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This study aimed to compare the accuracy of three electronic apex locators (EALs), Raypex 5, Apex NRG and ProPex II, in locating the apical foramen (AF) in vivo. Thirty multi-rooted teeth were included in the study. Distances from the file tip to the radiographic apex from the buccal (R1) and mesial (R2) aspect were measured after extraction. The distance from the file tip to the AF (L) was measured microscopically. Raypex 5, Apex NRG and ProPex II were accurate to within ± 0.5 mm in 84.6%, 78.6% and 66.7% of cases, respectively. R1, R2 and L measurements between the EALs were not statistically different (P > 0.05). R1 and L correlated positively (r(2) = 0.817; P < 0.001). There were no significant differences in all measurements between vital and non-vital root canals (P > 0.05). There was no statistically significant difference between the EALs. There was a positive correlation between electronic and radiographic measurements when locating the AF.

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Background/Aim: Radiopacity enables radiographic visualization, which is significant in diagnostic procedures and assessment of the quality of endodontic filling. It is important to compare newly developed endodontic sealers with materials that are already in clinical use in order to promote evidence-based dentistry. The aim of our study was to evaluate radiopacity of different calcium silicate-based sealers in comparison with control, epoxy resin-based sealer. The null hypothesis was that there were no statistically significant differences in radiopacity of the tested sealers. Material and Methods: Premixed (TotalFill BC Sealer, EndoSequence BC Sealer, Ceraseal, Bio-C Sealer), two-component (BioRoot RCS, MTA Fillapex, Bioceramic Root Canal Sealer, GuttaFlow Bioseal) calcium silicate-based sealers and AH Plus, as a control, were used. Specimens were radiographed using a Radiovisiography (RVG-4) CCD (charge-coupled devices)-based digital sensor. Results: Ceraseal had the highest, while Bioceramic Root Canal Sealer had the lowest radiopacity. Bioceramic Root Canal Sealer and MTA Fillapex had radiopacity significantly lower than all other sealers. Radiopacity level of AH Plus, was similar to premixed and significantly higher than radiopacities of all two-component endodontic sealers. Conclusions: Calcium silicate-based sealers radiopacity ranged from slightly above minimal required value (3mm), to a value higher than control sealer. Premixed endodontic sealers showed similar radiopacity as AH Plus which suggests that their clinical performance, in terms of visibility on dental radiograms, should be similar

Background: Premixedcalcium silicate-based sealers are ready-to-use, injectable materials with advantageous biological properties that create environment favorable for periapical tissues repair and health. The aim of our study was to examine the radiopacities of premixed calcium silicate-based sealers:TotalFill BCSealer, EndoSequence BC Sealer, Ceraseal, Bio-C Sealer and to compare them with epoxy-basedsealer, AH Plus. Material and methods: Three specimens (2 mm thick and 5 mm in diameter) of each sealer were radiographed using charge-coupled device-baseddigital sensor (Trophy Radiology, Cedex, France) along with an aluminum stepwedge reference.For radiopacity determination, a graph of the logarithm of aluminum thickness versus radiographic density was plotted and a calibration curve was generated. Radiopacities were assessed from the graph and presented as millimeters of aluminum per millimeter of material (mmAl).ANOVA with a post hoc Tukey test was used for statistical analysis and significance was set at 0.05. Results: Radiopacity values of EndoSequence BC Sealer and Bio-C Sealerwere significantly lower than radiopacities of Ceraseal and AH Plus. Differences in values between EndoSequence BC Sealer and Bio-C Sealer as well as between Ceraseal and AH Plus were nonsignificant. TotalFill BC Sealer was nonsignificantly different from all other sealers. Conclusion: Premixed calcium silicate-based endodontic sealers evaluated in our study had radiopacity values higher than 9 mmAl, in ascending order,from Bio-C Sealer, EndoSequence BC Sealer, TotalFill BC Sealer to Ceraseal.

Introduction. Deformations and fractures of Ni-Ti instruments during chemomechanical instrumentation of root canals occur due to the action of cyclic and torsional forces. The aim of this research was to analyze the surfaces of the working parts of Mtwo instruments after preparation of root canals with different curvatures using SEM and determine possible changes and deformations after instrumentation. Materials and methods. The study included 3 sets of Mtwo (VDW, Munich, Germany) instruments. Each set was used to instrument 10 canals in three experimental groups (straight, slightly curved, and highly curved canals). Instrumentation was carried out using crown-down technique with the following irrigation solutions, 2% NaOCl (CHLORAXID 2%, Cerkamed, Polska) and Distilled water (Iva, Serbia) in the amount of 5 cm3. The apical and middle third of the instruments were scanned in two directions using SEM at different magnifications (150-2000X). The SEM images were analyzed using qualitative analysis for the presence of different irregularities according to Eggert et al. Statistical analysis of obtained data was performed using Fisher test at a confidence level of 5% (? = 0.05). Results. Most defects (37.3%) were observed in instruments used in highly curved canals, followed by the instruments of the second group (35.6%), and the least defects were (27.1%) observed in the group with straight canals. Higher prevalence of defects was observed in the apical thirds of instruments (54.2%), especially in the experimental group of curved canals where the highest presence was observed (20.3%). The presence of production grooves was observed in all instruments, and the most common types of defects after instrumentation were the appearance of corrosion and changes in the cutting edges. In the group with extremely curved canals fractures were observed in two instruments (10/0.04 and 15/0.05). Conclusion. Root canal curvature significantly affects the occurrence of deformations and fractures of Ni-Ti rotating instruments. The most common types of defects were grooves, corrosion and changes in the blade edges. Mtwo instruments showed deformations in terms of thread changes, microfractures and two complete fractures.