Iranian Endodontic Journal

Introduction: This randomized controlled clinical study sought to evaluate the success rate of inferior alveolar nerve block (IANB) during the endodontic management of mandibular molars with symptomatic irreversible pulpitis in women taking selective serotonin reuptake inhibitor (SSRI) antidepressants. Materials and Methods: Ninety adult female patients over 18 years of age who were diagnosed with symptomatic irreversible pulpitis of a mandibular molar were recruited in this study. The patients were equally assigned to SSRI user group (including citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline), who had taken an SSRI, and non-SSRI user group, who had not taken any SSRIs at all. All patients in both groups received 3.6 mL of 2% lidocaine with 1:80,000 epinephrine using conventional IANB injection. Access cavity was prepared 15 min after the injection. Lip numbness was necessary for all patients. Success was determined as no or mild pain upon access cavity preparation and/or instrumentation based on the Heft-Parker visual analog scale recordings. Data were analyzed using the chi-square test Mann-Whitney U test, and t-test. Results: The success rate was 55.6% for SSRI users and 44.4% for non-SSRI users, and no statistically significant difference was observed between the two groups (x²=1.1, P=0.292). Conclusions: Based on the results of this study, taking SSRI antidepressants could not affect the anesthetic success rate of IANB for mandibular molars with symptomatic irreversible pulpitis in women.

Introduction: The aim of this study was to examine the cyclic fatigue resistances #16 ProGlider, #15.02 Scout RaCe, #15.03 NeoNiti, One G and Path-File NiTi glide path files in S-shaped artificial canals. Materials and Methods: Twenty files from each group were tested. An artificial groove simulating double (S-shaped) curved canal measuring 1.5 mm in width at the top level decreasing towards the apical reaching 0.3 mm at the tip having a 0.06 taper, 18 mm in length, and 1.5 in depth machined in a stainless steel block was used in this study. Resistance to cyclic fatigue was determined by counting the numbers of cycles to failure (NCF). Furthermore, the fragment length of the fractured tips and angle and radius of curvature formed by each file in each trajectory were evaluated. The data were analyzed using the one-way analysis of variance and Tukey’s HSD test and the level of significance was set at 5%. Results: NeoNiti GPS and Scout RaCe glide path files showed significantly higher NCF values compared to other evaluated glide path files (P<0.001) but no significant difference when compared with each other (P=0.67). Conclusion: Based on this in vitro study NeoNiti GPS and Scout RaCe glide path files had the highest cyclic fatigue resistance in simulated double (S-shaped) curved artificial canals among the evaluated path finding files. Therefore, it seems that they can be used with more confidence in endodontic treatment of S-shaped canals clinically.

Introduction: This study aimed to evaluate the success rate of bypassing three NiTi rotary files (RaCe^®, Hero 642^®, and K3^®), fractured in various root canal locations of extracted mandibular molars with two different canal curvatures. Materials and Methods: Ninety freshly extracted human first or second mandibular molars were selected. Three millimeters of the file tip (RaCe^®, Hero 642^®, and K3^®), was fractured intentionally in the mesiobuccal root canal of each tooth by weakening the file in the last 3 mm of files #30 with 4% taper and preparing the root canals with two different degrees of curvature (n=30). Then, bypass possibility of the fractured files was evaluated using #8, #10, and #15 K-files and compared in different groups. In addition, the rate of accidental procedural errors was compared between these groups. Data were analyzed with univariate analysis and logistic regression models at a significance level of 0.05. Results: The overall success rate of bypassing was 61.1%. RaCe^® files had the highest and the K3^® files had the lowest bypass possibility rates (P=0.01); the greater the degree of canal curvature, the less successful the bypass procedure (P=0.01). The fracture of the files used to bypass was the most prevalent error. Conclusion: Based on this in vitro study the type of fractured file and the amount of canal curvature affected the success rate of the bypassing technique. In RaCe^® files and the mild curvature group, the success rate was the highest.

Introduction: Various studies have recommended using calcium-enriched mixture (CEM) cement in different endodontic treatments, including vital pulp therapy. However, possible reciprocal effects of the covering glass ionomer cement (GIC) on their mechanical properties have not been yet investigated in detail. The current research aimed to experimentally evaluate the surface microhardness of CEM cement and the covering GICs after different application/testing times. Materials and Methods: Using stainless steel moulds (8×4×4 mm), CEM cement samples were prepared (n=120) and randomly divided into 12 experimental groups (n=10). CEM cement with thickness of 4 mm was inserted into the moulds, and the remaining spaces were filled with self-cured or light-cured resin-modified GICs at three-time intervals; immediate, in 15 min and after 24 h. Then, the samples were incubated for one and seven days. Using a Vickers microhardness tester, the microhardness of CEM and GICs was measured. The data were analyzed using two-way ANOVA and Tukey’s test, and the significance level was set at 5% (P<0.05). Results: The reciprocal effects of the type/time of application of GICs on the surface microhardness of CEM cement or GICs were statistically significant (P<0.001). The surface microhardness of CEM cement and both covering GICs significantly increased over time and in seven-day samples was significantly higher than in one-day samples (P<0.05). Conclusions: Low surface microhardness of CEM/GICs in short-term (24 h) seems transient; and appears to be compensated over a longer period (i.e. 7-day). Therefore, using GICs adjacent to CEM cement in single-visit restorative treatments may be advocated

Introduction: The aim of this study was to evaluate the AH Plus sealer penetration into dentinal tubules after root canal retreatment followed by two additional cleaning methods. Methods and Materials: Thirty-two mandibular premolars with single canal were prepared up to the F4 ProTaper Universal instrument and filled by a single cone technique with the addition of Rhodamine B dye to Endofill sealer. For the retreatment procedure, the teeth were randomly divided into four experimental groups (n=8) as follows: Reciproc R40 with ultrasonic activation (RU), Reciproc R40 with sonic agitation (RS), ProTaper Next until X4 instrument with ultrasonic activation (PTNU), and ProTaper Next (X4) with sonic activation (PTNS). A new root canal filling was done using a System B technique, and the AH Plus sealer was mixed with Fluorescein dye. The roots were axial sectioned at 3, 5, and 7 mm from the apex and were assessed by a confocal laser scanning microscopy using the method of epifluorescence with wavelengths of absorption and emission for rhodamine B and fluorescein. In the obtained images, the sealer penetration into the dentinal tubules was evaluated. The data were converted into percentages and submitted to Mann-Whitney and Kruskal-Wallis followed by Dunn’s tests (P<0.05). Results: In all groups were found penetration of the AH Plus into the dentinal tubules. Statistical difference was found (P<0.05) in the ProTaper Next groups in relation the Reciproc groups for 3 mm root canal level regardless of additional cleaning method used. For the other sections the sealer penetration was similar (P>0.05) for all groups. Conclusion: Based on this ex vivo study the retreatment with ProTaper Next showed significantly greater penetration of AH Plus sealer into dentinal tubules in the apical third. The additional cleaning methods did not improve the removal of filling material in all sections evaluated.

Pulp canal obliteration (PCO) is a challenging clinical scenario in which canals must be located in progressively narrowing roots. Recently, proof of concept papers have, in parallel, introduced the combination of cone-beam computed tomography and surface scans for the construction of guides to pilot the negotiation and preparation of partially or completely obliterated pulp chambers and canals in anterior and posterior teeth. Authors’ purpose is to describe the treatment approach for teeth with PCO and previous iatrogenic deviation using guided endodontic technique. The clinical cases reported here show that technological evolutions should make guided endodontic procedures more widespread because their execution is relatively fast and safe even in the cases of root canal deviation. Treatment of teeth with pulp canal obliteration with deviations or perforation may be more effective with designed 3D printed access guides that seems to be a safe and clinically feasible method to locate root canals.

A detailed root canal morphology description is of utmost importance for the success of endodontic treatment. Therefore, clinicians require a thorough knowledge of the root canal anatomy and its variations and anomalies in all the tooth types. This study reports a permanent upper lateral incisor exhibiting an uncommon root canal system morphology: a single-rooted tooth with one main root canal bifurcating into two distinct root canals in the apical third, with two apical foramina (Type V root canal morphology).