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The main objective of this study was to evaluate the applicability and performance of a non-woven fabric filter designed as a biological post-treatment for an upflow anaerobic sludge blanket (UASB) reactor in wastewater treatment, with a specific focus on nitrification. The filter was set up to operate intermittently with a downward flow. It was constructed using polyvinyl chloride pipe with a diameter of 100 mm and a total height of 2 m. The filter medium comprised multiple non-woven fabric layers in discs forms, totaling 30 cm height, and covering the entire diameter of the reactor. Two distinct application rates were assessed in two phases: Phase I with a flow rate of 6 L·day−1 and an applied surface load of 0.76 m3·m−2·d−1 and Phase II with a flow rate of 9 L·day−1 and applied surface load of 1 m3·m−2·d−1. Chemical characterization was conducted on the influent and effluent of the filter, and quantification of nitrifying bacteria (ammonia-oxidizing bacteria [AOB] and nitrite-oxidizing bacteria [NOB]) was also performed. The results indicate that the average pH values of the effluent for both phases remained similar to the influent, at approximately eight, indicating that the flow rate difference did not significantly affect pH. However, significant alkalinity consumption was observed in both phases, with an average variation between influent and effluent of 186 (28%) and 169 mgCaCO3L−1 (31%) for Phases I and II, respectively. Ammonium nitrogen reduction was substantial: Phase I achieved 36% ammonia removal, with nitrite concentrations of 9.8 mgN.L−1 and nitrate concentrations of 13.7 mgN.L−1. Phase II achieved 54% ammonia removal, with nitrite concentrations of 2.1 mgN.L−1 and nitrate concentrations of 3.7 mgN.L−1. Regarding the quantification of AOB resulted in most probable numbers (MPN) of 8.3 × 105 and 1.6 × 108 per 100 mL, for Phases I and II, respectively. NOB were quantified at 2.5 × 103 MPN·100 mL−1 during the second phase. The findings demonstrate the potential of non-woven fabric filter as an effective post-treatment option for UASB reactor effluent, improving the quality of treated wastewater by physically removing organic products and enhancing nitrification processes. [ABSTRACT FROM AUTHOR]

Background: Eccentric instruments have been proposed as more effective and less time‐consuming for endodontic instrumentation. Aim: To compare biomechanical outcomes of different instrumentation systems and time undertaken for instrumentation in resin prototypes. Design: Sixty standardized prototypes of mandibular second primary molars were instrumented according to the following systems: K‐files, ProTaper Next (PTN), XP‐endo Shaper (XPS), XP‐endo Finisher (XPF), XP–Clean (XPC), and Sequence Baby File (SBF; n = 10/each). Irrigation was performed with saline with simultaneous aspiration, and time spent was recorded. The prototypes were micro‐CT‐scanned before and after the instrumentation, and image sets were reconstructed and registered. Non‐instrumented areas, accumulated debris, removed root material volume, and canal transportation were quantified. Data were analyzed through ANOVA, the Kruskal–Wallis test, and the Wilcoxon signed‐rank test (α = 5%). Results: K‐files and SBF resulted in more instrumentation time (p <.05). SBF, XPC and PTN removed less root dentine (p <.05), but PTN left more untouched areas (p <.05). Accumulated debris were lower for XPC and SBF (p <.05). Canal transportation was similar among the groups. Conclusion: Rotary systems reduced instrumentation time, whereas SBF and XPC resulted in more conservative instrumentation, with less debris accumulation and non‐instrumented areas. A dedicated paediatric endodontic system (SBF) outperformed eccentric instruments in terms of effectiveness. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the influence of different preparation tapers on the reduction in planktonic bacteria and biofilms of Enterococcus faecalis and Candida albicans in the apical third (4 mm) of the mesial roots of mandibular molars, correlating decontamination with canal shape. Methodology: After microtomography analysis for morphological standardization of the canals, 48 mandibular molar roots, each containing two canals (96 canals), were contaminated with E. faecalis and C. albicans and divided into four groups (n = 11) for canal instrumentation using ProDesign Logic 2 files with different tapers G (.03): # 25.03; G (.04): # 25.04; G (.05): # 25.05; and G (.06): # 25.06 and irrigation with 2.5% sodium hypochlorite. Four roots were examined under a scanning electron microscope (SEM) to qualitatively assess biofilm formation. Eight roots were used as the negative control group (samples were not contaminated). Bacteriological samples were taken exclusively from the apical third of the roots before and after chemical–mechanical preparation and bacterial counts were determined (CFU/mL). The final micro‐CT scan was used to quantify the volume variation and unprepared canal area in the apical third. Statistical analysis was performed using the Kruskal–Wallis, Student–Newman–Keuls and Wilcoxon tests for analysis of microbiological data. anova and the Tukey or Games–Howell test were used for analysis of micro‐CT data and Spearman's test for correlations (α = 5%). Results: All groups showed a significant reduction in bacteria (p <.05), with no statistically significant difference between groups. There was no significant difference in per cent volume increase between groups. The unprepared area (Δ%) was affected by the file used (p =.026) and was significantly lower for G (.06) compared to G (.03). There was no statistically significant correlation among bacterial reduction, volume and unprepared area (p >.05). Conclusion: The different preparation tapers influenced root canal shaping in the apical third but did not improve decontamination in this region. [ABSTRACT FROM AUTHOR]

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The objective of the study was to investigate the 5.25% sodium hypochlorite (NaOCl) penetration into the dentinal tubules after different irrigation methods. Seventy canines were stained with 1% crystal violet and divided into groups (n = 20): GEC—EasyClean; GPUI—E1 Irrisonic ultrasonic insert; GXP—XP‐Endo finisher; GPC—conventional irrigation and GNC—stained tooth without irrigation. Axial sections (16×) were assessed and irrigant penetration was quantified as a bleaching halo on the surface of the apical, middle and coronal third. In the apical third, GPUI promoted greater NaOCl penetration (p < 0.05). GXP was better than GEC (p < 0.05), as was GPC (p > 0.05). The GPUI and GXP groups were similar in the middle and coronal third (p > 0.05). GPUI and GXP showed better results than GEC (p < 0.05). GPUI was more effective in the apical third and like GXP in the cervical and middle third. [ABSTRACT FROM AUTHOR]