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This study analyzed the quality of obturation and physical properties of MTA Fillapex and AH Plus sealer. A sample of 30 human maxillary central incisors were instrumented with Protaper until a F5 (50/05) file. Both sealers were mixed with Rhodamine-B dye to allow visualization on a confocal laser-scanning microscope (CLSM). Next, the canals were filled using the single cone technique. After setting, all samples were sectioned at 2, 4, and 6 mm from the apex. CLSM was used to analyze the gaps and sealer penetration into the dentinal tubules. All samples were scanned 10 mu m below the dentin surface and images were recorded at 100x magnification using the fluorescent mode. Additionally, the solubility, flowability and setting time of the sealers were evaluated. All the measured quantities of the examined materials were evaluated for significant differences by means of statistical analysis. The CLSM analysis of the MTA Fillapex showed the highest percentage of gaps at all sections (P = 0.0001). Physical tests revealed adequate properties for both sealers except for a higher solubility of the MTA Fillapex (P = 0.0001). The MTA Fillapex presented flowability and intratubular penetration similar to the AH Plus. Nevertheless, the MTA Fillapex sealer presented a higher solubility and considerable quantity of gaps between the sealer/dentin interface in relation to the AH Plus sealer. Clinicians must take into consideration, the quality of endodontic sealers as it is essential in the outcome of the root canal filling. Microsc. Res. Tech. 77:1031-1036, 2014. (c) 2014 Wiley Periodicals, Inc.

Aim To evaluate the radiopacity, setting time, pH level, calcium ion release and solubility of white mineral trioxide aggregate (MTA; Angelus, Londrina, Pr, Brazil) with different powder-to-water ratios. Methodology Three MTA groups were prepared using 4 : 1, 3 : 1 and 2 : 1 powder-to-water ratios. For the radiopacity analysis, the 10 × 1 mm specimens were arranged on occlusal films with a cylinder of dentine and an aluminium stepwedge. The digitized radiographs were evaluated with Digora 1.51 software to determine the radiographic density. The setting time test was performed according to the American Society for Testing and Materials 266/08 standard specifications, but the specimens were made according to International Organization for Standardization 6876:2001. Thirty acrylic teeth with root-end filling material were immersed in ultrapure water for measurement of pH level and calcium ion release (atomic absorption spectrophotometer) at 3, 24, 72 and 168 h. In the solubility test, the root-end fillings of 30 acrylic teeth were scanned twice by a Micro-CT, before and after immersion in ultrapure water for 168 h. Digital data were reconstructed, and the volume (mm3) of the samples was obtained using CTan software (CTan v1.11.10.0, SkyScan). The data were statistically analysed by the anova, Tukey, Kruskal–Wallis and Dunn's tests. Results The radiopacity was higher (P

Aim To analyse several physicochemical properties of AH Plus (Dentsply DeTrey, Konstanz, Germany), including setting time, flow, radiopacity and the degree of conversion (DC); and to correlate the results with the source of the material: from the beginning, middle or end of the tubes in which they were supplied. Methodology Three experimental groups were established for each property investigated. Group 1 corresponded to material taken from the beginning of tubes A and B; Group 2 corresponded to material taken from the middle of each tube; and group 3 corresponded to that from the end of each tube. The setting time, flow and radiopacity were studied according to American National Standards Institute/American Dental Association (ANSI/ADA) Specification 57. DC was determined from infrared spectra, which were recorded at 1-h intervals for the first 6 h; then, at 2-h intervals for the next 14 h; then, at 24 and 30 h. Data were analysed statistically by analysis of variance (anova), Tukey–Kramer, Kruskal–Wallis and Dunn tests, with a significance level of 5%. Results Group 1 had a significantly longer setting time (2303 ± 1058 min) (P 0.05). Conclusion The results suggest that segregation occurs between the organic and inorganic components of AH Plus sealer, thereby changing the setting time, flow and radiopacity.

Ordinola-Zapata R, Bramante CM, Cavenago B, Graeff MSZ, Gomes de Moraes I, Marciano M, Duarte MAH. Antimicrobial effect of endodontic solutions used as final irrigants on a dentine biofilm model. International Endodontic Journal, 45, 162–168, 2012. Abstract Aim To evaluate the residual biovolume of live bacterial cells, the mean biofilm thickness and the substratum coverage found in mixed biofilms treated with different endodontic irrigant solutions. Methodology Twenty-five bovine dentine specimens were infected intraorally using a removable orthodontic device. Five samples were used for each irrigant solution: 2% chlorhexidine, 1% sodium hypochlorite (NaOCl), 10% citric acid, 17% EDTA and distilled water. The solutions were used for 5 min. The samples were stained using the Live/Dead technique and evaluated using a confocal microscope. Differences in the amount of total biovolume (μm3), number of surviving cells (μm3), mean biofilm thickness (μm) and substratum coverage (%) of the treated biofilms were determined using nonparametric statistical tests (P 0.05). The lower values of the studied parameters were found in 1% NaOCl-treated dentine (P 0.05). Conclusions One per cent sodium hypochlorite was the only irrigant that had a significant effect on biofilm viability and architecture.

Marciano MA, Ordinola-Zapata R, Cunha TVRN, Duarte MAH, Cavenago BC, Garcia RB, Bramante CM, Bernardineli N, Moraes IG. Analysis of four gutta-percha techniques used to fill mesial root canals of mandibular molars. International Endodontic Journal. Abstract Aim To compare the percentage of gutta-percha, sealer and voids and the influence of isthmuses in mesial root canals of mandibular molars filled with different techniques. Methodology Canals in 60 mesial roots of mandibular first molars were prepared with ProTaper instruments to size F2 (size 25, 0.08 taper) and filled using a single-cone, lateral compaction, System B or Thermafil techniques. An epoxy resin sealer was labelled with Rhodamine-B dye to allow analysis under a confocal microscope. The percentage of gutta-percha, sealer and area of voids was calculated at 2, 4 and 6 mm from the apex, using Image Tool 3.0 software. Statistical analysis was performed using nonparametric Kruskal–Wallis and Dunn tests (P