A Microleakage Study Of Gutta-percha/ah Plus And Resilon/real Self-etch Systems After Different Irrigation Protocols

The development and maintenance of the sealing of the root canal system is the key to the success of root canal treatment. The resin-based adhesive material has the potential to reduce the microleakage of the root canal because of its adhesive properties and penetration into dentinal walls. Moreover, the irrigation protocols may have an influence on the adhesiveness of resin-based sealers to root dentin. Objective: The objective of the present study was to evaluate the effect of different irrigant protocols on coronal bacterial microleakage of gutta-percha/AH Plus and Resilon/Real Seal Self-Etch systems. Material and Methods: One hundred ninety pre-molars were used. The teeth were divided into 18 experimental groups according to the irrigation protocols and filling materials used. The protocols used were: distilled water; sodium hypochlorite (NaOCl)+EDTA; NaOCl+H3PO4; NaOCl+EDTA+chlorhexidine (CHX); NaOCl+H3PO4+CHX; CHX+EDTA; CHX+ H3PO4; CHX+EDTA+CHX and CHX+H3PO4+CHX. Gutta-percha/AH Plus or Resilon/Real Seal SE were used as root-filling materials. The coronal microleakage was evaluated for 90 days against Enterococcus faecalis. Data were statistically analyzed using Kaplan-Meier survival test, Kruskal-Wallis and Mann-Whitney tests. Results: No significant difference was verified in the groups using chlorhexidine or sodium hypochlorite during the chemo-mechanical preparation followed by EDTA or phosphoric acid for smear layer removal. The same results were found for filling materials. However, the statistical analyses revealed that a final flush with 2% chlorhexidine reduced significantly the coronal microleakage. Conclusion: A final flush with 2% chlorhexidine after smear layer removal reduces coronal microleakage of teeth filled with gutta-percha/AH Plus or Resilon/Real Seal SE.223174179Adamo, H.L., Buruiana, R., Schertzer, L., Boylan, R.J., A comparison of MTA, Super EBA, comparison of MTA, Super EBA, composite and amalgam as root end filling materials using a bacterial microleakage model (1999) Int Endod J, 32, pp. 197-203Akisue, E., Tomita, V.S., Gavini, G., de Poli, F.J.A., Effect of the combination of sodium hypochlorite and chlorhexidine on dentinal permeability and scanning electron microscopy precipitate observation (2010) J Endod, 36, pp. 847-850Assis, D.F., Prado, M., Simão, R.A., Evaluation of the interaction between endodontic sealers and dentin treated with different irrigant solutions (2011) J Endod, 37, pp. 1550-1552Baumgartner, G., Zehnder, M., Paqué, F., Enterococcus faecalis type strain leakage through root canals filled with Gutta-Percha/ AH Plus or Resilon/Epiphany (2007) J Endod, 33, pp. 45-47Berber, V.B., Gomes, B.P., Sena, N.T., Vianna, M.E., Ferraz, C.C., Zaia, A.A., Efficacy of various concentrations of NaOCl and instrumentation techniques in reducing Enterococcus faecalis within root canals and dentinal tubules (2006) Int Endod J, 39, pp. 10-17Carrilho, M.R., Carvalho, R.M., Goes, M.F., di Hipólito, V., Geraldeli, S., Tay, F.R., Chlorhexidine preserves dentin bond in vitro (2007) J Dent Res, 86, pp. 90-94Chailertvanitkul, P., Saunders, W.P., Mackenzie, D., Coronal leakage of obturated root canals after long-term storage using a polymicrobial marker (1997) J Endod, 23, pp. 610-613De-Deus, G., Namen, F., Galan Jr., J., Zehnder, M., Soft chelating irrigation protocol optimizes bonding quality of Resilon/Epiphany root fillings (2008) J Endod, 34, pp. 703-705Fransen, J.N., He, J., Glickman, G.N., Rios, A., Shulman, J.D., Honeyman, A., Comparative assessment of ActiV GP/glass ionomer sealer, Resilon/Epiphany, and gutta-percha/AH plus obturation: A bacterial leakage study (2008) J Endod, 34, pp. 725-727Gomes, B.P., Sato, E., Ferraz, C.C., Teixeira, F.B., Zaia, A.A., Souza-Filho, F.J., Evaluation of time required for recontamination of coronally sealed canals medicated with calcium hydroxide and chlorhexidine (2003) Int Endod J, 36, pp. 604-609Hashem, A.A., Ghoneim, A.G., Lutfy, R.A., Fouda, M.Y., The effect of different irrigating solutions on bond strength of two root canalfilling systems (2009) J Endod, 35, pp. 537-540Hirai, V.H., Silva, N.U.X., Westphalen, V.P., Perin, C.P., Carneiro, E., Fariniuk, L.F., Comparative analysis of leakage in root canal fillings performed with gutta-percha and Resilon cones with AH Plus and Epiphany sealers (2010) Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 109, pp. e131-e135Imura, N., Otani, S.M., Campos, M.J., Jardim Jr., E.G., Zuolo, M.L., Bacterial penetration through temporary restorative materials in root-canal-treated teeth in vitro (1997) Int Endod J, 23, pp. 1-5Jacobovitz, M., Vianna, M.E., Pandolfelli, V.C., Oliveira, I.R., Rossetto, H.L., Gomes, B.P., Root canal filling with cements based on mineral aggregates: An in vitro analysis of bacterial microleakage (2009) Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 108, pp. 140-144Malone III, K.H., Donnelly, J.C., In vitro evaluation of coronal microleakage in obturated root canals without restorations (1997) J Endod, 23, pp. 35-38Nair, U., Ghattas, S., Saber, M., Natera, M., Walker, C., Pileggi, R., A comparative evaluation of the sealing ability of 2 root-end filling materials: An in vitro leakage study using Enterococcus faecalis (2011) Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 112, pp. e74-e77Neelakantan, P., Subbarao, C., Subbarao, C.V., De-Deus, G., Zehnder, M., The impact of root dentine conditioning on sealing ability and push-out bond strength of an epoxy resin root canal sealer (2011) Int Endod J, 44, pp. 491-498Park, D.S., Torabinejad, M., Shabahang, S., The effect of MTAD on the coronal leakage of obturated root canals (2004) J Endod, 30, pp. 890-892Prado, M., Gusman, H., Gomes, B.P., Simão, R.A., Scanning electron microscopic investigation of the effectiveness of phosphoric acid in smear layer removal when compared with EDTA and citric acid (2011) J Endod, 37, pp. 255-258Prado, M., Simão, R.A., Gomes, B.P., Effect of different irrigation protocols on resin sealer bond strength to dentin (2013) J Endod, 39, pp. 689-692Rosenthal, S., Spångberg, L., Safavi, K., Chlorhexidine substantivity in root canal dentin (2004) Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 98, pp. 488-492Saleh, I.M., Ruyter, I.E., Haapasalo, M., ørstavik, D., Bacterial penetration along different root canal filling materials in the presence or absence of smear layer (2008) Int Endod J, 41, pp. 32-40Sharifian, M.R., Shokouhinejad, N., Aligholi, M., Jafari, Z., Effect of chlorhexidine on coronal microleakage from root canals obturated with Resilon/Epiphany Self-Etch (2010) J Oral Sci, 52, pp. 83-87Shemesh, H., Wu, M.K., Wesselink, P.R., Leakage along apical root fillings with and without smear layer using two different leakage models: A two-month longitudinal ex vivo study (2006) Int Endod J, 39, pp. 968-976Shipper, G., ørstavik, D., Teixeira, F.B., Trope, M., An evaluation of microbial leakage in roots filled with a thermoplastic synthetic polymer-based root canal filling material (Resilon) (2004) J Endod, 30, pp. 342-347Shokouhinejad, N., Sharifian, M.R., Aligholi, M., Assadian, H., Tabor, R.K., Nekoofar, M.H., The sealing ability of resilon and gutta-parcha following different smear layer removal methods: An ex vivo study (2010) Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 110, pp. e45-e49Stratton, R.K., Apicella, M.J., Mines, P., A fluid filtration comparison of gutta-percha versus Resilon, a new soft resin endodontic obturation system (2006) J Endod, 32, pp. 642-645Vianna, M.E., Gomes, B.P., Sena, N.T., Zaia, A.A., Ferraz, C.C.R.F., Souza-Filho, F.J., In vitro 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The Spatial Properties of L- and M-Cone Inputs to Electroretinograms That Reflect Different Types of Post-Receptoral Processing

yesWe studied the spatial arrangement of L- and M-cone driven electroretinograms (ERGs) reflecting the activity of magno- and parvocellular pathways. L- and M-cone isolating sine wave stimuli were created with a four primary LED stimulator using triple silent substitution paradigms. Temporal frequencies were 8 and 12 Hz, to reflect cone opponent activity, and 30, 36 and 48 Hz to reflect luminance activity. The responses were measured for full-field stimuli and for different circular and annular stimuli. The ERG data confirm the presence of two different mechanisms at intermediate and high temporal frequencies. The responses measured at high temporal frequencies strongly depended upon spatial stimulus configuration. In the full-field conditions, the L-cone driven responses were substantially larger than the full-field M-cone driven responses and also than the L-cone driven responses with smaller stimuli. The M-cone driven responses at full-field and with 70° diameter stimuli displayed similar amplitudes. The L- and M-cone driven responses measured at 8 and 12 Hz were of similar amplitude and approximately in counter-phase. The amplitudes were constant for most stimulus configurations. The results indicate that, when the ERG reflects luminance activity, it is positively correlated with stimulus size. Beyond 35° retinal eccentricity, the retina mainly contains L-cones. Small stimuli are sufficient to obtain maximal ERGs at low temporal frequencies where the ERGs are also sensitive to cone-opponent processin

Number of consumers and days of display necessary for the assessment of meat colour acceptability

Visual assessment is regarded as the gold standard to evaluate meat colour shelf-life, but it is costly and time consuming. To address this issue, this paper aims to evaluate the number of consumers and days of display that are necessaries in order to assess the colour shelf-life of meat, presented with different methods, all using images. Photographs of thirty-six lamb steaks were taken just after cutting (day 0) and on each of the following days until the 14th day of display under standardized conditions. Images were presented in three different manners: 1) with days of display and animals in random order (Random); 2) days of display in sequential and animals in random order (Sequential); and, 3) days of display and animals in sequential order (Animal); they were presented to 211 consumers who evaluated visual acceptability on a 9-point scale. At day zero, visual acceptability scores were the highest in Animal, followed by Sequential, and then by the Random (P <.05) method. Scores decreased over time for all methods tested (P <.05). The Random method presented the highest standard deviation; however, an increase in standard deviation among consumers along days of display was observed for all methods tested (P <.05). Shelf-life determined by regression varied according to the method of presentation (7.83, 7.00 and 7.54 days for Random, Sequential and Animal, respectively). A minimum number of 4 day points before and 4 day points after neutral scores had been reached (scores = 5.0) were necessary in order to obtain a robust model. The minimum number of required consumers (a = 0.05; d = 0.1 and ß = 0.2 or 0.1) varied according to methodology: it was 81 to 109 consumers for Random, 69 to 92 for Sequential, and 55 to 74 for Animal. Our study indicates that an optimal number of days and evaluators can be calculated depending on the manner of sample presentation. These findings should be taken into account in further studies that aim to balance data reliability with the cost involved in meat colour analyses

Exciton G Factor Of Type-ii Inp Gaas Single Quantum Dots

We investigated the magneto-optical properties of type-II InP GaAs quantum dots using single-dot spectroscopy. The emission energy from individual dots presents a quadratic diamagnetic shift and a linear Zeeman splitting as a function of magnetic fields up to 10 T, as previously observed for type-I systems. We analyzed the in-plane localization of the carriers using the diamagnetic shift results. The values for the exciton g factor obtained for a large number of a InP GaAs dots are mainly constant, independent of the emission energy, and therefore, of the quantum dot dimensions. The result is attributed to the weak confinement of the holes in type-II InP GaAs quantum dots. © 2006 The American Physical Society.733Toda, Y., Shinomori, S., Suzuki, K., Arakawa, Y., (1998) Appl. Phys. Lett., 73, p. 517. , APPLAB 0003-6951 10.1063/1.121919Bayer, M., Kuther, A., Schäfer, F., Reithmaier, J.P., Forchel, A., (1999) Phys. Rev. B, 60, p. 8481. , PRBMDO. 0163-1829. 10.1103/PhysRevB.60.R8481Sugisaki, M., Ren, H.-W., Nishi, K., Sugou, S., Okuno, T., Masumoto, Y., (1998) Physica B, 256-258, p. 169. , PHYBE3 0921-4526Kotlyar, R., Reinecke, T.L., Bayer, M., Forchel, A., (2001) Phys. Rev. B, 63, p. 085310. , PRBMDO 0163-1829 10.1103/PhysRevB.63.085310Ribeiro, E., Govorov, A.O., Carvalho Jr., W., Medeiros-Ribeiro, G., (2004) Phys. Rev. Lett., 92, p. 126402. , PRLTAO 0031-9007 10.1103/PhysRevLett.92.126402Janssens, K.L., Partoens, B., Peeters, F.M., (2002) Phys. Rev. B, 66, p. 075314. , PRBMDO 0163-1829 10.1103/PhysRevB.66.075314Kalameitsev, A.B., Kovalev, V.M., Govorov, A.O., (1989) JETP Lett., 68, p. 669. , JTPLA2 0021-3640 10.1134/1.567926Sugisaki, M., Ren, H.W., Nair, S.V., Nishi, K., Masumoto, Y., (2002) Phys. Rev. B, 66, p. 235309. , PRBMDO 0163-1829 10.1103/PhysRevB.66.235309Godoy, M.P.F., Nakaema, M.K.K., Iikawa, F., Carvalho Jr., W., Ribeiro, E., Gobby, A.L., (2004) Rev. Sci. Instrum., 75, p. 1947. , RSINAK 0034-6748 10.1063/1.1753090Walck, S.N., Reinecke, T.L., (1998) Phys. Rev. B, 57, p. 9088. , PRBMDO 0163-1829 10.1103/PhysRevB.57.9088Laheld, U.E.H., Pedersen, F.B., Hemmer, P.C., (1993) Phys. Rev. B, 48, p. 4659. , PRBMDO 0163-1829 10.1103/PhysRevB.48.4659Bastard, G., Mendez, E.E., Chang, L.L., Esaki, L., (1982) Phys. Rev. B, 26, p. 1974. , PRBMDO 0163-1829 10.1103/PhysRevB.26.1974Nakaoka, T., Saito, T., Tatebayashi, J., Arakawa, Y., (2004) Phys. Rev. B, 70, p. 235337. , PRBMDO 0163-1829 10.1103/PhysRevB.70.235337Yugova, I.A., Ya. Gerlovin, I., Davydov, V.G., Ignatiev, I.V., Kozin, I.E., Ren, H.W., Sugisaki, M., Masumoto, Y., (2002) Phys. Rev. B, 66, p. 235309. , PRBMDO 0163-1829 10.1103/PhysRevB.66.235309Willmann, F., Suga, S., Dreybrodt, W., Cho, K., (1974) Solid State Commun., 14, p. 783. , SSCOA4 0038-1098Landi, S.M., Tribuzy, C.V.B., Souza, P.L., Butendeich, R., Bittencourt, A.C., Marques, G.E., (2003) Phys. Rev. B, 67, p. 085304. , PRBMDO 0163-1829 10.1103/PhysRevB.67.08530

Nucleation and growth of biomimetic apatite layers on 3D plotted biodegradable polymeric scaffolds : effect of static and dynamic coating conditions

Apatite layers were grown on the surface of newly developed starch/polycaprolactone (SPCL)-based scaffolds by a 3D plotting technology. To produce the biomimetic coatings, a sodium silicate gel was used as nucleating agent, followed by immersion in a simulated body fluid (SBF) solution. After growing a stable apatite layer for 7 days, the scaffolds were placed in SBF under static, agitated (80 strokes min!1) and circulating flow perfusion (Q = 4 ml min!1; tR = 15 s) for up to 14 days. The materials were characterized by scanning electron microscopy/energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and thin-film X-ray diffraction. Cross-sections were obtained and the coating thickness was measured. The elemental composition of solution and coatings was monitored by inductively coupled plasma spectroscopy. After only 6 h of immersion in SBF it was possible to observe the formation of small nuclei of an amorphous calcium phosphate (ACP) layer. After subsequent SBF immersion from 7 to 14 days under static, agitated and circulating flow perfusion conditions, these layers grew into bone-like nanocrystalline carbonated apatites covering each scaffold fiber without compromising its initial morphology. No differences in the apatite composition/chemical structure were detectable between the coating conditions. In case of flow perfusion, the coating thickness was significantly higher. This condition, besides mimicking better the biological milieu, allowed for the coating of complex architectures at higher rates, which can greatly reduce the coating step.The authors acknowledge the Portuguese Foundation for Science and Technology (PhD grant to A.L.O., SFRH/BD/10956/2002 and post-doctoral Grant to R.A.S., SFRH/BPD/17151/2004, under the POCTI Program). This work was partially supported by FCT through POCTI and/or FEDER programmes and also partially supported by the EU Project HIPPOCRATES (NMP3-CT-2003-505758) and EXPERTISSUES (NMP-CT-2004-500283)

The Relativistic Factor in the Orbital Dynamics of Point Masses

There is a growing population of relativistically relevant minor bodies in the Solar System and a growing population of massive extrasolar planets with orbits very close to the central star where relativistic effects should have some signature. Our purpose is to review how general relativity affects the orbital dynamics of the planetary systems and to define a suitable relativistic correction for Solar System orbital studies when only point masses are considered. Using relativistic formulae for the N body problem suited for a planetary system given in the literature we present a series of numerical orbital integrations designed to test the relevance of the effects due to the general theory of relativity in the case of our Solar System. Comparison between different algorithms for accounting for the relativistic corrections are performed. Relativistic effects generated by the Sun or by the central star are the most relevant ones and produce evident modifications in the secular dynamics of the inner Solar System. The Kozai mechanism, for example, is modified due to the relativistic effects on the argument of the perihelion. Relativistic effects generated by planets instead are of very low relevance but detectable in numerical simulations

Search for the Rare Decay KL --> pi0 ee

The KTeV/E799 experiment at Fermilab has searched for the rare kaon decay KL--> pi0ee. This mode is expected to have a significant CP violating component. The measurement of its branching ratio could support the Standard Model or could indicate the existence of new physics. This letter reports new results from the 1999-2000 data set. One event is observed with an expected background at 0.99 +/- 0.35 events. We set a limit on the branching ratio of 3.5 x 10^(-10) at the 90% confidence level. Combining the results with the dataset taken in 1997 yields the final KTeV result: BR(KL --> pi0 ee) < 2.8 x 10^(-10) at 90% CL.Comment: 4 pages, three figure