RESUMO
Objectives: The target of the current study was to evaluate and compare the shaping ability and buckling resistance of various single-file systems (TruNatomy [TRN], WaveOne gold [WOG], and XP-Endo Shaper [XPS]). Materials and Methods: Thirty recently extracted human first mandibular molars were chosen with severely curved mesiobuccal (MB) canals. Following access cavity preparation and determination of working length, teeth were randomly divided into three groups (n = 10) according to the instrumentation technique used, Group 1 (TRN), Group 2 (WOG), and Group 3 (XPS). Preinstrumentation and postinstrumentation, cone-beam computed tomography images were recorded at 3, 5, and 8 mm from the apex representing apical, middle, and coronal levels under the same circumstances, superimposed, and then canal transportation was determined using a particular equation. For buckling resistance calculation, files were loaded in the axial direction of the shaft and the maximum load was determined during the deflection of the file. One-way analysis of variance and Tukey test at 5% significance level were used to analyze data. Pearson's correlation between shaping ability and buckling resistance was performed. Results: XPS and TRN displayed significantly less canal transportation than WOG at the coronal and middle levels. While WOG recorded the highest value of buckling resistance, XPS recorded the least. Conclusions: XPS and TRN preserved the original curvature slightly better than WOG, while WOG reported the highest buckling resistance. There was a positive correlation between canal transportation and instrument resistance to buckle. Clinical Relevance: Preservation of the original shape of the canal after instrumentation is beneficial.
RESUMO
Objective: This study aims to assess the impact of re-establishing apical patency on the quantity of debris extruded through the apex after three supplementary retreatment files (TruNatomy (TRN), WaveOne Gold (WOG), and XP endo Finisher R (XPFR)). Materials and Methods: Eighty single-rooted mandibular premolars were prepared with ProTaper Universal rotary systems (PTU) up to F3 and obturated. The samples were divided into two main groups according to the presence or absence of the apical patency (n = 40), GI with apical patency and GII without apical patency. Based on the file system, which was adopted to eliminate the previous filling, each group had four subgroups (n = 10). In GI PTUR and GII PTUR, ProTaper Universal retreatment files (PTUR) were utilized only to remove the most primary filling material (control groups). In the other groups (PTUR) used, it was first followed by supplementary files. The quantity of debris extruded by different retreatment file systems was determined and compared to the corresponding control group with or without apical patency. Data were analyzed using a two-way ANOVA with a post hoc Tukey's multiple comparison test at a 5% significance level. Results: There was a statistically significant difference among the control and experimental groups. XPFR had the least quantity of extruded debris. Apical patency did not affect the debris extrusion. Conclusion: All tested files led to a significant apical debris extrusion regardless of apical patency.
