Australian Endodontic Journal最新文献

The aim of this study was to evaluate the fit of matched gutta-percha (GP) points in tooth root canals after preparation with their corresponding rotary files. Single canal human tooth roots were matched according to root canal volume and eccentricity. Forty-five roots were divided into three experimental groups (n = 15) and sequentially prepared with either SybronEndo TF Adaptive SM2, ProTaper Next X2 or ProTaper Ultimate F2 files to working length. The corresponding GP points were placed into the prepared root canals without cement and scanned with micro-computed tomographic imaging. The unfilled volume and unfilled areas at 1, 3, 5 and 7 mm from working length were evaluated. Over one-third of the root canal space remained unfilled in all groups. There was no significant difference between unfilled areas measured at the different distances. Unprepared and unfilled spaces remained in root canals after preparation with rotary files when filled with the corresponding GP points.

Accurate working length determination is crucial for root canal treatment. This ex vivo study evaluated the accuracy of a standalone apex locator (Root ZX Mini) and two integrated apex locator-endomotors (EnDrive and X-Smart Pro+) under different intracanal conditions. Seventy-two extracted single-rooted mandibular premolars were decoronated and standardised. The actual canal length (AML) was determined microscopically, and electronic working lengths (EWL) obtained. Measurements were taken after canal patency and drying with paper points or following irrigation with saline, sodium hypochlorite, or ethylenediaminetetraacetic acid. All devices and intracanal conditions exhibited negative deviations, with EWLs shorter than AML, ranging from −0.15 to −0.50 mm, thus remaining within clinically acceptable limits. Significant differences were observed among devices and canal contents (p < 0.05), with EnDrive showing the least deviation, particularly in the presence of sodium hypochlorite. These findings support the reliability of integrated apex locator-endomotors, though measurement accuracy may be affected by irrigant type.

This study aimed to evaluate the fracture resistance of different bonding materials used in fragment reattachment for uncomplicated crown fractures, compared to direct composite resin restoration. Sixty human maxillary incisors were divided into five groups (n = 12): G1, control; G2, direct composite resin; G3, flowable composite; G4, preheated composite; G5, self-adhesive resin cement. After simulated fractures and thermocycling, fracture resistance was tested using a universal machine. Data were analysed with one-way ANOVA and Tukey's test (α = 0.05). G1 showed the highest resistance (75.7 ± 10.5 MPa); G2 the lowest (44.7 ± 7.9 MPa). G4 and G5 showed significantly higher resistance than G2 (p < 0.001). No significant difference was found amongst G3–G5 (p > 0.05). Preheated composite and self-adhesive resin cement demonstrated improved fracture resistance compared to direct composite resin. Appropriate material selection may enhance the long-term performance of fragment reattachment in uncomplicated crown fractures.

This retrospective study assessed the fracture incidence of Reciproc R25 and X1 Blue 25.06 files after up to three uses in 1720 root canals (1620 teeth) treated by a specialist. A standardised protocol was followed for all procedures. Periapical radiographs with the fractured instrument were used to evaluate the fragment's location and size and to determine the root curvature's angle. Data included fracture site (apical, middle, coronal) and management (removal, bypass or retention). Files were inspected post-use; non-deformed ones were sterilised and reused. Descriptive statistical analysis was performed using STATA 14. Among 1317 canals treated with R25 and 403 with X1 Blue, six fractures occurred: four R25 (0.3%) and two X1 Blue (0.5%). Four fractures were in molars, all in the apical third. Two fragments were bypassed, one removed, and three retained. Results indicate low fracture rates for both file systems, even with repeated use in primary treatments.

This in vitro study evaluated the effectiveness of irrigation techniques (IT)—conventional irrigation (CI), ultrasonic activation (UA), and iVac system (IA)- using 2.5% NaOCl and saline in reducing Enterococcus faecalis, Escherichia coli and Candida albicans in root canals and intratubular dentine. It also assessed the reduction of lipopolysaccharides (LPS) and apical extrusion. Lower premolar roots were contaminated and divided based on IT and irrigants, with saline as control. Microbiological and LPS samples were collected before and after IT. The apical extrusion volume was determined. Results showed that when NaOCl was used, there was no statistical difference between the ITs regarding CFU reduction and between UA and IA regarding LPS reduction. When saline was used, IA was the most effective technique in reducing CFU and LPS. Regarding apical extrusion, IA caused the lowest irrigant extrusion. In conclusion, IA reduced the levels of LPS, microorganisms and apical extrusion.