PurposeThe purpose of the present study was to investigate the effect of the different irrigant combinations used in final irrigation on the push-out bond strength of root canal sealers that have different compositions. Materials and MethodsIn total 60 dentinal slices in 1 mm thickness were collected from 15 extracted mandibular premolar teeth; 4 slices from each tooth. 3 canal-like artificial cavities were opened on each dentinal slice. Samples were divided into 4 experimental groups, each of which consisted of 15 samples. In group 1, samples were immersed in 5.25% NaOCl and 17% EDTA solutions respectively; in group 2, immersed in 5.25% NaOCl and 2% CHX solutions respectively; in group 3, immersed in 5.25% NaOCl, 17% EDTA and 2% CHX solutions respectively; and in group 4 immersed in distilled water. After drying with absorbent papers, each cavity in dentinal slice sample was filled with different sealer (Endoseal MTA, Tech Biosealer Endo or AH Plus). Two days later, the push-out bond examination was performed. ResultsAH Plus showed higher push-out bond strength value in two combinations (group 2 and 3) in which final irrigants contained CHX (p<0.001). Dentinal push-out bond strengths of root canal sealers from Endoseal MTA and Tech BioSealer Endo were not affected by final irrigant (p=0.965). ConclusionUsing CHX after NaOCl in final irrigant increases push-out strength of epoxy resinbased sealer but, did not create any difference in dentinal push-out bond strength of calcium silicate-based sealers.

Objectives: The purpose of this study was to investigate the volumetriclinear analysis and to present a new axial classification of root resorptions using cone beam computed tomography (CBCT). Materials and Methods:A total of 43 teeth with root resorption (external cervical resorption (ECR) (n=27), external replacement resorption (ERR) (n=4) and internal root resorption (IRR) (n=12)) from 34 patients were included in this study. On CBCT images of teeth, the volume of total tooth and resorption for the volumetric analysis, the widest lengths of resorptions and the amount of thinnest dentin thickness around them for the linear analysis were measured, and volumetric/linear measurements were compared according to age and gender. In addition, the eight regional axial classification was performed, and these regions were compared. Data were evaluated using Shapiro-Wilk, Pearson's r., Kruskal-Wallis and Dwass-Steel-Critchlow-Fligner post-hoc tests. Significance was set at p=0.05 for statistical analysis.Results: No significant difference was found between the volumetric and linear measurements of ECRs, ERRs, and IRRs. No difference between genders in volumetric and linear measurements of ECRs and IRRs, except total tooth volume, was higher in males than in females in ECRs (p<0.05).With increasing age in ECRs, the buccal dentin thickness increased, and bucco-lingual length and total tooth volume decreased (p<0.05). In axial classification, ECRs were mostly found in lingual, while IRRs and ERRs did not show regional differences. Conclusions:Although root resorptions had different localizations and classifications, they did not differ in terms of volumetric and linear measurements due to having similar nature. Using CBCT imaging, the volumetric/linear analysis and axial classification of resorptions, and demographic differences according to these parameters can help clinicians in understanding the nature of resorption and in determining appropriate management.

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This study aimed to examine the amount of apically extruded debris and time during retreatment with five current file systems, which exhibit various kinematic movements. One hundred upper central incisors were shaped with manual files and filled using the thermoplastic injection method. The root canal fillings in each group (n = 20) were removed using the Genius (GN), ProTaper Next (PTN), Reciproc (RCP) Blue, Tango‐Endo (TE) and Twisted File Adaptive (TFA) file systems. The apically extruded debris was collected in preweighed Eppendorf tubes. Time to reach working length and total time were also recorded. The PTN, RCP Blue and TFA instruments caused significantly less apically extruded debris and shorter total retreatment time than the GN and TE file systems (p < 0.05). The time to reach the working length was the shortest in the PTN group compared to the other groups (p < 0.05). All file systems extruded debris while removing the root canal filling.

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