Ex vivo evaluation of the accuracy of four electronic foraminal locators during endodontic retreatment.

The present study aimed to evaluate the accuracy of four different Electronic Foraminal Locators (EFLs): Root ZX II (J. Morita, Tokyo, Japan), RomiApex A15 (Romidan, Kiryat-Ono, Israel), FinePex (Schuster, Porto Alegre, Brazil) and VDW Gold (VDW, Munich, Germany), in determining root length during endodontic retreatment steps. Twenty-seven human unirooted teeth had their crowns sectioned to standardize the teeth to 17 mm. The actual tooth length was visualized with an operating microscope and a #15 file juxtaposed to the apical foramen. Teeth were instrumented with files R25 and R40, and at the end of each instrumentation, measurements of root canal lengths were made with files #25 and #40. Then, the teeth had their root canals filled with standardized Gutta-Percha R40 cones and Endofill cement, and after seven days, they were uncovered with R25 and R40 files, respectively. New measurements were made with #25 and #40 files between the uncovering with each file. The data were statistically analyzed by ANOVA and Chi-square tests, considered significant when P<0.05. All devices tended to under-measurement when the obturating material was partially removed with the R25 file. When the canals were uncovered with the R40 instrument, the effectiveness of the appliances increased significantly (P<0.05). At 0.40 mm diameter, the mean accuracy of the Romiapex A15 appliance was statistically lower than the other EFLs (P<0.001), showing a tendency to over-measurement. In conclusion, all the tested appliances showed similar efficacy when acceptable limits were observed. The permanence of the remaining filling material in the apical third influenced the accuracy and efficacy of EFLs in endodontic retreatment cases. Key words:Endodontics, odontometry, apical foramen.

Ex vivo evaluation of the accuracy of four electronic foraminal locators.

Background: To evaluate the accuracy of four different Electronic Foraminal Locators (EFLs): Root ZX II (J. Morita, Tokyo, Japan), Romiapex A15 (Romidan, Kiryat-Ono, Israel), FinePex (Schuster, Porto Alegre, Brazil), and VDW Gold (VDW, Munich, Germany), in determining root canal length. Material and Methods: Twenty-seven human single-rooted teeth had their crowns sectioned at the cementoenamel junction, and the actual length of the tooth was obtained by visualizing with an operative microscope a #15 file placed adjacent to the apical foramen. The teeth were instrumented with R25 and R40 files, and at the end of each instrumentation, measurements of the lengths of the root canals were made with #25 and #40 files. The data were statistically analyzed by ANOVA and chi-square tests and were considered significant when P<0.05. All devices showed a tendency to underestimate measurements by 0.25 mm diameter. Results: The mean accuracy of the Root ZX II appliance was statistically lower than the other EFLs (P<0.001). For the 0.40 mm diameter, the mean accuracy of the Romiapex A15 appliance was statistically higher than the other LEFs (P<0.001). However, when the diameter was 0.40 mm, only the Romiapex A15 device tended to overmeasure. Regarding the acceptable limits of variation, it was observed that the devices showed similar efficiency in determining odontometry (P>0.05), both with diameters of 0.25 mm and 0.40 mm. Conclusions: It was concluded that the devices presented similar and adequate efficacy when observing the limits of acceptable measurements. It was observed that increasing the apical diameter did not influence the accuracy of EFLs in determining root canal lengths. Key words:Endodontics, working length, electronic foraminal locators, endodontic treatment.

Internal configuration of maxillary molars in a subpopulation of Brazil's Northeast region: A CBCT analysis.

The present study aimed to evaluate the internal configuration of the maxillary molars of a population from the Northeast region of Brazil. Cone-beam computed tomography (CBCT) exams from 512 patients (1501 teeth) were evaluated regarding the anatomical configuration of the root canal system, according to Vertucci's classification. The images were obtained using a Prexion 3D scanner operating at 90 kVp and 4 mA. The voxel size was 0.125 mm and the cut thickness was 1 mm. The images were then analyzed in the Prexion 3D Viewer software. The data were analyzed statistically by Pearson's chi-square test, with 5% of significance. The first and second molars presented three roots in 99.14% and 87.27% of the cases, respectively. In relation to the number of canals, the first and second molars had a significantly higher frequency of three and four root canals respectively, presenting a higher prevalence of types I and II (p < 0.001). The second mesiobuccal canal (MB2) was observed in 48.21% and 22.72% of the first and second molars, respectively (p < 0.001). The identification of the MB2 canal was greater in young and adult patients (p < 0.001), presenting a higher prevalence in male patients (p < 0.001). The internal configuration of the MB root was influenced by gender and by age, presenting a higher prevalence of the MB2 in male patients younger than 50 years of age.

Penetration of bioceramic and epoxy-resin endodontic cements into lateral canals.

The aim of the present study was to assess the penetration capacity of two endodontic cements, Endosequence BC Sealer and AH Plus, in artificial lateral canals. Twenty-six two-rooted, maxillary first premolars were instrumented to size 40.06 using K3 files. In each root, six lateral canals of two diameters (0.06 and 0.10 mm) were created with a working length of 2, 4, and 6 mm. The specimens were randomly divided into two groups according to the endodontic cement to be used (Endosequence BC Sealer and AH Plus) and obturated by the single-cone technique. The specimens were imaged by digital periapical radiography and scores from 0 to 4 were attributed according to the degree of penetration by sealers into the lateral canals. Data were analyzed statistically by Kruskal-Wallis and Student-Newman-Keuls tests, and a significance level of p < 0.05 was adopted. No significant difference was observed between the two endodontic cements used to fill the simulated lateral canals (p > 0.05). The diameter of lateral canals only influenced the capacity of the Endosequence BC Sealer in filling the canals, and presented greater penetration in the lateral canals of diameter 0.10 mm (p < 0.05). We concluded that the bioceramic endodontic cement Endosequence BC Sealer presented similar ability as AH Plus to fill simulated lateral canals.

Internal configuration of maxillary molars in a subpopulation of Brazil's Northeast region: A CBCT analysis

Abstract The present study aimed to evaluate the internal configuration of the maxillary molars of a population from the Northeast region of Brazil. Cone-beam computed tomography (CBCT) exams from 512 patients (1501 teeth) were evaluated regarding the anatomical configuration of the root canal system, according to Vertucci's classification. The images were obtained using a Prexion 3D scanner operating at 90 kVp and 4 mA. The voxel size was 0.125 mm and the cut thickness was 1 mm. The images were then analyzed in the Prexion 3D Viewer software. The data were analyzed statistically by Pearson's chi-square test, with 5% of significance. The first and second molars presented three roots in 99.14% and 87.27% of the cases, respectively. In relation to the number of canals, the first and second molars had a significantly higher frequency of three and four root canals respectively, presenting a higher prevalence of types I and II (p < 0.001). The second mesiobuccal canal (MB2) was observed in 48.21% and 22.72% of the first and second molars, respectively (p < 0.001). The identification of the MB2 canal was greater in young and adult patients (p < 0.001), presenting a higher prevalence in male patients (p < 0.001). The internal configuration of the MB root was influenced by gender and by age, presenting a higher prevalence of the MB2 in male patients younger than 50 years of age.

Penetration of bioceramic and epoxy-resin endodontic cements into lateral canals

Abstract: The aim of the present study was to assess the penetration capacity of two endodontic cements, Endosequence BC Sealer and AH Plus, in artificial lateral canals. Twenty-six two-rooted, maxillary first premolars were instrumented to size 40.06 using K3 files. In each root, six lateral canals of two diameters (0.06 and 0.10 mm) were created with a working length of 2, 4, and 6 mm. The specimens were randomly divided into two groups according to the endodontic cement to be used (Endosequence BC Sealer and AH Plus) and obturated by the single-cone technique. The specimens were imaged by digital periapical radiography and scores from 0 to 4 were attributed according to the degree of penetration by sealers into the lateral canals. Data were analyzed statistically by Kruskal-Wallis and Student-Newman-Keuls tests, and a significance level of p < 0.05 was adopted. No significant difference was observed between the two endodontic cements used to fill the simulated lateral canals (p > 0.05). The diameter of lateral canals only influenced the capacity of the Endosequence BC Sealer in filling the canals, and presented greater penetration in the lateral canals of diameter 0.10 mm (p < 0.05). We concluded that the bioceramic endodontic cement Endosequence BC Sealer presented similar ability as AH Plus to fill simulated lateral canals.