Analysis of Demineralized Chemical Substances for Disinfecting Gutta-percha Cones.

INTRODUCTION: The aim of the present research was to evaluate the effectiveness of 5% malic acid, 17% EDTA and 10% citric acid solutions used to disinfect gutta-percha cones contaminated by Enterococcusfaecalis (ATCC 29212). METHODS AND MATERIALS: Two hundred and ten previously sterilized gutta-percha cones were contaminated with E. faecalis at concentration of 1.5×108 CFU/mL. The cones were immersed in 5% malic acid, 17% EDTA, 10% citric acid, 1% NaOCl and 2.5% NaOCl for 1, 5 and 10 min. Then each cone was kept in Eppendorf tubes containing BHI sterile solution at 37°C for 48 h. The presence of turbidity in BHI solution was analyzed. The results were statistically analyzed by Kruskal-Wallis test and 5% Dunn comparisons. P-value was considered statistically significant when P<0.05. RESULTS: Regardless of exposure time, 1% NaOCl and 2.5% NaOCl were the most effective agents for rapid disinfection of gutta-percha cones (P<0.001). All specimens immersed in experimental demineralized solutions presented bacterial growth (P>0.05). CONCLUSION: Demineralized solutions tested were not effective for elimination of Enterococcus faecalis on the surface of gutta-percha cones.

Root ZX Electronic Foramen Locator: An Ex Vivo Study of Its Three Models' Precision and Reproducibility.

Although Root ZX is considered the gold standard electronic foramen locator (EFL), two variations of this device were launched, however without different operating mechanisms. This investigation aims to evaluate the precision of Root ZX (RZX), Root ZX II (RII), and Root ZX Mini (RM) EFLs. After access cavity preparation, 32 mandibular single rooted human premolars had their real length measured with the aid of a #15 K-type manual file under magnification (25x). Electronic measurements were performed by the devices in an alternate order until the apical foramen was reached (0.0). Each measurement was performed with adjusted file to the real length of the teeth and verified with a digital caliper. The accuracy of the EFLs was 68.8% (RZX), 65.8% (RII), and 68.8% (RM), considering ±0.5 mm as a margin of tolerance. The mean errors of the devices were 0.37 ± 0.25 mm (RZX), 0.41 ± 0.34 mm (RII), and 0.32 ± 0.28 mm (RM). ANOVA and Tukey test were applied to analyze the obtained data, which showed that there were no statistically significant differences among the locators (P > .05). It can be concluded that the three tested devices demonstrated precise measurements of the real length of the canal without performance differences among them.

Comparison of apical leakage between canals filled with gutta-percha/AH-Plus and the Resilon/Epiphany System, when submitted to two filling techniques.

The purpose of this study was to compare the level of apical leakage between canals filled with gutta-percha/AH-Plus (GP) and the Resilon/Epiphany System (RES), when submitted to two filling techniques. Seventy extracted teeth were instrumented and randomly divided into four experimental groups in accordance with the material and techniques used [lateral condensation and Hybrid technique (HT)] and two control groups. After 7 days in an oven (37 degrees C, 100% humidity), the teeth were immersed in India ink and cleared. Leakage was measured by the NIH imageJ program. With respect to the presence of leakage, there was no difference between the filling techniques (p > 0.05), but there was a statistically significant difference when RES was compared with GP (p < 0.05), which leaked more than RES. With RES, leakage was confined to the apical third and HT could be used to thermoplasticize RES with satisfactory results.

Methodologies for assessment of apical and coronal leakage of endodontic filling materials: a critical review.

Apical leakage continues to be a topic of great interest, because in spite of the advances in Endodontics, clinical failures still occur. Most failures are probably attributed to the proliferation of bacteria that remain viable after chemical-mechanical preparation and cause periapical tissue irritation. Coronal leakage has aroused researchers' interest over the last few years, since canals may be re-contaminated after loss of coronal sealing or fracture of the remaining tooth. In this review, the various methodologies used for assessing root canal sealing capacity are critically analyzed, as they are not standardized, which makes it difficult to compare the results obtained when different methodologies are used, even though the same substrate is being assessed.

Evaluation of pH levels and calcium ion release in various calcium hydroxide endodontic dressings.

OBJECTIVE: The purpose of this study was to evaluate Ca(2+) release and pH of 3 calcium hydroxide-based products used routinely as intracanal dressings, as well as the new gutta-percha points with calcium hydroxide. STUDY DESIGN: The pH and Ca(2+) release were assessed using Calen with camphorated paramonochlorophenol, saline calcium hydroxide paste, LC paste (Lopes and Costa paste-calcium hydroxide with olive oil), and calcium hydroxide containing gutta-percha points. The materials were inserted in polyethylene tubes and immersed in deionized water. The pH variation and Ca(2+) release were monitored periodically for 4 weeks. RESULTS: After 72 hours, materials 1 and 2 raise the pH from 9.6 and 8.2 to 11.4 and 11.3, respectively, while a small change was observed for materials 3 and 4. The calcium concentration released from materials 1, 2, 3, and 4 after 72 hours was 6.54, 4.98, 1.31, and 1.74 mg/dL, respectively. CONCLUSION: Calen plus camphorated paramonochlorophenol and saline calcium hydroxide paste exhibited the highest calcium release and pH levels.