A comparative assessment of different techniques for obturation with endoflas in primary molars: An In vivo Study.

PURPOSE: The rationale of this in vivo study was to evaluate and compare different obturation techniques for the intracanal conveyance of Endoflas in the primary molars using conventional radiography. MATERIALS AND METHODS: Thirty-eight children (4-9 years old) with total of 45 pulpally infected primary mandibular molars indicated for pulpectomy were categorized into three groups (i) endodontic pluggers, (ii) lentulospirals, and (iii) NaviTips, respectively, for obturation with Endoflas. The level of obturation and the presence of voids were evaluated radiographically, and the obtained data were statistically analyzed using Chi-square test. RESULTS: The results showed no significant difference between the three techniques to deliver Endoflas. Motor-driven lentulospirals showed better results (64.4% optimal fillings) compared to the pluggers (62.2%), but NaviTips showed poor results (48.9%) for the level of obturation (P > 0.05). Voids were observed in all the techniques used. Pluggers and lentulospirals showed similar results with greater void-free canals, whereas NaviTip system showed more voids which was statistically not significant (P > 0.05). CONCLUSION: Motor-driven lentulospiral and pluggers were almost equally efficient to fill Endoflas to an optimal level, devoid of voids, and both were considered better compared to NaviTip system.

Fundamental studies of methyl iodide adsorption in DABCO impregnated activated carbons.

Methyl iodide capture from a water vapor stream using 1,4-diazabicyclo[2.2.2]octane (DABCO)-impregnated activated carbons is, for the first time, fundamentally described here on the atomic level by means of both molecular dynamics and grand canonical Monte Carlo simulations. A molecular dynamics annealing strategy was adopted to mimic the DABCO experimental impregnation procedure in a selected slitlike carbon pore. Predictions, restricted to the micropore region, are made about the adsorption isotherms of methyl iodide, water, and nitrogen on both impregnated and bare activated carbon models. Experimental and simulated nitrogen adsorption isotherms are compared for the validation of the impregnation strategy. Selectivity analyses of the preferential adsorption toward methyl iodide over water are also reported. These simulated adsorption isotherms sum up to previous experimental studies to provide an enhanced picture for this adsorption system of widespread use at nuclear plant HVAC facilities for the capture of radioactive iodine compounds.

Moving away from methyl bromide: political economy of pesticide transition for California strawberries since 2004.

We examine the progress of the phaseout of the use of the pesticide methyl bromide in the production of California field strawberries. This phaseout is required under the Montreal Protocol and has been contentious in this sector, which receives exemptions from the schedule initially agreed under the treaty, and in international negotiations over the future of the Protocol. We examine the various ex-ante predictions of the impacts on growers, consumers and trade patterns in light of several years of declining allocations under the Critical Use provisions of the Protocol and the 2010 approval of iodomethane for use in California and subsequent 2012 withdrawal of this alternative from the US market. We find that, contrary to ex-ante industry claims, the years of declining methyl bromide use have been years of rising yields, acreage, exports, revenues and market share for California growers, even when faced with a global recession and increased imports from Mexican growers who retain the right to use the chemical under the Protocol. This has implications for the Protocol as a whole and for the remainder of the US phaseout of this chemical in particular.

Contrast-enhanced microcomputed tomography using intraperitoneal contrast injection for the assessment of tumor-burden in liver metastasis models.

OBJECTIVES: To determine if intraperitoneally (IP) administered contrast (iohexol), used in conjunction with a liver-specific agent (Fenestra), can improve measurement precision and accuracy when quantifying tumor volume from micro-CT images of a liver metastasis model. MATERIALS AND METHODS: We compared images acquired with Fenestra alone to images acquired with the combination of Fenestra and IP iohexol. The variability in tumor volume and tumor-burden measurement was evaluated for both techniques. The tumor-burden measurement accuracy of both in vivo techniques was determined by comparison with tumor-burden quantified from ex vivo images. RESULTS: : The addition of IP iohexol decreased measurement variability for individual tumors and overall tumor-burden by 4-8 fold and 2-3 fold, respectively. IP iohexol significantly improved the accuracy of tumor-burden measurement for both low and high tumor-burdened animals. CONCLUSIONS: The combination of IP iohexol with Fenestra provides superior delineation of liver tumors, in comparison to Fenestra alone. The complete tumor delineation provided by this imaging strategy allows for noninvasive quantification of liver tumor-burden.

An in vitro assessment of iodoform gutta-percha.

The purpose of this study was to test the ability of a commercially available iodoform gutta-percha, to delay infiltration of Enterococcus faecalis using a microleakage model. Seventy extracted single-rooted teeth were decoronated and biomechanically prepared using hand and rotary instruments. Thirty roots were obturated laterally with iodoform gutta-percha and another 30 with regular gutta-percha. Both groups were suspended in sterile BHI broth. An inoculum of E. faecalis suspension was placed at the coronal end of each root, incubated and replenished daily. The apical broth was observed for turbidity, indicating bacterial microleakage. Samples were observed for 32 days, and data was analyzed to compare microleakage between the two groups. The results showed no significant difference between the iodoform and regular gutta-percha samples in delaying microleakage of E. faecalis (p > 0.05).

Assessment of antibacterial activity of endodontic sealers by a direct contact test.

It is recognized that endodontic success depends on bacterial elimination from the root and root canal system. Antibacterial activity of endodontic sealers can improve the success rate of endodontic treatment, provided the physical properties are not compromised. The aim of this study was to evaluate the antimicrobial properties of two endodontic sealers (AH26 and Endoflas) using a direct contact test (DCT) which was designed for this purpose. The DCT is based on measuring the effect of close contact between test bacteria and the tested material on the kinetics of bacterial outgrowth using a temperature controlled microplate spectrophotometer (THERMOmax). For comparison, the agar diffusion test (ADT) was performed for both materials. The results of the DCT showed that Endoflas was a significantly more potent bacterial growth inhibitor than AH26, whereas when assessed with the ADT, AH26 was capable of producing a larger inhibition zone than Endoflas. The DCT, by being quantitative and virtually independent of solubility and diffusion, was found more suitable to assay solid surfaces. The results demonstrated the added value of DCT in the study of the antimicrobial properties of endodontic sealers.