. The severed block of earth becomes buoyant in the grout and floats on a thick layer of grout, which then cures into an impermeable barrier. The ''Interim Report on task 1 and 2'' which is incorporated into this report as appendix A, provided theoretical derivations, field validation of formulas, a detailed quantitative engineering description of the technique, engineering drawings of the hardware, and a computer model of how the process would perform in a wide variety of soil conditions common to DOE waste burial sites. The accomplishments of task 1 and 2 are also summarized herein Task 3 work product provides a comprehensive field test plan in Appendix B and a health and safety plan in Appendix C and proposal for a field-scale demonstration of the EarthSaw barrier technology. The final report on the subcontracted stress analysis is provided in Appendix D. A copy of the unified computer model is provided as individual non-functional images of each sheet of the spreadsheet and separately as a Microsoft Excel 2000 file.

  7. Natural Fissures of Lung- Anatomical Basis of Surgical Techniques and Imaging

    Directory of Open Access Journals (Sweden)

    Sumita Dutta

    2013-04-01

    Full Text Available Background The fissures in lung enhances uniform expansion.These fissures may be complete, incomplete or absent.A detailed knowledge of variations of classical and accessory fissures is necessary for proper radiological interpretation.It is a guide to cardiothoracic surgeons performing segmental lung resections, lobectomies to have an uncomplicated perioperative outcome. So,the cadaveric study was done to note the morphological variation of the fissures of lung in eastern Indian population and compare it with previous studies. Methods 102 lungs obtained during dissection of formalin fixed cadavers in Calcutta National Medical College,Kolkata and preserved in 10% formalin were thoroughly studied to note every morphological details of fissures present in the lungs. Results 44% of left lungs had classically complete oblique fissure compared to 26.92% on the right. No oblique fissure could be detected in 8% lungs of left and 11.54% of right side. Horizontal fissure was completely absent in 34.6%. Various degree of parenchymal fusion was more common on the right side.None of the oblique fissures had uniform depth. Conclusion Comparison with other studies shows wide regional variations in morphological patterns of lung fissures,implying environmental and genetic factors in its development .Present study unfolds that parenchymal fusion of various extent is a very common entity of oblique fissure of lung. So more lung parenchyma has to be dissected to reach the bronchi and pulmonary arteries during partial lung resection which naturally might lead to peroperative hemorrhage and more postoperative complications.This knowledge of anatomy of fissures of lung may also help clarifying confusing radiographic findings. [Natl J Med Res 2013; 3(2.000: 117-121

  8. The 1981 eruptive fissure on Mt. Etna: considerations on its exploration and genesis

    Directory of Open Access Journals (Sweden)

    Angelo Leotta

    1998-01-01

    Full Text Available This paper is targeted to an analysis of features common to various fissure caves on Mt. Etna, Sicily. The Authors report the preliminary results of the exploration carried out in the 1981 eruptive fissure, the technical problems met during the exploration, the flow trends and the different courses of the molten material inside the fissure, the particular morphologies. A genetic model is proposed, different from those characterising the lava tube cave genesis, and links are suggested between the various fissures and the main tectonic stress systems operating on Mt. Etna, as well as the morpho-structural conditions of the volcanic edifice of Mt. Etna.

  9. Experimental investigation and numerical simulation on the effect of fissure water pressure in vertical sliding surface

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Lei; LI; Shihai; LIAN; Zhenzhong; WANG; Yuannian

    2005-01-01

    This paper studies the effect of fissure water pressure in different fractures on the critical angle of landslide by laboratory investigation and numerical simulation in order to understand the mechanisms of fissure water pressure on landslide stability. Laboratory observations show that the effect of fissure water pressure on the critical angle of landslide is little when the distance between water-holding fracture and slope toe is three times greater than the depth of fissure water. These experimental results are also simulated by a three-dimensional face-to-face contact discrete element method. This method has included the fissure water pressure and can accurately calculate the critical angle of jointed slope when fissure water pressure in vertical sliding surface exists.Numerical results are in good agreement with experimental observations. It is revealed that the location of water-holding structural surface is important to landslide stability. The ratio of the distance between water-holding fissure and slope toe to the depth of fissure water is a key parameter to justify the effect of fissure water pressure on the critical angle of landslide.

  10. Development of a Teat Bio-sealant and Evaluation of its Technological and Functional Properties.

    Science.gov (United States)

    Serna-Cock, Liliana; Pabón-Rodríguez, Omar Vladimir

    2016-06-01

    A teat bio-sealant was developed using Weissella cibaria, and the bio-sealant's technological and functional properties were assessed. The development included four experimental phases that were analyzed using independent experimental designs. Initially, sterilized or pasteurized Aloe vera gels were used, and the effect of heat treatment was investigated. In the second phase, the effects of time, storage temperature, and addition of cryopreservatives on the viability of the probiotic were observed. The third phase consisted of evaluating the synergistic effects of the cryopreservatives. The fourth phase involved selecting a material that would provide viscosity to the teat sealant. Technological and functional properties were measured in terms of viability of W. cibaria, and antimicrobial activity against Staphylococcus aureus and Streptococcus agalactiae was also analyzed. A mixture of milk powder and glycerol preserved this antimicrobial activity. Pullulan provided greater viscosity and maintained the technological and functional properties of the bio-sealant for 29 days. This teat bio-sealant can be used as an alternative for the prevention of bovine mastitis.

  11. Pitting of malaria parasites and spherocyte formation

    Directory of Open Access Journals (Sweden)

    Gichuki Charity W

    2006-07-01

    Full Text Available Abstract Background A high prevalence of spherocytes was detected in blood smears of children enrolled in a case control study conducted in the malaria holoendemic Lake Victoria basin. It was speculated that the spherocytes reflect intraerythrocytic removal of malarial parasites with a concurrent removal of RBC membrane through a process analogous to pitting of intraerythrocytic inclusion bodies. Pitting and re-circulation of RBCs devoid of malaria parasites could be a host mechanism for parasite clearance while minimizing the anaemia that would occur were the entire parasitized RBC removed. The prior demonstration of RBCs containing ring-infected erythrocyte surface antigen (pf 155 or RESA but no intracellular parasites, support the idea of pitting. Methods An in vitro model was developed to examine the phenomenon of pitting and spherocyte formation in Plasmodium falciparum infected RBCs (iRBC co-incubated with human macrophages. In vivo application of this model was evaluated using blood specimens from patients attending Kisumu Ditrict Hospital. RBCs were probed with anti-RESA monoclonal antibody and a DNA stain (propidium iodide. Flow cytometry and fluorescent microscopy was used to compare RBCs containing both the antigen and the parasites to those that were only RESA positive. Results Co-incubation of iRBC and tumor necrosis factor-alpha activated macrophages led to pitting (14% ± 1.31% macrophages with engulfed trophozoites as opposed to erythrophagocytosis (5.33% ± 0.95% (P Conclusion It is proposed that in malaria holoendemic areas where prevalence of asexual stage parasites approaches 100% in children, RBCs with pitted parasites are re-circulated and pitting may produce spherocytes.

  12. Vital Signs: Dental Sealant Use and Untreated Tooth Decay Among U.S. School-Aged Children.

    Science.gov (United States)

    Griffin, Susan O; Wei, Liang; Gooch, Barbara F; Weno, Katherine; Espinoza, Lorena

    2016-10-21

    Tooth decay is one of the greatest unmet treatment needs among children. Pain and suffering associated with untreated dental disease can lead to problems with eating, speaking, and learning. School-based dental sealant programs (SBSP) deliver a highly effective intervention to prevent tooth decay in children who might not receive regular dental care. SBSPs benefits exceed their costs when they target children at high risk for tooth decay. CDC used data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 to estimate current prevalences of sealant use and untreated tooth decay among low-income (≤185% of federal poverty level) and higher-income children aged 6-11 years and compared these estimates with 1999-2004 NHANES data. The mean number of decayed and filled first molars (DFFM) was estimated for children with and without sealants. Averted tooth decay resulting from increasing sealant use prevalence was also estimated. All reported differences are significant at p<0.05. From 1999-2004 to 2011-2014, among low- and higher-income children, sealant use prevalence increased by 16.2 and 8.8 percentage points to 38.7% and 47.8%, respectively. Among low-income children aged 7-11 years, the mean DFFM was almost three times higher among children without sealants (0.82) than among children with sealants. Approximately 6.5 million low-income children could potentially benefit from the delivery of sealants through SBSP. The prevalence of dental sealant use has increased; however, most children have not received sealants. Increasing sealant use prevalence could substantially reduce untreated decay, associated problems, and dental treatment costs.

  13. Use of gelatin-thrombin matrix haemostatic sealant in neurosurgery: Anaesthetic implications and review of literature

    Directory of Open Access Journals (Sweden)

    Puneet Khanna

    2015-01-01

    Full Text Available The topical haemostatic agents have been developed to be used as adjunctive measures to promote haemostasis. These include bone wax, absorbable gel sponges, microfibrillar collagen, oxidised regenerated cellulose, gelatin sponges with thrombin, gelatin-thrombin matrix sealant or fibrin sealants. Gelatin-thrombin matrix sealant is a mixture of a bovine-derived gelatin matrix and human-derived thrombin component that are mixed together at the time of use. This agent has been found to be more effective haemostat than thrombin-soaked gelatine sponges. The possible adverse effects of this can be transmission of diseases from human or bovine sources, allergic reactions, thromboembolism, disseminated intravascular coagulopathy (DIC, perilesional oedema, and compression of neural tissue. Although it is used routinely in the operating room, there is little literature available on the perioperative implications with use of intraoperative gelatin-thrombin matrix sealant. Here, we present clinical report of 20 neurosurgical patients where the sealant was used and literature in view of current evidence has been reviewed.

  14. Baseline Risk Assessment for the F-Area Burning/Rubble Pits and Rubble Pit

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, E. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1996-03-01

    This document provides an overview of the Savannah River Site (SRS) and a description of the F-Area Burning/Rubble Pits (BRPs) and Rubble Pit (RP) unit. It also describes the objectives and scope of the baseline risk assessment (BRA).

  15. Polychlorinated biphenyls (PCBs) in indoor air originating from sealants in contaminated and uncontaminated apartments within the same housing estate

    DEFF Research Database (Denmark)

    Frederiksen, Marie; Meyer, Harald William; Ebbehøj, Niels Erik;

    2012-01-01

    Twenty-four congeners of polychlorinated biphenyls (PCBs) were measured in 83 air samples and 20 elastic sealants samples of apartments with PCB-containing sealants. In addition, PCBs were measured in 21 air samples from reference apartments located in an uncontaminated section of the same estate...

  16. Estimating emissions from adhesives and sealants uses and manufacturing for environmental risk assessments.

    Science.gov (United States)

    Tolls, Johannes; Gómez, Divina; Guhl, Walter; Funk, Torsten; Seger, Erich; Wind, Thorsten

    2016-01-01

    Regulation (EC) No 1907/2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) requires that environmental exposure assessments be performed for all uses of dangerous substances that are marketed in the European Union in quantities above 10 tons per year. The quantification of emissions to the environment is a key step in this process. This publication describes the derivation of release factors and gives guidance for estimating use rates for quantifying the emissions from the manufacturing and application of adhesives and sealants. Release factors available for coatings and paints are read across to adhesives or sealants based on similarities between these 2 product groups with regard to chemical composition and to processing during manufacturing and application. The granular emission scenarios in these documents are mapped to the broad emission scenarios for adhesives or sealants. According to the mapping, the worst-case release factors for coatings or paints are identified and assigned to the adhesives or sealants scenarios. The resulting 10 specific environmental release categories (SPERCs) for adhesives and sealants are defined by differentiating between solvent and nonsolvent ingredients and between water-borne and solvent-borne or solvent-free products. These cover the vast majority of the production processes and uses and are more realistic than the 5 relevant emission estimation defaults provided in the REACH guidance. They are accompanied with adhesive or sealant consumption rates in the EU and with guidance for estimating conservative substance use rates at a generic level. The approach of combining conservative SPERC release factors with conservative estimates of substance rates is likely to yield emission estimates that tend to overpredict actual releases. Because this qualifies the approach for use in lower-tier environmental exposure assessment, the Association of the European Adhesive & Sealant Industry

  17. Glass-ceramic sealant for solid oxide fuel cells application: Characterization and performance in dual atmosphere

    Science.gov (United States)

    Sabato, A. G.; Cempura, G.; Montinaro, D.; Chrysanthou, A.; Salvo, M.; Bernardo, E.; Secco, M.; Smeacetto, F.

    2016-10-01

    A glass-ceramic composition was designed and tested for use as a sealant in solid oxide fuel cell (SOFC) planar stack design. The crystallization behaviour was investigated by calculating the Avrami parameter (n) and the activation energy for crystallization (Ec) was obtained. The calculated values for n and Ec were 3 and 413.5 kJ/mol respectively. The results of thermal analyses indicate that this composition shows no overlap between the sintering and crystallization stages and thus an almost pore-free sealant can be deposited and sintered at 850 °C in air for 30 min. A gas tightness test has been carried out at 800 °C for 1100 h in dual atmosphere (Ar-H2 and air) without recording any leakage. Morphological and crystalline phase analyses were conducted prior and following tests in dual atmospheres in order to assess the compatibility of the proposed sealant with the metallic interconnect.

  18. NELL-1 increases pre-osteoblast mineralization using both phosphate transporter Pit1 and Pit2

    Energy Technology Data Exchange (ETDEWEB)

    Cowan, Catherine M. [Department of Bioengineering, University of California, Los Angeles, 420 Westwood Plaza,7523 Boelter Hall, Los Angeles, CA 90095 (United States); Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Zhang, Xinli; James, Aaron W.; Mari Kim, T.; Sun, Nichole [Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Wu, Benjamin [Department of Bioengineering, University of California, Los Angeles, 420 Westwood Plaza,7523 Boelter Hall, Los Angeles, CA 90095 (United States); Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Ting, Kang [Dental and Craniofacial Research Institute and Section of Orthodontics, School of Dentistry, University of California, Los Angeles, 40833 Le Conte Ave, Los Angeles, CA 90095 (United States); Soo, Chia, E-mail: bsoo@ucla.edu [UCLA and Orthopaedic Hospital Department of Orthopaedic Surgery and the Orthopaedic, Hospital Research Center, University of California, Los Angeles, 2641 Charles E. Young Dr. South, Los Angeles, CA 90095 (United States)

    2012-06-08

    Highlights: Black-Right-Pointing-Pointer NELL-1 accelerates extracellular matrix mineralization in MC3T3-E1 pre-osteoblasts. Black-Right-Pointing-Pointer NELL-1 significantly increases intracellular inorganic phosphate levels. Black-Right-Pointing-Pointer NELL-1 positively regulates osteogenesis but not proliferation in MC3T3-E1 cells. Black-Right-Pointing-Pointer NELL-1 regulates inorganic phosphate transporter activity. -- Abstract: NELL-1 is a potent osteoinductive molecule that enhances bone formation in multiple animal models through currently unidentified pathways. In the present manuscript, we hypothesized that NELL-1 may regulate osteogenic differentiation accompanied by alteration of inorganic phosphate (Pi) entry into the osteoblast via sodium dependent phosphate (NaPi) transporters. To determine this, MC3T3-E1 pre-osteoblasts were cultured in the presence of recombinant human (rh)NELL-1 or rhBMP-2. Analysis was performed for intracellular Pi levels through malachite green staining, Pit-1 and Pit-2 expression, and forced upregulation of Pit-1 and Pit-2. Results showed rhNELL-1 to increase MC3T3-E1 matrix mineralization and Pi influx associated with activation of both Pit-1 and Pit-2 channels, with significantly increased Pit-2 production. In contrast, Pi transport elicited by rhBMP-2 showed to be associated with increased Pit-1 production only. Next, neutralizing antibodies against Pit-1 and Pit-2 completely abrogated the Pi influx effect of rhNELL-1, suggesting rhNELL-1 is dependent on both transporters. These results identify one potential mechanism of action for rhNELL-1 induced osteogenesis and highlight a fundamental difference between NELL-1 and BMP-2 signaling.

  19. Fissure formation in coke. 2: Effect of heating rate, shrinkage and coke strength

    Energy Technology Data Exchange (ETDEWEB)

    D.R. Jenkins; M.R. Mahoney [CSIRO, North Ryde, NSW (Australia). Mathematical and Information Sciences

    2010-07-15

    We investigate the effects of the heating rate, coke shrinkage and coke breakage strength upon the fissure pattern developed in a coke oven charge during carbonisation. This is done principally using a mechanistic model of the formation of fissures, which considers them to be an array of equally spaced fissures, whose depth follows a 'period doubling' pattern based upon the time history of the fissures. The model results are compared with pilot scale coke oven experiments. The results show that the effect of heating rate on the fissure pattern is different to the effect of coke shrinkage, while the effect of coke breakage strength on the pattern is less pronounced. The results can be seen in both the shape and size of resulting coke lumps after stabilisation. The approach gives the opportunity to consider means of controlling the carbonisation process in order to tune the size of the coke lumps produced. 7 refs., 18 figs., 4 tabs.

  20. Groundwater-Mining-Induced Subsidence and Earth Fissures in Cedar Valley, Southwestern Utah

    Science.gov (United States)

    Knudsen, T. R.; Inkenbrandt, P.; Lund, W. R.; Lowe, M.; Bowman, S. D.

    2014-12-01

    Groundwater pumping in excess of recharge (groundwater mining) has lowered the potentiometric surface in Cedar Valley, southwestern Utah, by as much as 114 feet since 1939. Lowering the potentiometric surface (head decline) has caused permanent compaction of fine-grained sediments of the Cedar Valley aquifer. Recently acquired interferometric synthetic aperture radar (InSAR) imagery shows that land subsidence is occurring over an ~100 square-mile area, including two pronounced subsidence bowls in the northeastern (Enoch graben) and southwestern (Quichapa Lake area) parts of the valley. A lack of accurate historical benchmark elevation data over much of the valley prevents detailed long-term quantification of subsidence. In response to the land subsidence, earth fissures have formed along the margins of the Enoch graben and north and west of Quichapa Lake. Our initial inventory of Cedar Valley fissures, which relied on aerial-photography analysis, identified 3.9 miles of fissures in 2009. With newly acquired light detection and ranging (LiDAR) coverage in 2011, we more than doubled the total length of mapped fissures to 8.3 miles. Fissures on the west side of the Enoch graben exhibit ongoing vertical surface displacement with rates as high as 1.7 inches/year. The largest Enoch-graben-west fissure has displaced street surfaces, curb and gutter, and sidewalks, and has reversed the flow direction of a sewer line in a partially developed subdivision. Several Cedar Valley fissures are closely associated with, and in some places coincident with, mapped Quaternary faults. While the majority of Cedar Valley fissures are mapped in agricultural areas, continued groundwater mining and resultant subsidence will likely cause existing fissures to lengthen and new fissures to form that may eventually impact other developed areas of the valley.

  1. Demonstration and Validation of a High-Performance Floor-Sealant System to Reduce Concrete Degradation

    Science.gov (United States)

    2015-05-01

    System to Reduce Concrete Degradation Final Report on Project F10-AR02 Co ns tr uc tio n En gi ne er in g R es ea rc h La bo ra to ry Clint...of a High-Performance Floor-Sealant System to Reduce Concrete Degradation Final Report on Project F10-AR02 Clint A. Wilson and Susan A. Drozdz...Under Project F10-AR02, “Application of an Innovative, High Performance Concrete Floor Sealant at Hunter Army Airfield, Georgia” ERDC/CERL TR-15-9 ii

  2. Role of Fibrin Sealants in Liver Surgery

    NARCIS (Netherlands)

    de Boer, Marieke T.; Boonstra, Elizabeth A.; Lisman, Ton; Porte, Robert J.

    2012-01-01

    Background: Fibrin sealants are widely used in liver surgery. The aim of this article is to review the literature on evidence of hemostatic and biliostatic capacities of different fibrin sealants in liver surgery. Methods: In PubMed, a literature search was done with the search terms 'fibrin sealant

  3. Open Pit Optimisation and Design: A Stepwise Approach*

    African Journals Online (AJOL)

    Michael

    2015-12-02

    Dec 2, 2015 ... holes were used for the analysis. ... retrieval and analysis, using Surpac software. .... economic and technical parameters were used to produce a set of nested pits. Fig. 4 depicts a summarised flow chart for the pit optimisation.

  4. 76 FR 64237 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Adhesives and Sealants Rule

    Science.gov (United States)

    2011-10-18

    ... pertains to amendments to Maryland's rule for the control of volatile organic compound (VOC) emissions from... regulation for the control of VOC emissions from adhesives and sealants. EPA is approving this SIP revision... miscellaneous industrial adhesives control techniques guideline (CTG) category in accordance with...

  5. Quantitative characterization and micro-CT mineral mapping of natural fissural enamel lesions.

    Science.gov (United States)

    Shahmoradi, Mahdi; Swain, Michael V

    2016-03-01

    The aim of this study was to characterize the mineral distribution pattern of natural fissural enamel lesions and to quantify structural parameters and mineral density of these lesions in comparison to proximal white spot enamel lesions. Imaging was undertaken using a high-resolution desktop micro-computed tomography system. A calibration equation was used to transform the grey level values of images into true mineral density values. The value of lesion parameters including the mineral density and the thickness of the surface layer of the enamel lesion were extracted from mineral density profiles. The thickness of the surface layer showed variation among different lesions and it ranged from 0-90 μm in proximal lesions and 0-137 μm in fissural lesions. The average thickness of surface layer in fissural lesions was significantly higher than smooth surface proximal lesions. Sound fissural enamel showed lower mineral density compared to proximal enamel. Micro-CT and the suggested de-noising and visualization method provide an efficient high-resolution approach for non-destructive evaluation of fissural lesions. Using these methods, the current study revealed the exclusive pattern and structure of fissural enamel lesions which may provide a basis for future studies on prevention and remineralization of these lesions. The common demineralization pattern of fissural lesions, which indicates the extension of the lesion in two directions towards the pulp horns, may explain the early inflammation and symptoms of the pulp in fissural lesions even when the lesion base appears far from the pulp roof in normal radiographs. In addition, the presence of the surface layer, indicates that vigorous probing of the occlusal fissures may lead to breakage and cavitation of the enamel lesions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Long-Standing Motor and Sensory Recovery following Acute Fibrin Sealant Based Neonatal Sciatic Nerve Repair

    Directory of Open Access Journals (Sweden)

    Natalia Perussi Biscola

    2016-01-01

    Full Text Available Brachial plexus lesion results in loss of motor and sensory function, being more harmful in the neonate. Therefore, this study evaluated neuroprotection and regeneration after neonatal peripheral nerve coaptation with fibrin sealant. Thus, P2 neonatal Lewis rats were divided into three groups: AX: sciatic nerve axotomy (SNA without treatment; AX+FS: SNA followed by end-to-end coaptation with fibrin sealant derived from snake venom; AX+CFS: SNA followed by end-to-end coaptation with commercial fibrin sealant. Results were analyzed 4, 8, and 12 weeks after lesion. Astrogliosis, microglial reaction, and synapse preservation were evaluated by immunohistochemistry. Neuronal survival, axonal regeneration, and ultrastructural changes at ventral spinal cord were also investigated. Sensory-motor recovery was behaviorally studied. Coaptation preserved synaptic covering on lesioned motoneurons and led to neuronal survival. Reactive gliosis and microglial reaction decreased in the same groups (AX+FS, AX+CFS at 4 weeks. Regarding axonal regeneration, coaptation allowed recovery of greater number of myelinated fibers, with improved morphometric parameters. Preservation of inhibitory synaptic terminals was accompanied by significant improvement in the motor as well as in the nociceptive recovery. Overall, the present data suggest that acute repair of neonatal peripheral nerves with fibrin sealant results in neuroprotection and regeneration of motor and sensory axons.

  7. Safety and efficacy of a novel, dry powder fibrin sealant for hemostasis in hepatic resection.

    NARCIS (Netherlands)

    Ruitenbeek, K.; Ayez, N.; Verhoef, C.; Wilt, J.H.W. de; Bottema, J.; Rijken, A.M.; Rij, M. van; Koopman, J; Zuckerman, L.A.; Frohna, P.; Porte, R.J.

    2014-01-01

    BACKGROUND/AIMS: Fibrocaps is a dry powder fibrin sealant containing human plasma-derived fibrinogen and thrombin. The safety, efficacy, and application methods for Fibrocaps were evaluated in an exploratory, first-in-human, noncomparative, clinical study. METHODS: Patients with minor bleeding/oozin

  8. Safety and Efficacy of a Novel, Dry Powder Fibrin Sealant for Hemostasis in Hepatic Resection

    NARCIS (Netherlands)

    Ruitenbeek, Karin; Ayez, N.; Verhoef, C.; de Wilt, J. Hans W.; Bottema, Jan; Rijken, Arjen M.; van Rij, Monique; Koopman, Jaap; Zuckerman, Linda A.; Frohna, Paul; Porte, Robert J.

    2014-01-01

    Background/Aims: Fibrocaps is a dry powder fibrin sealant containing human plasma-derived fibrinogen and thrombin. The safety, efficacy, and application methods for Fibrocaps were evaluated in an exploratory, first-in-human, non-comparative, clinical study. Methods: Patients with minor bleeding/oozi

  9. Radon penetration of concrete slab cracks, joints, pipe penetrations, and sealants

    NARCIS (Netherlands)

    Nielson, KK; Rogers, VC; Holt, RB; Pugh, TD; Grondzik, WA; deMeijer, RJ

    1997-01-01

    Radon movement through 12 test slabs with different cracks, pipe penetrations, cold joints, masonry blocks, sealants, and tensile stresses characterized the importance of these anomalous structural domains, Diffusive and advective radon transport were measured with steady-state air pressure differen

  10. Synthesis and Application of a Novel Organosilane Modifier for Surface Paintability of Organosiloxane Sealants

    Institute of Scientific and Technical Information of China (English)

    Wen Fei WANG; Qiang ZHENG; Hong Guo HU; Wei Wei LIN

    2005-01-01

    A novel organosilane, N-n-butyl-γ-aminopropylmethyldimethoxysilane was synthesized through aminization reaction and the chemical structure of resulting products was characterized by 1HNMR, 13CNMR, FT-IR and elemental analysis. The results of test on probation for this organosilane proved that it was effective to modify surface-paintability of organosiloxane sealants.

  11. Mosh pits and Circle pits: Collective motion at heavy metal concerts

    Science.gov (United States)

    Bierbaum, Matthew; Silverberg, Jesse L.; Sethna, James P.; Cohen, Itai

    2013-03-01

    Heavy metal concerts present an extreme environment in which large crowds (~102 -105) of humans experience very loud music (~ 130 dB) in sync with bright, flashing lights, often while intoxicated. In this setting, we find two types of collective motion: mosh pits, in which participants collide with each other randomly in a manner resembling an ideal gas, and circle pits, in which participants run collectively in a circle forming a vortex of people. We model these two collective behaviors using a flocking model and find qualitative and quantitative agreement with the behaviors found in videos of metal concerts. Futhermore, we find a phase diagram showing the transition from a mosh pit to a circle pit as well as a predicted third phase, lane formation.

  12. Modeling and numerical study of transfers in fissured environments; Modelisation et etude numerique des transferts en milieux fissures

    Energy Technology Data Exchange (ETDEWEB)

    Granet, S.

    2000-01-28

    Oil recovery from fractured reservoirs plays a very important role in the petroleum industry. Some of the world most productive oil fields are located in naturally fractured reservoirs. Modelling flow in such a fracture network is a very complex problem. This is conventionally done using a specific idealized model. This model is based on the Warren and Root representation and on a dual porosity, dual permeability approach. A simplified formulation of matrix-fracture fluid transfers uses a pseudo-steady-state transfer equation involving a constant exchange coefficient. Such a choice is one of the main difficulties of this approach. To get a better understanding of the simplifications involved in the dual porosity approach a reference model must be available. To obtain such a fine description, we have developed a new methodology. This technique called 'the fissure element methodology' is based on a specific gridding of the fractured medium. The fissure network is gridded with linear elements coupled with an unstructured triangular grid of matrix. An appropriate finite volume scheme has been developed to provide a good description of the flow. The numerical development of is precisely described. A simulator has been developed using this method. Several simulations have been realised. Comparisons have been done with different dual-porosity dual-permeability models. A reflexion concerning the choice of the exchange coefficient used in the dual porosity model is then proposed. This new tool has permit to have a better understanding of the production mechanisms of a complex fractured reservoir. (author)

  13. Interacting Effects Induced by Two Neighboring Pits Considering Relative Position Parameters and Pit Depth

    Directory of Open Access Journals (Sweden)

    Yongfang Huang

    2017-04-01

    Full Text Available For pre-corroded aluminum alloy 7075-T6, the interacting effects of two neighboring pits on the stress concentration are comprehensively analyzed by considering various relative position parameters (inclination angle θ and dimensionless spacing parameter λ and pit depth (d with the finite element method. According to the severity of the stress concentration, the critical corrosion regions, bearing high susceptibility to fatigue damage, are determined for intersecting and adjacent pits, respectively. A straightforward approach is accordingly proposed to conservatively estimate the combined stress concentration factor induced by two neighboring pits, and a concrete application example is presented. It is found that for intersecting pits, the normalized stress concentration factor Ktnor increases with the increase of θ and λ and always reaches its maximum at θ = 90°, yet for adjacent pits, Ktnor decreases with the increase of λ and the maximum value appears at a slight asymmetric location. The simulations reveal that Ktnor follows a linear and an exponential relationship with the dimensionless depth parameter Rd for intersecting and adjacent cases, respectively.

  14. Pits, pipes, ponds--and me.

    Science.gov (United States)

    Mara, Duncan

    2013-05-01

    My life in low-cost sanitation and low-cost wastewater treatment and the use of treated wastewater in agriculture and aquaculture really has been 'pits, pipes and ponds' - 'pits' are low-cost sanitation technologies (LCST) such as VIP latrines and pour-flush toilets; 'pipes' are low-cost sewerage, principally condominial (simplified) sewerage; and 'ponds' are low-cost wastewater treatment systems, especially waste stabilization ponds, and the use of treated wastewater in agriculture and aquaculture. 'Pits' were mainly working on World Bank LCST research projects, with fieldwork principally in Zimbabwe, 'pipes' were working on condominial sewerage projects in Brazil and disseminating this LCST to a wider global audience, and 'ponds' were waste stabilization ponds, with fieldwork mainly in Brazil, Colombia, Portugal and the United Kingdom, the development of aerated rock filters to polish facultative-pond effluents, and the human-health aspects of treated wastewater use in agriculture and aquaculture, with fieldwork in Brazil and the UK, and the application of quantitative microbial risk analysis. The paper provides a professional perspective and lessons from historical developments and gives recommended future directions based on my career working on low-cost sanitation technologies and treated wastewater use in agriculture and aquaculture.

  15. Distribution, formation mechanisms, and significance of lunar pits

    Science.gov (United States)

    Wagner, Robert V.; Robinson, Mark S.

    2014-07-01

    Lunar Reconnaissance Orbiter Camera images reveal the presence of steep-walled pits in mare basalt (n = 8), impact melt deposits (n = 221), and highland terrain (n = 2). Pits represent evidence of subsurface voids of unknown extents. By analogy with terrestrial counterparts, the voids associated with mare pits may extend for hundreds of meters to kilometers in length, thereby providing extensive potential habitats and access to subsurface geology. Because of their small sizes relative to the local equilibrium crater diameters, the mare pits are likely to be post-flow features rather than volcanic skylights. The impact melt pits are indirect evidence both of extensive subsurface movement of impact melt and of exploitable sublunarean voids. Due to the small sizes of pits (mare, highland, and impact melt) and the absolute ages of their host materials, it is likely that most pits formed as secondary features.

  16. DENTAL CARIES IN SIX, 12 AND 15 YEAR OLD VENDA ...

    African Journals Online (AJOL)

    hi-tech

    2004-05-05

    May 5, 2004 ... Technique. This study indicates that preventive oral health measures should be implemented .... Clinical Examinations:The examination was conducted according to ..... by oral hygienists who can place fissure-sealants and.

  17. Use of occlusal sealant in a community program and caries incidence in high- and low-risk children

    Directory of Open Access Journals (Sweden)

    Vânia Baldini

    2011-08-01

    Full Text Available OBJECTIVE: The aims of this study were to investigate the effectiveness of sealant placement under the guidelines of the Oral Health Promotion Program for Children and Adolescents (Portugal, and to test the influence of clinical and socioeconomic variables on the DMFT increment in 277 children, born in 1997. MATERIAL AND METHODS: A dental hygienist performed the initial examinations and sealant placement (Helioseal, Vivadent on the permanent first molars in 2005. These activities were registered in dental records that were assessed in 2007. Children were classified according to caries risk at baseline [high (HR: DMFT+dmft>0; low (LR: DMFT+dmft=0 risk] and sealant placement as follows: HR-S and LR-S Groups (with sealant placement; HR-NS and LR-NS Groups (without sealant placement. A calibrated dentist performed the final examination in 2007 at school, based on the World Health Organization recommendations. The variables collected were: dental caries, visible dental plaque, malocclusions, and socioeconomic level (questionnaire sent to children's parents. For univariate (Chi-square or Fisher tests and multivariate (Multiple logistic regression analyses the DMFT increment >0 was selected as dependent variable. RESULTS: Approximately 17.0% of the children showed DMFT increment>0 (mean=0.25. High-risk children presented a significant increase in the number of decayed and/or filled teeth. These children had 7.94 more chance of developing caries. Children who did not receive sealant were 1.8 more prone to have DMFT increment >0. CONCLUSION: It appears that sealant placement was effective in preventing dental caries development. Moreover, the variables "risk" and "sealant placement" were predictors for DMFT increment in the studied children.

  18. Relationship of Resistivity with Water Content and Fissures of Unsaturated Expansive Soils

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The development of fissures in expansive soils has a great effect on the stability of slope.Of the three phases of soils, the gas phase and solid phase are relatively insulated, so the average resistivity of soils can be calculated from the resistivity of the liquid phase.On this basis, the two-part model of resistivity changing with the water saturation of the expansive soil can be deduced.A 2-D resistance grid model is established based on simulating the resistance of vertically developed fissures.Variation in measured resistance of vertically developed fissures at different positions can be calculated from this model.Fissure development can be inversely determined from the variation in the measured resistance.Finally, the model is verified by an indoor resistivity test for remolded soil samples, indicating that the test result agrees well with that of the model established.

  19. Fluorine mapping in sound and carious fissures of human teeth using PIGE

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, H. [Department of Restorative Dentistry and Endodontology, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, 565-0871 (Japan)]. E-mail: yhiroko@dent.osaka-u.ac.jp; Nomachi, M. [Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043 (Japan); Yasuda, K. [Wakasa wan Energy Research Center, Tsuruga, Fukui, 914-0192 (Japan); Iwami, Y. [Department of Restorative Dentistry and Endodontology, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, 565-0871 (Japan); Ebisu, S. [Department of Restorative Dentistry and Endodontology, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, 565-0871 (Japan); Sakai, T. [Advanced Radiation Technology Center, Japan Atomic Energy, Research Institute (JAERI), Takasaki, Gunma, 370-1292 (Japan); Fukuda, M. [Advanced Radiation Technology Center, Japan Atomic Energy, Research Institute (JAERI), Takasaki, Gunma, 370-1292 (Japan)

    2005-04-01

    By using the PIGE technique at JAERI Takasaki, we measured fluorine (F) distribution in a micro area of occlusal fissures in the enamel of human teeth. The fissures were classified into three groups: Group I, no caries; Group II, incipient caries; Group III, advanced caries. The extracted teeth were embedded in epoxy resin and cut along the longitudinal axis through the fissures. The F concentration in the fissure at the cut surface was measured. A 1.7 MeV proton beam accelerated by the TIARA single-ended accelerator was delivered to a micro-beam apparatus. The beam spot size was about 1 {mu}m with a beam current of about 100 pA. A nuclear reaction, {sup 19}F (p,{alpha}{gamma}){sup 16}O, was used to measure the F concentration and gamma-rays from this reaction were detected with a 4' NaI(Tl) detector. X-rays induced by proton were detected with a Ge detector to measure calcium concentration and the beam intensity was monitored with the X-ray yield from a copper foil for quantitative analysis. The obtained results were shown as two-dimensional mapping. In all specimens, an F concentration was observed around the fissure. The F concentration varied depending on the location of the fissure and decreased towards the inner part of the tooth. The maximum F concentration values in the measured area ranged from 3500-11700 ppm (mean 6000 ppm) in Group I, 2400-10700 ppm (mean = 6300 ppm) in Group II, and 5200-16900 ppm (mean = 9300 ppm) in Group III. Although high F concentrations tended to be measured in the carious fissures, high values were also recognized in the sound fissures. More studies are necessary to clarify the relationship between F and carious lesions.

  20. Fissure formation in coke. 1: The mechanism of fissuring

    Energy Technology Data Exchange (ETDEWEB)

    D.R. Jenkins; M.R. Mahoney; J.C. Keating [CSIRO Mathematical and Information Sciences, North Ryde, NSW (Australia)

    2010-07-15

    Pilot scale coke oven experiments, in which carbonisation has been arrested after 2 and 4 h, have been used to identify key aspects of the initial formation and propagation of fissuring in coke. The experiments show that the primary fissure network is formed within the first few hours of coking and the fissures propagate towards the centre of the oven as coking progresses. They also show that some of the initially formed fissures stop propagating, thus increasing the effective fissure spacing as coking continues. A model for the propagation of regular crack arrays has been used to identify the cause of the initial formation of the fissure network, evaluate the fissure spacing and explain the fissure coarsening effect. The coarsening is shown to be due to an instability, in the form of every second fissure stopping. The formation of lateral fissures is shown to be due to tensile stress formation near the tips of stopped fissures and also to increased shrinkage due to a maximum in the coke contraction coefficient at around 700{sup o}C. 45 refs., 11 figs., 1 tab.

  1. Experimental Study of the Aging and Self-Healing of Glass/Ceramic Sealant Used in SOFCs

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wenning N.; Sun, Xin; Koeppel, Brian J.; Khaleel, Mohammad A.

    2010-01-01

    High operating temperatures of solid oxide fuel cells (SOFCs) require that sealant must function at a high temperature between 600oC and 900oC and in the oxidizing and reducing environments of fuel and air. This paper describes tests to investigate the temporal evolution of the volume fraction of ceramic phases, the evolution of micro-damage, and the self-healing behavior of the glass ceramic sealant used in SOFCs. It was found that after the initial sintering process, further crystallization of the glass ceramic sealant does not stop, but slows down and reduces the residual glass content while boosting the ceramic crystalline content. Under the long-term operating environment, distinct fibrous and needle-like crystals in the amorphous phase disappeared, and smeared/diffused phase boundaries between the glass phase and ceramic phase were observed. Meanwhile, the micro-damage was induced by the cooling-down process from the operating temperature to the room temperature, which can potentially degrade the mechanical properties of the glass/ceramic sealant. The glass/ceramic sealant self-healed upon reheating to the SOFC operating temperature, which can restore the mechanical performance of the glass/ceramic sealant.

  2. Comparing the etiology and treatment of skin fissure in traditional and conventional medicine; a brief review

    Directory of Open Access Journals (Sweden)

    A. Jedkareh

    2016-01-01

    Full Text Available Dry skin is a common problem which affects wound healing, severity of other skin diseases and quality of life of people. One of its undesirable effects is fissure that is a cutaneous condition in which there is a linear loss of epidermis and dermis with sharply defined, nearly vertical walls. In the present study, we have investigated the etiology of the disease and its treatments in conventional medicine and Iranian Traditional Medicine (ITM. Two traditional medicine references, current scientific data bases and medicinal texts were explored with the selected keywords such as "sheqaq-e-poosti", "skin fissure" and "dry skin" to find the etiology and treatment of skin fissure. From the view point of both conventional medicine and ITM, dry skin is the cause of skin fissure and some causes of dry skin are similar. In conventional medicine, moisturizers are mainly used for treatment of dry skin; while in ITM some herbs, oils and other natural remedies have been used. A topical dosage form which was called "qeirooti", a mixture of wax and oil, was used to treat skin fissure in ITM. It comprised of oily ingredients that acted as occlusives and also some herbal components that directly improved dry skin (similar to moisturizers. Components efficacy of traditional dosage forms for treatment of dry skin lead us to study about formulation of “qeirooti” for treatment of dry skin.

  3. Newborn with Prenatally Diagnosed Choroidal Fissure Cyst and Panhypopituitarism and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Ritu Chitkara

    2011-12-01

    Full Text Available Little has been reported on fetal diagnosis of choroidal fissure cysts and prediction of the clinical complications that can result. We describe the case of a near-term male infant with prenatally diagnosed choroidal fissure cyst and bilateral clubfeet. His prolonged course in the neonatal intensive care nursery was marked by severe panhypopituitarism, late-onset diabetes insipidus, placement of a cystoperitoneal shunt, and episodes of sepsis. Postnatal genetic evaluation also revealed an interstitial deletion involving most of band 10q26.12 and the proximal half of band 10q26.13. The patient had multiple readmissions for medical and surgical indications and died at 6 months of age. This case represents the severe end of the spectrum of medical complications for children with choroidal fissure cysts. It highlights not only the importance of comprehensive evaluation and multidisciplinary management and counseling in such cases, but also the need for heightened vigilance in these patients.

  4. Characterization and the Pattern of Surfaces of Sealant with nano size Composite Materials

    Science.gov (United States)

    Quddos, A.; Samtio, N. H.; Syed, A. M.

    2013-06-01

    Nano composite sealant is low viscosity, room temperature cured, opaque and flowable nature. They have variety of uses such as potting, pressure sealant and shock resistant. Most important factor influencing use of fillers in polymer composites is their ability to effectively transfer the applied load in the matrix. The effective utilization of fillers in composites for structural applications depends strongly on the ability to disperse the nano fillers homogeneously in the matrix without damaging them. R-Belite supper epoxy adhesive (RBSEA) were formulated with different nano fillers (KCl, Al2O3, ZrO2, SiO2, ZrO2) at room temperature. The composite were prepared with the 0.02 to 0.10 weight ratios to promote the nucleation of the nanoparticles in the applied sealant. Two main problems which arise in improving the properties are poor dispersion of the fillers in the composite and weak bonding between nano fillers and the matrix. These problems are solved by mechanical and chemical means. It was observed that mechanical properties like tensile strength, elongation hardness etc and thermal properties were also improved with incorporation of nanofillers in the working applied polymer matrix. The dispersion of nano fillers in polymer matrix is studied by Scanning electron microscopy (SEM). The results confirm the presence of nanomaterial in RBSEA/fillers nanocomposites. SEM is also used to characterize the pattern of surfaces with nano size composite materials.

  5. Comparative study of Ksharasutra suturing and Lord's anal dilatation in the management of Parikartika (chronic fissure-in-ano)

    OpenAIRE

    2014-01-01

    Background: Parikartika resembles fissure-in-ano which is very common among all ano-rectal disorders. In Ayurvedic texts, Parikartika is described as a complication of Vamana and Virechana as well as complication of Atisara. Ksharasutra was proved successful in the management of fistula-in-ano, piles, and there is a need to try its efficacy in fissure-in-ano. Aim: To evaluate the role of Ksharasutra suturing (KSS) in fissure bed in chronic fissure-in-ano. Materials and Methods: Total 100 pati...

  6. THE EFFECT OF BONDING AND SURFACE SEALANT APPLICATION ON POSTOPERATIVE SENSITIVITY FROM POSTERIOR COMPOSITES

    Directory of Open Access Journals (Sweden)

    Neslihan TEKÇE

    2015-10-01

    Full Text Available Purpose: The purpose of the study was to evaluate the postoperative sensitivity of posterior Class I composite restoration at short-term, restorated with two different all-in-one self-etch adhesives with or without surface sealant application. Materials and Methods: 44 restorations were inserted in 11 patients who required Class I restorations in their molars. Each patient received 4 restorations, thus four groups were formed; (1 G-Aenial Bond (GC, Japan; (2 Clearfil S3 Bond (Kuraray, Japan; (3 G-Aenial Bond+Fortify Plus (Bisco, USA, (4 Clearfil S3 Bond+Fortify Plus. Sensitivity was evaluated at 24h, 7, 15, and 30 days using cold air, ice, and pressure stimuli using a visual analog scale. Comparisons of continuous variables between the sensitivity evaluations were performed using the Friedman’s One-Way Analysis of Variance with repeated measures test (p0.05. The use of Clearfil S3 Bond resulted in almost the same level of postoperative sensitivity as did the use of G-Aenial Bond. The highest sensitivity scores were observed for the surface sealant applied teeth without any statistical significance (p>0.05. Conclusions: Self etch adhesives displayed postoperative sensitivity. The sensitivity scores slightly decreased at the end of 30 days (p>0.05. Surface sealant application did not result in a decrease in sensitivity scores for either dentin adhesives.

  7. Influence of pH and oxygen-inhibited layer on fluoride release properties of fluoride sealant.

    Science.gov (United States)

    Shen, C; Shokry, T E; Anusavice, K J

    2007-04-01

    This study tested the hypothesis that the oxygen-inhibited layer on a light-cured methacrylate based resin and the pH of the storage medium would increase significantly the initial fluoride release and long-term release rate from fluoride dental sealant. Forty-eight discs (16-mm diameter x 1-mm thick) were made from FluroShield (<5 wt% NaF) and Helioseal F (<30 wt% fluorosilicate glass) sealants. For each sealant, 24 discs were cured through a Mylar strip that covered the surface and the remaining 24 discs were cured in air allowing formation of the oxygen-inhibited surface. Each specimen in the 24-disc groups was stored individually in 25-mL vials, and divided into four six-vial groups to receive 10 mL of pH4-pH7 (designation of pH 4-7) lactate buffer solutions. The buffer solutions were replaced periodically up to 121 days. The cumulative fluoride release over time was used to determine the coefficients for short-term and long-term release. Two-way ANOVA showed that the mean coefficient values for either sealant were significantly influenced by the curing condition (p<0.0001) and pH (p<0.0001), except for short-term release from NaF sealant. The duration of short-term release was much longer for the fluorosilicate glass sealant. Both pH and the source of fluoride source incorporated in the sealant play significant roles in fluoride release.

  8. Numerical simulation and damage analysis of fissure field evolution law in a single coal seam mining

    Institute of Scientific and Technical Information of China (English)

    Feng; Gao; Xingguang; Liu; Chaofeng; Ge; Hongmei; Cheng

    2012-01-01

    Based on the different deformation and failure laws of coal and rock materials under tensile or compressive loads,the damage variable was defined to divide three phases from the damage and rupture point of view in order to reveal the fissured field evolution characteristics and spatial distribution of coal and rock in the single coal seam mining with low permeability and rich methane.According to the corresponding damage constitutive equations,the secondary development of the finite element program was completed.The fissures field evolution law of a coal mine with single coal seam mining was calculated and analyzed by this new program and the distribution areas and failure degree of the surrounding coal and rock structures with damage,fissure or rupture are given on the condition of mining.This paper provides a scientific basis for quantitative research and evaluation of the safe simultaneous production of coal and gas.

  9. Patrón de liberación de flúor in vitro en sellantes fluorados de resina In vitro fluoride-release profile of fluoridated resin-based sealants

    Directory of Open Access Journals (Sweden)

    S Gómez

    2011-12-01

    Full Text Available Objetivo: Comparar in vitro la cantidad de fluoruros liberados por los principales sellantes de puntos y fisuras basados en resina comercialmente disponibles en Latinoamérica. Material y Métodos: Se evaluó la liberación de fluoruros in vitro en tres sellantes fluorados de puntos y fisuras: Helioseal F (HF, Fissurit F (FF, Clinpro (CF y Delton (D, sin flúor como control. Se utilizaron 28 discos de 12 mm de diámetro y 2 mm de espesor (n=7 por grupo. Las muestras fueron almacenadas en 5 ml de agua ultra de-ionizada con pH neutro a 37º C por 93 días. La liberación de fluoruros fue medida mediante un electrodo iónico selectivo a los 1, 2, 3, 8, 15, 28 y 93 días. Los datos fueron analizados con el test ANOVA y Tukey (pAim: To compare in vitro the amount of fluoride released from the main pit and fissure sealant resin-based on commercially available in Latin America. Materials and Methods: Twenty-eight samples of 12 x 2 mm were made from three commercial fluoridated resin-based sealants: Helioseal F (HF, Fissurit F (FF, Clinpro (CF and without fluoride Delton (D, as a control. Samples were stored in 5 ml of deionized water at 37° C and neutral pH. Fluoride releases were measured at 1, 2, 3, 8, 15, 28 and 93 days with an ion-selective electrode. Data were analyzed using ANOVA and one-way and Tukey (p0.05. Conclusion: The fluoride-release profile is similar for the fluoridated resin-based sealants under study: a high release during the first two days and afterwards, a very slow release. These results can explain the lack of differences in caries rate between fluoridated and non-fluoridated resin-based sealants observed in clinical trials.

  10. EXPERIMENTAL AND FIELD STUDY ON MINING-PIT MIGRATION

    Institute of Scientific and Technical Information of China (English)

    S. Ali Akbar Salehi NEYSHABOURI; Ali FARHADZADEH; Ata AMINI

    2002-01-01

    Rivers are one of the most essential sources of sand and gravel supply for civil works. However,undesirable effects of irregular in-stream mining have been reported on natural sources, environment and infrastructures close to rivers. Therefore, it is necessary to find the effects of mining on rivers in more details. This research concentrates on mining-pit migration phenomenon and its effects on the channel bed.This paper reports an experimental study on the migration of rectangular mining pits and variation of longitudinal profile in the channel bed composed of rather uniform sediments. Different values of widths and lengths were used for pit while pit depths and flow variables were kept constant. The results show that the migration speed changes with the length/width ratio of the pit. The migration speed in convection period is higher than that in diffusion period. In addition, by increasing the length or width, filling rate of pit increases, where the effect of width is more important than the effect of the length. Also is reported in this paper a field study on the changes of three pits excavated at different locations of a river. Some similarities between the pit migration in the straight reach of the river and that of the experimental work is realized and presented.

  11. Crevice and pitting corrosion behavior of stainless steels in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Zaragoza-Ayala, A.E.; Orozco-Cruz, R. [Univ. Autonoma de Campeche (Mexico). Programa de Corrosion del Golfo de Mexico

    1999-11-01

    Pitting and crevice corrosion tests in natural seawater were performed on a series of stainless steels (i.e., S31603, N08904, S32304, S31803, S32520, N08925 and S31266) in order to determine their resistance to these types of localized corrosion. Open circuit potential (OCP) measurements for these alloys show for short exposure times an ennoblement in the OCP. After a certain time, occasional fall and rise in the OCP values was observed, which can be related to nucleation and repassivation of pits and/or crevices on the metal surface. Analysis of the electrochemical behavior and microscopic observations shows that only S31603 and S32304 alloys were susceptible to crevice and pitting corrosion, whereas the remaining alloys exhibited good resistance. Pitting potentials determined by the potentiodynamic technique also show S3 1603 and S32304 are susceptible to pitting corrosion under the experimental conditions used in this work.

  12. Sylvian fissure lipoma with angiomatous component and associated brain malformation: A case report.

    Directory of Open Access Journals (Sweden)

    Shruti Thakur

    2013-12-01

    Full Text Available Intracranial lipomas are congenital malformations. These uncommon lesions have an incidence of 0.1 to 1.7% of all intracranial tumors. Most cases are located at midline and 5% are along the sylvian fissures. If symptomatic, seizures are the most common symptom. These tumors are slow growing and have favorable outcome. We report a case of a 25-year-old man whose CT and MRI revealed a lesion in right sylvian fissure suggesting a lipoma with abnormal vasculature and overlying cortical dysplasia.

  13. Methods and preliminary findings of a cost-effectiveness study of glass-ionomer-based and composite resin sealant materials after 2 yr

    NARCIS (Netherlands)

    Goldman, A.S.; Chen, X.; Fan, M.; Frencken, J.E.F.M.

    2014-01-01

    The cost-effectiveness of glass-carbomer, conventional high-viscosity glass-ionomer cement (HVGIC) [without or with heat (light-emitting diode (LED) thermocuring) application], and composite resin sealants were compared after 2 yr in function. Estimated net costs per sealant were obtained from data

  14. Abnormalities of cerebellar foliation and fissuration: classification, neurogenetics and clinicoradiological correlations

    Energy Technology Data Exchange (ETDEWEB)

    Demaerel, P. [University Hospital, Department of Radiology, Herestraat 49, 3000 Leuven (Belgium)

    2002-08-01

    Several genes have been found to influence the different cells involved in the processes of foliation and fissuration in the mouse and rat cerebellum. In the light of these new concepts and on the basis of the imaging findings in 42 patients, a classification is proposed for abnormalities of foliation and fissuration. On the basis of recent genetic and experimental evidence on mechanisms which control the origin of the cerebellum, it is suggested that abnormalities of foliation and fissuration form a single group, with a spectrum of severity. Some patients have only abnormal fissuration of the anterior lobe (type 1a) and others additional dysplasia of the anterior and part of the posterior lobe (type 1b). Extension of abnormalities into the hemispheres is often seen in the latter group. A second group has vermian and hemisphere abnormalities (type 2). In addition to the malformation of the anterior lobe of the vermis, three different hemispheric lesions can be seen in this group: cortical dysgenesis, hypertrophy of the cerebellar cortex, and malorientation of the folia. The mild abnormalities (type 1a) can be considered an incidental observation without clinical relevance. The moderate and severe cerebellar anomalies (type 1b and 2) are always associated with cerebellar symptoms and/or signs. (orig.)

  15. Tensions and Fissures: The Politics of Standardised Testing and Accountability in Ontario, 1995-2015

    Science.gov (United States)

    Pinto, Laura Elizabeth

    2016-01-01

    While Ontario has received international accolades for its enactment of province-wide standardised testing upon the formation of the Education Quality and Accountability Office (EQAO), a closer look at provincial assessments over a 20-year span reveals successes as well as systemic tensions and fissures. The purpose of this paper is twofold.…

  16. Coal and rock fissure evolution and distribution characteristics of multi-seam mining

    Institute of Scientific and Technical Information of China (English)

    Zhang Dongming; Qi Xiaohan; Yin Guangzhi; Zheng Binbin

    2013-01-01

    Henan Pingdingshan No.10 mine is prone to both coal and gas outbursts. The E9-10 coal seam is the main coal-producing seam but has poor quality ventilation, thus making it relatively difficult for gas extraction. The F15 coal seam, at its lower section, is not prone to coal and gas outbursts. The average seam separa-tion distance of 150 m is greater than the upper limit for underside protective seam mining. Based on borehole imaging technology for field exploration of coal and rock fracture characteristics and discrete element numerical simulation, we have studied the evolution laws and distribution characteristics of the coal and rock fissure field between these two coal seams. By analysis of the influential effect of group F coal mining on the E9-10 coal seam, we have shown that a number of small fissures also develop in the area some 150 m above the overlying strata. The width and number of the fissures also increase with the extent of mining activity. Most of the fissures develop at a low angle or even parallel to the strata. The results show that the mining of the F15 coal seam has the effect of improving the permeability of the E9-10 coal seam.

  17. Drainage pits in cohesionless materials: implications for surface of Phobos.

    Science.gov (United States)

    Horstman, K C; Melosh, H J

    1989-09-10

    Viking orbiter images show grooves and chains of pits crossing the surface of Phobos, many of which converge toward the large crater Stickney or its antipode. Although it has been proposed that the pits and grooves are chains of secondary craters, their morphology and geometric relations suggest that they are the surface traces of fractures in the underlying solid body of Phobos. Several models have been proposed to explain the pits, of which the most plausible are gas venting and drainage of regolith into open fractures. the latter mechanism is best supported by the image data and is the mechanism studied in this investigation. Drainage pits and fissures are modeled experimentally by using two rigid substrate plates placed edge to edge and covered by uniform thicknesses of dry fragmental debris (simulated regolith). Fracture extension is simulated by drawing the plates apart, allowing drainage of regolith into the newly created void. A typical drainage experiment begins with a shallow depression on the surface of the regolith, above the open fissure. Increased drainage causes local drainage pits to form; continued drainage causes the pits to coalesce, forming a cuspate groove. The resulting experimental patterns of pits and grooves have pronounced similarities to those observed on Phobos. Characteristics such as lack of raised rims, linearity of grooves and chains of pits, uniform spacing of pits, and progression from discrete pits to cuspate grooves are the same in the experiments and on Phobos. In contrast, gas-venting pits occur in irregular chains and have raised rims. These experiments thus indicate that the Phobos grooves and pits formed as drainage structures. The pit spacing in an experiment is measured at the time that the maximum number of pits forms, prior to groove development. The average pit spacing is compared to the regolith thickness for each material. Regression line fits indicate that the average spacing of drainage pits in unconsolidated

  18. Methods for monitoring land subsidence and earth fissures in the Western USA

    Science.gov (United States)

    Fergason, K. C.; Rucker, M. L.; Panda, B. B.

    2015-11-01

    Depletion of groundwater resources in many deep alluvial basin aquifers in the Western USA is causing land subsidence, as it does in many regions worldwide. Land subsidence can severely and adversely impact infrastructure by changing the ground elevation, ground slope (grade) and through the development of ground cracks known as earth fissures that can erode into large gullies. Earth fissures have the potential to compromise the foundations of dams, levees, and other infrastructure and cause failure. Subsequent to an evaluation of the overall subsidence experienced in the vicinity of subsidence-impacted infrastructure, a detailed investigation to search for earth fissures, and design and/or mitigation of potentially effected infrastructure, a focused monitoring system should be designed and implemented. Its purpose is to provide data, and ultimately knowledge, to reduce the potential adverse impacts of land subsidence and earth fissure development to the pertinent infrastructure. This risk reduction is realized by quantifying the rate and distribution of ground deformation, and to detect ground rupture if it occurs, in the vicinity of the infrastructure. The authors have successfully designed and implemented monitoring systems capable of quantifying rates and distributions of ground subsidence and detection of ground rupture at multiple locations throughout the Western USA for several types of infrastructure including dams, levees, channels, basins, roadways, and mining facilities. Effective subsidence and earth fissure monitoring requires understanding and quantification of historic subsidence, estimation of potential future subsidence, delineation of the risk for earth fissures that could impact infrastructure, and motivation and resources to continue monitoring through time. A successful monitoring system provides the means to measure ground deformation, grade changes, displacement, and anticipate and assess the potential for earth fissuring. Employing multiple

  19. Collector sealants and breathing. Final Report, 25 September 1978-31 December 1979

    Energy Technology Data Exchange (ETDEWEB)

    Mendelsohn, M A; Luck, R M; Yeoman, F A; Navish, Jr, F W

    1980-02-20

    The objectives of this program were: (1) to investigate the pertinent properties of a variety of possible sealants for solar collectors and identify the most promising candidates, and (2) to study the effect of breathing in flat-plate, thermal solar collector units. The study involved two types of sealants, Class PS which includes preformed seals or gaskets and Class SC which includes sealing compounds or caulks. It was the intent of the study to obtain data regarding initial properties of candidate elastomers from manufacturers and from the technical literature and to use those sources to provide data pertaining to endurance of these materials under environmental service conditions. Where necessary, these data were augmented by experimental measurements. Environmental stresses evaluated by these measurements included elevated temperatures, moisture, ultraviolet light, ozone and oxygen, and fungus. The second major area of the work involved a study of the effects of materials used and design on the durability of solar collectors. Factors such as design, fabrication, materials of construction, seals and sealing techniques and absorber plate coatings were observed on actual field units removed from service. Such phenomena as leakage, corrosion and formation of deposits on glazing and absorber plate were noted. An evaluation of the properties of several desiccants was made in order to providemeans to mitigate the deleterious effects of water on collector life. Adsorbents for organic degradation products of sealants were also investigated in order to protect the glazing and absorber plate from deposited coatings. Since adsorbents and desiccants in general tend to take up both water and organic decomposition products, relative affinities of a number of these agents for water and for organic compounds were determined . Results are presented in detail.

  20. Collector sealants and breathing. Mid-term report, September 25, 1978-May 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Mendelsohn, M. A.; Yeoman, F. A.; Luck, R. M.; Navish, Jr, F. W.; Meier, J. F.

    1978-01-01

    The objectives of this program are: (1) to investigate the pertinent properties of a variety of possible sealants for solar collectors and identify the most promising candidates and to study the effect of breathing in flat-plate, thermal solar collector units. The study involves two types of sealants, Class PS which includes performed seals or gaskets and Class SC which includes sealing compounds or caulks. It is the intent of the study to obtain data regarding initial properties of candidate elastomers from manufacturers and from the technical literature and to use those sources to provide data pertaining to endurance of these materials under environmental service conditions. Where necessary, these data are being augmented by experimental measurements. Environmental stresses to be evaluated by these measuremets include elevated temperatures, moisture, ultraviolet light, ozone and oxygen, and fungus. The second major area of the work involves a study of the effects of materials used and design on the durability of solar collectors. Factors such as design, fabrication, materials of construction, seals and sealing techniques and absorber plate coatings were observed on actual field units removed from service. Such phenomena as leakage, corrosion and formation of deposits on glazing and absorber plate were noted. An evaluation of the properties of several desiccants is being made in order to provide means to mitigate the deleterious effects of water on collector life.Absorbents for organic degradation products of sealants are also being investigated in order to protect the glazing and absorber plate from deposited coatings. Since adsorbents and desiccants in general tend to take up both waer and organic decomposition products, relative affinities of a number of these agents for water and for organic compounds are being determined.

  1. Painless ulcers and fissures of toes: Hereditary sensory neuropathy, not leprosy

    Directory of Open Access Journals (Sweden)

    Angoori Gnaneshwar Rao

    2016-01-01

    Full Text Available Hereditary sensory neuropathies (HSN are rare genetically determined neuropathies. They often manifest as painless injuries in children. We present HSN in a 5-year-old boy who presented with recurrent fissuring and ulceration involving both great toes.

  2. Avaliação da microinfiltração marginal e profundidade de penetração dos cimentos de ionômero de vidro utilizados como selantes oclusais Evaluation of marginal microleakage and depth of penetration of glass ionomer cements used as occlusal sealants

    Directory of Open Access Journals (Sweden)

    Marina de Lourdes Calvo Fracasso

    2005-09-01

    Full Text Available OBJETIVE: the aim of this study was to conduct an in vitro comparison of marginal microleakage (MM and the depth of penetration (DP of glass ionomer cements (GIC and a resin sealant (RS into occlusal pit and fissures. METHODS: for that purpose, 60 intact third molars were equally distributed to 5 groups: G1 - 37% phosphoric acid / Delton; G2 - 40% polyacrylic acid / Ketac-Molar / nail varnish; G3 - Fuji Plus conditioner / Fuji Plus/ nail varnish; G4 -37% phosphoric acid / Vitremer / Finishing gloss; G5 -37% phosphoric acid / Vitremer prepared with a 1:4 ratio of powder / Finishing gloss. The teeth were submitted to a thermal treatment corresponding to 300 cycles (15 sec, 5/55(0C, followed by complete coating with nail varnish, except for 1mm beyond the contour of the sealant. Afterwards, the teeth were immersed in 0.5% basic fuchsine for 24 hours. Thereafter, the teeth were sectioned in buccolingual direction and microscopically analyzed (150x magnification by means of predetermined scores. The results were subject to the Kruskal-Wallis test. RESULTS: there was no statistical difference between the materials tested in relation to the DP, being that all groups displayed nearly complete filling of the fissures. No sealant material was able to prevent dye penetration; however, the GICs provided better results of MM, with significant difference when compared to the RS. CONCLUSION: all materials investigated presented a satisfactory degree of penetration into the fissures; however, the glass ionomer cements displayed better performance in the marginal microleakage test compared to the resin sealant.OBJETIVO: o objetivo deste estudo foi comparar in vitro a microinfiltração marginal (MM e o grau de profundidade de penetração (DP de cimentos de ionômero de vidro (CIV e um selante resinoso (SR em fossas e fissuras oclusais. MATERIAIS E MÉTODOS: para tanto, 60 terceiros molares hígidos foram igualmente distribuídos em 5 grupos: G1- ácido fosf

  3. Effects of menthol essence and breast milk on the improvement of nipple fissures in breastfeeding women

    Directory of Open Access Journals (Sweden)

    Sedigheh Amir Ali Akbari

    2014-01-01

    Full Text Available Background: Nipple fissure is a common disorder during breastfeeding. With high prevalence of nipple fissures and its impacts on breastfeeding, as well as the existence of evidence in favor of the application of peppermint as an antiinflammatory and antiinfection herb, the purpose of this study is to determine the effect of Menthol essence on improving nipple fissures in the primiparous breastfeeding women. Materials and Methods: This study was conducted using a clinical trial method. Samples were divided randomly into two groups of 55 women. The women in the peppermint group applied four drops of Menthol essence on their nipple and areola after each feeding. The control group applied four drops of their own milk on the nipple and areola after each feeding. Then, the two groups were studied on days 10 and 14 postpartum. For intensity of pain, the visual analog scale (0-10 cm and to measure the severity of damage, Amir scale (1-10 cm were applied and the existence or lack of nipple discharge was also recorded. The data were analyzed using SPSS 17 software. Results: The mean intensity of pain and nipple fissure before treatment (8.55 ± 1.74 and day 10 after delivery (4.26 ± 1.57 and before treatment and day 14 after delivery in the case group (1.32 ± 1.02 had a significant difference (P < 0.001. Nipple discharge between the two groups, before treatment (%75.2 and day 10 after delivery (%31.6 and before treatment and day 14 after delivery (%15.7, the case group had a significant difference (P < 0.001. Conclusion: Menthol essence can improve nipple fissures in the primiparous breastfeeding women.

  4. Land subsidence, Ground Fissures and Buried Faults: InSAR Monitoring of Ciudad Guzmán (Jalisco, Mexico

    Directory of Open Access Journals (Sweden)

    Carlo Alberto Brunori

    2015-07-01

    Full Text Available We study land subsidence processes and the associated ground fissuring, affecting an active graben filled by thick unconsolidated deposits by means of InSAR techniques and fieldwork. On 21 September 2012, Ciudad Guzmán (Jalisco, Mexico was struck by ground fissures of about 1.5 km of length, causing the deformation of the roads and the propagation of fissures in adjacent buildings. The field survey showed that fissures alignment is coincident with the escarpments produced on 19 September 1985, when a strong earthquake with magnitude 8.1 struck central Mexico. In order to detect and map the spatio-temporal features of the processes that led to the 2012 ground fissures, we applied InSAR multi-temporal techniques to process ENVISAT-ASAR and RADARSAT-2 satellite SAR images acquired between 2003 and 2012. We detect up to 20 mm/year of subsidence of the northwestern part of Ciudad Guzmán. These incremental movements are consistent with the ground fissures observed in 2012. Based on interferometric results, field data and 2D numerical model, we suggest that ground deformations and fissuring are due to the presence of areal subsidence correlated with variable sediment thickness and differential compaction, partly driven by the exploitation of the aquifers and controlled by the distribution and position of buried faults.

  5. Radon penetration of concrete slab cracks, joints, pipe penetrations, and sealants.

    Science.gov (United States)

    Nielson, K K; Rogers, V C; Holt, R B; Pugh, T D; Grondzik, W A; de Meijer, R J

    1997-10-01

    Radon movement through 12 test slabs with different cracks, pipe penetrations, cold joints, masonry blocks, sealants, and tensile stresses characterized the importance of these anomalous structural domains. Diffusive and advective radon transport were measured with steady-state air pressure differences controlled throughout the deltaP = 0 to 60 Pa range. Diffusion coefficients (deltaP = 0) initially averaged 6.5 x 10(-8) m2 s(-1) among nine slabs with only 8% standard deviation, but increased due to drying by 0.16% per day over a 2-y period to an average of 2.0 x 10(-7) m2 s(-1). An asphalt coating reduced diffusion sixfold but an acrylic surface sealant had no effect. Diffusion was 42 times higher in solid masonry blocks than in concrete and was not affected by small cracks. Advective transport (deltaP permeability), pipe penetrations, and caulked gaps, but was significant for cracks, disturbed pipe penetrations, cold joints, masonry blocks, and concrete under tensile stress. Crack areas calculated to be as small as 10(-7) m2 significantly increased radon advection. Algebraic expressions predict air velocity and effective crack width from enhanced radon transport and air pressures. Masonry blocks, open cracks, and slab cold joints enhance radon penetration but stressed slabs, undisturbed pipe penetrations, and sealed cracks may not.

  6. Influence of irradiation by a novel CO2 9.3-μm short-pulsed laser on sealant bond strength.

    Science.gov (United States)

    Rechmann, P; Sherathiya, K; Kinsel, R; Vaderhobli, R; Rechmann, B M T

    2017-04-01

    that is made caries-resistant with CO2 9.3-μm short-pulsed laser irradiation showed at least equal or significantly higher shear bond strength to pit and fissure sealants than non-laser-irradiated enamel. The risk of a sealant failure due to CO2 9.3-μm short-pulsed laser irradiation appears reduced. If additional laser ablation is required before placing a sealant, the CO2 9.3-μm enamel laser-cut showed equivalent or superior bond strength to a flowable sealant.

  7. Effect of whitening and desensitizing dentifrices on composite surfaces treated with surface sealants.

    Science.gov (United States)

    Dos Santos, Paulo Henrique; Brogin, Fabiana Ferres; Catelan, Anderson; Suzuki, Thaís Yumi Umeda; Guedes, Ana Paula Albuquerque; Pavan, Sabrina; Assunção, Wirley Gonçalves; Briso, André Luiz Fraga

    2013-05-01

    This study evaluated the effect of different dentifrices on the microhardness and surface roughness of composite surfaces covered by surface sealants. Samples of Filtek P60 were made and divided into groups, in accordance with surface treatments: G1 - Fortify; G2 - Fortify Plus; G3 - control (none). For Knoop microhardness evaluation, the specimens were placed in a microdurometer, under a load of 50 g for 15 sec. The analyses of surface roughness were carried out individually in a profilometer. The specimens were submitted to toothbrushing using dentifrices: Colgate Maximum Protection Anti-caries, Colgate Whitening or Sensodyne, diluted in distilled water (1:3) for 30 000 cycles. The results showed that the control group (G3) presented the highest microhardness values. The control group presented, before toothbrushing, the lowest surface roughness values, and after toothbrushing there were no differences among the experimental groups. The maintenance of the lowest values of microhardness demonstrated the effectiveness of these sealant materials to support the abrasive wear. © 2012 Wiley Publishing Asia Pty Ltd.

  8. Can earthquake fissures predispose hillslopes to landslides? - Evidence from Central and East Asia

    Science.gov (United States)

    Sidle, Roy C.; Gomi, Takashi; Rajapbaev, Muslim; Chyngozhoev, Nurstan

    2017-04-01

    Factors affecting earthquake-initiated landslides include earthquake magnitude, focal depth, and seismic wave propagation and attenuation. In contrast to rainfall-initiated landslides, earthquake-induced landslides often occur on convex slopes and near ridgelines. Here we present evidence from Fergana Basin, Kyrgyzstan and Kumamoto, Japan on how fissures developed during earthquakes may promote subsequent initiation of rainfall-triggered landslides. More than 1800 recent major landslides in hilly terrain and soft sediments of the Fergana Basin have been largely attributed to accumulation of heavy rainfall and snowmelt. While no large earthquakes have occurred in the Fergana Basin, smaller earthquakes have generated fissures near ridgelines and on convex slopes. The connection of fissures, developed years or decades before slope failure, with preferential transport of rainwater and runoff into the soil has not been previously investigated. Fissures have been observed to expand with time, particularly during subsequent minor earthquakes, further promoting preferential infiltration. Because the soil mantle does not have large contrasts in permeability that would define a slip plane for landslides, it appears that the position and depth of these fissures may control the location and depth of failures. Zones in the soil where surficial inputs of water are preferentially transported, augment natural subsurface accumulation of antecedent rainfall. Many landslides in the eastern Fergana Basin occur after several months of accumulated precipitation and groundwater has been observed emerging on critical hillside locations (near ridgelines and on convex slopes) prior to slope failure. During the 2016 Kumamoto Earthquake (M 7.3), many landslides were triggered in forest and grassland hillslopes near Mount Aso. All of these earthquakes were shallow (focal depths about 10 km), causing high shaking intensity and ground rupturing. Because soils were relatively dry during these

  9. Sealant retention is better assessed through colour photographs than through the replica and the visual examination methods

    NARCIS (Netherlands)

    Hu, X.; Fan, M.; Rong, W.; Lo, E.C.; Bronkhorst, E.M.; Frencken, J.E.F.M.

    2014-01-01

    The aim of this study was to test the hypothesis that the colour photograph method has a higher level of validity for assessing sealant retention than the visual clinical examination and replica methods. Sealed molars were assessed by two evaluators. The scores for the three methods were compared ag

  10. Creep Behavior of Glass/Ceramic Sealant and its Effect on Long-term Performance of Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wenning N.; Sun, Xin; Koeppel, Brian J.; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2009-10-14

    The creep behavior of glass or glass-ceramic sealant materials used in solid oxide fuel cells (SOFCs) becomes relevant under SOFC operating temperatures. In this paper, the creep of glass-ceramic sealants was experimentally examined, and a standard linear solid model was applied to capture the creep behavior of glass ceramic sealant materials developed for planar SOFCs at high temperatures. The parameters of this model were determined based on the creep test results. Furthermore, the creep model was incorporated into finite-element software programs SOFC-MP and Mentat-FC developed at Pacific Northwest National Laboratory for multi-physics simulation of SOFCs. The effect of creep of glass ceramic sealant materials on the long-term performance of SOFC stacks was investigated by studying the stability of the flow channels and the stress redistribution in the glass seal and on the various interfaces of the glass seal with other layers. Finite element analyses were performed to quantify the stresses in various parts. The stresses in glass seals were released because of creep behavior during operations.

  11. Sealants for preventing dental decay in the permanent teeth

    DEFF Research Database (Denmark)

    Ahovuo-Saloranta, Anneli; Forss, Helena; Walsh, Tanya;

    2013-01-01

    or the baseline caries prevalence.- Resin-based sealant compared with no sealant: Compared to control without sealant, second or third or fourth generation resin-based sealants prevented caries in first permanent molars in children aged 5 to 10 years (at 2 years of follow-up odds ratio (OR) 0.12, 95% confidence...... 2012). SELECTION CRITERIA: Randomised or quasi-randomised controlled trials of at least 12 months duration comparing sealants for preventing caries of occlusal or approximal surfaces of premolar or molar teeth with no sealant or different type of sealant in children and adolescents under 20 years...... of age. DATA COLLECTION AND ANALYSIS: Two review authors independently screened search results, extracted data and assessed trial quality. We calculated the odds ratio (OR) for caries or no caries on occlusal surfaces of permanent molar teeth. For trials with a split-mouth design, the Becker...

  12. Characterization of transport mechanisms and determinants critical for Na+-dependent Pi symport of the PiT family paralogs human PiT1 and PiT2

    DEFF Research Database (Denmark)

    Bøttger, Pernille; Hede, Susanne E; Grunnet, Morten

    2006-01-01

    The general phosphate need in mammalian cells is accommodated by members of the P(i) transport (PiT) family (SLC20), which use either Na(+) or H(+) to mediate inorganic phosphate (P(i)) symport. The mammalian PiT paralogs PiT1 and PiT2 are Na(+)-dependent P(i) (NaP(i)) transporters and are exploi......The general phosphate need in mammalian cells is accommodated by members of the P(i) transport (PiT) family (SLC20), which use either Na(+) or H(+) to mediate inorganic phosphate (P(i)) symport. The mammalian PiT paralogs PiT1 and PiT2 are Na(+)-dependent P(i) (NaP(i)) transporters...... and are exploited by a group of retroviruses for cell entry. Human PiT1 and PiT2 were characterized by expression in Xenopus laevis oocytes with (32)P(i) as a traceable P(i) source. For PiT1, the Michaelis-Menten constant for P(i) was determined as 322.5 +/- 124.5 microM. PiT2 was analyzed for the first time...

  13. Efficacy of Quilting Sutures and Fibrin Sealant Together for Prevention of Seroma in Extended Latissimus Dorsi Flap Donor Sites

    Directory of Open Access Journals (Sweden)

    In Soo Shin

    2012-09-01

    Full Text Available BackgroundThe extended latissimus dorsi flap is important for breast reconstruction. Unfortunately, donor site seroma is the most common complication of extended latissimus dorsi flap for breast reconstruction. Although using fibrin sealant in the donor site reduces the rate of seroma formation, donor site seroma remains a troublesome complication. The purpose of this study was to analyze the effectiveness of the combination of quilting sutures and fibrin sealant in the latissimus dorsi donor site for the prevention of seroma.MethodsForty-six patients who underwent breast reconstruction with extended latissimus flap were enrolled in the study. The patients received either fibrin sealant (group 1, n=25 or a combination of fibrin sealant and quilting sutures (group 2, n=21 in the extended latissimus dorsi donor site. Outcome measures were obtained from the incidence, volume of postoperative seroma, total drainage amount, indwelling period of drainage, and duration of hospital stay.ResultsThe incidence of seroma was 76% in group 1 and 42.9% in group 2 (P=0.022. We also found significant reductions in seroma volume (P=0.043, total drainage amount (P=0.002, indwelling period of drainage (P=0.01, and frequency of aspiration (P=0.043. The quilting sutures did not affect the rate of drainage, tube reinsertion, or hospital stay.ConclusionsThe use of quilting sutures combined with fibrin sealant on the latissimus dorsi flap donor site is helpful for reducing the overall seroma volume, frequency of aspiration, and total drainage amount.

  14. Natural Treatments for Fissure in Ano Used by Traditional Persian Scholars, Razi (Rhazes) and Ibn Sina (Avicenna).

    Science.gov (United States)

    Derakhshan, Ali Reza

    2016-06-08

    Most cases of chronic fissure do not respond to medical treatment. Razi and Ibn Sina were 2 of the best-known scientists of ancient Persia. The purpose of this study was to find out new scientific evidence in modern medicine about their recommendations, in order to find certain clues to conduct useful researches in the future. First, treatments of anal fissure mentioned by Razi and Ibn Sina were reviewed. Then, literature search was made in electronic databases including PubMed, Scopus, and Google Scholar. Management of anal fissure according to Razi's and Ibn Sina's practices is done based on 3 interventions: lifestyle modifications, drug treatments, and manual procedures. Almost all remedies suggested by Razi and Ibn Sina have shown their effects on fissure in ano via several mechanisms of action in many in vitro and in vivo studies; Still there is lack of human studies on the subject. © The Author(s) 2016.

  15. Comparison of botox and lateral internal sphincterotomy treatment outcomes in chronic anal fissures

    Directory of Open Access Journals (Sweden)

    Tolga Dinç

    2014-03-01

    Full Text Available Objective: Both botox and lateral internal sfinkterotomi are treatment technics used in chronic anal fissure; provide the relaxation of anal sphincter and as a result of this, healing occurs. Aim of this study is to compare efficacy of botox and LIS treatment in chronic anal fissure and discussing with the literature. Methods: 60 of 66 patients who has chronic anal fissure, that we reached, treated but not healed with medical therapy, appealed to the Dr. Sami Ulus Hospital included the study. Gender, age, fissure localization, complaints (pain, bleeding, itching, constipation, complaint length, recurrences after treatment, continence conditions and complications of patients were registered. Results: Sixty patients were enrolled the study. Of the 60 patients; 38(63.3% were male and 22 (27.7% were female. Mean age of all patients was 35.93 ± 11.45 (21 -60. Pain was the common complaint of the all patients. 10 (32.3% recurrence were detected in botox treatment group (Group-I, only 1 (3.4% recurrence was in LIS group (Group-II. There was no complication as an incontinence in group-I but 3 cases with incontinence (10.39% were obtained in group-II. In the evaluation of these 3 cases by Cleveland Clinic Continence Scoring System, 2 cases classified as gas incontinence and 1 case as moderate fecal incontinence. Conclusion: Although botulinum toxin injection seen as an alternative treatment method with low complication rates such as incontinence, high recurrence is an important shortcoming of this technic. LIS performed by experienced surgeons remained the most popular treatment modality with low complication rates and great deal of healing success.

  16. Increasing efficacy and reducing side effects in treatment of chronic anal fissures

    Science.gov (United States)

    Hang, Minh Tuan H.; Smith, Betsy E.; Keck, Carson; Keshavarzian, Ali; Sedghi, Shahriar

    2017-01-01

    Abstract This is a single institution nonexperimental study intended to analyze the therapeutic efficacy of topical diazepam in treating symptoms of chronic anal fissures. Anal fissures are a common cause of anal pain. Conventional treatments include nonsteroidal anti-inflammatory drugs, topical creams, such as nitroglycerin and nifedipine, and surgery. However, these treatments are usually suboptimally efficacious or have deterring side effects. Patients at an outpatient community center with a diagnosis of a chronic anal fissure were prescribed either topical 2% (n = 19) or 4% (n = 18) diazepam cream between January 2013 and February 2015. We retrospectively analyzed their responses to treatment. All 19 patients using 2% diazepam cream experienced a positive response in pain, whereas 47.4% experienced a complete response, with a numerical rating scale (NRS) score of 0 (0–10). Eighty-eight percent of patients using 4% dose had a positive response in pain, whereas 23.5% experienced a complete response. Ninety-four percent of patients using 2% dose had a positive response in anal bleeding, whereas 68.8% experienced a complete response with an anal bleeding score (ABS) of 2 (2–9). Ninety-four percent of patients using 4% dose had a positive response in anal bleeding, whereas 64.7% experienced a complete response. Only 1 patient reported a side effect from diazepam cream—perianal pruritus. Both 2% and 4% topical diazepam provided significant pain and bleeding relief from chronic anal fissures that were refractory to conventional therapies. There were insignificant differences when assessing independent comparisons for pain and bleeding between the doses. PMID:28514300

  17. Fissure formation in coke. 3: Coke size distribution and statistical analysis

    Energy Technology Data Exchange (ETDEWEB)

    D.R. Jenkins; D.E. Shaw; M.R. Mahoney [CSIRO, North Ryde, NSW (Australia). Mathematical and Information Sciences

    2010-07-15

    A model of coke stabilization, based on a fundamental model of fissuring during carbonisation is used to demonstrate the applicability of the fissuring model to actual coke size distributions. The results indicate that the degree of stabilization is important in determining the size distribution. A modified form of the Weibull distribution is shown to provide a better representation of the whole coke size distribution compared to the Rosin-Rammler distribution, which is generally only fitted to the lump coke. A statistical analysis of a large number of experiments in a pilot scale coke oven shows reasonably good prediction of the coke mean size, based on parameters related to blend rank, amount of low rank coal, fluidity and ash. However, the prediction of measures of the spread of the size distribution is more problematic. The fissuring model, the size distribution representation and the statistical analysis together provide a comprehensive capability for understanding and predicting the mean size and distribution of coke lumps produced during carbonisation. 12 refs., 16 figs., 4 tabs.

  18. Economic evaluation of dental sealants: A systematic literature review.

    Science.gov (United States)

    Akinlotan, Marvellous; Chen, Bradley; Fontanilla, Tiana M; Chen, Annie; Fan, Victoria Y

    2017-09-06

    To systematically review the literature on economic evaluations of dental sealants and examine the costs and effectiveness of caries prevention using sealants. Of 21 full-text articles examined, a total of 13 were included in this study. These studies are grouped by the type of intervention as follows: (i) sealants compared with no sealants; (ii) sealants compared with other forms of caries prevention; (iii) resin-based sealants compared with glass-ionomer sealants; (iv) different sealing strategies in primary teeth; (v) different sealing strategies in permanent teeth; and (vi) sealants based on school- or clinic-based setting of delivery. All currency is reported in constant 2010 US$. Cost-effectiveness analyses differed due to varying study designs, assumptions, sealant delivery settings, outcomes, caries risk assessment and study durations. Findings varied on the cost-effectiveness of sealants compared with other caries-preventive strategies. Under the assumption of equal caries risk, always sealing primary molars appeared to be the most effective strategy, whereas risk-based sealing was the optimal strategy with differing caries risk. Studies that assessed sealing strategies in permanent teeth reported that risk-based sealing was more cost-effective than not sealing, but they differed on the cost-effectiveness of risk-based seal compared with non-risk-based seal. Sealants delivered in school settings had mixed results on costs but were as equally effective as sealants delivered in private practices. The cost-effectiveness of sealants is dependent on the conditions of delivery. The list of cost-effectiveness ratios for each intervention can support policy makers to estimate expected returns on their investments in dental sealants. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. An Experimental and Numerical Study on Cracking Behavior of Brittle Sandstone Containing Two Non-coplanar Fissures Under Uniaxial Compression

    Science.gov (United States)

    Yang, Sheng-Qi; Tian, Wen-Ling; Huang, Yan-Hua; Ranjith, P. G.; Ju, Yang

    2016-04-01

    To understand the fracture mechanism in all kinds of rock engineering, it is important to investigate the fracture evolution behavior of pre-fissured rock. In this research, we conducted uniaxial compression experiments to evaluate the influence of ligament angle on the strength, deformability, and fracture coalescence behavior of rectangular prismatic specimens (80 × 160 × 30 mm) of brittle sandstone containing two non-coplanar fissures. The experimental results show that the peak strength of sandstone containing two non-coplanar fissures depends on the ligament angle, but the elastic modulus is not closely related to the ligament angle. With the increase of ligament angle, the peak strength decreased at a ligament angle of 60°, before increasing up to our maximum ligament angle of 120°. Crack initiation, propagation, and coalescence were all observed and characterized from the inner and outer tips of pre-existing non-coplanar fissures using photographic monitoring. Based on the results, the sequence of crack evolution in sandstone containing two non-coplanar fissures was analyzed in detail. In order to fully understand the crack evolution mechanism of brittle sandstone, numerical simulations using PFC2D were performed for specimens containing two non-coplanar fissures under uniaxial compression. The results are in good agreement with the experimental results. By analyzing the stress field, the crack evolution mechanism in brittle sandstone containing two non-coplanar fissures under uniaxial compression is revealed. These experimental and numerical results are expected to improve the understanding of the unstable fracture mechanism of fissured rock engineering structures.

  20. Endobronchial valves in severe emphysematous patients: CT evaluation of lung fissures completeness, treatment radiological response and quantitative emphysema analysis

    Directory of Open Access Journals (Sweden)

    Marcel Koenigkam-Santos

    2013-02-01

    Full Text Available OBJECTIVE: To evaluate lung fissures completeness, post-treatment radiological response and quantitative CT analysis (QCTA in a population of severe emphysematous patients submitted to endobronchial valves (EBV implantation. MATERIALS AND METHODS: Multi-detectors CT exams of 29 patients were studied, using thin-section low dose protocol without contrast. Two radiologists retrospectively reviewed all images in consensus; fissures completeness was estimated in 5% increments and post-EBV radiological response (target lobe atelectasis/volume loss was evaluated. QCTA was performed in pre and post-treatment scans using a fully automated software. RESULTS: CT response was present in 16/29 patients. In the negative CT response group, all 13 patients presented incomplete fissures, and mean oblique fissures completeness was 72.8%, against 88.3% in the other group. QCTA most significant results showed a reduced post-treatment total lung volume (LV (mean 542 ml, reduced EBV-submitted LV (700 ml and reduced emphysema volume (331.4 ml in the positive response group, which also showed improved functional tests. CONCLUSION: EBV benefit is most likely in patients who have complete interlobar fissures and develop lobar atelectasis. In patients with no radiological response we observed a higher prevalence of incomplete fissures and a greater degree of incompleteness. The fully automated QCTA detected the post-treatment alterations, especially in the treated lung analysis.

  1. Endobronchial valves in severe emphysematous patients: CT evaluation of lung fissures completeness, treatment radiological response and quantitative emphysema analysis

    Energy Technology Data Exchange (ETDEWEB)

    Koenigkam-Santos, Marcel, E-mail: marcelk46@yahoo.com.br, E-mail: marcelk46@usp.b [Universidade de Sao Paulo (HCFMRP/USP), Ribeirao Preto, SP (Brazil). Hospital das Clinicas da Faculdade de Medicina; Paula, Wagner Diniz de [University of Brasilia (UnB), DF (Brazil). Brasilia University Hospital; Gompelmann, Daniela [University of Heidelberg (Germany). Department of Pneumology and Respiratory Medicine of the Chest Clinic (Thoraxklinik); Kauczor, Hans-Ulrich [University of Heidelberg (Germany). Department of Diagnostic and Interventional Radiology; Heussel, Claus Peter; Puderbach, Michael [University of Heidelberg (Germany). Department of Diagnostic and Interventional Radiology with Nuclear Medicine of the Chest Clinic (Thoraxklinik)

    2013-01-15

    Objective: To evaluate lung fissures completeness, post-treatment radiological response and quantitative CT analysis (QCTA) in a population of severe emphysematous patients submitted to endobronchial valves (EBV) implantation. Materials and Methods: Multi-detectors CT exams of 29 patients were studied, using thin-section low dose protocol without contrast. Two radiologists retrospectively reviewed all images in consensus; fissures completeness was estimated in 5% increments and post-EBV radiological response (target lobe atelectasis/volume loss) was evaluated. QCTA was performed in pre and post-treatment scans using a fully automated software. Results: CT response was present in 16/29 patients. In the negative CT response group, all 13 patients presented incomplete fissures, and mean oblique fissures completeness was 72.8%, against 88.3% in the other group. QCTA most significant results showed a reduced post-treatment total lung volume (LV) (mean 542 ml), reduced EBV-submitted LV (700 ml) and reduced emphysema volume (331.4 ml) in the positive response group, which also showed improved functional tests. Conclusion: EBV benefit is most likely in patients who have complete interlobar fissures and develop lobar atelectasis. In patients with no radiological response we observed a higher prevalence of incomplete fissures and a greater degree of incompleteness. The fully automated QCTA detected the post-treatment alterations, especially in the treated lung analysis. (author)

  2. Understanding Cavitation Intensity through Pitting and Pressure Pulse Analysis

    Science.gov (United States)

    Jayaprakash, A.; Singh, S.; Choi, J.-K.; Chahine, G.

    2011-11-01

    Cavitation erosion is of interest to the designers of ship propulsion devices because of its detrimental effects. One of the difficulties of predicting cavitation erosion is that the intensity of cavitation is not well predicted or defined. In this work we attempt to define the intensity of a cavitation erosion field through analysis of cavitation induced erosion pits and pressure pulses. In the pitting tests, material samples were subjected to cavitation field for a short duration of time selected within the test sample's incubation period, so that the test sample undergoes plastic deformation only. The sample material reacts to these cavitation events by undergoing localized permanent deformation, called pits. The resulting pitted sample surfaces were then optically scanned and analyzed. The pressure signals under cavitating jets and ultrasonic horns, for different conditions, were experimentally recorded using high frequency response pressure transducers. From the analysis of the pitting data and recorded pressure signals, we propose a model that describes the statistics, which in the future can be used to define the cavitation field intensity. Support for this work was provided by Office of Naval Research (ONR) under contract number N00014-08-C-0450, monitored by Dr. Ki-Han Kim.

  3. Variations of Lung Fissures: A Cadaveric Study

    Directory of Open Access Journals (Sweden)

    Ambali Manoj P

    2014-01-01

    Full Text Available Background: The presence of fissures in the normal lungs enhances uniform expansion and hence facilitates more air intake. Accessory and incomplete fissures of varying depth can be seen in unusual locations of the lung, delimiting abnormal lobes which correspond to the normal bronchopulmonary segments. The knowledge of anatomical variations of lung fissures is essential for clinicians, surgeons, and for radiologist for recognizing various images of related abnormalities because an accessory or anomalous fissure can be mistaken for a lung lesion or an atypical appearance of pleural effusion. Aims and Objectives: The aim of the present study is to observe the variations of lung fissures in Indian population. Fifty pairs (right- 50; left- 50 of lungs were used for this study. Each lung was studied carefully for number of fissures whether complete or incomplete or absent. Presences of accessory fissures were noted. Results: We observed complete absence of fissures in two right and left lungs. Accessory fissures were present in 38% right lungs and 32% in left lungs. Conclusion: Incidence of absence of oblique fissure and accessory fissure was greater in our present work when compared our results with other authors. Considering this we feel that more elaborative study should be done on this topic which will throw more light on this.

  4. Diagnosis and Prevention Strategies for Dental Caries

    Science.gov (United States)

    Lee, Yoon

    2013-01-01

    Dental caries is one of the oldest and most common diseases found in humans. With the recent shift from the surgical model, which emphasized restorative treatment, to a medical model of disease management, newer strategies emphasize disease prevention and conservation of tooth structure. For early detection and monitoring of caries, rather than waiting until a cavity is formed and restorative treatment is needed, devices such as DIAGNOdent, Digital Imaging Fiber-Optic Transillumination, quantitative light-induced fluorescence, and the Electronic Caries Monitor have been introduced. For caries prevention, oral hygiene measures, fluoride application, pit-and-fissure sealants, the use of xylitol, the development of a dental caries vaccine, and the role of the primary caregiver for infants are briefly discussed. PMID:26064846

  5. Percutaneous BioOrganic Sealing of Duodenal Fistulas: Case Report and Review of Biological Sealants with Potential Use in Interventional Radiology

    Energy Technology Data Exchange (ETDEWEB)

    Wadhwa, Vibhor, E-mail: vwadhwa1@jhmi.edu [Johns Hopkins University School of Medicine, Division of Vascular & Interventional Radiology (United States); Leeper, William R., E-mail: rob.leeper@jhmi.edu [Johns Hopkins University School of Medicine, Department of Surgery (United States); Tamrazi, Anobel, E-mail: atamraz1@jhmi.edu [Johns Hopkins University School of Medicine, Division of Vascular & Interventional Radiology (United States)

    2015-08-15

    Biological sealants are being increasingly used in a variety of surgical specialties for their hemostatic and sealing capabilities. However, their use in interventional radiology has not been widely reported. The authors describe a case of duodenal perforation occurring after 15 years of gastric bypass surgery, in whom surgical diversion was unsuccessfully attempted and the leakage was successfully controlled using percutaneous administration of a combination of biological and organic sealants.

  6. Environmentally Friendly Adhesives and Sealants for Army Applications

    Science.gov (United States)

    2008-12-01

    the Torque Seal. All of the adhesives tested were non - Newtonian shear thinning fluids (ASTM, 2005), and thus the viscosity changes with shear...temperature. The sample was re- weighed and then heated to 50ºC for 1 week to increase the evaporation rate of the residual solvent. To ensure complete...adhesion, fluid resistance, and weathering relative to the baseline product. Dry time is slightly longer, but not enough to raise any concerns with

  7. Caries-preventive Effect of Supervised Toothbrushing and Sealants

    NARCIS (Netherlands)

    Hilgert, L.A.; Leal, S.C.; Mulder, J.; Creugers, N.H.J.; Frencken, J.E.F.M.

    2015-01-01

    To investigate the effectiveness of 3 caries-preventive measures on high- and low-caries risk occlusal surfaces of first permanent molars over 3 y. This cluster-randomized controlled clinical trial covered 242 schoolchildren, 6 to 7 y old, from low socioeconomic areas. At baseline, caries risk was a

  8. Mathematical Optimization Models and Methods for Open-Pit Mining

    OpenAIRE

    Amankwah, Henry

    2011-01-01

    Open-pit mining is an operation in which blocks from the ground are dug to extract the ore contained in them, and in this process a deeper and deeper pit is formed until the mining operation ends. Mining is often a highly complex industrial operation, with respect to both technological and planning aspects. The latter may involve decisions about which ore to mine and in which order. Furthermore, mining operations are typically capital intensive and long-term, and subject to uncertainties rega...

  9. HRCT evaluation of the accessory fissures of the lung

    Energy Technology Data Exchange (ETDEWEB)

    Yildiz, Altan E-mail: ayildiz@mersin.edu.tr; Goelpinar, Fulya; Calikoglu, Mukadder; Duce, Meltem Nass; Oezer, Caner; Apaydin, F. Demir

    2004-03-01

    Introduction: The purpose of this study was to classify the accessory fissures of the lung and to assess their frequency by using high-resolution CT. Methods and patients: HRCT scans of 115 patients were prospectively reviewed. 1 mm thin sections were obtained at 10 mm intervals with a scan time of 1.9 s. The fissure and its relationship to the segmental bronchovascular structures were then evaluated on transverse sections. Results: Forty-four accessory fissures were detected in 35 of 115 patients. The most common accessory fissure was the inferior accessory fissure (12%). The second most common accessory fissure was the left minor fissure (8%). The right superior accessory fissure (5%), the accessory fissure between the medial and lateral segments of the right middle lobe (5%), and the accessory fissure between the superior and inferior segments of the lingula (5%) were seen in equal frequencies. Also, intersegmental accessory fissures, namely the fissure between the anterobasal and laterobasal of both the right (1%) and the left (2%) lower lobes were detected. We found only one subsegmental accessory fissure. Discussion and conclusion: The inferior accessory fissure and the left minor fissure were the most common accessory fissures in our study.

  10. The Pits

    Science.gov (United States)

    2006-01-01

    8 March 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of a pit chain on the lower, northern flank of the giant martian volcano, Arsia Mons. Pits such as these commonly form as a result of collapse of surface materials into a subsurface void, possibly along a fault or into an old lava tube. The layered material, exposed near the top of several of the pits, is shedding house-sized boulders which can be seen resting on the sloping sidewalls and floors of many of the pits. Location near: 6.7oS, 120.1oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Southern Summer

  11. Organo-selenium-containing dental sealant inhibits bacterial biofilm.

    Science.gov (United States)

    Tran, P; Hamood, A; Mosley, T; Gray, T; Jarvis, C; Webster, D; Amaechi, B; Enos, T; Reid, T

    2013-05-01

    Oral bacteria, including Streptococcus mutans and Streptococcus salivarius, contribute to tooth decay and plaque formation; therefore, it is essential to develop strategies to prevent dental caries and plaque formation. We recently showed that organo-selenium compounds covalently attached to different biomaterials inhibited bacterial biofilms. Our current study investigates the efficacy of an organo-selenium dental sealant (SeLECT-Defense(TM) sealant) in inhibiting S. mutans and S. salivarius biofilm formation in vitro. The organo-selenium was synthesized and covalently attached to dental sealant material via standard polymer chemistry. By colony-forming unit (CFU) assay and confocal microscopy, SeLECT-Defense(TM) sealant was found to completely inhibit the development of S. mutans and S. salivarius biofilms. To assess the durability of the anti-biofilm effect, we soaked the SeLECT-Defense(TM) sealant in PBS for 2 mos at 37°C and found that the biofilm-inhibitory effect was not diminished after soaking. To determine if organo-selenium inhibits bacterial growth under the sealant, we placed SeLECT-Defense sealant over a lawn of S. mutans. In contrast to a control sealant, SeLECT-Defense(TM) sealant completely inhibited the growth of S. mutans. These results suggest that the inhibitory effect of SeLECT-Defense(TM) sealant against S. mutans and S. salivarius biofilms is very effective and durable.

  12. Burn Pits

    Science.gov (United States)

    ... Enter ZIP code here Enter ZIP code here Burn Pits Burn Pits Registry Studies Photo: U.S. Department ... the health of deployed Veterans. Health effects from burn pit smoke Toxins in burn pit smoke may ...

  13. Effectiveness of Dry Cow Therapy Comprising Antibiotic Treatment, Internal Teat Sealant, and α-Tocopherol Against New Intramammary Infections in Cows

    Directory of Open Access Journals (Sweden)

    Cengiz Mehmet

    2015-04-01

    Full Text Available The aim of this study was to evaluate the preventive effectiveness of dry cow therapy based on antibiotic, internal teat sealant, and α-tocopherol administered separately or in various combinations at drying-off The study was performed on 322 uninfected quarters of 95 cows originating from three dairy herds. The new intramammary infection rates after calving were measured to evaluate the effectiveness. The quarters were divided into six groups differing in treatment, namely: control group (group C, n = 40 and five treatment groups. Treatment groups were arranged as follows: group A (antibiotic alone, n = 81, group AS (antibiotic + sealant, n = 40, group AST (antibiotic + sealant + α-tocopherol, n = 40, group T (α-tocopherol alone, n = 40, group S (sealant alone, n = 81. New infection rate amounted to 47.5% in group C. The treatment in group AST significantly prevented from the occurrence of new intramammary infections (12.5%, P 0.05, although the use of the sealant alone (group S decreased the risk of new infection (24.7%, P 0.05. Increased α-tocopherol level (P < 0.05 was detected after calving in the quarters from cows that received α-tocopherol injections. In conclusion, the combination of antibiotic, internal teat sealant, and α-tocopherol used in dry cow therapy showed a significantly better preventive effect against new intramammary infections, than the therapeutics administered separately.

  14. Microleakage of Sealants after Phosphoric Acid, Er: YAG Laser and Air Abrasion Enamel Conditioning: Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Fumes, Ana Caroline; Longo, Daniele Lucca; De Rossi, Andiara; Fidalgo, Tatiana Kelly da Silva; de Paula E Silva, Francisco Wanderley Garcia; Borsatto, Maria Cristina; Küchler, Erika Calvano

    The aim of this systematic review and meta-analysis is to answer the focused question: Does the application of phosphoric acid, Er:YAG laser and air abrasion enamel conditioning methods previous to the oclusal sealant application in human permanent molars influence the microleakage? A literature research was carried out in the Pubmed Medline, Web of Science, Scopus and Cochrane databases using with the MeSH terms and keyword search strategy. A supplemental hand search of the references of retrieved articles was also performed. Inclusion criteria comprised ex vivo studies (extracted teeth) with permanent human teeth that used chemical (phosphoric acid) or mechanical (Er:YAG laser and air abrasion) conditioning methods previous the sealant application. The studies should evaluate microleakage as an outcome. Meta-analysis pooled plot were obtained comparing the microleakage after pre-treatment with phosphoric acid, Er:YAG and air abrasion enamel conditioning for sealant application using RevMan software. The search resulted in 164 articles, 55 records were excluded because they were duplicated. The analysis of titles and abstracts resulted in the exclusion of 105 studies. Four studies were included in the systematic review and the meta-analysis. According to the risk of bias evaluation, the four studies were considered low risk of bias. The meta-analysis showed that phosphoric acid had lower microleakage than Er:YAG laser (p air abrasion (p air abrasion (p > 0.05). The evidence supports that the pretreatment with phosphoric acid leads lower microleakage in oclusal sealants than Er:YAG laser and air abrasion.

  15. Structural evaluation of W-211 flexible receiver platforms and tank pit walls

    Energy Technology Data Exchange (ETDEWEB)

    Shrivastava, H.P.

    1997-11-03

    This document is a structural analysis of the Flexible Receiver Platforms and the tank-pit wall during removal of equipment and during a accidental drop of that equipment. The platform and the pit walls must withstand a accidental drop of a mixer and transfer pumps in specific pits in tanks 102-AP and 104-AP. A mixer pump will be removed from riser 11 in pit 2A on tank 241-AP-102. A transfer pump will be removed from riser 13 in pit 2D on tank 241-AP-102 and another transfer pump will be removed from riser 3A in pit 4A on tank 241-AP-104.

  16. Influences of soil hydraulic and mechanical parameters on land subsidence and ground fissures caused by groundwater exploitation

    Institute of Scientific and Technical Information of China (English)

    陈兴贤; 骆祖江; 周世玲

    2014-01-01

    In order to study the influences of hydraulic and mechanical parameters on land subsidence and ground fissure caused by groundwater exploitation, based on the Biot’s consolidation theory and combined with the nonlinear rheological theory of soil, the constitutive relation in Biot’s consolidation theory is extended to include the viscoelastic plasticity, and the dynamic relationship among the porosity, the hydraulic conductivity, the parameters of soil deformation and effective stress is also considered, a three-dimensional full coupling mathematical model is established and applied to the study of land subsidence and ground fissures of Cangzhou in Hebei Province, through the analysis of parameter sensitivity, the influences of soil hydraulic and mechanical parame-ters on land subsidence and ground fissure are revealed. It is shown that the elastic modulus E , the Poisson ratio, the specific yield m and the soil cohesion c have a great influence on the land subsidence and the ground fissures. In addition, the vertical hydraulic conductivity zk and the horizontal hydraulic conductivity ks also have a great influence on the land subsidence and the ground fissures.

  17. Relation between in-vitro wear and nanomechanical properties of commercial light-cured dental composites coated with surface sealants

    Directory of Open Access Journals (Sweden)

    Emanuel Santos Jr

    2013-01-01

    Full Text Available This work investigates the correlation between the in-vitro wear resistance and the nanomechanical properties of dental sealants commercially available. Mechanical properties, namely hardness (H and elastic modulus (E, were assessed by nanoindentation technique. The coated samples presented lower H and E values than the Z250 composite resin substrate. Such measurements were used to calculate H/E ratios. Wear tests were carried out in water by using a pin-on-plate apparatus. Scars formed on the samples were qualitatively examined by optical microscopy, while their wear depths were measured by contact profilometry. Based on the findings, an empirical correlation between the wear depths and H/E was obtained. A high H/E ratio was associated to surfaces with enhanced wear resistance. For the tribological conditions here employed, the H/E ratio could be, therefore, considered a useful parameter for ranking the in-vitro wear of dental sealants.

  18. A new heterologous fibrin sealant as a scaffold to cartilage repair-Experimental study and preliminary results.

    Science.gov (United States)

    de Barros, Caio Nunes; Miluzzi Yamada, Ana Lúcia; Junior, Rui Seabra F; Barraviera, Benedito; Hussni, Carlos Alberto; de Souza, Jaqueline Brandão; Watanabe, Marcos Jun; Rodrigues, Celso Antônio; Garcia Alves, Ana Liz

    2016-07-01

    Autologous fibrin gel is commonly used as a scaffold for filling defects in articular cartilage. This biomaterial can also be used as a sealant to control small hemorrhages and is especially helpful in situations where tissue reparation capacity is limited. In particular, fibrin can act as a scaffold for various cell types because it can accommodate cell migration, differentiation, and proliferation. Despite knowledge of the advantages of this biomaterial and mastery of the techniques required for its application, the durability of several types of sealant at the site of injury remains questionable. Due to the importance of such data for evaluating the quality and efficiency of fibrin gel formulations on its use as a scaffold, this study sought to analyze the heterologous fibrin sealant developed from the venom of Crotalus durissus terrificus using studies in ovine experimental models. The fibrin gel developed from the venom of this snake was shown to act as a safe, stable, and durable scaffold for up to seven days, without causing adverse side effects. Fibrin gel produced from the venom of the Crotalus durissus terrificus snake possesses many clinical and surgical uses. It presents the potential to be used as a biomaterial to help repair skin lesions or control bleeding, and it may also be used as a scaffold when applied together with various cell types. The intralesional use of the fibrin gel from the venom of this snake may improve surgical and clinical treatments in addition to being inexpensive and adequately consistent, durable, and stable. The new heterologous fibrin sealant is a scaffold candidate to cartilage repair in this study.

  19. A new heterologous fibrin sealant as a scaffold to cartilage repair—Experimental study and preliminary results

    Science.gov (United States)

    de Barros, Caio Nunes; Miluzzi Yamada, Ana Lúcia; Junior, Rui Seabra F; Barraviera, Benedito; Hussni, Carlos Alberto; de Souza, Jaqueline Brandão; Watanabe, Marcos Jun; Rodrigues, Celso Antônio

    2015-01-01

    Autologous fibrin gel is commonly used as a scaffold for filling defects in articular cartilage. This biomaterial can also be used as a sealant to control small hemorrhages and is especially helpful in situations where tissue reparation capacity is limited. In particular, fibrin can act as a scaffold for various cell types because it can accommodate cell migration, differentiation, and proliferation. Despite knowledge of the advantages of this biomaterial and mastery of the techniques required for its application, the durability of several types of sealant at the site of injury remains questionable. Due to the importance of such data for evaluating the quality and efficiency of fibrin gel formulations on its use as a scaffold, this study sought to analyze the heterologous fibrin sealant developed from the venom of Crotalus durissus terrificus using studies in ovine experimental models. The fibrin gel developed from the venom of this snake was shown to act as a safe, stable, and durable scaffold for up to seven days, without causing adverse side effects. Fibrin gel produced from the venom of the Crotalus durissus terrificus snake possesses many clinical and surgical uses. It presents the potential to be used as a biomaterial to help repair skin lesions or control bleeding, and it may also be used as a scaffold when applied together with various cell types. The intralesional use of the fibrin gel from the venom of this snake may improve surgical and clinical treatments in addition to being inexpensive and adequately consistent, durable, and stable. The new heterologous fibrin sealant is a scaffold candidate to cartilage repair in this study. PMID:26264444

  20. Bitter pit in apples: pre- and postharvest factors: A review

    Directory of Open Access Journals (Sweden)

    Tomislav Jemrić

    2016-12-01

    Full Text Available Bitter pit is a physiological disorder that significantly reduces the quality of apples. Although it has been detected since the beginning of the last century, still there is little known about the mechanism of its occurrence. According to numerous studies, bitter pit is formed as a result of calcium deficiency in the fruit. Some authors cite the high concentration of gibberellins, later in the production season, most probably caused by excessive activity of the roots, as the chief causative factor. Beside Ca, there are several factors that can also contribute to its development, like imbalance among some mineral elements (N, P, K and Mg, cultivar, rootstock, the ratio of vegetative and generative growth, post-harvest treatments and the storage methods. There are some prediction models available that can estimate the risk of bitter pit in apples, but even those are not always reliable. The aim of this review was to encompass the pre and postharvest factors which cause bitter pit and point out the directions for solving this problem.

  1. COMPARATIVE STUDY OF LATERAL SPHINCTEROTOMY AND LATERAL SPHINCTEROTOMY WITH V-Y ADVANCEMENT FLAP IN TREATMENT OF CHRONIC ANAL FISSURE

    Directory of Open Access Journals (Sweden)

    S. Meenaa Saravanaperumaal

    2016-12-01

    Full Text Available BACKGROUND Anal fissure is an elongated ulcer in the long axis of lower anal canal. The most frequent site for anal fissure is midline posteriorly and followed by midline anteriorly. It causes severe pain during defecation and rectal bleeding that stain the tissue or streaks the stools. Chronic anal fissure has traditionally been treated by surgery, an effective and standard procedure that results in healing in 90-95% of cases. Lateral sphincterotomy heals chronic anal fissure in 90% of cases that is associated with incontinence to flatus and faeces. Anal advancement flaps was used to cover the chronic anal fissure. Using anal flaps to resurface chronic or recurrent anal fissure to promote wound healing and to assess the added advantage over lateral sphincterotomy in tissues of complete epithelialisation; time of relief of pain; persistent symptoms; patient satisfaction and quality of life. The aim of the study is to- 1. Compare the efficacy of lateral sphincterotomy against lateral sphincterotomy with V-Y advancement flap in treatment of chronic anal fissures. 2. Assess the added advantages of V-Y advancement flap in treatment of chronic anal fissure in terms of wound healing, time of relief of pain, persistent symptoms and patients’ satisfaction. 3. Compare the complications associated with procedures. MATERIALS AND METHODS A study of 50 patients was done. It included 26 females and 24 males. In that, lateral sphincterotomy alone was done in 25 patients and lateral sphincterotomy along with anal advancement flap was done in 25 patients. RESULTS In group A patients only lateral sphincterotomy done. In group B lateral sphincterotomy with anal advancement flap done. Anal advancement flap done by ‘v’ shaped flap formed of skin and subcutaneous tissue was elevated incontinuity with excised tissue to allow to cover the tissue defect. Flap should be broad based with adequate blood supply and avoid tension while suturing with 3-0 vicryl. A study

  2. A novel hemostatic sealant composed of gelatin,transglutaminase and thrombin effectively controls liver trauma-induced bleeding in dogs

    Institute of Scientific and Technical Information of China (English)

    Xia XIE; Jiang-ke TIAN; Fa-qin LV; Rong WU; Wen-bo TANG; Yu-kun LUO; Ya-qin HUANG

    2013-01-01

    Aim:A novel hemostatic sealant based on the in situ gel formation of gelatin catalyzed by thrombin and crosslinked by transglutaminase was designed.The aim of this study was to investigate the efficacy of the hemostatic sealant in control of bleeding caused by liver trauma in dogs.Methods:Hepatic trauma that mimicked the grade Ⅲ-Ⅳ rupture of liver was made in 20 dogs.The traumatic lesion was topically administered the hemostatic sealant (treatment group,n=10),or a thrombin solution (control group,n=10).The time to achieve hemostasis and the blood loss were measured.Contrast-enhanced ultrasound (CEUS) examination was performed in each animal on d 3,d 7,and d 10 d postoperatively to study the healing of the lesions.Results:The mean time to achieve hemostasis in the treatment group was significantly shorter than that in the control group (1.20±0.33 vs 6.70±0.64 min,P<0.05).The mean blood loss in the treatment group was significantly less than that in the control group (47.22±8.61 vs 79.29±11.97 mL,P<0.05).In CEUS examination,the traumatic lesions in the treatment group became significantly smaller on d 3,and disappeared on d 7,whereas the lesions in the control group still existed on d 10.Ascites were never found during 10 d follow-up in the treatment group but were observed on d 3 and d 7 in the control group.Conclusion:Compared with thrombin,the novel hemostatic sealant shows much better efficacy in hemostasis and may promote wound healing in dog liver trauma.

  3. Mechanism of Pitting Corrosion Protection of Metals and Alloys

    OpenAIRE

    Vladimir Alexandrovich Grachev; Andrei Evgenievich Rozen; Gennadii Vasilievich Kozlov; Andrei Andreievich Rozen

    2016-01-01

    In this article authors set out a principle of pitting corrosion protection, suggested a new class of multilayer materials with high corrosion resistance. They substantiated the choice of the layers for the multilayer material designed for exploitation in oxidizing and non-oxidizing environment. The sphere of application of the multilayer materials was defined.

  4. Characterization of mechanics and cytocompatibility of fibrin-genipin annulus fibrosus sealant with the addition of cell adhesion molecules.

    Science.gov (United States)

    Guterl, Clare C; Torre, Olivia M; Purmessur, Devina; Dave, Khyati; Likhitpanichkul, Morakot; Hecht, Andrew C; Nicoll, Steven B; Iatridis, James C

    2014-09-01

    There is an unmet clinical need for a biomaterial sealant capable of repairing small annulus fibrosus (AF) defects. Causes of these defects include painful intervertebral disc herniations, microdiscectomy procedures, morbidity associated with needle puncture injury from discography, and future nucleus replacement procedures. This study describes the enhancements of a fibrin gel through genipin crosslinking (FibGen) and the addition of the cell adhesion molecules (CAMs), fibronectin and collagen. The gel's performance as a potential AF sealant is assessed using a series of in vitro tests. FibGen gels with CAMs had equivalent adhesive strength, gene expression, cytomorphology, and cell proliferation as fibrin alone. However, FibGen gels had enhanced material behaviors that were tunable to higher shear stiffness values and approximated human annulus tissue as compared with fibrin alone, were more dimensionally stable, and had a slower in vitro degradation rate. Cytomorphology of human AF cells cultured on FibGen gels exhibited increased elongation compared with fibrin alone, and the addition of CAMs to FibGen did not significantly affect elongation. This FibGen gel offers the promise of being used as a sealant material to repair small AF defects or to be used in combination with other biomaterials as an adhesive for larger defects.

  5. Understanding the link between circumferential dikes and eruptive fissures around calderas based on numerical and analog models

    Science.gov (United States)

    Corbi, Fabio; Rivalta, Eleonora; Pinel, Virginie; Maccaferri, Francesco; Acocella, Valerio

    2016-06-01

    Active calderas are seldom associated with circumferential eruptive fissures, but eroded magmatic complexes reveal widespread circumferential dikes. This suggests that, while the conditions to emplace circumferential dikes are easily met, mechanisms must prevent them from reaching the surface. We explain this discrepancy with experiments of air injection into gelatin shaped as a volcano with caldera. Analog dikes show variable deflection, depending on the competition between overpressure, Pe, and topographic unloading, Pl; when Pl/Pe = 4.8-5.3, the dikes propagate orthogonal to the least compressive stress. Due to the unloading, they become circumferential and stall below the caldera rim; buoyancy is fundamental for the further rise and circumferential fissure development. Numerical models quantitatively constrain the stress orientation within the gelatin, explaining the observed circumferential dikes. Our results explain how dikes propagate below the rim of felsic and mafic calderas, but only in the latter they are prone to feed circumferential fissures.

  6. Dental Sealants Prevent Cavities PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2016-10-18

    This 60 second public service announcement is based on the October 2016 CDC Vital Signs report. Dental sealants, applied soon after a child's permanent molars come in, can protect against cavities for up to nine years. Applying sealants in schools for low-income children could save millions in dental treatment costs.  Created: 10/18/2016 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 10/18/2016.

  7. Traditional preventive treatment options

    DEFF Research Database (Denmark)

    Longbottom, C; Ekstrand, K; Zero, D

    2009-01-01

    Preventive treatment options can be divided into primary, secondary and tertiary prevention techniques, which can involve patient- or professionally applied methods. These include: oral hygiene (instruction), pit and fissure sealants ('temporary' or 'permanent'), fluoride applications (patient...

  8. Review and Study of Physics Driven Pitting Corrosion Modeling in 2024-T3 Aluminum Alloys (Postprint)

    Science.gov (United States)

    2015-05-01

    measuring the maximum pit size and its effect on the fatigue life. Microstructure and corrosion currents were neglected. In this paper we present the...Figure 2 Appearance of the pits on the surface of 7075 -T6 (Wang et al., 2003) Proc. of SPIE Vol. 9437 94372E-2 2 Distribution Statement A. Approved... density (Harlow and Wei, 1994). It can be seen that the definition of pitting current Ip is the key element in the pitting corrosion modeling, which

  9. Deep Orbital Dermoid Cyst Bulging into the Superior Orbital Fissure: Clinical Presentation and Management

    Science.gov (United States)

    Kumar, Ravinder; Vyas, Kapil; Jaiswal, Gagan; Bhargava, Abhishek; Kundu, Jyoti

    2017-01-01

    Purpose: To present a case of deep orbital dermoid cyst with emphasis on clinical presentation, imaging spectrum, differential diagnosis and management. Case Report: A 28-year-old female was referred to our hospital with chief complaint of drooping of right eyelid and progressive headache. Ocular motility, visual acuity and fundus examination were normal. computed tomography (CT) and magnetic resonance imaging (MRI) revealed a well-defined, intraosseous deep orbital dermoid cyst (5.9 mm × 12.5 mm) located near the apex of right orbit, extending from greater wing of sphenoid into the superior orbital fissure. Due to occulomotor nerve (superior and inferior divisions) compression which passes through the superior orbital fissure, ipsilateral headache and ptosis occurred. Complete surgical excision of cyst was performed using noninvasive extracranial lateral orbitotomy approach. After removal of the cyst, curette and cutting drill were used to thoroughly remove any residual cystic content. Histopathological analysis confirmed the diagnosis. The healing was uneventful postoperatively. Conclusion: CT and MRI are easy, reliable, safe and effective imaging methods for establishing the diagnosis of orbital dermoid cyst. Size, location and manifestations are the most important determinants of the disease management. Complete surgical excision without rupture of the cyst is the treatment of choice. PMID:28299014

  10. Hypertrophied anal papillae and fibrous anal polyps, should they be removed during anal fissure surgery?

    Institute of Scientific and Technical Information of China (English)

    Pravin J. Gupta

    2004-01-01

    AIM: Hypertrophied anal papillae and fibrous anal polyps are not given due importance in the proctology practice.They are mostly ignored being considered as normal structures. The present study was aimed to demonstrate that hypertrophied anal papillae and fibrous anal polyps could cause symptoms to the patients and that they should be removed in treatment of patients with chronic fissure in anus.METHODS: Two groups of patients were studied. A hundred patients were studied in group A in which the associated fibrous polyp or papillae were removed by radio frequency surgical device after a lateral subcutaneous sphincterotomy for relieving the sphincter spasm. Another group of a hundred patients who also had papillae or fibrous polyps, were treated by lateral sphincterotomy alone. They were followed up for one year.RESULTS: Eighty-nine percent patients from group A expressed their satisfaction with the treatment in comparison to only 64% from group B who underwent sphincterotomy alone with the papillae or anal polyps left untreated. Group A patients showed a marked reduction with regard to pain and irritation during defecation (P= 0.0011),pricking or foreign body sensation in the anus (P = 0.0006)and pruritus or wetness around the anal verge (P = 0.0008).CONCLUSION: Hypertrophied anal papillae and fibrous anal polyps should be removed during treatment of chronic anal fissure. This would add to effectiveness and completeness of the procedure.

  11. Effect of PIT tags on the survival and recruitment of Great Tits Parus major

    NARCIS (Netherlands)

    Nicolaus, Marion; Bouwman, Karen M.; Dingemanse, Niels J.

    2008-01-01

    We describe the use of subcutaneous passive integrated transponder (PIT) tags in nestling and adult Great Tits Parus major. We investigated whether subcutaneous PIT tags affected fledging success, winter condition, survival and/or recruitment. We found no negative effects of PIT tags on any of these

  12. A systematic review and meta-analysis of the treatment of anal fissure.

    Science.gov (United States)

    Nelson, R L; Manuel, D; Gumienny, C; Spencer, B; Patel, K; Schmitt, K; Castillo, D; Bravo, A; Yeboah-Sampong, A

    2017-08-09

    Anal fissure has a very large number of treatment options. The choice is difficult. In an effort to assist in that, choice presented here is a systematic review and meta-analysis of all published treatments for anal fissure that have been studied in randomized controlled trials. Randomized trials were sought in the Cochrane Controlled Trials Register, Medline, EMBASE and the trials registry sites clinicaltrials.gov and who/int/ictrp/search/en. Abstracts were screened, full-text studies chosen, and finally eligible studies selected and abstracted. The review was then divided into those studies that compared two or more surgical procedures and those that had at least one arm that was non-surgical. Studies were further categorized by the specific interventions and comparisons. The outcome assessed was treatment failure. Negative effects of treatment assessed were headache and anal incontinence. Risk of bias was assessed for each study, and the strength of the evidence of each comparison was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. One hundred and forty-eight eligible trials were found and assessed, 31 in the surgical group and 117 in the non-surgical group. There were 14 different operations described in the surgical group and 29 different non-surgical treatments in the non-surgical group along with partial lateral internal sphincterotomy (LIS). There were 61 different comparisons. Of these, 47 were reported in 2 or fewer studies, usually with quite small patient samples. The largest single comparison was glyceryl trinitrate (GTN) versus control with 19 studies. GTN was more effective than control in sustained cure (OR 0.68; 95% CI 0.63-0.77), but the quality of evidence was very poor because of severe heterogeneity, and risk of bias due to inadequate clinical follow-up. The only comparison to have a GRADE quality of evidence of high was a subgroup analysis of LIS versus any medical therapy (OR 0.12; CI 0

  13. Effect of alkyl chain length on the interfacial strength of surgical sealants composed of hydrophobically-modified Alaska-pollock-derived gelatins and poly(ethylene)glycol-based four-armed crosslinker.

    Science.gov (United States)

    Mizuta, Ryo; Ito, Temmei; Taguchi, Tetsushi

    2016-10-01

    Surgical sealants are widely used clinically. Fibrin sealant is a commonly used sealant, but is ineffective under wet conditions during surgery. In this study, we developed surgical sealants composed of hydrophobically modified Alaska-pollock-derived gelatins (hm-ApGltns) with different alkyl chain lengths from C3 to C18 and a poly(ethylene)glycol-based 4-armed crosslinker (4S-PEG). The burst strength of the hm-ApGltns-based sealant was evaluated using a fresh porcine blood vessel and was found to increase with increasing alkyl chain length from 167±22 to 299±43mmHg when the substitution ratio of amino groups of ApGltn was around 10mol%. The maximum burst strength was observed when stearoyl-group modified ApGltn (Ste-ApGltn)/4S-PEG-based sealant was used, displaying 3-fold higher burst strength than the original ApGltn (Org-ApGltn)/4S-PEG sealant, and 10-fold higher than the commercial fibrin sealant. Ste-ApGltn/4S-PEG-based sealant was biodegraded in rat subcutaneous tissue within 8 weeks without severe inflammation. By molecular interaction analysis using surface plasmon resonance, the binding constant of Ste-ApGltn to fibronectin was found to be 9-fold higher than that of Org-ApGltn. Therefore, the developed sealant, in particular the Ste-ApGltn/4S-PEG-based sealant, has potential applications in the field of cardiovascular surgery as well as thoracic surgery. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Fire-retardant and fire-barrier poly(vinyl acetate composites for sealant application

    Directory of Open Access Journals (Sweden)

    2010-02-01

    Full Text Available Fire-retardant ceramifying poly(vinyl acetate (PVAc sealants have been prepared. The degradation of PVA was integrated with the action of the fire retardants to reduce flammable gases, produce carbonaceous char and convert the fillers into a self-supporting ceramic barrier. PVA is readily degraded by elimination of acetic acid, yielding a char that provides a transitory phase as the filler particles fuse into a ceramic mass. Acetic acid is eliminated at similar temperature to the release of water from magnesium hydroxide fire-retardant, thereby diluting flammable acetic acid. The residual oxide from the fire-retardant filler and structural filler are fused by a flux, zinc borate. The degradative and ceramifying processes were characterised using thermogravimetry, infrared spectroscopy, scanning electron microscopy and ceramic strength. Thermogravimetry of the composites was compared with additive mass loss curves calculated from the components. Deviations between the experimental and additive curves revealed interactions between the components in the composites. The modulus of the PVAc composites and the strength of their ceramic residues after combustion were determined.

  15. Women miners in developing countries: pit women and others

    Energy Technology Data Exchange (ETDEWEB)

    Kuntala Lahiri-Dutt; Martha Macintyre [Australian National University (Australia). Research School of Pacific and Asian Studies

    2006-05-15

    Contrary to their masculine portrayal, mines have always employed women in valuable and productive roles. Yet, pit life continues to be represented as a masculine world of work, legitimizing men as the only mineworkers and large, mechanized, and capitalized operations as the only form of mining. Bringing together a range of case studies of women miners from past and present in Asia, the Pacific Region, Latin America and Africa, this book makes visible the roles and contributions of women as miners. It also highlights the importance of engendering small and informal mining in the developing world as compared to the early European and American mines. The book shows that women are engaged in various kinds of mining and illustrates how gender and inequality are constructed and sustained in the mines, and also how ethnic identities intersect with those gendered identities. Chapters dealing with coal mining include: Introduction: Where life is in the pits (and elsewhere) and gendered; Japanese coal mining: women discovered; Mining gender at work in the Indian collieries: identity construction; Women in the mining industry of contemporary China; Roti do, ya goli do! (give us bread, or give us bullets!): stories of struggles of women workers in Bhowra colliery, India and Globalization and women's work in the mine pits in East Kalimantan, Indonesia. 17 ills.

  16. Evaluation of asbestos exposure within the automotive repair industry: a study involving removal of asbestos-containing body sealants and drive clutch replacement.

    Science.gov (United States)

    Blake, Charles L; Dotson, G Scott; Harbison, Raymond D

    2008-12-01

    Two independent assessments were performed of airborne asbestos concentrations generated during automotive repair work on vintage vehicles . The first involved removal of asbestos-containing seam sealant, and the second involved servicing of a drive clutch. Despite the relatively high concentrations (5.6-28%) of chrysotile fibers detected within bulk samples of seam sealant, the average asbestos concentration for personal breathing zone (PBZ) samples during seam sealant removal was 0.006 f/cc (fibers/cubic centimeter of air). Many other air samples contained asbestos at or below the analytical limit of detection (LOD). Pneumatic chiseling of the sealant material during removal resulted in 69% of area air samples containing asbestos. Use of this impact tool liberated more asbestos than hand scraping. Asbestos fibers were only detected in air samples collected during the installation of a replacement clutch. The highest asbestos corrected airborne fiber concentration observed during clutch installation was 0.0028 f/cc. This value is approximately 100 times lower than Occupational Safety and Health Administration's (OSHA) permissible exposure limit (PEL) of 0.1f/cc. The airborne asbestos concentrations observed during the servicing of vintage vehicles with asbestos-containing seam sealant and clutches are comparable to levels reported for repair work involving brake components and gaskets.

  17. Distribution and abundance of pit vipers (Reptilia: Viperidae along the Western Ghats of Goa, India

    Directory of Open Access Journals (Sweden)

    N.S. Sawant

    2010-09-01

    Full Text Available The distribution and abundance of pit vipers in the Western Ghats namely Trimeresurus gramineus (Bamboo Pit Viper, T. malabaricus (Malabar Pit Viper and Hypnale hypnale (Hump-nosed Pit Viper was investigated in five wildlife sanctuaries of Goa from 2005 to 2009. Seasonal day-night data was collected based on band transect methods. All the pit viper species showed specific habitat preferences and their abundance changed with season. They were most abundant during monsoon. H. hypnale extended its range to the adjoining cashew plantations during the post monsoon and winter.

  18. Aulogous fibrin sealant (Vivostat ® in the neurosurgical practice: Part II: Vertebro-spinal procedures

    Directory of Open Access Journals (Sweden)

    Francesca Graziano

    2016-01-01

    Conclusions: In this preliminary study, the application of autologous fibrin sealant with Vivostat ® resulted in rapid hemostasis and/or acted as an effective dural sealant. Although this product appears to be safe and effective, further investigations are warranted.

  19. The effect of internal teat sealant products (Teatseal and Orbeseal) on intramammary infection, clinical mastitis, and somatic cell counts in lactating dairy cows: a meta-analysis.

    Science.gov (United States)

    Rabiee, A R; Lean, I J

    2013-01-01

    The objective of this study was to assess the efficacy of internal teat sealant products containing bismuth subnitrate (Teatseal and Orbeseal; Pfizer Animal Health, West Ryde, Australia) when used alone, or in the presence of antibiotic dry cow therapy (ADCT), before or at drying off on the incidence of new intramammary infections (IMI), clinical mastitis, and milk somatic cell count (SCC) during lactation. The literature search identified 18 English-language publications on the use of Teatseal in dairy cattle. A total of 12 studies with 17 subtrials or comparisons including 13 positive control subtrials (internal teat sealant and ADCT vs. ADCT) and 4 negative control subtrials (internal teat sealant vs. untreated) examining IMI were included in the analysis. Internal teat sealants, alone or in the presence of ADCT, reduced the risk of acquiring new IMI after calving by 25% [risk ratio (RR)=0.75; 95% confidence interval (CI): 0.67 to 0.83]. Internal teat sealants reduced the risk of IMI by 73% compared with untreated cows (RR=0.27; 95% CI: 0.13 to 0.55). The results of both meta-analyses of IMI, with positive and negative controls, were heterogeneous [I(2) (a statistic that describes the proportion of total variation in study effect estimates that is due to heterogeneity)=65.4 and 92.1%]. No farm or cow factors studied significantly contributed to the heterogeneity of the results. A total of 16 studies (21 subtrials), including 14 positive control subtrials and 7 negative control subtrials, examining clinical mastitis were included in the analysis. Internal teat sealants alone and in the presence of ADCT reduced the risk of clinical mastitis after calving in lactating cows by 29% (RR=0.71; 95% CI: 0.62 to 0.82), and 48% (RR=0.52; 95% CI: 0.37 to 0.75), respectively. The results of the meta-analysis on clinical mastitis with positive controls were homogeneous (I(2)=33.6%), whereas the results of studies with negative controls were heterogeneous (I(2)=60.4%). No farm

  20. Fine mapping and introgressing qFIS1-2, a major QTL for kernel fissure resistance in rice (Oryza sativa L.)

    Science.gov (United States)

    Rice (Oryza sativa L.) kernel fissuring increases breakage during milling and decreases the value of processed rice. This study employed molecular gene tagging methods to fine-map a fissure resistance (FR) locus in ‘Cybonnet’, a semidwarf tropical japonica cultivar, as well as transfer this trait to...

  1. Aspirated pits in wetwood and micromorphology of microbial degradation in subalpine fir

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yaoli; CAI Liping; XU Yongji

    2006-01-01

    Differentiating from normal wood,pit membranes in wetwood of subalpine fir contain bacteria of water drop shape or orbicular shape,and flaky shape,as observed using Scanning Electronic Microscope.Not only are ray parenchyma cells in wetwood partially degraded but also margo strands in pit membranes are somewhat degraded by bacterial activities.Most of the bordered-pit membranes in normal wood are unaspirated in green conditions and the proportions of aspirated pits in earlywood and latewood account for only 6.8% and 13.4%,respectively.Nevertheless,most of the bordered-pit membranes in wetwood are aspirated in green conditions and the proportions of aspirated pits account for 77.7% and 72.1%,respectively.The problem of hard-to-dry for subalpine fir could be reasoned from the considerable amount of aspirated pit membranes in wetwood.

  2. Effect of Feeding Date Pits on Milk Production, Composition and Blood Parameters of Lactating Ardi Goats.

    Science.gov (United States)

    Al-Suwaiegh, S B

    2016-04-01

    Twenty Ardi lactating goats were used to investigate the effect of substituting 10%, 15%, and 20% of concentrate feed with date pits on milk production, composition, and blood parameters. Four isocaloric and isonitrogenous dietary treatments were used. Four levels (0% [control], 10%, 15%, and 20%) of date pits were used to replace concentrate feed. The forages to concentrate ratio used was 60 to 40. Dry matter intake (DMI) of goats fed diets containing 10% and 15% date pits was significantly (pdate pits were significantly (pdate pits. Goats fed a diet containing 20% date pits was significantly (pdate pits exhibited no significant differences in the total protein percent compared to those fed a diet containing 20% date pits. Triglyceride was significantly higher for goats fed diets containing 10% and 20% date pits compared to those fed 15% date pits. Results obtained in the present study suggest that date pits can be added up to 20% of the concentrate feeds into lactating Ardi goat diets without negative effects on their productive performance.

  3. Markov chain model helps predict pitting corrosion depth and rate in underground pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Caleyo, F.; Velazquez, J.C.; Hallen, J. M. [ESIQIE, Instituto Politecnico Nacional, Mexico D. F. (Mexico); Esquivel-Amezcua, A. [PEMEX PEP Region Sur, Villahermosa, Tabasco (Mexico); Valor, A. [Universidad de la Habana, Vedado, La Habana (Cuba)

    2010-07-01

    Recent reports place pipeline corrosion costs in North America at seven billion dollars per year. Pitting corrosion causes the higher percentage of failures among other corrosion mechanisms. This has motivated multiple modelling studies to be focused on corrosion pitting of underground pipelines. In this study, a continuous-time, non-homogenous pure birth Markov chain serves to model external pitting corrosion in buried pipelines. The analytical solution of Kolmogorov's forward equations for this type of Markov process gives the transition probability function in a discrete space of pit depths. The transition probability function can be completely identified by making a correlation between the stochastic pit depth mean and the deterministic mean obtained experimentally. The model proposed in this study can be applied to pitting corrosion data from repeated in-line pipeline inspections. Case studies presented in this work show how pipeline inspection and maintenance planning can be improved by using the proposed Markovian model for pitting corrosion.

  4. Evaluation of palpebral fissure and orbital volume after bimatoprost 0.03% orbital injections. Experimental study in rats

    Directory of Open Access Journals (Sweden)

    Nilson Lopes da Fonseca Junior

    2014-12-01

    Full Text Available Objective: To evaluate in experimental animals the changes of the palpebral fissure and the orbital volume after orbital injection of bimatoprost 0.03%. Methods: Two main groups of Wistar rats were analyzed, one after orbital injection of bimatoprost 0.03% and another, a control group, after orbital injection of saline solution. The calculation of the palpebral fissure was done on images by means of computer processing, using the program Image J. After taking photographs, the animals were submitted to bilateral orbital exenteration and the volume was calculated in all the animals by the water displacement method (Archimedes’ Principle. Results: While comparing the measurements of the palpebral fissure and the orbital volume among animals given an injection with bimatoprost 0.03% and the control group it was found that there were no statistically significant differences. Conclusions: In this study there were no statistically significant differences in the measurement of the vertical palpebral fissure and the orbital volume among animals given the orbital injection of bimatoprost 0.03% and the animals of the control group.

  5. Anal Fissure

    Science.gov (United States)

    ... Assessment and Safety Committee Initiatives Past Presidents Healthcare Economics Committee 2017 Tripartite Meeting Search form Search Login Join Now Find a Surgeon You are here Patients / Educational ...

  6. Anal Fissures

    Science.gov (United States)

    ... nav nav, .header-9#header-section #main-nav, #overlay-menu nav, #mobile-menu, #one-page-nav li . ... zinc oxide, 1% hydrocortisone cream and products like Preparation H can help soothe the area. Instead of ...

  7. Pit Water Storage Ottrupgaard

    DEFF Research Database (Denmark)

    Heller, Alfred

    2000-01-01

    The pit water storage, a seasonal thermal storage, was built in 1993 with floating lid and hybrid clay-polymer for pit lining. The storage was leaking severe and solutions were to be found. In the paper solutions for pit lining and floating lids are discussed, cost estimations given and coming...

  8. Pit Water Storage Ottrupgaard

    DEFF Research Database (Denmark)

    Heller, Alfred

    2000-01-01

    The pit water storage, a seasonal thermal storage, was built in 1993 with floating lid and hybrid clay-polymer for pit lining. The storage was leaking severe and solutions were to be found. In the paper solutions for pit lining and floating lids are discussed, cost estimations given and coming...

  9. Application of fibrin sealant at the urethrovesical anastomosis in robotic assisted radical prostatectomy: does it enable earlier Foley catheter and Jackson-Pratt drain removal?

    Science.gov (United States)

    Flury, Sarah C; Starnes, Danielle N; Steers, William D

    2008-01-01

    Leakage at the urethrovesical anastomosis in the post-operative period can result in morbidity including ileus. We examined the effectiveness of using a fibrin sealant at the anastomosis to limit urine leakage thereby facilitating earlier Jackson-Pratt drain and Foley catheter removal following robotic assisted laparoscopic prostatectomy (RALRP). Forty consecutive patients underwent RALRP by one surgeon at our institution. The first 20 patients underwent standard operation and served as the control group. The subsequent 20 patients underwent the same operation with addition of fibrin sealant following a running absorbable sutured urethrovesical anastomosis. The two groups were compared for age (60.5 vs. 58.2 years), pre-operative PSA (5.23 vs. 4.71), Gleason score (6.3 vs. 6.5), stage at resection, and prostate size at resection (51.7 vs. 47.7 g). Wilcoxon rank sum test determined no statistically significant differences in the groups. Patients in the fibrin sealant group had 1.3 versus 2.1 days with a Jackson-Pratt drain, 9.75 versus 12.1 days with a catheter, and an average of 38.6 versus 63.2 cc of drainage per shift. Catheters were removed when a cystogram demonstrated no extravasation of contrast. Two patients in the control group and no patients in the fibrin sealant group had large-volume leakage and ileus post-operatively. In patients undergoing RALRP, application of fibrin sealant at the urethrovesical anastomosis appears to facilitate sealing, thereby allowing earlier removal of the JP drain, by 0.8 days, and the Foley catheter, by 2.35 days, than in controls. No patients in the fibrin sealant group suffered post-operative ileus. This adjunct may be especially useful early in the learning process to reduce morbidity.

  10. Marginal leakage of two newer glass-ionomer-based sealant materials assessed using micro-CT.

    NARCIS (Netherlands)

    Chen, X.; Cuijpers, V.M.J.I.; Fan, M.; Frencken, J.E.F.M.

    2010-01-01

    OBJECTIVES: To test newer glass-ionomer-based materials as sealant materials. One glass-ionomer sealant was light-cured to obtain an early setting reaction. The null-hypothesis tested was: there is no difference in marginal leakage of sealants produced with high-viscosity glass-ionomer, with and wit

  11. ACCESSORY FISSURE OF RIGHT LUNG: A REPORT OF TWO CASES

    Directory of Open Access Journals (Sweden)

    Sarita Behera

    2014-06-01

    Full Text Available Right lung is divided into upper (superior, middle and lower (Inferior lobes by an oblique and a horizontal fissure.Oblique fissure passes spirally from posterior border to inferior border deep into the lung separating the lower lobe from upper and middle lobes. A short horizontal fissure passes horizontally forwards from the oblique fissure at midaxillary line to meet the anterior border at 4th costochondral junction. This separates the upper lobe from the middle lobe. During routine dissection in 2010-11 undergraduate batch, we came across two cases of right lungs where an accessory fissure was extending horizontally backwards from the oblique fissure at mid axillary line towards the vertebral part of medial surface. In the 1st case, this accessory fissure was not meeting the normal horizontal fissure where as in the 2nd case it was meeting. This accessory fissure separates the lower lobe into a superior and an inferior segment. Knowledge of different types of accessory fissures is important because it may mislead the radiological findings, may act as a barrier to spread of infection creating a sharply marginated pneumonia which can wrongly be interpretated as atelectasis or consolidation. Identification of completeness of fissure is important prior to lobectomy, because individuals with incomplete fissures are more prone to develop postoperative air leak. Considering the clinical importance of such anomalies, anatomical knowledge and prior awareness of accessory fissures in the lungs may be important for clinicians and radiologists.

  12. Fibrin sealant use in pilonidal sinus: Systematic review

    Institute of Scientific and Technical Information of China (English)

    Cuneyt Kayaalp; Ismail Ertugrul; Kerem Tolan; Fatih Sumer

    2016-01-01

    AIM: To review the current data about the success rates of fibrin sealant use in pilonidal disease.METHODS: Fibrin sealant can be used for different purposes in pilonidal sinus treatment, such as filling in the sinus tracts, covering the open wound after excision and lay-open treatment, or obliterating the subcutaneous dead space before skin closure. We searched Pubmed, Google-Scholar, Ebsco-Host, clinicaltrials, and Cochrane databases and found nine studies eligible for analysis; these studies included a total of 217 patients(84% male, mean age 24.2 ± 7.8). RESULTS: In cases where fibrin sealant was used to obliterate the subcutaneous dead space, there was no reduction in wound complication rates(9.8% vs 14.6%, P = 0.48). In cases where sealant was used to cover the laid-open area, the wound healing time and patient comfort were reported better than in previous studies(mean 17 d, 88% satisfaction). When fibrin sealant was used to fill the sinus tracts, the recurrence rate was around 20%, despite the highly selected grouping of patients.CONCLUSION: Consequently, using fibrin sealant to decrease the risk of seroma formation was determined to be an ineffective course of action. It was not advisable to fill the sinus tracts with fibrin sealant because it was not superior to other cost-effective and minimally invasive treatments. New comparative studies can be conducted to confirm the results of sealant use in covering the laid-open area.

  13. Fibrin sealant use in pilonidal sinus: Systematic review.

    Science.gov (United States)

    Kayaalp, Cuneyt; Ertugrul, Ismail; Tolan, Kerem; Sumer, Fatih

    2016-03-27

    To review the current data about the success rates of fibrin sealant use in pilonidal disease. Fibrin sealant can be used for different purposes in pilonidal sinus treatment, such as filling in the sinus tracts, covering the open wound after excision and lay-open treatment, or obliterating the subcutaneous dead space before skin closure. We searched Pubmed, Google-Scholar, Ebsco-Host, clinicaltrials, and Cochrane databases and found nine studies eligible for analysis; these studies included a total of 217 patients (84% male, mean age 24.2 ± 7.8). In cases where fibrin sealant was used to obliterate the subcutaneous dead space, there was no reduction in wound complication rates (9.8% vs 14.6%, P = 0.48). In cases where sealant was used to cover the laid-open area, the wound healing time and patient comfort were reported better than in previous studies (mean 17 d, 88% satisfaction). When fibrin sealant was used to fill the sinus tracts, the recurrence rate was around 20%, despite the highly selected grouping of patients. Consequently, using fibrin sealant to decrease the risk of seroma formation was determined to be an ineffective course of action. It was not advisable to fill the sinus tracts with fibrin sealant because it was not superior to other cost-effective and minimally invasive treatments. New comparative studies can be conducted to confirm the results of sealant use in covering the laid-open area.

  14. Sealant versus Fluoride in Primary Molars of Kindergarten Children Regularly Receiving Fluoride Varnish: One-Year Randomized Clinical Trial Follow-Up.

    Science.gov (United States)

    Honkala, Sisko; ElSalhy, Mohamed; Shyama, Maddi; Al-Mutawa, Sabiha A; Boodai, Hanan; Honkala, Eino

    2015-01-01

    The objectives of this study were to measure the caries preventive effect of sealants applied to occlusal surfaces of primary molars compared to fluoride varnish applications, and to assess the retention rate of sealants after 1 year. 147 first-grade pupils from two kindergarten schools in Kuwait, whose parents gave their written consent, were included. The children were examined by one dentist using the International Caries Detection and Assessment System. After the examination, sealants and fluoride varnish were applied on the selected occlusal surfaces of primary molars by another dentist. The jaw quadrant for intervention was selected randomly; molars on the contralateral side of the mouth received the contralateral intervention. Examinations and intervention were provided on the school premises in the mobile dental unit with a portable spotlight. Moisture was controlled by cotton rolls, suction and air drying. The follow-up examinations were conducted after 1 year. All children received fluoride varnish before and 6 months after the intervention. From 267 matched pairs of occlusal surfaces of primary molars, varnished surfaces were significantly more likely to develop new caries lesions than the sealed ones (odds ratio = 2.92; 95% confidence interval = 1.82-4.71) during the 1-year follow-up. The majority (73.0%) of the sealants were completely retained and 15.1% partially. Sealing fissures seems to be better in preventing occlusal caries lesions in primary molars than applying only fluoride varnish. After 1 year, the majority of sealants were retained sound. © 2015 S. Karger AG, Basel.

  15. Subsurface Gas Flow and Ice Grain Acceleration within Enceladus and Europa Fissures: 2D DSMC Models

    Science.gov (United States)

    Tucker, O. J.; Combi, M. R.; Tenishev, V.

    2014-12-01

    The ejection of material from geysers is a ubiquitous occurrence on outer solar system bodies. Water vapor plumes have been observed emanating from the southern hemispheres of Enceladus and Europa (Hansen et al. 2011, Roth et al. 2014), and N2plumes carrying ice and ark particles on Triton (Soderblom et al. 2009). The gas and ice grain distributions in the Enceladus plume depend on the subsurface gas properties and the geometry of the fissures e.g., (Schmidt et al. 2008, Ingersoll et al. 2010). Of course the fissures can have complex geometries due to tidal stresses, melting, freezing etc., but directly sampled and inferred gas and grain properties for the plume (source rate, bulk velocity, terminal grain velocity) can be used to provide a basis to constrain characteristic dimensions of vent width and depth. We used a 2-dimensional Direct Simulation Monte Carlo (DSMC) technique to model venting from both axi-symmetric canyons with widths ~2 km and narrow jets with widths ~15-40 m. For all of our vent geometries, considered the water vapor source rates (1027­ - 1028 s-1) and bulk gas velocities (~330 - 670 m/s) obtained at the surface were consistent with inferred values obtained by fits of the data for the plume densities (1026 - 1028 s-1, 250 - 1000 m/s) respectively. However, when using the resulting DSMC gas distribution for the canyon geometries to integrate the trajectories of ice grains we found it insufficient to accelerate submicron ice grains to Enceladus' escape speed. On the other hand, the gas distributions in the jet like vents accelerated grains > 10 μm significantly above Enceladus' escape speed. It has been suggested that micron-sized grains are ejected from the vents with speeds comparable to the Enceladus escape speed. Here we report on these results including comparisons to results obtained from 1D models as well as discuss the implications of our plume model results. We also show preliminary results for similar considerations applied to Europa

  16. Comparing Central Peak and Central Pit Craters on Mercury and Mars: Implications for Crustal Strength

    Science.gov (United States)

    Barlow, Nadine G.; Horstman, Ryan M.

    2016-10-01

    We have measured and classified 20,782 impact craters on Mercury and 24,495 craters on Mars 5 km in diameter and larger for a comparison study of these features. We identified 1144 floor pit and 638 summit pit craters on Mars and 32 summit pit craters but no floor pits on Mercury. We also identified 1682 central peak craters on Mars and 1764 on Mercury. We computed the ratio of the pit or basal peak diameter to the crater diameter in each case and compared the results for the two bodies. Summit pits on Mars have a median pit-to-crater diameter (Dp/Dc) ratio of 0.12 compared to 0.09 on Mercury, indicating pits are slightly larger relative to their parent crater on Mars. We find no correlation of the distribution of Mercury's central pits with features attributed to volatiles, i.e. radar-bright polar craters and craters containing hollows. This indicates that Mercury's central pits form by collapse of a weak brecciated core in the central peak and do not require the presence of volatiles, as is commonly assumed for central pit formation. The median peak-to-crater diameter (Dpk/Dc) ratio for the peaks on which summit pits are found on both bodies is statistically identical to that of the respective normal unpitted central peaks. This indicates that the peaks on which summit pits occur form in the same manner as normal central peaks but subsequently undergo core collapse to create the summit pit. Interestingly, the median Dpk/Dc for Martian peaks is twice as high as for their Mercurian counterparts (0.30 versus 0.15, respectively). Because Mercury and Mars have essentially the same surface gravity, the only major difference between the two bodies that could explain this observation is target characteristics. Prior studies of the composition of the crust and the detection of larger-than-normal secondary craters have led to the proposal that Mercury's crust is stronger than the crusts of the other terrestrial planets. Mercury's low number of central pit craters, the

  17. Pluto: Pits and mantles on uplands north and east of Sputnik Planitia

    Science.gov (United States)

    Howard, Alan D.; Moore, Jeffrey M.; White, Oliver L.; Umurhan, Orkan M.; Schenk, Paul M.; Grundy, William M.; Schmitt, Bernard; Philippe, Sylvain; McKinnon, William B.; Spencer, John R.; Beyer, Ross A.; Stern, S. Alan; Ennico, Kimberly; Olkin, Cathy B.; Weaver, Harold A.; Young, Leslie A.

    2017-09-01

    The highlands region north and east of Sputnik Planitia can be subdivided into seven terrain types based on their physiographic expression. The northern rough uplands are characterized by jagged uplands and broad troughs, and it may contain a deeply-eroded ancient mantle. Dissected terrain has been interpreted to have been eroded by paleo-glaciation. The smooth uplands and pits terrain contains broad, rolling uplands surrounding complexes of pits, some of which contain smooth floors. The uplands are mantled by smooth-surfaced deposits possibly derived from adjacent pits through low-power explosive cryovolcanism or through slow vapor condensation. The eroded smooth uplands appear to have originally been smooth uplands and pits terrain modified by small-scale sublimation pitting. The bright pitted uplands features intricate texturing by reticulate ridges that may have originated by sublimation erosion, volatile condensation, or both. The bladed terrain is characterized by parallel ridges oriented north-south and is discussed in a separate paper. The dark uplands are mantled with reddish deposits that may be atmospherically deposited tholins. Their presence has affected long-term landform evolution. Widespread pit complexes occur on most of the terrain units. Most appear to be associated with tectonic lineations. Some pits are floored by broad expanses of ices, whereas most feature deep, conical depressions. A few pit complexes are enclosed by elevated rims of uncertain origin.

  18. [Optic nerve pits: clinical and therapeutic review of 21 cases].

    Science.gov (United States)

    Montenegro, M; Bonnet, M

    1989-01-01

    A retrospective study of optic nerve pits in patients referred to our clinic during the last 15 years was conducted. The study included 21 eyes in 19 patients. The optic pit was associated with a serous macular detachment (SMD) in 19 eyes (90%). Various treatments of the SMD were used depending on the time period. Systemic corticosteroids were used in five patients. The SMD did not respond to this treatment. Argon laser photocoagulation was applied to the temporal side of the optic disc in five patients. Intravitreal injection of pure gas was used as an adjunct to photocoagulation treatment in eleven eyes. Pure SF 6 was used in 8 eyes, and C 3 F 8 in 3 eyes. The follow-up after treatment was over 6 months in 10 patients who underwent photocoagulation or the combination of photocoagulation and gas injection. The SMD remained unchanged in two eyes which underwent photocoagulation treatment without gas injection. In the group of patients treated by photocoagulation in association with SF 6 injection, the SMD totally reattached in one eye, decreased in 2 eyes and remained unchanged in 2 eyes. Total resorption of subretinal fluid and permanent retinal reattachment occurred in the 3 eyes treated by intravitreal injection of pure C 3 F 8 as an adjunct to photocoagulation treatment. Further clinical investigations on large series of patients are required to determine whether prolonged retinal tamponade by C 3 F 8 gas in association with photocoagulation treatment is a valuable method in the management of SMD complicating optic nerve pits.

  19. Mechanical Behavior of Brittle Rock-Like Specimens with Pre-existing Fissures Under Uniaxial Loading: Experimental Studies and Particle Mechanics Approach

    Science.gov (United States)

    Cao, Ri-hong; Cao, Ping; Lin, Hang; Pu, Cheng-zhi; Ou, Ke

    2016-03-01

    Joints and fissures with similar orientation or characteristics are common in natural rocks; the inclination and density of the fissures affect the mechanical properties and failure mechanism of the rock mass. However, the strength, crack coalescence pattern, and failure mode of rock specimens containing multi-fissures have not been studied comprehensively. In this paper, combining similar material testing and discrete element numerical method (PFC2D), the peak strength and failure characteristics of rock-like materials with multi-fissures are explored. Rock-like specimens were made of cement and sand and pre-existing fissures created by inserting steel shims into cement mortar paste and removing them during curing. The peak strength of multi-fissure specimens depends on the fissure angle α (which is measured counterclockwise from horizontal) and fissure number ( N f). Under uniaxial compressional loading, the peak strength increased with increasing α. The material strength was lowest for α = 25°, and highest for α = 90°. The influence of N f on the peak strength depended on α. For α = 25° and 45°, N f had a strong effect on the peak strength, while for higher α values, especially for the 90° sample, there were no obvious changes in peak strength with different N f. Under uniaxial compression, the coalescence modes between the fissures can be classified into three categories: S-mode, T-mode, and M-mode. Moreover, the failure mode can be classified into four categories: mixed failure, shear failure, stepped path failure, and intact failure. The failure mode of the specimen depends on α and N f. The peak strength and failure modes in the numerically simulated and experimental results are in good agreement.

  20. Autologous platelet gel and fibrin sealant enhance the efficacy of total knee arthroplasty: improved range of motion, decreased length of stay and a reduced incidence of arthrofibrosis.

    Science.gov (United States)

    Everts, Peter A M; Devilee, Roger J J; Oosterbos, Cornelis J M; Mahoney, Christine Brown; Schattenkerk, Maarten Eeftinck; Knape, Johannes T A; van Zundert, André

    2007-07-01

    In this study we describe the potential role of autologous platelet gel and fibrin sealant in unilateral total knee arthroplasty to improve the postoperative range of motion and to reduce the incidence of arthrofibrosis. Total knee arthroplasty is often associated with a considerable amount of post-operative blood loss. Persistent limited motion directly after surgery may ultimately result in arthrofibrosis. To counteract these effects we investigated whether the use of autologous derived platelet gel and fibrin sealant would reduce postoperative blood loss, decrease the impaired range of motion and the incidence of arthrofibrosis. All patients were consecutively operated and assigned to the study or control groups. Study group patients (n = 85) were treated with the application of autologous platelet gel and fibrin sealant at the end of surgery. Eighty patients were operated without the use of platelet gel and fibrin sealant, and served as the control group. The postoperative hemoglobin decrease, range of motion and length of hospitalization were recorded. During a 5-month postoperative period patients were followed to observe the incidence of arthrofibrosis. In patients in the treatment group the hemoglobin concentration in blood decreased significantly less when compared to the control group. They also showed a superior postoperative range of motion when compared to those of the control group (P arthrofibrosis and subsequent forced manipulation was significantly less (P arthrofibrosis.

  1. Autologous platelet gel and fibrin sealant enhance the efficacy of total knee arthroplasty : improved range of motion, decreased length of stay and a reduced incidence of arthrofibrosis

    NARCIS (Netherlands)

    Everts, Peter A. M.; Devilee, Roger J. J.; Oosterbos, Cornelis J. M.; Mahoney, Christine Brown; Schattenkerk, Maarten Eeftinck; Knape, Johannes T. A.; van Zundert, Andre

    2007-01-01

    In this study we describe the potential role of autologous platelet gel and fibrin sealant in unilateral total knee arthroplasty to improve the postoperative range of motion and to reduce the incidence of arthrofibrosis. Total knee arthroplasty is often associated with a considerable amount of post-

  2. Autologous platelet gel and fibrin sealant enhance the efficacy of total knee arthroplasty : improved range of motion, decreased length of stay and a reduced incidence of arthrofibrosis

    NARCIS (Netherlands)

    Everts, Peter A. M.; Devilee, Roger J. J.; Oosterbos, Cornelis J. M.; Mahoney, Christine Brown; Schattenkerk, Maarten Eeftinck; Knape, Johannes T. A.; van Zundert, Andre

    2007-01-01

    In this study we describe the potential role of autologous platelet gel and fibrin sealant in unilateral total knee arthroplasty to improve the postoperative range of motion and to reduce the incidence of arthrofibrosis. Total knee arthroplasty is often associated with a considerable amount of post-

  3. Effect of Temperature and Cl-Concentration on Pitting of 2205 Duplex Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    DONG Chaofang; LUO Hong; XIAO Kui; SUN Ting; LIU Qian; LI Xiaogang

    2011-01-01

    The electrochemical behaviors of 2205 duplex stainless steel in NaCl solution with different temperatures and concentrations were studied by gravimetric tests,potentiodynamic polarization,electrochemical impedance spectroscopy and scanning electron microscopy.The experimental results show that temperature and chloride concentration have a great influence on the pitting resistance of 2205 duplex stainless steels.They not only effect the corrosion rate of pitting,but also change the shape of the pits.When NaCl solution was in low concentration and temperature below the critical pitting temperature,pits were very small and scattered with hemisphere-like shape.On the contrary,the pits of 2205 duplex stainless steel were large and sometimes had a lacy cover when the NaCl concentration was higher and the temperature was 70℃.

  4. Promoting oral health: interventions for preventing dental caries, oral and pharyngeal cancers, and sports-related craniofacial injuries. A report on recommendations of the task force on community preventive services.

    Science.gov (United States)

    2001-11-30

    The Task Force on Community Preventive Services (the Task Force) has conducted systematic reviews of the evidence of effectiveness of selected population-based interventions to prevent and control dental caries (tooth decay), oral (mouth) and pharyngeal (throat) cancers, and sports-related craniofacial injuries. The Task Force strongly recommends community water fluoridation and school-based or school-linked pit and fissure sealant delivery programs for prevention and control of dental caries. Using the rules of evidence it has established, the Task Force found insufficient evidence of effectiveness or ineffectiveness of the remaining interventions reviewed. Therefore, the Task Force makes no recommendation for or against use of statewide or communitywide sealant promotion programs, population-based interventions for early detection of precancers and cancers, or population-based interventions to encourage use of helmets, facemasks, and mouthguards to reduce oral-facial trauma in contact sports. The Task Force's finding of insufficient evidence indicates the need for more research on intervention effectiveness. Until the results of such research become available, readers are encouraged to judge the usefulness of these interventions by other criteria. This report presents additional information regarding the recommendations, briefly describes how the reviews were conducted, and provides information designed to help apply the strongly recommended interventions locally.

  5. Application of Glass Sealant for SOFC

    Institute of Scientific and Technical Information of China (English)

    Piao Jinhua; Sun Kening; Zhang Naiqing; Zhou Derui

    2004-01-01

    Glass and glass-ceramic materials were investigated as SOFC seals at 800 ~ 850 ℃. The material was based on the glass and glass-ceramic in the BaO-CaO-Al2O3-SiO2-La2O3-B2O3 system. The sealant has a minimum thermal expansion mismatch with yttria-stabilized zirconia (YSZ)electrolyte and Ni/gYSZ for the anode. The sealant has a superior stability during the process of operation in SOFC and can withstand thermal shock during the process of thermal cycling. The results show that the BaO-CaO-Al2O3-SiO2-La2O3-B2O3 system sealant can be used as sealing materials for SOFC.

  6. Influence of surface sealant on the translucency of composite resin: effect of immersion time and immersion media

    Directory of Open Access Journals (Sweden)

    Patrícia Petromilli Nordi Sasso Garcia

    2008-06-01

    Full Text Available This study evaluated the effect of surface sealant on the translucency of composite resin immersed in different solutions. The study involved the following materials: Charisma, Fortify and coffee, Coca-Cola®, tea and artificial saliva as solutions. Sixty-four specimens (n = 8 were manufactured and immersed in artificial saliva at 37 ± 1 °C. Samples were immersed in the solutions for three times a day and re-immersed in artificial saliva until the translucency readings. The measurements were carried out at nine times: T1 - 24 hours after specimen preparation, T2 - 24 hours after immersion in the solutions, T3 - 48 hours and T4 to T9 - 7, 14, 21, 30, 60 and 90 days, respectively, after immersion. The translucency values were measured using a JOUAN device. The results were subjected to ANOVA and Tukey's test at 5%. The surface sealant was not able to protect the composite resin against staining, the coffee showed the strongest staining action, followed by tea and regarding immersion time, a significant alteration was noted in the translucency of composite resin after 21 days.

  7. Assessment of Concrete Repair Techniques for Radiologically Contaminated Tank Farm Pump and Valve Pits

    Energy Technology Data Exchange (ETDEWEB)

    MINTEER, D.J.

    2000-09-19

    As part of the scope of Project W-314, ''Tank Farm Restoration and Safe Operations,'' the condition of pump and valve pit walls and floors is being assessed, and repairs made as needed, to support upgrading the infrastructure necessary to safely transfer tank waste for treatment. Flaws in the surfaces of the pits (e.g., concrete crack/faults, protective coating deterioration) must be repaired to ensure containment integrity and to facilitate future decontamination of the pits. This engineering study presents a cost/risk/benefit evaluation of concrete and protective coating repair methods in pump and valve pits using various manual and remote tool systems.

  8. Recent ground fissures in the Hetao basin, Inner Mongolia, China

    Science.gov (United States)

    He, Zhongtai; Ma, Baoqi; Long, Jianyu; Zhang, Hao; Liang, Kuan; Jiang, Dawei

    2017-10-01

    Ground fissures are a geological hazard with complex formation mechanisms. Increasing amounts of human activity have created more ground fissures, which can destroy buildings and threaten human security. Some ground fissures indicate potentially devastating earthquakes, so we must pay attention to these hazards. This paper documents recently discovered ground fissures in the Hetao basin. These ground fissures are located along the frontal margins of the terraces of the Sertengshan piedmont fault. These fissures are 600-1600 m long, 5-50 cm wide, and at most 1 m deep. These ground fissures emerged after 2010 and ruptured newly constructed roads and field ridges. The deep geodynamic mechanisms within this extensional environment, which is dominated by NE-SW principal compressive shear, involve N-S tensile stress, which has produced continuous subsidence in the Hetao basin and continuous activity along the Sertengshan piedmont fault since the late Quaternary. Trenches across the ground fissures reveal that the fissures are the latest manifestation of the activity of preexisting faults and are the result of creep-slip movement along the faults. The groundwater level in the Hetao basin has been dropping since the 1960s because of overexploitation, resulting in subsidence. When the tensile stress exceeds the ultimate tensile strength of the strata, the strata rupture along preexisting faults, producing ground fissures. Thus, the Sertengshan piedmont fault planes are the structural foundation of the ground fissures, and groundwater extraction induces the development of ground fissures.

  9. Inorganic carbon cycle in soil-rock-groundwater system in karst and fissured aquifers

    Directory of Open Access Journals (Sweden)

    Ajda Koceli

    2013-12-01

    Full Text Available The paper presents a systematic analysis of the isotopic composition of carbon (δ13CCaCO3 in carbonate rocks in central Slovenia, representing karst and fissured aquifers, and share of carbon contributions from carbonate dissolution and degradation of organic matter in aquifers, calculated from the mass balance equation. 59 samples of rocks (mainly dolomites from Upper Permian to Upper Triassic age were analyzed. Samples of carbonate rocks were pulverized and ground to fraction of 45 μm and for determination of δ13CCaCO3 analyzed with mass spectrometer for analyses of stable isotopes of light elements-IRMS. The same method was used for determination of isotopic composition of dissolved inorganic carbon (δ13CDIC in groundwater for 54 of 59 locations. Values of δ13CCaCO3 are in the range from -2.0 ‰ to +4.1 ‰, with an average δ13CCaCO3 value of +2.2 ‰. These values are typical for marine carbonates with δ13CCaCO3 around 0 ‰, although δ13CCaCO3 values differ between groups depending on the origin and age. Early diagenetic dolomites have relatively higher values of δ13CCaCO3 compared to other analyzed samples. The lowest values of δ13CCaCO3 were observed in Cordevolian and Bača dolomite, probably due to late diagenesis, during which meteoric water with lower isotopic carbon composition circulated in the process of sedimentation. Values of δ13CDIC range from -14.6 ‰ to -8.2 ‰. Higher δ13CDIC values (-8.2 ‰ indicate a low proportion of soil CO2 in the aquifer and rapid infiltration, while lower values (-14.6 ‰ indicate higher proportion of soil CO2 in the aquifer and slower infiltration. Calculated contributions of carbon from organic matter / dissolution of carbonates in the karstic and fissured aquifers s how a similar proportion (50 % : 50 %.

  10. The syndrome of pit of the lower lip and its association with cleft palate

    Directory of Open Access Journals (Sweden)

    Bhavna Kaul

    2014-01-01

    Full Text Available The Van der Woude syndrome is a rare autosomal dominant developmental malformation usually associated with lower lip pits, cleft lip and palate. These congenital lip pits appear, clinically, as a malformation in the vermilion border of the lip, with or without excretion. Obligate carriers of this dominant mutation may have lip pits alone, cleft(s alone, clefts and pits or neither. Here, we present a case report of a 10 year-old male patient with Van der Woude syndrome and a brief literature on its treatment modalities.

  11. Printability and inspectability of programmed pit defects on teh masks in EUV lithography

    Energy Technology Data Exchange (ETDEWEB)

    Kang, I.-Y.; Seo, H.-S.; Ahn, B.-S.; Lee, D.-G.; Kim, D.; Huh, S.; Koh, C.-W.; Cha, B.; Kim, S.-S.; Cho, H.-K.; Mochi, I.; Goldberg, K. A.

    2010-03-12

    Printability and inspectability of phase defects in ELlVL mask originated from substrate pit were investigated. For this purpose, PDMs with programmed pits on substrate were fabricated using different ML sources from several suppliers. Simulations with 32-nm HP L/S show that substrate pits with below {approx}20 nm in depth would not be printed on the wafer if they could be smoothed by ML process down to {approx}1 nm in depth on ML surface. Through the investigation of inspectability for programmed pits, minimum pit sizes detected by KLA6xx, AIT, and M7360 depend on ML smoothing performance. Furthermore, printability results for pit defects also correlate with smoothed pit sizes. AIT results for pattemed mask with 32-nm HP L/S represents that minimum printable size of pits could be {approx}28.3 nm of SEVD. In addition, printability of pits became more printable as defocus moves to (-) directions. Consequently, printability of phase defects strongly depends on their locations with respect to those of absorber patterns. This indicates that defect compensation by pattern shift could be a key technique to realize zero printable phase defects in EUVL masks.

  12. 硅酮密封胶失效研究及其模型的建立%Structural Silicone Sealant Aging Failure Analysis and the Practical Failure Model

    Institute of Scientific and Technical Information of China (English)

    李倩; 夏美霞; 彭浩; 何潇俊

    2016-01-01

    In order to analyze the effect of structural silicone sealants’ compatibility and adhesion to safety and service life of glass curtain, this paper described various measures for solving the aging of structural silicone sealant. Causes of thermal aging and thermal weightlessness are analyzed through total organic silicon polymer(silicone+silicone oil) preliminarily; and the artificial acceleration is utilized for aging to simulate the actual effect of high temperature to failure of silicone sealant. The results showed that, the thermal aging and thermal weightlessness had significantly damage on the tensile strength and adhesive area of silicone sealant. The total amount of organic silicon polymer(silicone+silicone oil) determined the quality and service life of structural silicone sealants. Salt spray and cleaning agent for building had a great influence on high modulus sealant, but it had no effect on the deformation of low modulus sealant. The decay rate of structural silicone sealant increased with the temperature rising and heat treatment time changing, through establishing the model for the practical application in engineering construction.%为了分析硅酮结构密封胶的相容性和粘结性对玻璃幕墙安全性和使用寿命的影响,阐述了各种老化处理对硅酮结构密封胶失效的影响。通过有机硅聚合物总量(硅胶+硅油)来初步分析了热老化-热失重的原因,并通过人工加速老化模拟实际高温对硅酮结构胶失效的影响。结果表明,热老化-热失重对硅酮结构密封胶的拉伸强度和粘结破坏面积影响显著。有机硅聚合物总量(硅胶+硅油)决定了硅酮结构密封胶的质量和使用寿命。盐雾和建筑物清洁剂对高模量胶影响很大,但基本不影响低模量胶的形变能力。通过构建硅酮结构密封胶在工程中的实际应用情况试验模型,硅酮结构密封胶的衰减率随温度升高和高温处理时间增加而增加。

  13. Sylvian Fissure and Parietal Anatomy in Children with Autism Spectrum Disorder

    Science.gov (United States)

    Knaus, Tracey A.; Tager-Flusberg, Helen; Foundas, Anne L.

    2012-01-01

    Autism spectrum disorder (ASD) is characterized by deficits in social functioning and language and communication, with restricted interests or stereotyped behaviors. Anatomical differences have been found in the parietal cortex in children with ASD, but parietal subregions and associations between Sylvian fissure (SF) and parietal anatomy have not been explored. In this study, SF length and anterior and posterior parietal volumes were measured on MRI in 30 right-handed boys with ASD and 30 right-handed typically developing boys (7–14 years), matched on age and non-verbal IQ. There was leftward SF and anterior parietal asymmetry, and rightward posterior parietal asymmetry, across groups. There were associations between SF and parietal asymmetries, with slight group differences. Typical SF asymmetry was associated with typical anterior and posterior parietal asymmetry, in both groups. In the atypical SF asymmetry group, controls had atypical parietal asymmetry, whereas in ASD there were more equal numbers of individuals with typical as atypical anterior parietal asymmetry. We did not find significant anatomical-behavioral associations. Our findings of more individuals in the ASD group having a dissociation between cortical asymmetries warrants further investigation of these subgroups and emphasizes the importance of investigating anatomical relationships in addition to group differences in individual regions. PMID:22713374

  14. Sylvian Fissure and Parietal Anatomy in Children with Autism Spectrum Disorder

    Directory of Open Access Journals (Sweden)

    Tracey A. Knaus

    2012-01-01

    Full Text Available Autism spectrum disorder (ASD is characterized by deficits in social functioning and language and communication, with restricted interests or stereotyped behaviors. Anatomical differences have been found in the parietal cortex in children with ASD, but parietal subregions and associations between Sylvian fissure (SF and parietal anatomy have not been explored. In this study, SF length and anterior and posterior parietal volumes were measured on MRI in 30 right-handed boys with ASD and 30 right-handed typically developing boys (7–14 years, matched on age and non-verbal IQ. There was leftward SF and anterior parietal asymmetry, and rightward posterior parietal asymmetry, across groups. There were associations between SF and parietal asymmetries, with slight group differences. Typical SF asymmetry was associated with typical anterior and posterior parietal asymmetry, in both groups. In the atypical SF asymmetry group, controls had atypical parietal asymmetry, whereas in ASD there were more equal numbers of individuals with typical as atypical anterior parietal asymmetry. We did not find significant anatomical-behavioral associations. Our findings of more individuals in the ASD group having a dissociation between cortical asymmetries warrants further investigation of these subgroups and emphasizes the importance of investigating anatomical relationships in addition to group differences in individual regions.

  15. Anal fissure - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100154.htm Anal fissure - series—Normal anatomy To use the sharing ... rectum through which passes stool during defecation. The anal sphincter is a critical mechanism for control of ...

  16. Fluid flow on 3D triangulated fissures: conservative piece-wise constant velocity fields and associated transport processes

    CERN Document Server

    Morales, Fernando A

    2016-01-01

    For a fissured medium with uncertainty in the knowledge of fractures' geometry, a conservative tangential flow field is constructed, which is consistent with the physics of stationary fluid flow in porous media and an interpolated geometry of the cracks. The flow field permits computing preferential fluid flow directions of the medium, rates of mechanical energy dissipations and a stochastic matrix modeling stream lines and fluid mass transportation, for the analysis of solute/contaminant mass advection-diffusion as well as drainage times.

  17. Micromorphology and systematic distribution of pit membrane thickenings in Oleaceae: Tori and pseudo-tori

    NARCIS (Netherlands)

    Rabaey, D.; Huysmans, S.; Lens, F.; Smets, E.; Jansen, S.

    2008-01-01

    Recent studies on the functional significance of pit membranes in water conducting cells have renewed general interest in their micromorphology. At least two types of pit membrane thickenings have been described in angiosperm families, i.e. genuine tori and pseudo-tori. This study explores the distr

  18. Cellular resolution optical access to brain regions in fissures: imaging medial prefrontal cortex and grid cells in entorhinal cortex.

    Science.gov (United States)

    Low, Ryan J; Gu, Yi; Tank, David W

    2014-12-30

    In vivo two-photon microscopy provides the foundation for an array of powerful techniques for optically measuring and perturbing neural circuits. However, challenging tissue properties and geometry have prevented high-resolution optical access to regions situated within deep fissures. These regions include the medial prefrontal and medial entorhinal cortex (mPFC and MEC), which are of broad scientific and clinical interest. Here, we present a method for in vivo, subcellular resolution optical access to the mPFC and MEC using microprisms inserted into the fissures. We chronically imaged the mPFC and MEC in mice running on a spherical treadmill, using two-photon laser-scanning microscopy and genetically encoded calcium indicators to measure network activity. In the MEC, we imaged grid cells, a widely studied cell type essential to memory and spatial information processing. These cells exhibited spatially modulated activity during navigation in a virtual reality environment. This method should be extendable to other brain regions situated within deep fissures, and opens up these regions for study at cellular resolution in behaving animals using a rapidly expanding palette of optical tools for perturbing and measuring network structure and function.

  19. Probable recent water/lava source fissures in the Cerberus Plains: stratigraphic and crater count age constraints

    Science.gov (United States)

    Thomas, R.

    2012-09-01

    The Cerberus Plains have received increasing attention in recent years due to evidence from highresolution imagery that they are some of the youngest surfaces on Mars. The plains are incised by large outflow channels, possibly as recently as 20Ma in the case of Athabasca Valles [2]. These channels are generally thought to be water-carved [1,3], though it is possible they were incised by turbulent lava [8]. As recently as 10Ma or less [5] both the channels and the plains around them are proposed to have been draped with lava [7]. Thus the recent activity forming the Cerberus Plains probably required large volumes of both water and lava. The problem which arises is a source. Cerberus Fossae have been suggested as the source of the Athabasca Valles outflows [3,6], but topographic and stratigraphic issues have arisen which make this unlikely: for example, a streamlined island spans the fossa where water and/or lava is said to have originated [4]. No other specific sources have been identified. As plains volcanism often obscures its fissures, sources should be searched for in features elevated above the plain. New HiRISE images have shown just such a feature: a wrinkle ridge south of Cerberus Fossae incised by a series of fissures. Every fissure has associated channels and deposits indicating outflow onto the plains surrounding the ridge. Until now, the stratigraphic history of these features was poorly known, with Tanaka et al.'s [9] geological map considering the area only on the broadest scale. This study produces small-scale geomorphological maps to establish the stratigraphic relationships between the fissure-sourced outflows and the plains surrounding the ridge to test the hypothesis that they were the source of the plains material. Crater counting is also conducted to supplement stratigraphic observations and give tentative ages.

  20. Increasing efficacy and reducing side effects in treatment of chronic anal fissures: A study of topical diazepam therapy.

    Science.gov (United States)

    Hang, Minh Tuan H; Smith, Betsy E; Keck, Carson; Keshavarzian, Ali; Sedghi, Shahriar

    2017-05-01

    This is a single institution nonexperimental study intended to analyze the therapeutic efficacy of topical diazepam in treating symptoms of chronic anal fissures.Anal fissures are a common cause of anal pain. Conventional treatments include nonsteroidal anti-inflammatory drugs, topical creams, such as nitroglycerin and nifedipine, and surgery. However, these treatments are usually suboptimally efficacious or have deterring side effects.Patients at an outpatient community center with a diagnosis of a chronic anal fissure were prescribed either topical 2% (n = 19) or 4% (n = 18) diazepam cream between January 2013 and February 2015. We retrospectively analyzed their responses to treatment.All 19 patients using 2% diazepam cream experienced a positive response in pain, whereas 47.4% experienced a complete response, with a numerical rating scale (NRS) score of 0 (0-10). Eighty-eight percent of patients using 4% dose had a positive response in pain, whereas 23.5% experienced a complete response. Ninety-four percent of patients using 2% dose had a positive response in anal bleeding, whereas 68.8% experienced a complete response with an anal bleeding score (ABS) of 2 (2-9). Ninety-four percent of patients using 4% dose had a positive response in anal bleeding, whereas 64.7% experienced a complete response. Only 1 patient reported a side effect from diazepam cream-perianal pruritus.Both 2% and 4% topical diazepam provided significant pain and bleeding relief from chronic anal fissures that were refractory to conventional therapies. There were insignificant differences when assessing independent comparisons for pain and bleeding between the doses.

  1. The architecture and shallow conduits of Laki-type pyroclastic cones: insights into a basaltic fissure eruption

    Science.gov (United States)

    Reynolds, P.; Brown, R. J.; Thordarson, T.; Llewellin, E. W.

    2016-05-01

    Pyroclastic cones built along basaltic fissures provide important volcanological information, but it is often difficult to examine the early-erupted products due to burial by later products. Furthermore, it is rare to see the link between the feeder dyke and overlying cone fully exposed. In this study, we detail the architecture of a hybrid spatter cone, scoria half-cone and feeder dyke that has been dissected to below the pre-eruption surface by glacial floods. The cones were constructed during the 6-8 ka Rauðuborgir-Kvensöðul fissure eruption in North Iceland during Hawaiian- and Strombolian-style activities. Widening of their feeder dyke in the shallow sub-surface to produce an upward flaring morphology was accommodated by country rock removal and elastic host rock deformation. Ballistic calculations and stratigraphic relationships indicate that the scoria half-cone was constructed early in the eruption from the deposits of a lava fountain ~100 m high. A decline in fountain height and the generation of abundant welded deposits resulted in the formation of a nested spatter cone within the scoria half-cone. The cones are similar in structure and size to the hybrid scoria and spatter cones produced during the 15-km3 1783 Laki eruption and serve as a valuable window into the construction of pyroclastic edifices during basaltic fissure eruptions.

  2. Morphologic Study of Superior Temporal Sulcus-Amygdaloid Body and Lateral Fissure-Amygdaloid Body Surgical Approach by Using Magnetic Resonance Imaging Volume Rendering.

    Science.gov (United States)

    Qu, Yuan; Ren, Bichen; Chang, Xiaoyu; Zhang, Jinnan; Li, Youqiong; Duan, Haobo; Cheng, Kailiang; Wang, Jincheng

    2016-01-01

    In this research, 83 patients were measured by magnetic resonance imaging volume rendering technique. The authors acquired the curve length of the superior temporal sulcus and the lateral fissure on the cerebral hemisphere, the shortest distance from the superior temporal sulcus and the lateral fissure to the center of amygdaloid body separately, the vertical diameter, the transversal diameter, and the anteroposterior diameter of the amygdaloid body and the 2 approach angles between the median sagittal plane and the shortest segment from the superior temporal sulcus to the center of amygdaloid body and the shortest segment from lateral fissure to the center of the amygdaloid body. At the same time, we preliminarily oriented the 2 points of the superior temporal sulcus and the lateral fissure, which are closest to the center of amygdaloid body, aimed at finding out the best entrance points of surgical approach through the superior temporal sulcus and the lateral fissure to the amygdaloid body and reducing the damage to the nerve fibers or blood vessels during the operation. The results indicate that the point at the front side 1/4 of the superior temporal sulcus may be the ideal surgical approach entrance point and the point at the front side 1/3 of the lateral fissure. There is no difference between 2 cerebral hemispheres (P < 0.05).

  3. PROGRESS IN GROUND FISSURES AND ITS HAZARD RESEARCH%地裂缝及其灾害研究的新进展

    Institute of Scientific and Technical Information of China (English)

    王景明; 刘科; 王春梅

    2001-01-01

    已查明我国26个省市出现具一定规模的地裂缝1 003处,6 000多条。其中80%是构造地裂缝,它们是地壳浅表层破裂。区域地裂缝与强震区分布一致,活跃期也相吻合,它们是同一构造应力场作用的不同构造现象,区域地裂缝释放地壳应变能远超过同期强震能量释放的总和。作为动力源的地裂缝活动使同期地质体发生位移产生形变场和应力场,并通过地基使建筑物结构等失稳失效破坏成灾,估算全国地裂缝造成的损失为91.2亿元,其中华北区损失占70%。地裂缝已构成一个新的独立的灾种。%It generally discusses the main progress in ground fissures studyingin in our country's.Investigation showes that:there are 1 003 places (more than 6 000 strips) where ground fissures are on a certain extent scale and knockout in 26 provinces and cities in China.Among which tectonic ground fissures occupies about 80%.The ground fissures of wriggle fault occupies 15%~20.8% and that of territorial slight cracking occupies 79.2%~85% among tectonic ground fissures.Tectonic ground fissures are territorial superficial crack of lithosphere.They are domino effect of wriggle crack in rock and soil.   According to the pattern of distribution,the degree of development,the type of cause of formation and tectonic background,it can be marked off four distributed regions of ground fissures such as the NANHUA,the big North of China,the Northeast and the West.In every place the degree of development of ground fissures is corresponding to the degree of lithosphere motion at the location.In the big North of China,the earth is basically steady once,and the length of the ground fissures with earthquake and without earthquake separately add up to 321 km and 497 km.In the West,the lithosphere is relatively unsteady,and that separately add up to 2 696 km and 2.5 km.In the Nanhua and the Northeast,lithosphere is relatively steady,and the non

  4. Intervascular pit membranes with a torus in the wood of Ulmus (Ulmaceae) and related genera

    NARCIS (Netherlands)

    Jansen, S.; Choat, B.; Vinckier, S.; Lens, F.; Schols, P.; Smets, E.

    2004-01-01

    • The distribution of intervascular pit membranes with a torus was investigated in juvenile wood samples of 19 species of Ulmus and seven related genera. • A staining solution of safranin and alcian blue (35 : 65) was recommended to distinguish torus-bearing pit membranes using light microscopy. • I

  5. Radon release and dispersion from an open pit uranium mine

    Energy Technology Data Exchange (ETDEWEB)

    Kisieleski, W.E.

    1980-06-01

    Radon-222 flux from representative sections of the United Nuclear St. Anthony open-pit mine complex was measured. The collected radon was adsorbed on activated charcoal and the radon activity was measured by gamma spectroscopy. System design, calibration, and the procedure to determine radon flux density (pCi/m/sup 2/.s) are described. A continuous series of radon flux densities were measured over a 5-month period at a control point in the mine. The average flux density at the control point was 1.9 pCi/m/sup 2/.s. A close correlation between radon flux density variations and changes in barometric pressure was observed by a comparison of meteorological data and average daily radon flux density measured at the control point. The release rate from each section of the mine was calculated from the average radon flux density and the area of the section, as determined from enlarged aerial photographs. The average radon flux density for eight locations over the ore-bearing section was 7.3 pCi/m/sup 2/.s. The average flux density for four locations over undisturbed topsoil was 0.17 pCi/m/sup 2/.s. The average Ra-226 content of ten samples taken from the ore-bearing region was 102 pCi/g ore. The ratio of radon flux density to radium content (specific flux) was 0.072. The release rate from the entire St. Anthony open pit was determined to be 3.5 x 10/sup 5/ pCi/s. This rate is comparable to the natural release of radon from one square mile of undisturbed topsoil. 16 refs., 31 figs., 11 tabs.

  6. Annealing to Mitigate Pitting in Electropolished Niobium Coupons and SRF Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Cooley, L.D.; Hahn, E.; Hicks, D.; Romanenko, A.; Schuessler, R.; Thompson, C.; /Fermilab

    2011-06-08

    Ongoing studies at Fermilab investigate whether dislocations and other factors instigate pitting during cavity electropolishing (EP), despite careful processing controls and the inherent leveling mechanism of EP itself. Here, cold-worked niobium coupons, which exhibited increased tendencies for pitting in our past study, were annealed in a high vacuum furnace and subsequently processed by EP. Laser confocal scanning microscopy and special defect counting algorithms were used to assess the population of pits formed. Hardness measurements indicated that annealing for 2 hours at 800 C produced recovery, whereas annealing for 12 hours at 600 C did not, as is consistent with known changes for cavities annealed in a similar way. The 800 C anneal was effective in some cases but not others, and we discuss reasons why tendencies for pitting remain. We discuss implications for cavities and continued work to understand pitting.

  7. Cavitation pitting and erosion of aluminum 6061-T6 in mineral oil water

    Science.gov (United States)

    Rao, B. C. S.; Buckley, D. H.

    1983-01-01

    Cavitation erosion studies of aluminum 6061-T6 in mineral oil and in ordinary tap water are presented. The maximum erosion rate (MDPR, or mean depth of penetration rate) in mineral oil was about four times that in water. The MDPR in mineral oil decreased continuously with time, but the MDPR in water remained approximately constant. The cavitation pits in mineral oil were of smaller diameter and depth than the pits in water. Treating the pits as spherical segments, we computed the radius r of the sphere. The logarithm of h/a, where h is the pit depth and 2a is the top width of the pit, was linear when plotted against the logarithm of 2r/h - 1.

  8. Dermoscopy of Pitted Keratolysis

    Directory of Open Access Journals (Sweden)

    Lauren L. Lockwood

    2010-08-01

    Full Text Available Irritated hyperhidrotic soles with multiple small pits are pathognomonic for pitted keratolysis (PK. Here we show the dermatoscopic view of typical pits that can ensure the diagnosis. PK is a plantar infection caused by Gram-positive bacteria, particularly Corynebacterium. Increases in skin surface pH, hyperhidrosis, and prolonged occlusion allow these bacteria to proliferate. The diagnosis is fundamentally clinical and treatment generally consists of a combination of hygienic measures, correcting plantar hyperhidrosis and topical antimicrobials.

  9. Central Shops Burning/Rubble Pit 631-6G Additonal Sampling and Monitor Well Installation Report

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, E. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1995-02-01

    The Central Shops Burning/Rubble Pit 631-6G was constructed in 1951 as an unlined earthen pit in surficial sediments for disposal and incineration of potentially hazardous substances, such as metals and organic solvents.

  10. Modeling and simulation of pit chemistry of 304 austenitic stainless steel under applied stress in sodium chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yuhui, E-mail: yhhuang@ecust.edu.cn [Key Laboratory of Pressure Systems and Safety, MOE, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237 (China); Tu, Shan-Tung; Xuan, Fu-Zhen [Key Laboratory of Pressure Systems and Safety, MOE, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237 (China)

    2013-04-15

    Highlights: ► A corrosion model was developed to simulate a stressed metal surface with a pit. ► The stress state in the pit bottom was coupled with the local corrosion environment. ► An analytical expression was established for current density of deformed pit surface. ► Local deformation had a strong effect on potential and species concentration in pits. -- Abstract: A mathematical model for simulating the active dissolution of a pit on stressed metal surface had been developed. Based on active dissolution mechanism, dissolution current density on the pit surface was assumed and extended through accounting for the thermal activation energy and the multiaxial stress state in pit bottom. The influence of applied tensile stress, pit radius and temperature was addressed. The distribution of solution potential and species concentration was predicted for different applied tensile stresses based on finite element calculations.

  11. Evidence of Effectiveness of Current Therapies to Prevent and Treat Early Childhood Caries

    DEFF Research Database (Denmark)

    Twetman, Svante; Dhar, Vineet

    2015-01-01

    PURPOSE: The purpose of this paper was to systematically review the quality of evidence related to self-applied and professionally applied fluorides, antimicrobial agents, fissure sealants, temporary restorations, and restorative care for the prevention and management of early childhood caries (E...

  12. Heart rate and core temperature responses of elite pit crews during automobile races.

    Science.gov (United States)

    Ferguson, David P; Bowen, Robert S; Lightfoot, J Timothy

    2011-08-01

    There is limited information regarding the physiological and psychological demands of the racing environment, and the subsequent effect on the performance of pit crew athletes. The purpose of this study was to evaluate heart rates (HRs) and core body temperatures (CTs) of pit crew athletes in the race environment. The HR and CT of pit crew athletes (n = 7) and control subjects were measured during 6 National Association for Stock Car Automobile Racing Sprint Cup races using ingestible sensors (HQ Inc, Palmetto, FL, USA). The HR and CT were measured before each race, at 15-minute intervals during the race, and upon completion of each pit stop. Compared to the control subject at each race, the pit crew athletes had significantly (p = 0.014) lower core temperatures (CTs). The pit crew athletes displayed higher HRs on the asphalt tracks than on concrete tracks (p = 0.011), and HR responses of the crew members were significantly (p = 0.012) different between pit crew positions, with the tire changers and jackman exhibiting higher HRs than the tire carriers. Unexpectedly, the CTs of the pit crew athletes were not elevated in the race environment, despite high ambient temperatures and the extensive fire-protection equipment (e.g., helmet, suit, gloves) each pit crew athlete wore. The lack of CT change is possibly the result of the increased HR more efficiently shunting blood to the skin and dissipating heat as a consequence of the athletes' extensive training regimen and ensuing heat acclimation. Additionally, it is possible that psychological stress unique to several of the tracks provided an additive effect resulting in increased heart rates.

  13. Effect of halide ions on passivation and pitting corrosion of copper in alkaline solutions

    Energy Technology Data Exchange (ETDEWEB)

    Gad Allah, A.G.; Abou-Romia, M.M.; Badawy, W.A.; Rehan, H.H. (Cairo Univ., Gizeh (Egypt). Dept. of Chemistry)

    1991-11-01

    The passivity of copper in NaOH and borate buffer solutions containing chloride, bromide and fluoride ions was studied by using cyclic voltammetry and potentiostatic current transient measurements. At scan rates >> 20 mVs{sup -1}, the addition of halide ions does not nearly affect the cyclic voltammograms in the absence of pitting. But they differ considerably in presence of pitting. The pitting potential was found to depend on the solution pH and decreased linearly with increase of logarithm of halide ion concentration. The current transients in the passivity as well as in the pitting potential regions were analyzed. Before the pitting, i-time curves were rather similar to those obtained in the plain solutions. At times > 20 seconds, the current varies linearly with the reciprocal of the square root of time indicating diffusional characteristics of the metal corrosion through the passive layer. In presence of pitting, the pitting current versus time relations fit the Engell-Stolica equation. (orig.).

  14. Central Pit and Dome Formation as Seen in Occator Crater, Ceres

    Science.gov (United States)

    Schenk, Paul M.; Buczkowski, Debra; Scully, Jennifer E. C.; De Sanctis, Maria Cristina; Schmidt, Britney E.; O'Brien, David P.; Hiesinger, Harald; Sizemore, Hanna G.; Ammannito, Eleonora; Raymond, Carol; Russell, Christopher T.; Dawn Science Team

    2016-10-01

    Dawn mapping of Ceres revealed that central depressions (or pits) are common in craters >75 km. The best preserved of these is Occator (D~92 km), where the pit is associated with a major bright deposit dominated by carbonates. The pit is ~9 km wide, 600-800 m deep and flanked by asymmetric massifs 0.7 to 1.3 km high. The pit is partially filled by a fractured central dome ~3 km wide and 700 m high. Fracturing could have been due to dome inflation by "magma" or by subsurface freezing of ice. Within the bright material, two color units are mapped, including a paler surface unit and a more yellowish to reddish unit exposed within the most fractured parts of the dome surface and at small bright spots, at least some of which could be post-Occator small craters. Some bright materials form as discrete small spots midslope along the pit wall and others avoid small hills, suggesting partial topographic control. Stratigraphic relations are ambiguous but suggest formation of a smooth carapace some meters thick that was subsequently disrupted by fractures crossing the floor of Occator, and by uplift of the dome surface. Pit and dome morphologies, including dome fracturing are potentially analogous to central pits and domes in many craters on Ganymede and Callisto, suggesting some commonality in formation processes. The absence of center pits or domes on Saturnian satellites could be related to much lower temperatures on those bodies. The prominence of central pits and domes on Ceres confirms the importance of volatile materials, mostly likely water ice, in the outer layers of Ceres, especially as compared to Vesta.

  15. Atypical pit craters on Mars: new insights from THEMIS, CTX and HiRISE observations

    Science.gov (United States)

    Cushing, Glen; Okubo, Chris H.; Titus, Timothy N.

    2015-01-01

    More than 100 pit craters in the Tharsis region of Mars exhibit morphologies, diameters and thermal behaviors that diverge from the much larger bowl-shaped pit craters that occur in most regions across Mars. These Atypical Pit Craters (APCs) generally have sharp and distinct rims, vertical or overhanging walls that extend down to their floors, surface diameters of ~50-350 m, and high depth-to-diameter (d/D) ratios that are usually greater than 0.3 (which is an upper-range value for impacts and bowl-shaped pit craters), and can exceed values of 1.8. Observations by the Mars Odyssey THermal Emission Imaging System (THEMIS) show that APC floor temperatures are warmer at night, and fluctuate with much lower diurnal amplitudes than nearby surfaces or adjacent bowl-shaped pit craters. Kīlauea volcano, Hawai'i, hosts pit craters that formed through subsurface collapse into active volcanic dikes, resulting in pits that can appear morphologically analogous to either APCs or bowl-shaped pit craters. Partially-drained dikes are sometimes exposed within the lower walls and floors of these terrestrial APC analogs and can form extensive cave systems with unique microclimates. Similar caves in martian pit craters are of great interest for astrobiology. This study uses new observations by the Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) and Context Camera (CTX) to refine previous work where seven APCs were described from lower-resolution THEMIS visible-wavelength (VIS) observations. Here, we identify locations of 115 APCs, map their distribution across the Tharsis region, characterize their internal morphologies with high-resolution observations, and discuss possible formation mechanisms.

  16. Prevalence of Dental Caries and Periodontal Disease in Mexican American Children Aged 5 to 17 Years: Results from Southwestern HHANES, 1982-83.

    Science.gov (United States)

    Ismail, Amid L.; And Others

    1987-01-01

    Dental caries and periodontal disease in Mexican American children of the southwestern United States occur mainly in molars, lending strong support for the use of fissure sealants as a preventive procedure. This study also reports on the prevalence of fillings decay and gingivitis in this population. (VM)

  17. Enamel Pit Defects and Taurodontism in a Patient with Ring Chromosome 14 and 47,XXX.

    Science.gov (United States)

    Townsend, Janice A; Lacour, Letitia; Scheuerle, Angela E

    2017-01-15

    The purpose of this paper is to describe the clinical findings and management of a case involving a patient with co-occurring ring chromosome 14 syndrome and 47,XXX presenting with enamel pit defects and taurodontism. Ring chromosome 14 syndrome is an unusual condition with uncontrolled seizure disorder as its most significant finding; 47,XXX (trisomy X; triple X) is a more common condition and has characteristic physical and behavioral findings. Neither condition has been associated with enamel pit defects.

  18. Earth Fissures in Su-Xi-Chang Region, Jiangsu, China

    Science.gov (United States)

    Wang, Guang-ya; You, Greg; Zhu, Jin-qi; Yu, Jun; Li, Wei

    2016-11-01

    The earth fissures in the Su-Xi-Chang area are caused by differential land subsidence due to long-term excessive groundwater withdrawal and controlled by the bedrock ridge or cliff underlying. There have been more than 15 earth fissures in the area since 1989. The field investigations have lasted for more than 20 years. The earth fissures generally have a main fissure and a number of secondary ones parallel to the main one. The main fissure (crack) has a scarp, is steeply dipping, and can be more than 2000 m long. Geophysical surveys (2D or 3D seismic investigation, controlled source audio frequency magnetotelluric sounding, and electric sounding) combined with geological drilling are effective for the investigation of earth fissures. Geodetic leveling is effective to monitor the ground deformation across the earth fissure, so is the extensometer for the opening of the fissure. The activities of earth fissures are directly related to different stages of land subsidence and controlled by geological abnormalities. Most earth fissures in the area are still active.

  19. Cargo and dynamin regulate clathrin-coated pit maturation.

    Directory of Open Access Journals (Sweden)

    Dinah Loerke

    2009-03-01

    Full Text Available Total internal reflection fluorescence microscopy (TIR-FM has become a powerful tool for studying clathrin-mediated endocytosis. However, due to difficulties in tracking and quantifying their heterogeneous dynamic behavior, detailed analyses have been restricted to a limited number of selected clathrin-coated pits (CCPs. To identify intermediates in the formation of clathrin-coated vesicles and factors that regulate progression through these stages, we used particle-tracking software and statistical methods to establish an unbiased and complete inventory of all visible CCP trajectories. We identified three dynamically distinct CCP subpopulations: two short-lived subpopulations corresponding to aborted intermediates, and one longer-lived productive subpopulation. In a manner dependent on AP2 adaptor complexes, increasing cargo concentration significantly enhances the maturation efficiency of productive CCPs, but has only minor effects on their lifetimes. In contrast, small interfering RNA (siRNA depletion of dynamin-2 GTPase and reintroduction of wild-type or mutant dynamin-1 revealed dynamin's role in controlling the turnover of abortive intermediates and the rate of CCP maturation. From these data, we infer the existence of an endocytic restriction or checkpoint, responsive to cargo and regulated by dynamin.

  20. The cycle of instability: stress release and fissure flow as controls on gully head retreat

    Science.gov (United States)

    Collison, A. J. C.

    2001-01-01

    Gully head and wall retreat has commonly been attributed to fluvial scour and head collapse as a result of soil saturation, sapping or piping. The empirical evidence to substantiate these conceptual models is sparse, however, and often contradictory. This paper explores the hydrological and mechanical controls on gully head and wall stability by modelling the hydrology, stability and elastic deformation of a marl gully complex in Granada Province, south-east Spain. The hydrological and slope-stability simulations show that saturated conditions can be reached only where preferential fissure flow channels water from tension cracks into the base of the gully head, and that vertical or subvertical heads will be stable unless saturation is achieved. Owing to the high unsaturated strengths of marl measured in this research, failure in unsaturated conditions is possible only where the gully head wall is significantly undercut. Head retreat thus requires the formation of either a tension crack or an undercut hollow. Finite-element stress analysis of eroding slopes reveals a build up of shear stress at the gully head base, and a second stress anomaly just upslope of the head wall. Although tension cracks on gully heads have often been attributed to slope unloading, this research provides strong evidence that the so called sapping hollow commonly found in the gully headwall base is also a function of stress release. Although further research is needed, it seems possible that pop out failures in river channels may be caused by the same process. The hydrological analysis shows that, once a tension crack has developed, throughflow velocity in the gully headwall will increase by an order of magnitude, promoting piping and enlargement of this weakened area. It is, therefore, possible to envisage a cycle of gully expansion in which erosion, channel incision or human action unloads the slope below a gully head, leading to stress patterns that account for the tension crack and a

  1. A conceptual model of the hydrological influence of fissures on landslide activity

    Directory of Open Access Journals (Sweden)

    D. M. Krzeminska

    2012-06-01

    Full Text Available Hydrological processes control the behaviour of many unstable slopes, and their importance for landslide activity is generally accepted. The presence of fissures influences the storage capacity of a soil and affects the infiltration processes of rainfall. The effectiveness of the fissure network depends upon fissure size, their spatial distribution, and connectivity. Moreover, fissure connectivity is a dynamic characteristic, depending on the degree of saturation of the medium.

    This research aims to investigate the influence of the fissure network on hydrological responses of a landslide. Special attention is given to spatial and temporal variations in fissure connectivity, which makes fissures act both as preferential flow paths for deep infiltration (disconnected fissures and as lateral groundwater drains (connected fissures. To this end, the hydrological processes that control the exchange of water between the fissure network and the matrix have been included in a spatially distributed hydrological and slope stability model. The ensuing feedbacks in landslide hydrology were explored by running the model with one year of meteorological forcing. The effect of dynamic fissure connectivity was evaluated by comparing simulations with static fissure patterns to simulations in which these patterns change as a function of soil saturation. The results highlight that fissure connectivity and fissure permeability control the water distribution within landslides. Making the fissure connectivity function of soil moisture results in composite behaviour spanning the above end members and introduces stronger seasonality of the hydrological responses.

  2. Microstructure and pitting corrosion of 13CrNiMo weld metals

    Energy Technology Data Exchange (ETDEWEB)

    Bilmes, P.D. [Laboratorio de Investigaciones de Metalurgia Fisica ' Ing. Gregorio Cusminsky' (LIMF), Departamento Mecanica, Facultad de Ingenieria, Universidad Nacional de la Plata, calle 1 y 47, 1900 La Plata (Argentina); Llorente, C.L. [Laboratorio de Investigaciones de Metalurgia Fisica ' Ing. Gregorio Cusminsky' (LIMF), Departamento Mecanica, Facultad de Ingenieria, Universidad Nacional de la Plata, calle 1 y 47, 1900 La Plata (Argentina); Saire Huaman, L. [Instituto de Investigaciones, Fisicoquimicas Teoricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de la Plata, Sucursal 4-C.C. 16, 1900 La Plata (Argentina); Laboratorio de Ingenieria de Corrosion y Tecnologia Electroquimica (LICTE), Departamento Ingenieria Quimica, Facultad de Ingenieria, Universidad Nacional de la Plata, 1 y 47, 1900 La Plata (Argentina); Gassa, L.M. [Instituto de Investigaciones, Fisicoquimicas Teoricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de la Plata, Sucursal 4-C.C. 16, 1900 La Plata (Argentina); Laboratorio de Ingenieria de Corrosion y Tecnologia Electroquimica (LICTE), Departamento Ingenieria Quimica, Facultad de Ingenieria, Universidad Nacional de la Plata, 1 y 47, 1900 La Plata (Argentina); Gervasi, C.A. [Instituto de Investigaciones, Fisicoquimicas Teoricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de la Plata, Sucursal 4-C.C. 16, 1900 La Plata (Argentina) and Laboratorio de Ingenieria de Corrosion y Tecnologia Electroquimica (LICTE), Departamento Ingenieria Quimica, Facultad de Ingenieria, Universidad Nacional de la Plata, 1 y 47, 1900 La Plata (Argentina)]. E-mail: gervasi@inifta.unlp.edu.ar

    2006-10-15

    Cyclic potentiodynamic measurements and scanning electron microscopy were used to analyze susceptibility to pitting corrosion of 13CrNiMo weld metals. In order to carry out a critical assessment of the influence of microstructural factors on localized corrosion, different heat treatments were applied to the alloys under investigation. Volume fractions of austenite in tempered conditions as well as the amount and size of precipitated carbides strongly affect pitting resistance. Characteristic potentials (pitting potential and repassivation potential) increase according to the retained austenite content. Results can be discussed in terms of a model that describes the structural refinement resulting from a double-tempering procedure.

  3. Are eruptions from linear fissures and caldera ring dykes more likely to produce pyroclastic flows?

    Science.gov (United States)

    Jessop, D. E.; Gilchrist, J.; Jellinek, A. M.; Roche, O.

    2016-11-01

    Turbulent volcanic jets are produced by highly-energetic explosive eruptions and may form buoyant plumes that rise many tens of kilometres into the atmosphere to form umbrella clouds or collapse to generate ground-hugging pyroclastic flows. Ash injected into the atmosphere can be transported for many hundreds of kilometres with the potential to affect climate, disrupt global air travel and cause respiratory health problems. Pyroclastic flows, by contrast, are potentially catastrophic to populations and infrastructure close to the volcano. Key to which of these two behaviours will occur is the extent to which the mechanical entrainment and mixing of ambient air into the jet by large (entraining) eddies forming the jet edge changes the density of the air-ash mixture: low entrainment rates lead to pyroclastic flows and high entrainment rates give rise to buoyant plumes. Recent experiments on particle-laden (multi-phase) volcanic jets from flared and straight-sided circular openings suggest that the likelihood for buoyant plumes will depend strongly on the shape and internal geometry of the vent region. This newly recognised sensitivity of the fate of volcanic jets to the structure of the vent is a consequence of a complex dynamic coupling between the jet and entrained solid particles, an effect that has generally been overlooked in previous studies. Building on this work, here we use an extensive series of experiments on multi-phase turbulent jets from analogue linear fissures and annular ring fractures to explore whether the restrictive vent geometry during cataclysmic caldera-forming (CCF) eruptions will ultimately lead a relatively greater frequency of pyroclastic flows than eruptions from circular vents on stratovolcanoes. Our results, understood through scaling analyses and a one-dimensional theoretical model, show that entrainment is enhanced where particle motions contribute angular momentum to entraining eddies. However, because the size of the entraining

  4. Synthesis of new water expandable waterproofing sealant and its application%新型水膨胀防水密封胶的合成与应用

    Institute of Scientific and Technical Information of China (English)

    徐文君

    2009-01-01

    重点阐述了一种新型水膨胀防水密封胶的合成,包括丙烯酸类专用吸水树脂的组成配方和合成过程,以及以氯丁胶为主的基体胶料的选择;扼要介绍了该水膨胀防水密封胶的工程应用.%The article focuses on synthesis of a new water ex-pandable waterproofing sealant, including formulation of acrylic specific hydroscopic resin and its synthesis process and selection of neoprene -based rubbers. It also briefs the application of the sealant.

  5. Geophysical Exploration of Faults, Fissures, and Fractures at Four Sites in Mexicali, Baja California, Mexico

    Science.gov (United States)

    Lázaro-Mancilla, O.; Gonzalez-Fernandez, A.; Contreras-Corvera, A.; Stock, J. M.; Moreno-Ayala, D.; Ramirez-Hernandez, J.; Carreon-Diazconti, C.; Lopez, D. A. L.; Lopez, J. R.

    2014-12-01

    We conducted field geophysical measurements in areas in the City of Mexicali that are associated with geological faults, fissures, and fractures. The study sites are: 1) Instituto Tecnologico de Mexicali 2) The buried trace of the Michoacan de Ocampo fault in the urban zone 3) Rio Nuevo 4) A site reported by Frez (2013) with ground rupture SW of Cerro Prieto At Site 1, seismic reflection profiling used a cable with 24 geophones at 1 m spacing. The source was a 3.6 kg sledge hammer, with 3 impacts per shot point. 347 shot points at 2 m spacing provided 6 fold coverage along a straight line with minimal elevation changes. Sample rate was 2000/s, and record length 1 s; reflections were seen down to 0.3 s TWTT. Processing included: frequency filter, fk filter, predictive deconvolution, geometry, velocity analysis, NMO and stacking. Lateral changes in the seismic section are due to surface modification and/or the presence of faults.At site 2, we measured 222Radon in 36 locations along 17 profiles across the fault, using inherent alpha spectrometry with a Durridge RAD7 detector. Each site was measured at a depth of 60 cm, with 31 five-minute readings in a 3 hour period, interspersed with 10 minute of background purge and 3 five-minute background measurements. In a profile parallel to the fault, 78% of the readings were > 100 pCi/L, confirming the presence of the fault along the swath surveyed. At Site 3 we compiled observations of post-earthquake cracks, conducted reconnaissance, and measured some profiles using 100 MHz GPR. These observations showed that the cracks are associated with ground failure due to earthquake shaking. At Site 4 our new 222Radon gas measurements complemented a pre-existing profile that had high 222Radon values lacking a structural explanation. Related to this we found that this region has two NW-SE trending features: a magnetic anomaly low of 360 nT (Evans, Summer and Castillo, 1972) and a graben reported by the Mexican Geological Survey in 2003

  6. Modeling pitting corrosion of iron exposed to alkaline solutions containing nitrate and nitrite

    Science.gov (United States)

    Chen, Lifeng

    2001-07-01

    Pitting corrosion could be extremely serious for dilute high-level radioactive waste stored or processed in carbon steel tanks at the Savannah River Site. In these solutions, nitrate is an aggressive ion with respect to pitting of carbon steel while nitrite can be used as an inhibitor. Excessive additions of nitrite increase the risk of generating unstable nitrogen compounds during waste processing, and insufficient additions of nitrite could increase the risk of corrosion-induced failure. Thus there are strong incentives to obtain a fundamental understanding of the role of nitrite in pitting corrosion prevention with these solution chemistries. In this dissertation, both a 1-D and a 2-D model are used to study the pitting mechanism as a function of nitrite/nitrate ratios. The 1-D model used BAND(J) to test a reaction mechanism for the passivation behavior by comparing the predicted Open Circuit Potential (OCP) with OCP data from experiments at different NO2-/NO3- ratio. The model predictions are compared with Cyclic Potentiodynamic Polarization (CPP) experiments. A 2-D model was developed for the propagation of a pit in iron by writing subroutines for finite element software of GAMBIT and FIDAP. Geometrically distributed anodic and cathodic reactions are assumed. The results show three partial explanations describing the inhibition influence of nitrite to iron corrosion: the competing reduction reaction of nitrate to nitrite, the formation of Fe(OH)+, and the function of the porous film. The current distributions and the effect of porosity of the film on pH are also explained. The calculation results also show that rate of pit growth decreases as the pit diameter increases until it reaches a constant value. The profile of the local current density on the pit wall is parabolic for small pits and it changes to a linear distribution for large pits. The model predicts that addition of nitrite will decrease the production of ferrous ions and those can prevent iron from

  7. Passivation and pitting corrosion of. alpha. -brass (Cu/Zn: 63/37) in neutral buffer solutions containing chloride ions

    Energy Technology Data Exchange (ETDEWEB)

    Abd El-Rahman, H.A. (Cairo Univ., Gizeh (Egypt). Chemistry Dept.)

    1990-11-01

    The passivation behaviour and pitting corrosion of a commercial grade {alpha}-brass (Cu/Zn: 63/37) in neutral buffer solutions (borate and phosphate) in the presence and absence of chloride ions were investigated by electrochemical techniques. The results indicated the dezincification in absence of chloride ions at highly enough anodic potentials and both dezincification and pitting corrosion in the presence of chloride ions. The pitting susceptibility was found to depend on the composition of the buffer solution, chloride ion concentration and nature of the passive layer on the metal surface before pitting. Current transients corresponding to passivity, dezincification and pitting corrosion were identified and analyzed. (orig.).

  8. Pit-1 inhibits BRCA1 and sensitizes human breast tumors to cisplatin and vitamin D treatment

    Science.gov (United States)

    Seoane, Samuel; Arias, Efigenia; Sigueiro, Rita; Sendon-Lago, Juan; Martinez-Ordoñez, Anxo; Castelao, Esteban; Eiró, Noemí; Garcia-Caballero, Tomás; Macia, Manuel; Lopez-Lopez, Rafael; Maestro, Miguel; Vizoso, Francisco; Mouriño, Antonio; Perez-Fernandez, Roman

    2015-01-01

    The POU class 1 homeobox 1 (POU1F1, also known as Pit-1), pertaining to the Pit-Oct-Unc (POU) family of transcription factors, has been related to tumor growth and metastasis in breast. However, its role in response to breast cancer therapy is unknown. We found that Pit-1 down-regulated DNA-damage and repair genes, and specifically inhibited BRCA1 gene expression, sensitizing breast cancer cells to DNA-damage agents. Administration of 1α, 25-dihydroxy-3-epi-vitamin D3 (3-Epi, an endogenous low calcemic vitamin D metabolite) reduced Pit-1 expression, and synergized with cisplatin, thus, decreasing cell proliferation and apoptosis in vitro, and reducing tumor growth in vivo. In addition, fifteen primary cultures of human breast tumors showed significantly decreased proliferation when treated with 3-Epi+cisplatin, compared to cisplatin alone. This response positively correlated with Pit-1 levels. Our findings demonstrate that high levels of Pit-1 and reduced BRCA1 levels increase breast cancer cell susceptibility to 3-Epi+cisplatin therapy. PMID:25992773

  9. Deformation Control of Deep Excavation Pit and Numerical Simulation with Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The authors firstly introduce deformation control of deep excavation pit in detail, and then put forward new conceptions such as: effective coefficient of excavation pit, effective area, ineffective area and critical line, and also put forward the referential criteria of deformation control. The System of Optimization Design with Deformation Control of Deep Excavation Pit and Numerical Simulation with Finite Element Method (SDCDEFEM) is also briefly introduced. Factors influencing deformation of excavation pit are analyzed by the system. The measured and simulated data of maximum deformations (settlement, displacement and upheaval) and their positions are analyzed and discussed. The statistic formula estimating maximum deformations and their positions was gained, and economical-effective measures of deformation control were brought forward.

  10. Inter- and intraspecific variation in the distribution and number of pit organs (free neuromasts) of sharks and rays.

    Science.gov (United States)

    Peach, Meredith B

    2003-04-01

    The distribution of pit organs (free neuromasts) has previously been documented for several species of pelagic sharks, but is relatively poorly known for rays and bottom-dwelling (demersal) sharks. In the present study, the complete distribution of pit organs was mapped in the demersal sharks Heterodontus portusjacksoni, Orectolobus maculatus, Hemiscyllium ocellatum, Chiloscyllium punctatum, and Asymbolus analis, and the rays Rhinobatos typus, Aptychotrema rostrata, Trygonorrhina sp. A, Raja sp. A, and Myliobatis australis. All of these species had pit organs scattered over the dorsolateral surface. The sharks also had "mandibular" pit organs (and "umbilical" pit organs in C. punctatum and A. analis) on the ventral surface, while pit organs were sparse or absent on the ventral surface of rays. All of the species examined here, except for M. australis, also had a "spiracular" group of pit organs adjacent to the eye and/or spiracle. Spiracular pit organs were also recorded for the sawshark Pristiophorus sp. A and the skate Pavoraja nitida, although the remainder of pit organs were not mapped in these species. The distribution and number of pit organs varied both within and among species. Pit organ distribution was asymmetrical in each individual examined, but no particular trend towards left or right "handedness" was observed in any species. Although rays have been thought to have fewer pit organs than sharks in general, this was not the case in the present study. All of the species examined here had few pit organs compared to the pelagic sharks previously documented, but it is not clear whether this is due to ecological or phylogenetic causes. Copyright 2003 Wiley-Liss, Inc.

  11. Prediction of Pitting Corrosion Mass Loss for 304 Stainless Steel by Image Processing and BP Neural Network

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; LIANG Cheng-hao

    2005-01-01

    Image processing technique was employed to analyze pitting corrosion morphologies of 304 stainless steel exposed to FeCl3 environments. BP neural network models were developed for the prediction of pitting corrosion mass loss using the obtained data of the total and the average pit areas which were extracted from pitting binary image. The results showed that the predicted results obtained by the 2-5-1 type BP neural network model are in good agreement with the experimental data of pitting corrosion mass loss. The maximum relative error of prediction is 6.78%.

  12. Fabrication of high nitrogen austenitic stainless steels with excellent mechanical and pitting corrosion properties

    Institute of Scientific and Technical Information of China (English)

    Hua-bing Li; Zhou-hua Jiang; Yang Cao; Zu-rui Zhang

    2009-01-01

    18Cr18Mn2Mo0.9N high nitrogen austenitic stainless steel exhibits high strength and good ductility at room temperature. The steel shows typical duc-tile-brittle transition behavior and excellent pitting corrosion resistance properties.

  13. Study on Deep Well Dewatering Optimization Design in Deep Foundation Pit and Engineering Application

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Based on analyses of the theories of groundwater unsteady flow in deep well dewatering in the deep foundation pit, Theis equations are chosen to calculate and analyze the relationship between water level drawdown of confined aquifer and dewatering duration. In order to reduce engineering cost and diminish detrimental effect on ambient surrounding, optimization design target function based on the control of confined water drawdown and four restriction requisitions based on the control of safe water level, resistance to throwing up from the bottom of foundation pit, avoiding excessively great subsidence and unequal surface subsidence are proposed. A deep well dewatering project in the deep foundation pit is optimally designed. The calculated results including confined water level drawdown and surface subsidence are in close agreement with the measured results, and the optimization design can effectively control both surface subsidence outside foundation pit and unequal subsidence as a result of dewatering.

  14. Extraction and characterization of montmorency (Prunus cerasus L.) sour cherry pit oil

    Science.gov (United States)

    Montmorency sour cherry (Prunus cerasus L.) pit oil was extracted and characterized by various methods including: gas chromatography (GC), liquid chromatography coupled with mass spectrometry (LC-MS), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), differential scanning calorime...

  15. Short convalescence and minimal pain after out-patient Bascom's pit-pick operation

    DEFF Research Database (Denmark)

    Colov, Emilie Palmgren; Bertelsen, Claus Anders

    2011-01-01

    Treatment of pilonidal sinuses with Bascom's pit-pick operation can easily be performed under local analgesia. We describe pain during and after the operation, time to return to work, time to healing and success rate.......Treatment of pilonidal sinuses with Bascom's pit-pick operation can easily be performed under local analgesia. We describe pain during and after the operation, time to return to work, time to healing and success rate....

  16. Clinical and SEM assessment of ART high-viscosity glass-ionomer sealants after 8-13 years in 4 teeth.

    NARCIS (Netherlands)

    Frencken, J.E.F.M.; Wolke, J.G.C.

    2010-01-01

    OBJECTIVES: Resin composite sealants are retained longer than low-viscosity glass-ionomer sealants. Nevertheless, a systematic review showed that there is no evidence that resin composite sealants are superior to low-viscosity glass-ionomers in preventing dentine carious lesion development. This cas

  17. Regulation of cell proliferation and cell density by the inorganic phosphate transporter PiT1

    Directory of Open Access Journals (Sweden)

    Byskov Kristina

    2012-03-01

    Full Text Available Abstact Background The inorganic phosphate (Pi transporter, PiT1 (SLC20A1, is ubiquitously expressed in mammalian cells. It has previously been shown that down-regulation of PiT1 severely impaired the proliferation of two transformed human cells lines, HepG2 and HeLa, and the tumorigenicity of HeLa cells in nude mice. Moreover, PiT1 knock-out mice do not survive past E12.5 and from E10.5, the embryos were found to be growth-retarded and showed reduced proliferation of liver cells. Isolated mouse embryonic fibroblasts with knocked out as well as reduced PiT1 expression levels also exhibited impaired proliferation. Together these results suggest that a certain level of PiT1 is important for proliferation. We have here investigated the role of PiT1 in regulation of cell proliferation using two strictly density-inhibited cells lines, the murine MC3T3-E1 and NIH3T3 cells. Results We found that knock-down of PiT1 in MC3T3-E1 cells led to impaired proliferation supporting that at least a certain level of PiT1 is important for wildtype level of proliferation. We, however, also observed that MC3T3-E1 and NIH3T3 cells themselves regulate their endogenous PiT1 mRNA levels with lower levels in general correlating with decreased proliferation/increased cell density. Moreover, over-expression of human PiT1 led to increased proliferation of both MC3T3-E1 and NIH3T3 cultures and resulted in higher cell densities in cultures of these two strictly density-inhibited cell lines. In addition, when we transformed NIH3T3 cells by cultivation in fetal bovine serum, cells over-expressing human PiT1 formed more colonies in soft agar than control cells. Conclusions We conclude that not only is a certain level of PiT1 necessary for normal cell division as suggested by previously published studies, rather the cellular PiT1 level is involved in regulating cell proliferation and cell density and an increased PiT1 expression can indeed make NIH3T3 cells more sensitive to

  18. Experimental and numerical study on loading rate effects of rock-like material specimens containing two unparallel fissures

    Institute of Scientific and Technical Information of China (English)

    黄彦华; 杨圣奇; 曾卫

    2016-01-01

    A series of laboratory experiments and PFC numerical simulations for rock-like material specimens containing two unparallel fissures were carried out. On the basis of experimental and numerical results, the stress−strain curves, mechanical properties, AE events, cracking behavior and energy characteristics were analyzed to reveal the macro-mechanical behavior and meso-mechanism of pre-fissured specimens under different loading rates. Investigated results show that:1) When the loading rate is relatively low, the stress−strain curves show a brittle response. When the loading rate is relatively high, the curve shows a more ductile response. Both of the peak strength and elastic mudulus increase with the increase of loading rate, which can be expressed as power functions. 2) Four crack types are identified, i.e., tensile crack, shear crack, far-field crack and surface spalling. Moreover, the tensile crack, far-field crack and surface spalling are under tensile mechanism, while the shear crack is under shear mechanism. 3) The drops of the stress−strain curves all correspond to the crack initiation or coalescence, which is also linked to a sudden increasing in the accumulated micro-crack curve. 4) Both of the maximum bond force and energy have the similar trend with the increase of loading rate to peak strength, which indicates that the trend of peak strength can be explained by the meso-mechanics and energy.

  19. Unsuccessful vitrectomy without gas tamponade for macular retinal detachment and retinoschisis without optic disc pit.

    Science.gov (United States)

    Hotta, Kazuki

    2004-01-01

    The mechanism of subretinal fluid accumulation in optic disc pit maculopathy is unknown. A 67-year-old Japanese woman complaining of blurred vision in her right eye presented with a best-corrected visual acuity of 20/200. Slit-lamp biomicroscopy and optical coherence tomography examination showed maculopathy typically associated with optic disc pits, except that the patient had no optic disc pit. Long-acting gas tamponade was required to achieve reattachment of the retina and retinoschisis after initial failure of surgery using surgically induced vitreous detachment without either fluid-air exchange or gas injection. Vitreous traction may not have played a major role in introducing fluid into the submacular space in this case. Gas tamponade may be indispensable to achieve surgical success. This may also pertain to some cases of optic nerve pits.

  20. Design-only conceptual design report for pit disassembly and conversion facility. Rev 0

    Energy Technology Data Exchange (ETDEWEB)

    Zygmunt, S.; Christensen, L.; Richardson, C.

    1997-12-12

    This design-only conceptual design report (DOCDR) was prepared to support a funding request by the Department of Energy (DOE)-Office of Fissile Material Disposition (OFMD) for engineering design of the Pit Disassembly and Conversion Facility (PDCF) Project No. 99-D-141. The PDCF will be used to disassemble the nation`s inventory of surplus nuclear weapons pits and convert the plutonium recovered from those pits into a form suitable for storage, international inspection, and final disposition. The PDCF is a complex consisting of a hardened building that will contain the plutonium processes in a safe and secure manner, and conventional buildings and structures that will house support personnel, systems, and equipment. The PDCF uses the Advanced Recovery and Integrated Extraction System (ARIES), a low waste, modular pyroprocessing system to convert pits to plutonium oxide. The PDCF project consists of engineering and design, and construction of the buildings and structures, and engineering and design, procurement, installation, testing and start-up of equipment to disassemble pits and convert plutonium in pits to oxide form. The facility is planned to operate for 10 years, averaging 3.5 metric tons (3.86 tons) of plutonium metal per year. On conclusion of operations, the PDCF will be decontaminated and decommissioned.

  1. Native gold from volcanic gases at Tolbachik 1975-76 and 2012-13 Fissure Eruptions, Kamchatka

    Science.gov (United States)

    Chaplygin, Ilya; Yudovskaya, Marina; Vergasova, Lidiya; Mokhov, Andrey

    2015-12-01

    Aggregates and euhedral crystals of native gold were found in sublimates formed during New Tolbachik Fissure Eruption in 2012-2013 (NTFE). Gold-bearing sublimate samples were taken from a red-hot (690 °C) degassing fracture in the roof of an active lava tunnel 1.5 km from active Naboko cinder cone in May 2013. The gas condensate collected at 690 °C in this site contains 16 ppb Au, 190 ppb Ag and 1180 ppm Cu compared to 3 ppb Au, 39 ppb Ag and 9.7 ppm Cu in the condensate of pristine magmatic gas sampled at 1030 °C. The 690 °C volcanic gas is most likely a mix of magmatic gas and local snow buried under the lava flows as indicated by oxygen and hydrogen isotope compositions of the condensate. The lower-temperature gas enrichment in gold, copper and chlorine is resulted from evaporation of the 690 °C condensate during forced gas pumping at sampling. Native gold was also found in fumarolic encrustations collected from caverns in basalt lava flows with temperature up to 600 °C in June 2014, in a year after eruption finished. The native gold precipitation in newly formed Cu-rich sublimates together with the well known gold occurrences in cinder cones of 1975-1976 Large Tolbachik Fissure Eruption manifest a transport capability of oxidized volcanic gas.

  2. A Prospective Randomized Trial of Diltiazem Gel and Glyceryl Trinitrate Ointment on Treatment of Chronic Anal Fissure

    Directory of Open Access Journals (Sweden)

    M Akhondi-Meybodi

    2014-12-01

    Methods: This semi-experimental study consisted of sixty six outpatients (34 females and 32 males with chronic anal fissure, who referred to the gastroenterology clinic. Patients were randomly classified into two groups. Group A received GTN ointment (0.03%, whereas group B was treated with Diltiazem gel (2%. The treatment was administered twice daily for 8 weeks. Healing and side-effects were recorded to be compared after 8 weeks. Results: In group A, the anal fissure was thoroughly healed within 53.3% of patients, moderately healed for 6.7% of patients and not healed in 25.8% of patients. Moreover, side-effects were noted in 15(46.9% patients (P= 0.482. Two (6.2% patients had intolerable headache and discontinued the study, 11 (34.3% patients suffered from headache and 2 patients (6.2% were reported to have orthostatic hypotension. In group B, healing occurred in 21(67.7% out of 31 patients and 1 (3.2% case of headache was noted(P= 0.0001. Conclusion: The present study has demonstrated that topical diltiazem can be preferable to GTN owing to the absence of side-effects.

  3. Structural Design and Monitoring Analysis of Foundation Pit Support in Yiwu Huishang Tiandi

    Science.gov (United States)

    Zhang, Chunsu

    2017-08-01

    Huishang Tiandi deep foundation pit in Yiwu is a two-story basement,which is located in the downtown area and adjacent to the city center main traffic trunk. The surrounding environment is too com-plex to slope. The excavation depth is large, the formation is weak and complex, and the groundwater level is high.In order to ensure the safety of the foundation wall and the surrounding environment, the deformation of the foundation pit support is strictly controlled, and the deformation and internal force of the foundation supporting structure and the surrounding building are monitored.The deformation law of the foundation pit is obtained through the analysis of the horizontal displacement, the deformation rate of the supporting struc-ture, the surrounding environment of the foundation pit and the internal force of the anchor cable. The relia-bility and rationality of the design of foundation pit support are verified. It is of reference value for the de-sign and construction of other deep foundation pit engineering in Yiwu area.

  4. DIAGNOdent measurements and correlation with the depth and volume of minimally invasive cavity preparations.

    Science.gov (United States)

    Hamilton, James C; Gregory, William A; Valentine, John B

    2006-01-01

    In this clinical study, DIAGNOdent (KaVo) was used to assess previously diagnosed carious lesions in the pits and fissures of first and second molars. The measurements from this device were correlated with the depth and volume of the cavity preparations that resulted from minimal intervention to remove occlusal carious lesions. Twenty-five patients, 18 years of age and older, who were previously scheduled for an occlusal restoration due to caries, were recruited and enrolled in this clinical study. These patients had 48 qualifying teeth without previous restorations, sealants or other carious lesions. The occlusal surface of each study tooth was cleaned utilizing ProphyFlex2 (KaVo). Two dentists separately traced the pit and fissure system of each tooth using DIAGNOdent for two 15-second periods each. The peak reading of each of the four measurements was recorded. An impression of the occlusal surface of each tooth was recorded with a polyvinyl siloxane bite registration material. The carious lesions were removed with an air abrasion unit employing a 0.015-inch nozzle opening utilizing minimal operative intervention. A low viscosity polyvinyl siloxane was used to take an impression of the cavity preparation impression, using the bite registration impression to form the occlusal surface of the preparation impression. The preparation impression volume was calculated from its weight, using the known density of the impression material. The greatest depth of the preparation was measured. The Pearson correlation coefficient was used to investigate any relationship between depth or volume of the preparation impression and the DIAGNOdent measurements. The correlation for preparation volume and maximum DIAGNOdent measurement was 0.191 (p = 0.189). Other logical subsets of cases also did not result in any statistically significant correlations between the DIAGNOdent readings and the depth or volume of the final cavity preparations.

  5. Mineralization of human premolar occlusal fissures: a quantitative histochemical microanalysis

    OpenAIRE

    Campos, Antonio; Rodriguez, I. A.; Sanchez-Quevedo, M.C.; García, J. M.; Nieto-Albano, O.H.; Gómez de Ferraris, M. E.

    2000-01-01

    The mechanisms of cariogenesis in occlusal fissures remain elusive because of limited information about fissure structure and wall mineralization. The purpose of the present study was to determine the correlation between morphological patterns in occlusal fissures in human premolars and quantitative histochemical patterns of mineralization in the walls of these formations. We used scanning electron microscopy and quantitative X-ray microanalysis with the peak-t...

  6. Identifying and Reducing Health Risks Associated with Open-Air Burn Pits

    Science.gov (United States)

    2013-04-01

    results in the Periodic Occupational Exposure Monitoring Summary ( POEMS ). Based on his review of the POEMS data, CPT Pratt opined: “The long term...is inconclusive regarding whether exposure to burn pit emissions creates a long -term health risk for deployed personnel. Contrary to this position...Air Field was "unhealthy" and concluded that the primary contributor was the burn pit. He also listed potential long -term health risks associated

  7. Acidic pit lakes. The legacy of coal and metal surface mines

    Energy Technology Data Exchange (ETDEWEB)

    Geller, Walter; Schultze, Martin [Helmholtz Centre for Environmental Research - UFZ, Magdeburg (Germany); Wolkersdorfer, Christian (eds.) [Cape Breton Univ., Sydney, NS (Canada). Industrial Research Chair in Mine Water Remediation and Management; International Mine Water Association, Wendelstein (Germany). General Secretary; Kleinmann, Robert

    2013-07-01

    This monograph provides an international perspective on pit lakes in post-mining landscapes, including the problem of geogenic acidification. Much has been learned during the last decade through research and practical experience on how to mitigate or remediate the environmental problems of acidic pit lakes. In the first part of the book, general scientific issues are presented in 21 contributions from the fields of geo-environmental science, water chemistry, lake physics, lake modeling, and on the peculiar biological features that occur in the extreme habitats of acidic pit lakes. Another chapter provides an overview of methods currently used to remediate acidic pit lakes and treat outflowing acidic water. The second part of the book is a collection of regional surveys of pit lake problems from three European countries and Australia, and case studies of various individual representative lakes. A final case study provides an innovative approach to assessing the economic value of new pit lakes and balancing the costs and benefits, a valuable tool for decision makers.

  8. New pollution reduction technologies through tank sealing of slag and ashes pits

    Energy Technology Data Exchange (ETDEWEB)

    Bruell, A.; Revenco, V. [Institutul de Stuidii Si Proiectari Energetice S.A. (ISPE), Bucharest (Hungary)

    2002-07-01

    Under the Romanian environment protection law provision no. 137/1995, the existing slag and ashes pits raise problems due to the exfiltrations from the pits tank towards the phreatic water sheet. The design includes the following steps to be taken: pit bed waterproofing under new works; bed ends sealing, parallel with pit aggradation for dumps in operation; waterproofing of aggradation dikes. The conventional solution is clay plating. When works are performed under bad weather conditions, and clay must be brought from remote distances, the clay plating solution should be compared to the geocomponents one. The latter area combination of geotextiles and bentone material that can be placed easily, joint in situ, and can be paid at negative temperatures. Once wet, geo components become impermeable. The paper describes the sealing performed at the slag and ashes pit of Vales Ceplea at Turceni thermal power plant, and the sealing solution being developed at the Beterega Nord slag and ashes pit at Rovinari thermal power plant. The necessary geophysical characteristics of the material are pointed out.

  9. Computer aided design and analysis of Sapan Dalam open pit mine

    Energy Technology Data Exchange (ETDEWEB)

    Baafi, E.Y.; Milawarma, E.; Cusack, C. [University of Wollongong, Wollongong, NSW (Australia). Dept. of Civil and Mining Engineering

    1995-12-31

    The Sapan Dalam coal deposit of Indonesia consists of ten steeply dipping seams with thicknesses varying between 0.1 and 3.5 m and split by shale clay, silt and sandstone. The area contains four faults dipping about 75{degree} with four to 85 m vertical displacements. The complex nature of the deposit coupled with limited 27 exploration drillholes at an average spacing of 200 m made it difficult to create a realistic geological model. A three-dimensional gridded seam model gave a fair representation of the deposit. Attempts to create an optimum pit using the WHITTLE 3D pit optimiser proved unsuccessful since the pit optimiser is restricted to standard regular or fixed blocks. The gridded seam model was converted to a fixed block model prior to the optimum pit design. Smoothing and pit base controlling were also introduced to obtain a smoother pit. A mining scenario produced 3.6 million tonnes of coal, 28.4 million bcm of waste and 18.1 million US dollars revenue. 3 refs., 6 figs., 1 tab.

  10. Finger nail pitting in psoriasis and its relation with different variables

    Directory of Open Access Journals (Sweden)

    Satyendra Kumar Singh

    2013-01-01

    Full Text Available Incidence of pitting, vary considerably in different types of psoriasis. In clinical practice, toe nail examination is inconvenient. There are inadequate studies which show relation of nail pitting with duration and severity of the disease. The objective was to examine the incidence of finger nail pitting in all types of cutaneous psoriasis and its relation with different variables. This is a clinico-epidemiological study. A careful clinical examination of finger nails was done in day time. Severity of disease was calculated by psoriasis area severity index (PASI. Statistical analysis was done using Microcomputer statistics software (MSTAT. In study group, 621 patients and in control group 350 people were taken. Finger nail pitting was present in 37% (total number was 60 in 12% in study group. In control group, it was present in 10% (in all cases total number was 1 year duration group it was 40.5%.In mild psoriasis, pitting was present in 34.2%, while in severe cases it was 47.6%. Finger nail pitting is an important nail finding in psoriasis and its incidence increases with duration and severity of disease.

  11. Hawaiian fissure fountains: Quantifying vent and shallow conduit geometry, episode 1 of the 1969-1974 Mauna Ulu eruption: Chapter 17

    Science.gov (United States)

    Parcheta, Carolyn; Fagents, Sarah; Swanson, Donald A.; Houghton, Bruce; Ericksen, Todd; Carey, Rebecca; Cayol, Valérie; Poland, Michael P.; Weis, Dominique

    2015-01-01

    Geometries of shallow magmatic pathways feeding volcanic eruptions are poorly constrained, yet many key interpretations about eruption dynamics depend on knowledge of these geometries. Direct quantification is difficult because vents typically become blocked with lava at the end of eruptions. Indirect geophysical techniques have shed light on some volcanic conduit geometries, but the scales are too coarse to resolve narrow fissures (widths typically 1 m). Kīlauea's Mauna Ulu eruption, which started with 30 m. Direct measurements at the ground surface were augmented by tripod-mounted lidar measurements to quantify the shallow conduit geometry for three vents at a resolution factors influencing these parameters. In the past, simplified first-order fissure geometries have been used in computational modeling. Our data can provide more accurate conduit shapes for better understanding of shallow fissure fluid dynamics and how it controls eruptive behavior, especially if incorporated into computer models.

  12. Corrosion pathways in liquid sulfur run-down pits and other liquid sulfur handling facilities

    Energy Technology Data Exchange (ETDEWEB)

    Clark, P.D.; Dowling, N.I.; Huang, M.

    2010-01-15

    This poster presentation explained why sulfur pits deteriorate over time and provided the detailed chemistry of the mechanisms for the deterioration of concrete in sulfur pits. Liquid and solid sulfur may build up in the pore structure of the concrete, which is followed by chemical reactions. The sulfur formation inside the concrete pore structure is catalyzed by concrete constituents. The sulfate formation in sulfur pit concrete was described. The chemical process that produces the corrosion of re-enforcing steel rods used in the construction of sulfur pits was also described. The consequence of such corrosion is the loss of structural integrity. The secondary corrosion processes at concrete pit reinforcing steel were also presented. To limit the deterioration of sulfur pit concrete, high-density silica facing should be used on the concrete to prevent the ingress of gases into the concrete. Silica does not catalyze the conversion of hydrogen disulfide and sulfur dioxide to sulfur, so there is no formation of stable sulfates and acidic intermediates. 8 figs.

  13. Sealants for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Fergus, Jeffrey W. [Auburn University, Materials Research and Education Center, 275 Wilmore Laboratories, Auburn University, AL 36849 (United States)

    2005-09-09

    One of the major challenges for implementation of solid oxide fuel cells (SOFCs) is the development of suitable sealant materials to separate the air and fuel. Several approaches have been used to achieve the necessary adherence, mechanical integrity and stability, including both rigid seals (no applied load during operation) and compressive seals (load applied to seal during operation). The most common approach is to use rigid glass or glass-ceramic seals, the properties of which can be tailored specifically for use in SOFCs through variation of the glass composition. However, these ceramic materials are inherently brittle, so metallic, metallic-ceramic and ceramic-ceramic composite seals, in both the rigid and compressive configurations, have been developed. The use of multiphase seals allows for improvement in factors, such as wettability, compliance at interfaces and strain relief, to improve the gas-tightness and stability of the seal. In this paper, the different approaches for developing SOFC sealants are reviewed. (author)

  14. Botulinum toxin A injection for chronic anal fissures and anal sphincter spasm improves quality of life in recessive dystrophic epidermolysis bullosa

    Directory of Open Access Journals (Sweden)

    Cassandra Chaptini, MBBS

    2015-12-01

    Full Text Available We report a 20-year-old female with generalized, severe, recessive dystrophic epidermolysis bullosa who developed secondary chronic anal fissures. This resulted in anal sphincter spasm and severe, disabling pain. She was treated with five botulinum toxin A injections into the internal anal sphincter over a period of 2 years and gained marked improvement in her symptoms. This case demonstrates the successful use of botulinum toxin A injections to relieve anal sphincter spasm and fissuring, with long-term improvement.

  15. Herniation pits and their renaissance in association with femoroacetabular impingement; Herniation Pits und ihre Renaissance im Zusammenhang mit femoroazetabulaerem Impingement

    Energy Technology Data Exchange (ETDEWEB)

    Panzer, Stephonie [Unfallklinik Murnau (Germany). Radiologie; Augat, P. [Unfallklinik Murnau (Germany). Radiologie; Paracelsus Univ. Salzburg (Austria). Biomechanisches Labor; Scheidler, J. [Radiologischs Zentrum Muenchen-Pasing (Germany). Radiologie

    2010-07-15

    Hernitation pits (HPs) of the femoral neck were first described in 1982. The purpose of this paper is to summarize the information concerning HPs published since then and to show their association with the diagnosis of femoroacetabular impingement (FAI) which has occurred within the last years. HPs are predominantly located at the anterior-superior femoral neck with a typical radiological appearance, which makes it possible to differentiate them from the numerous differential diagnoses mentioned. In the early publications HPs were described as a separate entity, while recent studies increasingly assign them to intra-osseous ganglia. In contrast to the early publications depicting HPs as an incidental finding, they are currently mainly mentioned in association with FAI and at the same time are partly considered to be a radiological indicator of FAI. In summary, HPs should always be recognized and documented because they may contribute to the diagnosis of FAI which is essential for preventing or delaying osteoarthritis of the hip joint in the early stage. (orig.)

  16. An essential primer for understanding the role of topical hemostats, surgical sealants, and adhesives for maintaining hemostasis.

    Science.gov (United States)

    Gabay, Michael; Boucher, Bradley A

    2013-09-01

    A wide variety of topical hemostats are approved as adjunctive therapies in the maintenance of hemostasis during surgical procedures in which conventional methods are insufficient or not practical. A multidisciplinary approach to the selection and application of these agents requires input from all members of the surgical team including surgeons, perioperative nurses, blood bank specialists, and pharmacists. However, pharmacist knowledge regarding topical hemostats may be limited based on lack of formal education within college of pharmacy curricula as well as their use being predominantly in the operating room setting. Furthermore, some of these agents might be procured through central supply rather than the hospital pharmacy. Topical hemostats include agents that act as a mechanical barrier to bleeding and provide a physical matrix for clotting, biologically active agents that catalyze coagulation, combination therapies, and synthetic sealants and adhesives. Although many of the topical hemostats were approved for use before the requirement for clinical trials, this review provides an overview of the available clinical evidence regarding the appropriate uses and safety considerations associated with these agents. Proper use of these agents is vital to achieving the best clinical outcomes. Specifically, knowledge of the contraindications and potential adverse events associated with topical hemostats can help prevent unwanted outcomes. Therefore, an understanding of the benefits and potential risks associated with these agents will allow hospital pharmacists to assist in the development and implementation of institutional policies regarding the safe and effective use of hemostatic agents commonly used in the surgical suite.

  17. Assessment of the effect on blood loss and transfusion requirements when adding a polyethylene glycol sealant to the anastomotic closure of aortic procedures: a case–control analysis of 102 patients undergoing Bentall procedures

    Directory of Open Access Journals (Sweden)

    Natour Ehsan

    2012-10-01

    Full Text Available Abstract Background The use of CoSeal®, a polyethylene glycol sealant, in cardiac and vascular surgery for prevention of anastomotic bleeding has been subject to prior investigations. We analysed our perioperative data to determine the clinical benefit of using polyethylene glycol sealant to inhibit suture line bleeding in aortic surgery. Methods From January 2004 to June 2006, 124 patients underwent aortic surgical procedures such as full root replacements, reconstruction and/or replacement of ascending aorta and aortic arch procedures. A Bentall procedure was employed in 102 of these patients. In 48 of these, a polyethylene glycol sealant was added to the anastomotic closure of the aortic procedure (sealant group and the other 54 patients did not have this additive treatment to the suture line (control group. Results There were no significant between-group differences in the demographic characteristics of the patients undergoing Bentall procedures. Mean EuroSCORES (European System for Cardiac Operative Risk Evaluation were 13.7 ± 7.7 (sealant group and 14.4 ± 6.2 (control group, p = NS. The polyethylene glycol sealant group had reduced intraoperative and postoperative transfusion requirements (red blood cells: 761 ± 863 versus 1248 ± 1206 ml, p = 0.02; fresh frozen plasma: 413 ± 532 versus 779 ± 834 ml, p = 0.009; and less postoperative drainage loss (985 ± 972 versus 1709 ± 1302 ml, p = 0.002. A trend towards a lower rate of rethoracotomy was observed in the sealant group (1/48 versus 6/54, p = 0.07 and there was significantly less time spent in the intensive care unit or hospital (both p = 0.03. Based on hypothesis-generating calculations, the resulting economic benefit conferred by shorter intensive care unit and hospital stays, reduced transfusion requirements and a potentially lower rethoracotomy rate is estimated at €1,943 per patient in this data analysis

  18. DAMAGE MODEL OF CONTROL FISSURE IN PERILOUS ROCK

    Institute of Scientific and Technical Information of China (English)

    CHEN Hong-kai; TANG Hong-mei; YE Si-qiao

    2006-01-01

    Hitherto, perilous rock is the weakest topic in disasters studies. Specially,damage of control fissure under loads is one key technique in study of develop mechanism of perilous rock. Damage division of end area of control fissure was defined by authors,then calculation methods of timed-Poisson's ratio and timed-Young's modulus were established in damage mechanics theory. Further, the authors set up damage constitutive equation of control fissure, which founds important basis to numerical simulation for control fissure to develop.

  19. Discrete element modeling of Martian pit crater formation in response to extensional fracturing and dilational normal faulting

    Science.gov (United States)

    Smart, Kevin J.; Wyrick, Danielle Y.; Ferrill, David A.

    2011-04-01

    Pit craters, circular to elliptical depressions that lack a raised rim or ejecta deposits, are common on the surface of Mars. Similar structures are also found on Earth, Venus, the Moon, and smaller planetary bodies, including some asteroids. While it is generally accepted that these pits form in response to material drainage into a subsurface void space, the primary mechanism(s) responsible for creating the void is a subject of debate. Previously proposed mechanisms include collapse into lave tubes, dike injection, extensional fracturing, and dilational normal faulting. In this study, we employ two-dimensional discrete element models to assess both extensional fracturing and dilational normal faulting as mechanisms for forming pit craters. We also examine the effect of mechanical stratigraphy (alternating strong and weak layers) and variation in regolith thickness on pit morphology. Our simulations indicate that both extensional fracturing and dilational normal faulting are viable mechanisms. Both mechanisms lead to generally convex (steepening downward) slope profiles; extensional fracturing results in generally symmetric pits, whereas dilational normal faulting produces strongly asymmetric geometries. Pit width is established early, whereas pit depth increases later in the deformation history. Inclusion of mechanical stratigraphy results in wider and deeper pits, particularly for the dilational normal faulting, and the presence of strong near-surface layers leads to pits with distinct edges as observed on Mars. The modeling results suggest that a thicker regolith leads to wider but shallower pits that are less distinct and may be more difficult to detect in areas of thick regolith.

  20. Design approaches in quarrying and pit-mining reclamation

    Science.gov (United States)

    Arbogast, Belinda F.

    1999-01-01

    art show a celebration of beauty and experience -- abstract geology. The last design approach combines art and science in a human-nature ecosystem termed integration. With environmental concerns, an operating or reclaimed mine site can no longer be considered isolated from its surroundings. Site analysis of mine works needs to go beyond site-specific information and relate to the regional context of the greater landscape. Understanding design approach can turn undesirable features (mines and pits) into something perceived as desirable by the public.

  1. Viscous Glass Sealants for SOFC Applications

    Energy Technology Data Exchange (ETDEWEB)

    Scott Misture

    2012-09-30

    Two series of silicate glasses that contain gallium as the primary critical component have been identified and optimized for viscous sealing of solid oxide fuel cells operating from 650 to 850°C. Both series of glass sealants crystallize partially upon heat treatment and yield multiphase microstructures that allow viscous flow at temperatures as low as 650°C. A fully amorphous sealant was also developed by isolating, synthesizing and testing a silicate glass of the same composition as the remnant glassy phase in one of the two glass series. Of ~40 glasses tested for longer than 500 hours, a set of 5 glasses has been further tested for up to 1000h in air, wet hydrogen, and against both yttria-stabilized zirconia and aluminized stainless steel. In some cases the testing times reached 2000h. The reactivity testing has provided new insight into the effects of Y, Zr, and Al on bulk and surface crystallization in boro-gallio-silicate glasses, and demonstrated that at least 5 of the newly-developed glasses are viable viscous sealants.

  2. Fibrin Sealants in Dura Sealing: A Systematic Literature Review.

    Directory of Open Access Journals (Sweden)

    Felice Esposito

    Full Text Available Fibrin sealants are widely used in neurosurgery to seal the suture line, provide watertight closure, and prevent cerebrospinal fluid leaks. The aim of this systematic review is to summarize the current efficacy and safety literature of fibrin sealants in dura sealing and the prevention/treatment of cerebrospinal fluid leaks.A comprehensive electronic literature search was run in the following databases: Cochrane Database of Systematic Reviews, Cochrane Central Resister of Controlled Trials, clinicaltrials.gov, MEDLINE/PubMed, and EMBASE. Titles and abstracts of potential articles of interest were reviewed independently by 3 of the authors.A total of 1006 database records and additional records were identified. After screening for duplicates and relevance, a total of 78 articles were assessed by the investigators for eligibility. Thirty-eight were excluded and the full-text of 40 articles were included in the qualitative synthesis. Seven of these included only safety data and were included in the safety assessment. The remaining 33 articles included findings from 32 studies that enrolled a total of 2935 patients who were exposed to fibrin sealant. Among these 33 studies there were only 3 randomized controlled trials, with the remaining being prospective cohort analysis, case controlled studies, prospective or retrospective case series. One randomized controlled trial, with 89 patients exposed to fibrin sealant, found a greater rate of intraoperative watertight dura closure in the fibrin sealant group than the control group (92.1% versus 38.0%, p0.05. Other clinical trials evaluated the effect of fibrin sealant in the postoperative prevention of cerebrospinal fluid leaks. These were generally lower level evidence studies (ie, not prospective, randomized, controlled trials that were not designed or powered to demonstrate a significant advantage to fibrin sealant use. Two small case series studies evaluated the effect of fibrin sealants in

  3. Differential response of pitted morning glory and ivy leaf morning glory to acifluorfen, fomesafen, and lactofen

    Energy Technology Data Exchange (ETDEWEB)

    Higgins, J.M.

    1987-01-01

    Field and laboratory investigations were conducted to examine the response of soybeans (Glycine max (L.) Merr.), pitted morning glory (Ipomoea lacunosa L.number/sup 1/ IPOLA), and ivy leaf morning glory (Ipomoea hederacea (L.) Jacq. number IPOHE) to acifluorfen, fomesafen, and lactofen. In field studies, greatest soybean injury was observed with acifluorfen and lactofen. All treatments provided 80% or greater control of pitted morning glory 15 days after treatment. Only acifluorfen and fomesafen at 0.6 kg ai ha/sup -1/ provided 80% or greater ivy leaf morning glory. The differential response of pitted morning glory and ivy leaf morning glory to these diphenyl ether herbicides was reflected in soybean seed yields. In laboratory studies, 71 to 84% of applied /sup 14/C-acifluorfen was not absorbed into the leaf surface of ivy leaf morning glory. Thirty-two to 46% of applied acifluorfen was recovered from the leaf surface of pitted morning glory. Sixty-four percent of applied /sup 14/C-lactofen was recovered from leaf surfaces of both morning glory species 96 h after treatment. Treated leaves of pitted morning glory contained 35 to 37% more /sup 14/C-acifluorfen than ivy leaf morning glory. Less than 28% of applied /sup 14/C-lactofen was absorbed into treated leaves of both morning glory species at 24, 48, and 96 h harvests.

  4. Clinical and manometric evaluation of women with chronic anal fissure before and after internal subcutaneous lateral sphincterotomy

    Directory of Open Access Journals (Sweden)

    Silvana Marques e Silva

    2012-06-01

    Full Text Available OBJECTIVE: To evaluate clinical and manometric parameters of chronic anal fissure females undergoing lateral internal sphincterotomy (LIS. METHODS: A total of eight women with chronic anal fissure who underwent LIS were included in this study. The preoperative assessment was performed one week before surgery and included general and anorectal examination, anorectal manometry, and Jorge Wexner questionnaire. The post operative follow up was made every 15 days until complete healing. Jorge Wexner questionnaires and anorectal manometry were repeated at 1 month and 3 months after the surgery. Time to healing, manometric changes and complications were assessed. RESULTS: All patients had preoperative increased anal resting pressure. The resting pressures and anal canal length were significantly decreased 3 months after surgery. Patients' complaints of itching and bleeding were also reduced. Fissures healed in 7 patients and median healing time was 45 days. No complications were observed due to the procedure. One patient had transient incontinence to flatus. CONCLUSION: Lateral internal sphincterotomy provided clinical improvement and reduced resting pressure of the internal anal sphincter in women with chronic anal fissure.OBJETIVO: Avaliar a evolução clínica e manométrica de mulheres com fissura anal crônica submetidas à esfincterotomia lateral interna subcutânea. MÉTODOS: Estudo prospectivo com oito pacientes. A avaliação inicial foi realizada por meio de questionários, exame físico e manometria anorretal na semana anterior ao procedimento cirúrgico. Durante o período pós-operatório, as pacientes foram avaliadas clinicamente a cada 15 dias, até a cicatrização completa. Os questionários e a manometria anorretal foram repetidos 1 mês e 3 meses após a operação. Foi avaliado o tempo para cicatrização da fissura, as alterações manométricas e as complicações decorrentes do procedimento. RESULTADOS: Todas as pacientes

  5. Overview of the precursors and dynamics of the 2012-13 basaltic fissure eruption of Tolbachik Volcano, Kamchatka, Russia

    Science.gov (United States)

    Belousov, Alexander; Belousova, Marina; Edwards, Benjamin; Volynets, Anna; Melnikov, Dmitry

    2015-12-01

    We present a broad overview of the 2012-13 flank fissure eruption of Plosky Tolbachik Volcano in the central Kamchatka Peninsula. The eruption lasted more than nine months and produced approximately 0.55 km3 DRE (volume recalculated to a density of 2.8 g/cm3) of basaltic trachyandesite magma. The 2012-13 eruption of Tolbachik is one of the most voluminous historical eruptions of mafic magma at subduction related volcanoes globally, and it is the second largest at Kamchatka. The eruption was preceded by five months of elevated seismicity and ground inflation, both of which peaked a day before the eruption commenced on 27 November 2012. The batch of high-Al magma ascended from depths of 5-10 km; its apical part contained 54-55 wt.% SiO2, and the main body 52-53 wt.% SiO2. The eruption started by the opening of a 6 km-long radial fissure on the southwestern slope of the volcano that fed multi-vent phreatomagmatic and magmatic explosive activity, as well as intensive effusion of lava with an initial discharge of > 440 m3/s. After 10 days the eruption continued only at the lower part of the fissure, where explosive and effusive activity of Hawaiian-Strombolian type occurred from a lava pond in the crater of the main growing scoria cone. The discharge rate for the nine month long, effusion-dominated eruption gradually declined from 140 to 18 m3/s and formed a compound lava field with a total area of ~ 36 km2; the effusive activity evolved from high-discharge channel-fed 'a'a lavas to dominantly low-discharge tube-fed pahoehoe lavas. On 23 August, the effusion of lava ceased and the intra-crater lava pond drained. Weak Strombolian-type explosions continued for several more days on the crater bottom until the end of the eruption around 5 September 2013. Based on a broad array of new data collected during this eruption, we develop a model for the magma storage and transport system of Plosky Tolbachik that links the storage zones of the two main genetically related magma

  6. Research on positioning of Xi'an ground fissures with InSAR quality map

    Science.gov (United States)

    Xu, Li; Zhao, Chao-ying

    2011-02-01

    Xi'an ground fissure is a typical geo-hazard with nearly half a century history, which have been caused serious damages to roads, building and other civil facilities. Based on the theory of deformation de-correlation of the active ground fissures, this manuscript mainly investigated the positioning method of active ground fissures by analyzing the pseudo-coherence map of adaptively filtered differential interferogram. We took two ERS1 SAR data during 1992-1993 as an example to investigate the active fissures position during this period. Consequently, high consistency between newly detected fissures and the ground fissure map from engineering geological investigation can be achieved.

  7. Cost-effectiveness, in a randomized trial, of glass-ionomer-based and resin sealant materials after 4 yr

    NARCIS (Netherlands)

    Goldman, A.S.; Chen, X.; Fan, M.; Frencken, J.E.

    2016-01-01

    This study, conducted from a government program perspective, compared the incremental cost-effectiveness of oral health interventions, in particular their delivery to underserved populations in whom dental sealants constitute an important, high-yielding complement to toothbrushing in dental-caries

  8. Closure Report for Corrective Action Unit 544: Cellars, Mud Pits, and Oil Spills, Nevada National Security Site, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Mark Krauss and Catherine Birney

    2011-05-01

    This Closure Report (CR) presents information supporting the closure of Corrective Action Unit (CAU) 544: Cellars, Mud Pits, and Oil Spills, Nevada National Security Site, Nevada. This CR complies with the requirements of the Federal Fa