Cone-Beam Computed Tomography Assessment of Prevalence of Procedural Errors in Maxillary Posterior Teeth.

A range of procedural errors can occur when performing endodontic treatment on posterior teeth. These errors may decrease the success rate in endodontic practice. This study assessed the prevalence of procedural errors and the quality of endodontic treatments in maxillary molars and premolars using cone-beam computed tomography (CBCT). CBCT scans from two private radiology centers were assessed retrospectively to ensure the same calculated sample size of 327 teeth for each of the four maxillary posterior tooth types (a total of 1,308 endodontically treated teeth). Image sets were evaluated for procedural errors categorized as follows: obturation length (overfilling or underfilling by >2 mm short of the root apex), missed canals, perforations, strip perforations (with extrusion of material into the furcation area), separated instruments in the root canal space, and root fracture. Data were analyzed with SPSS version 20 (SPSS Inc., Chicago, IL, USA), and frequency data was assessed using the Monte Carlo test at the 0.05 level of significance. The procedural errors most commonly reported in the present study were from most frequent to least frequent: underfilled canals (50.0%), missed canals (27.5%), overfilled canals (12.5%), apical perforations (5.0%), separated instruments (3.1%), and root fractures (1.9%). No strip perforations (with extrusion of material into the furcation area) were seen in the study (0%). Underfilled and missed root canals were the most frequent procedural errors identified in the present study. These findings underline the importance of more consideration of critical working length management during all stages of root canal treatment, greater awareness of root canal anatomy, and the use of imaging and diagnostic devices that enhance the ability to identify and treat root canals both safely and effectively.

Evaluating In Vitro Performance of a Novel Stainless Steel Rotary System (Gentlefile) Based on Debris Extrusion and Instrumentation Time.

The new Gentlefile (GF) system, made of stainless steel and developed by MedicNRG in Kibbutz Afikim, Israel, claims to have advantages over traditional nickel-titanium files. However, research has shown that nickel-titanium files are mechanically superior due to their increased flexibility, cutting efficiency, and ability to maintain canal anatomy with less risk of procedural errors. This study compared the amount of debris extrusion and the time required for root canal instrumentation using GF versus the nickel-titanium ProTaper Universal (PTU) system and a manual step-back (MSB) stainless steel technique. This in vitro experimental study utilized 66 extracted human single-canal mandibular premolars with mature apices and root curvature of less than 10 degrees. The teeth were randomly divided into three groups (n = 22) and standardized for working length before being placed in preweighed vials. Group 1 was instrumented with PTU, Group 2 with GF, and Group 3 with the MSB technique. Extruded debris was collected in the vials, dried in an incubator, and weighed using the same scale. The change in weight indicates the debris amount. Instrumentation time was recorded using a stopwatch. The normal distribution of data was assessed using the Kolmogorov-Smirnov test. The groups were then compared regarding the amount of extruded debris and instrumentation time using the Kruskal-Wallis test and one-way ANOVA, followed by the Games-Howell test, respectively (alpha = 0.05). No significant difference in apical debris extrusion was found among the three groups (P > 0.05). However, a significant difference in instrumentation time was detected between the groups (P < 0.05). MSB instrumentation took significantly longer than both the PTU (P = 0.001) and GF (P = 0.001) systems. The GF system did not demonstrate reduced apical debris extrusion or faster instrumentation time compared to PTU. MSB had the longest instrumentation time compared to the other techniques.

In vitro apical extrusion of debris and instrumentation time following root canal instrumentation with Reciproc and Reciproc Blue instruments and a novel stainless steel rotary system (Gentlefile) versus manual instrumentation.

Background: This study compared apical extrusion of debris and instrumentation time following root canal instrumentation with Reciproc, Reciproc Blue, and Gentlefile (GF) rotary instruments versus the manual step-back technique. Methods: This in vitro study was conducted on 80 extracted mandibular premolars with mature apices and a root curvature of<10°. The teeth were randomly assigned to 4 groups (n=20), standardized regarding working length, and placed in pre-weighed vials. The root canals were instrumented with Reciproc, Reciproc Blue, and GF systems and the manual step-back technique in the four groups. The vials containing the collected debris were then dried and weighed. The instrumentation time was also recorded for each group. Data were analyzed with one-way ANOVA and post hoc Games-Howell test (α=0.05). Results: Minimum apical debris extrusion was noted in Reciproc, followed by Reciproc Blue, GF, and manual technique (P<0.05). Pairwise comparisons showed significantly lower apical extrusion of debris in the Reciproc compared with GF (P=0.015) and manual instrumentation (P=0.011) groups. The Reciproc system also had the shortest instrumentation time, followed by Reciproc Blue, GF, and manual instrumentation (P<0.05). Pairwise comparisons showed significant differences between all the systems (P<0.05) except between Reciproc and Reciproc Blue (P>0.05) in this respect. Conclusion: Although all systems caused apical extrusion of debris, manual instrumentation caused maximum extrusion of debris. In contrast, the Reciproc system was superior to others regarding minimal apical extrusion of debris and the shortest instrumentation time.

Prevalence and Morphology of C-Shaped Canals in Mandibular First and Second Molars of an Iranian Population: A Cone-Beam Computed Tomography Assessment.

Objectives: The complex anatomy of C-shaped canals poses challenges for clinicians compared to teeth with normal root canal anatomy. This study is aimed at evaluating the frequency and morphology of C-shaped canals in the mandibular first and second molars among an Iranian population using cone-beam computed tomography (CBCT). Materials and Methods: This cross-sectional study evaluated 369 CBCT scans from the archives of a radiology clinic in Ardabil, Iran. The sample included 248 mandibular first molars and 478 mandibular second molars. The presence of C-shaped canals and their classification, according to Fan et al., were evaluated at four levels: orifice, coronal, middle, and apical. Prevalence based on gender and tooth type was also assessed. Results: A total of 199 (53.9%) males and 170 (46.1%) females were evaluated. C-shaped canals were found in 11 (8 males/3 females) out of 248 (4.4%) first molars and in 20 (11 males/9 females) out of 478 (3.7%) second molars. The C2 configuration was most prevalent in the orifice, coronal, and middle levels of both molar types, while C3 and C4 morphologies were most commonly found apically in the second and first molars, respectively. A significant difference in configuration was found only at the coronal level between molar types. A significant association between gender and configuration was observed only at the orifice level of the second molars. No other significant differences were found (P > 0.05). Conclusion: C-shaped canal configurations should be expected in 4.4% of mandibular first molars and 3.7% of the second molars in this Iranian population, with a predominance of the C2 configuration in the orifice, coronal, and middle levels.

Postoperative pain after endodontic treatment of mandibular molars with two different instrumentation techniques: A randomized clinical trial.

Background: This study compared postoperative pain after endodontic treatment of mandibular molars with asymptomatic irreversible pulpitis with the RaCe rotary system and the crown-down versus the step-down technique. Materials and Methods: In this randomized clinical trial, 70 mandibular 1st and 2nd molars with asymptomatic irreversible pulpitis and normal periradicular state were randomly assigned to two groups for single-visit endodontic treatment with RaCe rotary system and the crown-down and the step-down technique (n = 35). Postoperative pain was assessed at 6, 12, 24, 48, 72, and 168 h postoperatively, using a Visual Analog Scale. Data were analyzed using SPSS 17 by repeated measures ANOVA, Chi-square test, independent sample t-test, and lLeast sSignificant Ddifference test. P < 0.05 was considered statistically significant. Results: The two groups were not significantly different regarding the pain scores at any time point (P > 0.05). Within-group comparisons showed a significant reduction in pain score over time, starting from 12 to 168 h, postoperatively (P < 0.05). Conclusion: The crown-down and step-down techniques had no significant difference regarding postoperative pain after endodontic treatment of mandibular molars with asymptomatic irreversible pulpitis with the RaCe rotary system.

Cone-Beam Computed Tomography Assessment of Quality of Endodontic Treatment and Prevalence of Procedural Errors in Mandibular Molars.

Objectives: This study assessed the quality of endodontic treatment and the prevalence of procedural errors in permanent mandibular molars using cone-beam computed tomography (CBCT). Materials and Methods: This cross-sectional study was conducted on 328 CBCT scans (182 females and 146 males) of endodontically treated mandibular molars retrieved from the archives of two radiology centers in Ardabil city, Iran, in 2019. Mandibular molars were evaluated on sagittal, coronal, and axial sections regarding obturation length, obturation density (voids), missed canals, broken instruments, apical perforation, strip perforation, ledge formation, transportation, root fracture, root resorption, and periapical lesions by a senior dental student under the supervision of an oral and maxillofacial radiologist and an endodontist. Differences between the frequency of procedural errors and tooth type and gender were analyzed by the chi-square test. Results: The frequency of underfilling, missed canals, overfilling, voids, apical perforation, transportation, ledge formation, broken instruments, root fracture, strip perforation, root resorption, and periapical lesions was 34.8%, 17.4%, 16.8%, 14.3%, 7.3%, 6.1%, 4.3%, 3%, 1.2%, 0.6%, 5.5%, and 46%, respectively. The frequency of root fracture was significantly higher in females than in males (P < 0.05). The prevalence of underfilling was the highest in right second molars (47.2%), followed by right first molars, left second molars, and left first molars (P < 0.005). The frequency of transportation was maximum in right first molars (10%), followed by right second molars, left first molars, and left second molars (P < 0.04). Conclusion: Underfilling, missed canals, and overfilling were the most prevalent procedural errors in mandibular molars in our study population.

Single Cone Obturation versus Cold Lateral Compaction Techniques with Bioceramic and Resin Sealers: Quality of Obturation and Push-Out Bond Strength.

Objectives: This study compared the obturation quality and push-out bond strength of single cone obturation (SCO) and cold lateral compaction (CLC) with AH-Plus and Sure Seal Root (SSR). Materials and Methods: This in vitro experimental study was conducted on 88 single-rootedsingle-canal teeth with straight roots that were randomly divided into four groups (n = 22). All teeth were decoronated and underwent cleaning and shaping. Obturation was performed with AH-Plus and SCO technique in group 1 (SAH), AH-Plus and CLC technique in group 2 (LAH), SSR and SCO technique in group 3 (SS), and SSR and CLC technique in group 4 (LS). The roots were then sectioned into 3-mm thick slices and underwent digital photography at x25 magnification to assess the quality of obturation in the coronal, middle, and apical thirds by Image J software. The PBS was measured by a universal testing machine. The mode of failure was also determined under a stereomicroscope. Results: The PBS was significantly higher in the LSS group than LAH and SAH groups, and also in the SSS group than the SAH group in all sections. The PBS in the LSS group was significantly higher than SSS in the coronal and middle thirds. Voids were significantly lower in LAH than in the SAH group in all sections. In LSS, voids in the coronal third were significantly lower than in LAH. In the middle third, voids in SSS were significantly lower than in SAH. The groups had no significant difference in the mode of failure (P > 0.05). The mean percentage of gutta-percha in the use of AH-Plus sealer was significantly higher than SSR (P < 0.05). The mean percentage of gutta-percha in the coronal third was lower than that in the middle and apical thirds (P < 0.05). Conclusion: SSR showed higher PBS and less voids than AH-Plus. High PBS of the CLC/SSR group showed that CLC should still be preferred to SCO, and in the case of using SCO, SSR should be preferred to AH-Plus.