Iranian Endodontic Journal

Introduction: The objective of this study was to evaluate the influence of the instrumentation kinematics on endodontic postoperative pain. Methods and Materials: PubMed, Scopus, Web of Science, Lilacs, Cochrane Library and the System for Information on Gray Literature in Europe were searched electronically without time or language limitations up to June 2020. Subsequently, data extraction, quality assessment and meta-analysis were conducted. The meta-analysis was performed using random-effects inverse-variance methods, and heterogeneity was tested using the I² index (P<0.05). Results: A total of 318 articles were successfully identified in the search. Sixteen studies were used in qualitative synthesis and fourteen used for quantitative synthesis. Meta-analysis showed that patients treated with reciprocating system had lower risk of pain 48 h after endodontic treatment (Risk ratio [RR]=1.04, 95% Confidence interval [CI]=1.01-1.06, P=0.003) (I²=0%), but the mean postoperative pain for the reciprocating system was greater  24 h post endodontic treatment (Standardized mean difference [SMD]=0.25, 95% CI=0.06 to 0.44, P=0.01) (I²=43%). Other time points presented similar rates of postoperative pain (P>0.05). The certainty of evidence ranges from very low to high. Conclusions: The rate of postoperative endodontic pain was low, and reciprocating systems evoked more pain within the 24 h interval. Overall, the incidence and level of postoperative pain did not vary between reciprocating and rotary systems. There is no consensus if there is a relationship between the kinematics (rotary and reciprocating) and the incidence of postoperative pain.

Introduction: Preventing recontamination of the obturated root canal is important for successful root canal treatment (RCT). The main purpose of this study was assessing the histological health of periradicular tissue in obturated root canals with or without coronal seal between two and six months. Methods and Materials: Sixty roots from five dogs with vital pulps were randomly assigned to one of the following five groups (n=12): Group 1, RCT and six months oral exposure; Group 2, RCT and immediate amalgam restoration; Group 3, RCT and amalgam restoration after two months exposure to the oral cavity; Group 4, RCT and amalgam restoration after four months exposure to the oral cavity; Group 5, RCT with two months exposure to oral cavity. The teeth were prepared and filled with gutta-percha and sealer using lateral condensation technique. Two intact root canals of each animal were regarded as the negative control group (n=10), and the two root canals exposed to the oral cavity constituted the positive one (n=10). After six months the animals were euthanized. The upper and lower jaws were removed and submitted for histological processing. Longitudinal sections were obtained from each root. After staining the sections, periradicular regions were examined histologically under light microscope. The Kruskal-Wallis and Mann-Whitney tests was used to analyze the data (P<0.05). Results: The results showed a significant difference between all groups (P<0.05). The negative control group was free of any inflammation. Two-by-two comparison revealed that the positive control group, Group 1 and Group 4 displayed the most intense inflammation. Groups 2, 3 and 5 showed similar results without developing any significant inflammation. Conclusion: Based upon the findings of this animal study, it can be recommended that the obturated root canals which are exposed to oral cavity for around four months or more should be retreated before crown restoration.

Introduction: Missing a root canal during endodontic treatment implicates the persistence of microbial infection within the root canal system. This study aims to evaluate the incidence and morphology of the second mesiobuccal canal in the maxillary first molars in the Jordanian population. Methods and Materials: Consecutive cone-beam computed tomography (CBCT) scans taken at Jordan University Hospital were assessed in this retrospective study. A total of 200 scans that were examined, 111 were included in this study. The scans that were included had to have a full view of the maxilla with at least one permanent maxillary first molar. The following data were collected: the presence of a second mesiobuccal canal, the configuration of the mesiobuccal canals, the status of the apical area and the mesiobuccal inter-orifice distance, if applicable. The prevalence and morphology of the second mesiobuccal canal was determined and its association with biological sex and right or left sidedness was measured using the Chi-Square test. Results: The prevalence of the second mesiobuccal canal in our sample of the Jordanian population was 87%, with the most common canal configuration being Vertucci type II. The average inter-orifice distance between first and second mesiobuccal canals was 1.9 ± 0.4 mm. Conclusion: This retrospective study is the first in Jordan to document the prevalence of the second mesiobuccal canal using CBCT, and it shows that the vast majority of teeth have a second mesiobuccal canal. The proper location and negotiation of this canal is of dire importance for endodontic therapy. 

Introduction: The aim of this study was to evaluate the possible associations between pre-established clinical variables and manifestation of postoperative pain after endodontic treatments performed by graduate students in endodontics, from June 2016 to December 2017. Methods and Materials: A total of 998 dental patient charts were included in the study. All the patients underwent the same clinical protocol. Possible associations between postoperative pain and clinical variables were investigated, including age, gender, type of tooth, type of treatment, pulpal diagnosis, periradicular diagnosis, instrumentation system used, number of sessions, previous symptom, procedural accident, and endodontic sealer extrusion. Patients were contacted by telephone 24 h and 7 days after treatment completion and were asked about the degree of postoperative pain they had experienced, using a four-level scoring system: 0, no pain; 1, mild pain (no medication was needed); 2, moderate pain (an analgesic or anti-inflammatory was needed); 3, severe pain. Fischer’s exact test, Pearson’s test, and logistic regression were used for the statistical analysis of the data. A significance level of 0.05 was used. Results: A total of 8.6% of the patients reported having experienced postoperative pain, 50% of which reported mild pain, 47.7%, moderate pain, and 2.3%, severe pain. The only variable significantly associated with postoperative endodontic pain was pre-endodontic treatment symptoms (Pearson’s test, P=0.0047). The logistic regression analysis indicated that the association between use of the Reciproc system and sealer extrusion posed a significant risk for postoperative endodontic pain. Conclusion: Based on this retrospective cohort study, the incidence of moderate and severe pain after endodontic treatment was low, and the only variable associated with a higher frequency of patients reporting postoperative endodontic pain was previous pain/symptoms. Therefore, in these cases, pain management methods such as the use of analgesics before treatment or immediately after treatment should be considered.

Introduction: The aim of this study was to synthesize and characterize calcium hydroxide (CH) nanoparticles [CH-NP] and compare the cytotoxicity of these materials with that of mineral trioxide aggregate (White MTA) in human dental pulp mesenchymal cells (hDPMCs) stimulated by lipopolysaccharide (LPS). Methods and Materials: The CH-NP were synthesized by the co-precipitation method, and the physical properties were investigated through X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive x-ray spectrometry (EDS). LPS-stimulated hDPMCs were placed in contact with different dilutions of culture media previously exposed to CH-NP and white MTA for 24 h. The groups were tested for cell viability by MTT formazan and Alamar Blue assays, the production of nitric oxide (NO) by Griess method and the production of reactive oxygen species (ROS) by means of the fluorescent oxidant-sensing probe 2’,7’-dichlorodihydrofluorescein diacetate (DCFH-DA). Control groups for viability test were maintained in DMEM (not LPS-stimulated). For NO and ROS production, negative control group was cells in DMEM, and positive control was cells stimulated by LPS. The results were statistically analyzed by two-way ANOVA, Tukey’s test and Dunnett’s test (ɑ=0.05). Results: The results showed that the cell viability remained above 50% in all materials, independent of the dilution in MTT formazan and Alamar Blue tests. MTA showed a reduction in NO production at dilutions of 1:4 to 1:32 compared with the positive control group (P<0.05). The tested materials exhibited lower ROS production by DPMCs than that by cells in the positive control group (P<0.05), and similar ROS production to the negative control group (P>0.05). Conclusion: The outcomes of present in vitro study showed that MTA and [CH-NP] were not cytotoxic materials, with MTA closer to the results of control group (DMEM). MTA and [CH-NP] reduced ROS production at basal levels, with MTA inhibiting NO production at higher dilutions.

Introduction: This study aimed to evaluate the effectiveness of N-acetylcysteine (NAC), photodynamic therapy (PDT) and NAC with supplemental PDT in optimizing the removal of bacteria from infected dentinal tubules of root canals infected with Enterococcus (E.) faecalis biofilm. Methods and Materials: Eighty human teeth were randomly divided into 5 groups (n=16) according to the intracanal medication used: saline solution (control); calcium hydroxide (CH); NAC; PDT; NAC+PDT. Ten samples from each group were prepared for microbiological culture analysis (CFU/mL) and were inoculated with E. faecalis suspension for 21 days for biofilm development; the other six samples from each group were prepared for scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) and submitted to a 5-days contamination protocol including eight centrifugation cycles on every other day for dentinal tubules infection. For antimicrobial activity analysis by microbiological culture, the root canals were contaminated with E. faecalis biofilm, instrumented and then medicated according to the experimental groups. Three samples were collected from the root canals: after 21-days of contamination, immediately after the instrumentation and 14-days after the medication according to the experimental groups. The morphology of E. faecalis biofilm on the root canal walls and bacterial cells viability were assessed by means of SEM and CLSM, respectively. One-way ANOVA and Repeated Measures ANOVA tests were used to analyze the obtained data statistically. Results: CFU/mL analysis showed that CH, NAC and NAC+PDT promoted greater antibacterial activity with statistically significant difference compared to saline solution and PDT (P<0.0001). However, saline solution and PDT were statistically similar. Illustrative images by SEM confirmed partially the CFU/mL results. CLSM showed that all groups were effective eliminating E. faecalis except for the saline solution group. Conclusions: Based on this in vitro study NAC was bactericidal against E. faecalis biofilms regardless PDT stimulation, presenting similar antimicrobial activity to CH.

Introduction: This study compared bacterial percolation and sealer penetration of a novel obturation technique with the ones of warm vertical condensation technique. Methods and Materials: A bacterial percolation test was carried out with 80 single rooted human teeth divided into 5 groups;  A (n=20): warm vertical condensation and AH-Plus, B (n=20): CPoint with AH-Plus, C (n= 20): CPoint with EndoSequence BC, +ve Control (n=10): teeth with no canal obturation, -ve Control (n=10): teeth with no access cavity. The samples were inoculated with a multispecies bacterial incoulum. Bacterial percolation was evaluated by turbidity. Confocal laser scanning microscopy (CLSM) was used to observe the presence of gaps and voids. Further 48 extracted human mandibular single-canal premolars were used to determine the sealer penetration. Slices of the samples were observed by CLSM to evaluate tubules penetration of the sealer. Kaplan Meyer survival, ANOVA one way and Tuckey HSD test and a Wilcoxon signed-rank test were utilised. Results: A Kaplan-Meier test showed no significant difference overall (P>0.05) between groups A, B and C. At 43 days, the group B showed a significantly inferior ability to prevent bacterial passage (P<0.05). The group C showed a deeper sealer penetration than group A and B with statistically significant differences (P<0.05) for the total penetration (ANOVA one way and Tukey HSD). A Wilcoxon signed-rank test showed statistically significant differences for the penetration in the middle-and apical third of the 3 groups. Conclusion: Based on this in vitro study, the single polymer-cone obturation technique with a resin based- and bioceramic based-sealer behaved similarly to the warm vertical obturation technique in preventing bacterial passage. The bioceramic sealer showed the deepest penetration but did not fully prevent bacterial leakage.

Fused or geminated teeth require complex and multi-faceted treatment to maintain their health, functionality, and appearance. The current paper describes the multidisciplinary/minimally invasive treatment of fused immature permanent teeth. A 9-year-old-girl with an abnormally large left permanent maxillary lateral incisor was referred to the Paediatric Outpatient Clinic. The treatment plan of the referring orthodontist included the extraction of left maxillary lateral incisor, which was fused to a supernumerary tooth, followed by subsequent orthodontic and prosthetic treatments. In the paraclinic evaluation, cone-beam computed tomography (CBCT) showed two separate roots and two root canals, with communication between the pulp chambers of the double teeth. The modified treatment plan was to section the geminated tooth, remove the supernumerary and save the lateral incisor. During the sectioning procedure, the pulp of the remaining tooth was inevitably exposed. Direct pulp capping with Biodentine™ was performed. Next, glass-ionomer cement was applied as a temporary restoration and the supernumerary tooth was removed. The distal surface of the tooth was restored two weeks later so as to re-establish the original shape of the lateral incisor. Clinical and radiographic control examinations revealed that the tooth was symptom-free. Follow-up appointments after 3, 6, 12 and 18 months included standard clinical examinations and sensivity tests including electric pulp testing, which showed a fully functional, healthy tooth with apical maturation. Careful clinical and radiographic evaluations/examinations are essential for determining the correct treatment of a double tooth. The proposed multidisciplinary and minimally invasive treatment of the double tooth using a bioactive cement may facilitate the maturation of immature teeth and result in a desirable aesthetics and function.

The numerous difficulties found during root canal treatments are due to anatomical variations in the radicular morphology. Maxillary premolars have highly varied root canal systems and shapes. This case report addresses two endodontic treatment cases of the maxillary first and second premolars with three canals and a summary of their anatomical forms. The article describes the diagnosis and clinical management of these teeth.