Setting time, flow, and radiopacity tests conformed to ANSI/ADA standardization. The dimensional change in all groups and the solubility of Epiphany were greater than values considered acceptable, with higher amounts of calcium ion release. Epiphany SE revealed more organized, compacted, and homogeneous polymers in a reduced resin matrix when compared with the other groups.

Summary Isotopically exchangeable cadmium and zinc (‘E values’) were measured on soils historically contaminated by sewage sludge and ones on zinc‐rich mine spoil. The E‐value assay involves determining the distribution of an added metal isotope, e.g. 109Cd, between the solid and solution phases of a soil suspension. The E values for both metals were found to be robust to changes in the position of the metal solid⇔solution equilibrium, even though the concentration of dissolved metal varied substantially with electrolyte composition and soil:solution ratio. Concentration of labile metal was also invariant over isotope equilibration times of 2–6 days. The use of a submicron filtration procedure, in addition to centrifuging at 2200 g, proved unnecessary if 0.1 m Ca electrolyte was used to suspend the soils. The proportion of ‘fixed’ metal, in non‐labile forms, apparently increased with increasing pH, although there was considerable variation in both sets of contaminated soil. Zinc and cadmium in the sludged soils were similarly labile. Several possible methods for the measurement of chemically reactive metal were explored for comparison with E values, including single extraction with 1 m CaCl2 and a ‘pool depletion’ (PD) method. The latter involves comparing solid⇔solution metal equilibria in two electrolytes with differing degrees of (solution) complex formation, 0.1 m Ca(NO3)2 and CaCl2. Both the single extraction and the PD method gave good estimates of E value for Cd, although the single extraction was more consistent. Neither technique was a useful substitute for determining labile Zn, because of weak chloro‐complexation of Zn2+. We therefore suggest that 1 m CaCl2 extraction of Cd alone be used as an alternative to E values to avoid the inconvenience of isotopic dilution procedures.

No abstract

Objectives The aim of this study was to evaluate the corrosion resistance of heat-treated (Reciproc and WaveOne) and non-heat-treated (ProTaper and Mtwo) superelastic nickel-titanium endodontic files when immersed in a 5.25% sodium hypochlorite solution. Materials and Methods Anodic polarization curves were obtained with potential sweeps that began at the open circuit potential or corrosion potential (E corr ). The pitting potential (E pit ) was identified on the anodic polarization curve as the potential at which a sudden increase in current was observed. The micromorphology of the 28 tested files was analyzed before and after the electrochemical assay using scanning electron microscope (SEM). The data were analyzed using 1-way analysis of variance with the post hoc Bonferroni test (for E corr ) and the Student t -test for independent samples (for E pit ). Results The mean E corr values were 0.506 V for ProTaper, 0.348 V for Mtwo, 0.542 V for Reciproc, and 0.321 V for WaveOne files. Only WaveOne and Protaper files exhibited pitting corrosion, with E pit values of 0.879 V and 0.904 V, respectively. On the SEM images of the ProTaper and WaveOne files, cavities suggestive of pitting corrosion were detected. Conclusions Signs of corrosion were observed in both heat-treated and non-heat-treated files. Of the evaluated files, WaveOne (a heat-treated file) and ProTaper (a non-heat-treated file) exhibited the lowest corrosion resistance.

Objective: The aim of this study was to evaluate the impact on the isolation and characterization of stem cells from pulp tissues obtained through rotary instrumentation techniques compared to the manual technique. Material and Methods: Thirty permanent teeth were included, 15 of which were instrumented with rotational technique (Protaper SX) and other 15 with manual technique. Cells obtained were characterized by flow cytometry and proliferation was evaluated by the MTT assay. The plasticity was evaluated for adipogenic, osteogenic and odontogenic differentiations. Results: Cells isolated from the pulp of permanent teeth, by manual techniques, presented fibroblast morphology and were able to differentiate successfully. All lineages expressed CD29, CD73, CD90, CD105, CD146, CD166 and were negative for CD31, CD34 and CD45. MTT assay showing significantly increased proliferation of hDPSCs in 5 and 7 days of the culture. Conclusion: The present study demonstrated that manual instrumentation technique is one of the best candidates to harvest dental pulp tissue as the dental stem cell source due to ability effective expanded with less tissue invasion. The technique of rotational instrumentation proved to be very harmful to the tissues of the dental pulp, and we can’t obtain cells using this technique.Keywords: Root Canal Therapy; Pulpectomy; Anatomy and Histology; Stem Cell.

No abstract

A BSTRACT Objectives: The purpose of this study was to compare the retention properties between fiberglass pins with chemically activated acrylic resin and metallic intraradicular retainers often used for the purpose of temporary prosthetic retention. Materials and Methods: Two mechanical tests, pushout and traction, were performed on specimens distributed in three groups ( n = 10) for each test; two metal pins G1: Metalpin Ângelus and G2: Provisional Pivot Jon in addition to one fiberglass pin G3: Whitepost DC-E, FGM. One-way analysis of variance (ANOVA) followed by Tukey’s post hoc test was used at the level of significance α = 0.05. Results: The fiberglass pins (G3) showed higher values in the traction test than the metal pins (G1 and G2) with a statistically significant difference ( P < 0.05); however, they performed similarly to the metal pin groups in the pushout test ( P > 0.05). They also presented a lower occurrence of failure in the relining acrylic resin. Conclusion: The study pointed out the use of fiberglass pins as suitable alternatives for provisional intracanal metallic retainers.

Objective: In this study, the effects of the low intensity laser were evaluated in the proliferation of human dental pulp stem cells (DPSCs). Design: These cells were irradiated every 12 hours for 72 hours or at 0 and 48 hours only, with a Red-InGaAlP laser (660nm, 30mW and 0.5 or 1J/cm 2) for 16 or 33 seconds and their proliferation was assessed by the MTT assay. In addition, the Trypan Blue assay was used to analyze the viability of DPSCs in the best parameter recorded by MTT. Results: It was observed that the lowest dose of the laser (0.5J/cm 2) in applications at 0 and 48 hours obtained the higher proliferation rates then all the other groups. Finally, through the Trypan Blue assay, we observed that the viability of the stem cells was not affected by the low intensity laser (0.5J/cm 2). Conclusions: Our data corroborate with other data from the literature and therefore suggest that the low intensity laser can be used in order to improve cell proliferation. However, further studies should be carried out in order to evaluate if these parameters can be used in other cell lines.