Letter to the Editor

Systematic Review

Physicomechanical Properties of Tertiary Monoblock in Endodontics: A Systematic Review and Meta-analysis

Thiago Machado Pereira, Evandro Piva, Wellington Luiz de Oliveira da Rosa, Antônio Marcos da Silva Nobreza, Kellin Pivatto, Andreza Maria Fábio Aranha , Jesus Djalma Pécora, Alvaro Henrique Borges

Iranian Endodontic Journal, Vol. 16 No. 3 (2021), 1 July 2021, Page 139-149

Introduction: A systematic review and meta-analysis were conducted to evaluate the physicomechanical properties of tertiary monoblock obturation with different obturation techniques. Methods and Materials: PubMed (MEDLINE), Web of Science, Scopus, the Cochrane Library, LILACS, IBECS, and BBO were searched time. PICO question was: “In extracted human teeth (Population), does tertiary monoblock obturation (Intervention) have superior physicomechanical properties (Outcome) compared to conventional obturation systems (Comparison)?”. Statistical analyses for push-out bond strength were performed with RevMan software by comparing the mean differences of each study, with a 95% confidence interval. Inverse variance was used as statistical method, random-effects models as analysis model, and heterogeneity between studies was assessed by Cochran’s Q test and I2 statistic (P <0.05). Results: Of 2162 studies retrieved, 31 were included in this review for “Study Characteristics”. Ten studies were included in the meta-analysis. Analysis demonstrated that conventional obturation had significantly higher push-out bond strength than tertiary monoblock obturation (P <0 .01), with a mean difference of −1.00 (95% CI, −1.41 to −0.58; I2=100%). Subgroups using single-cone and cold lateral condensation techniques showed significantly lower push-out bond strength for tertiary monoblock obturation (P <0.01), respectively with a mean difference of −0.09 (95% CI, −1.13 to −0.67; I2=97%) and of −1.97 (95% CI, −3.19 to −0.75; I2=100%). The warm vertical compaction subgroup showed no statistically significant difference between tertiary monoblock and conventional systems (P =0.13), with a mean difference of 0.49 (95% CI, −0.14 to 1.12; I2=10%). Conclusion: Tertiary monoblock systems have a push-out bond strength similar to conventional systems when used with warm vertical compaction.

Review Article

Clinical Differential Diagnosis between Nonodontogenic and Endodontic Radiolucent Lesions in Periapical Location: A Critical Review

Stephany Pimenta Carvalho, Carlos Estrela, Eneida Franco Vencio

Iranian Endodontic Journal, Vol. 16 No. 3 (2021), 1 July 2021, Page 150-157

In endodontics, accurate diagnoses are important for the selection of appropriate and successful therapy. Several nonendodontic entities in periapical location may resemble those of inflammatory endodontic origin and impact therapeutic approaches. The aim of this study was to review noninflammatory entities mimicking dentoalveolar abscesses or apical periodontitis and to discuss clinical and pathological features. In this review study, the authenticated search engine in PubMed (MEDLINE) database was used to find articles by using “Nonvital Pulp Dentoalveolar Abscess”, “Nonvital Pulp And Apical Periodontitis”, “Periapical Abscess“, “Chronic Dentoalveolar Abscess”, “Chronic Apical Periodontitis”, “Periapical Granuloma”, And “Radicular Cyst”. Each of these predefined keywords were combined with the terms “Misdiagnosed”, “Mimicking”, “Masquerading”, or “Simulating” to search for reported cases indexed from 1978 to 2020. All case reports fulfilling the selection criteria were reviewed to identify radiolucent nonendodontic periapical lesions focused on the questions: “Which pathological entities mimick radiolucent endodontic lesions in periapical location? Based on endodontic clinical parameters, what are the contrasting features?” Out of 426 articles, 111 were relevant to the subject, including a series of cases and case reports. Only well-documented English and recent papers were considered. A total of 30 noninflammatory entities appeared clinically as radiolucent endodontic lesion in periapical location. Lesions simulating chronic apical periodontitis represented 83.3% and dentoalveolar abscess 16.7%. Interestingly, primary malignancies and metastasis counted 43.3% and pain was a typical symptom. Swelling was a noncontributory clinical feature in distinguishing periapical lesions. Lack of pulp response was registered in 68.4% of nonedodontic lesions. A flowchart was generated to summarize clinicopathological aspects of radiolucent nonendodontic entities appearing as dentoalveolar abscesses or apical periodontitis In relation to clinical practice, it is very important for us to note that, a group of pathological entities may simulate radiolucencies of endodontic origin in periapical location, especially malignancies and non-inflammatory odontogenic lesions.

Original Article

Effects of Brown and Green Propolis on Bond Strength of Fiberglass Posts to Root Canal Dentin

Gislaine Figueiredo Zarza Arguello Gonçalves, Orlando Aguirre Guedes, Mateus Rodrigues Tonetto, Thaíse Ayres Bezerra Zuli, Álvaro Henrique Borges, Andreza Maria Fábio Aranha

Iranian Endodontic Journal, Vol. 16 No. 3 (2021), 1 July 2021, Page 158-163

Introduction: The purpose of this study was to evaluate the effect of brown and green propolis on bond strength of the fiberglass posts to root canal dentin, and to compare it with conventional endodontic irrigants. Methods and Materials: Sixty bovine teeth were selected, decoronated and randomly distributed into six groups (n=10), according to the irrigation solution: 0.9% saline solution (Control); 2% chlorhexidine (CHX); 5% malic acid (MA); 0.5% ethanolic extract of brown propolis (BP); 0.25% ethanolic extract of green propolis (GP); 2.5% sodium hypochlorite (NaOCl). After root canal treatment, fiber posts were cemented into prepared root canals with a self-adhesive resin cement. The roots were cross-sectioned to obtain two discs from each third and submitted to the micro push-out test. Failure patterns were evaluated under optical microscopy. The influence of irrigants agents was analyzed using one-way ANOVA followed by Games-Howell’s test (α=0.05). Failure modes were analyzed using Fischer’s exact test (α=0.05). Results: There were statistically significant differences among the groups (P<0.05). The control, NaOCl and BP groups showed the highest bond strength with no statistically significant difference between them (P>0.05). Adhesive failure type was the predominant in all groups. Conclusion: Based on this in vitro study, the use of 0.5% brown propolis did not influence the bond strength of fiberglass posts to root canal dentin, while the use of 0.25% green propolis did affect it negatively.

Cytotoxicity and Oxidative Stress Induction by Root Canal Sealers in Human Periodontal Ligament Fibroblasts: An in vitro Study

Malgorzata Pawinska, Grzegorz Szczurko, Elzbieta Luczaj-Cepowicz, Grazyna Marczuk-Kolada, Adam Holownia

Iranian Endodontic Journal, Vol. 16 No. 3 (2021), 1 July 2021, Page 164-175

Introduction: The aim of the study was to investigate the in vitro cytotoxicity, the profile of cell death, and the level of oxidative stress in human periodontal ligament fibroblasts (HPdLFs) after exposure to selected root canal sealers. Methods and Materials: Freshly mixed or set Endomethasone N (EN), RealSeal (RSEAL), Roeko Seal Automix (RSA), and Sealapex (SP) were incubated with HPdLFs. Fluorescein isothiocyanate (FITC)-annexin V (AnV) and propidium iodide (PI) staining followed by flow cytometry was used to identify the effects of the materials on cell viability and the profile of cell death. 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) with fluorescence-activated cell sorting was used to determine reactive oxygen species (ROS) formation in HPdLFs. Statistical analyses were performed using one-way ANOVA followed by post hoc tests, and significance was determined at P<0.05. Results: All materials reduced the viability of the cultured cells compared with the controls (P<0.05). Fresh SP and EN, and set RSA generated an increase of necrotic cells (P<0.05), whilst fresh RSEAL and RSA induced an elevation of apoptotic cells (P<0.001). Set RSEAL caused a rise in both apoptotic and necrotic cells compared with the controls (P<0.05). Fresh EN, RSEAL, and SP resulted in increased intracellular ROS generation compared with the negative control (P<0.001), whilst fresh RSA and all set materials were ineffective. Conclusions: This in vitro study showed us the materials tested were characterized by differentiated cytotoxic effects on HPdLFs. The fresh and set forms of sealers were capable of eliciting toxic action, inducing apoptosis and/or necrosis in HPdLFs. The toxic effects of fresh EN, RSEAL, and SP might have been due to the induction of oxidative stress in human periodontal fibroblasts. The cytotoxicity of RSA seemed to be related to the involvement of other mechanisms.

Survival Rates of Unrestorable Fracture of Endodontically Treated Anterior Teeth Restored with Resin Composites or Crowns: A Retrospective Cohort Study

Pimnara Phengudom, Danuchit Banomyong, Titalee Jirathanyanatt, Yaowaluk Ngoenwiwatkul, Warattama Suksaphar

Iranian Endodontic Journal, Vol. 16 No. 3 (2021), 1 July 2021, Page 176-183

Introduction: Current guidelines for the restoration of endodontically treated anterior teeth (ETT) are based on laboratory results and insufficient clinical findings. This retrospective cohort study aimed to compare the survival rates of ETT with unrestorable fracture restored with direct resin composite (DRC) or full coverage crown (FCC), and identify predisposing factors. Methods and Materials: Dental records and radiographs of ETT restored with DRC or FCC were collected from the dental charts of patients who received endodontic treatments and attended recall(s) from 2007 to 2019. Clinical/radiographic data and incidence of unrestorable fracture were recorded. Survival rates of ETT with unrestorable fracture treated with DRC and FCC were analyzed using Kaplan-Meier survival analysis and log-rank test, whereas predisposing factors were identified using Cox proportional-hazard model. Moreover, the survival rates of maxillary ETT with different sites of remaining cervical tooth structure were analyzed. Results: A total of 263 ETT with 157 DRC and 106 FCC were recruited. At an average recall period of 38 months, the survival rate of ETT restored with FCC was significantly higher (99.1%) than DRC (90.4%) (P<0.05). The predisposing factors of ETT with FCC were not identified; however, the identified predisposing factors of ETT with DRC were: (i) considered less than three walls of remaining cervical tooth structure, (ii) the ratio between root dentin thickness and root canal width at the cervical region was less than 1:1:1, (iii) loss of posterior-teeth support, and (iv) parafunctional habits. Maxillary ETT with complete or palatal structure had a significantly higher survival rate than those without the palatal structure (P<0.05). Conclusion: Based on the findings of the current cohort study, the survival rate of ETT with unrestorable fracture restored with FCC was significantly higher than DRC. However, ETT without predisposing factors were not susceptible to fracture and could be successfully restored with DRC.

The The Accuracy of Three Apex Locators in Determining the Location of Strip Root Perforation in Different Environments

Neda Shekarchizade, Alireza Farhad, Samira Khalifezade

Iranian Endodontic Journal, Vol. 16 No. 3 (2021), 1 July 2021, Page 184-188

Introduction: The purpose of this study was to assess the accuracy of Root ZX (J. Morita USA, Inc., Irvine, CA, USA), Raypex 6 (VDW, Munich, Germany) and i-Root (S-Denti Co. Ltd Seoul, Korea) electronic apex locators (EALs) in detecting strip root perforations in dry condition, and in presence of 0.9% saline (NaCl), 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), 17% ethylenediaminetetraacetic acid (EDTA) and blood. Methods and Materials: This ex vivo study evaluated 30 extracted human mandibular first molars. After mesiobuccal canal preparation, strip perforation was artificially created in the coronal third of the canal. The actual length (AL) of the canal to the perforation site was measured using a # 70 K-file under a stereomicroscope under 20× magnification. The teeth were then mounted in an alginate mold. The electronic length (EL) of the canal to the perforation site was measured by each apex locator in different environments. The difference between the EL and AL was calculated for each tooth. Statistical analyses were performed using the Friedman and post hoc Dunn tests at P<0.05 level of significance. Results: Most accurate measurements were seen in CHX environment for all three EALs. Root ZX mini in CHX environment showed most accurate reading but no significant difference was observed in three EALs in CHX environment. There was no significant difference between different environment in Root ZX mini (P>0.05). The most difference between the EL and AL were observed in NaOCl environment in Raypex and iRoot (P>0.05). Conclusion: Based on this ex-vivo study, the most accurate measurements were seen for all three EALs in CHX medium. The presence of irrigation solution affected the accuracy of all EALs. Root ZX showed better results compared to other EALs in determining the location of perforation in different environments, but this difference was not significant.

In Vitro Activity of Superoxide Water on Viability of Enterococcus faecalis Biofilm on Root Canal Wall

Sohrab Tour Savadkouhi, Mohadeseh Mohtasham Maram, Maryam Purhaji Bagher, Mohsen Afkar, Mahta Fazlyab

Iranian Endodontic Journal, Vol. 16 No. 3 (2021), 1 July 2021, Page 189-192

Introduction: The aim of this study was to compare the effect of root canal irrigation with superoxidized water and sodium hypochlorite on elimination of Enterococcus faecalis biofilm from the root canal walls. Methods and Materials: In this experimental study, a total of 32 extracted human central incisors were used. The crowns of all teeth were cut to length of 16 mm. After cleaning and shaping, then the specimens were sterilized in autoclave and then divided into four groups (n=8) as following: group 1 (positive control, root canal irrigation with normal saline), group 2 (negative control without biofilm), group 3 (root canal irrigation with sodium hypochlorite) and group 4 (root canal irrigation with superoxidized water). The bacterial suspension was inserted to root canals of teeth except for negative control group in order to form a microbial biofilm in incubator for 2 weeks. Then all the samples received root canal irrigation for 5 min based on their allocation. At the end, colony forming unit (CFU) was evaluated and biofilm formation and thickness was detected with scanning electron microscopy. The Kruskal Wallis and Dunn’s tests were done for biofilm thickness and CFU, respectively with the level of significance set at 0.05. Results: In negative control group no biofilm formation and CFU was present. The CFU counts and biofilm thickness were significantly different between the experimental groups (P=0.001) and both parameters were less in samples with hypochlorite irrigation compared to positive control (52.56±5.82 µm for biofilm thickness and 1.2×107 CFU) and samples irrigated with superoxidized water (2.92±1.76 µm for biofilm thickness and 5.4×104 CFU). Conclusion: Based on this in vitro study reduction in biofilm thickness and CFU/mL was 100% for sodium hypochlorite and for superoxidized water was 98% and 90% for reduction in biofilm thickness and CFU/mL, respectively.

Case Report

Two and Three-dimensional Parameters in Cone-beam Computed Tomography Monitoring of Apical Periodontitis in Traumatized Teeth: Case Report and Long-term Follow-up

Kênia Maria Soares de Toubes, Stephanie Quadros Tonelli, Caroline Felipe Magalhães Girelli , Eduardo Murad Villoria, Leonardo de Oliveira Buzatti Carneiro , Frank Ferreira Silveira

Iranian Endodontic Journal, Vol. 16 No. 3 (2021), 1 July 2021, Page 193-197

Assessment of apical periodontitis (AP) is a challenging task. This case report highlights the CBCT diagnosis and monitoring of periapical radiolucency (PR) using ITK-SNAP software 3.8v in a complex clinical scenario of three traumatized anterior teeth. An 11-year-old male patient complained of recurrent swelling and pain in the maxillary incisor region (teeth #11 and #21).  His parents reported a history of traumatic injury affecting these teeth two years back. Digital periapical radiographic (DPR) and cone-beam computed tomography (CBCT) were requested. PR was identified on teeth #11, #21, and # 22. In tooth #22, besides a PR, an area suggesting internal root resorption or oblique root fracture was observed. The teeth were shaped and dressing with calcium hydroxide Ca(OH)2. MTA repair was delivered to the apical portion of the canals (approximately 3 mm). The remainder of the canal was filled with thermoplastic gutta-percha and Endosequence sealer. After one year, the patient returned complaining of pain in tooth #11. Radiographically, the PR of tooth #11 did not reduce. A CBCT was taken, showing a reduction of radiolucency. The patient was clinical and radiographically re-evaluated for 6 months, and he remained asymptomatic. After three years of follow-up, the patient suffered a new trauma on teeth #11 and #21. As tooth #11 presents mobility and biting pain, a new CBCT was requested due to the risk of a possible root fracture. So, the PR was synchronously monitored with linear measurements and volumetric analysis using ITK-SNAP software 3.8v. In this case, the volumetric evaluation was essential to identify the PR's correct dimensions, reducing image interpretation's subjectivity. At 48-month follow-up, the patient was symptoms free and radiographically showed a reduction in the PR's size, compatible with osseous healing.

Multiple Microsurgery Intervention with Apicoectomy Guidance in Single Session: A Case Report

Warley Luciano Fonseca Tavares, Vinícius de Carvalho Machado, Francielen Oliveira Fonseca , Lucas Moreira Maia , Nelson Renato França Alves Silva , Antônio Paulino Ribeiro Sobrinho

Iranian Endodontic Journal, Vol. 16 No. 3 (2021), 1 July 2021, Page 198-204

The aim of this manuscript is to describe and discuss the advantages and obstacles of using a guided implant system adapted for endodontic microsurgery in the execution of a case with indication of multiple endodontic microsurgery intervention in a single appointment. Cone-beam computed tomography (CBCT) scans were aligned and processed with the planning software, complementing the Straumann® guided instruments. The drill handles of the system employed directed milling cutters and guided drills based on the sleeve-in-sleeve concept used in the osteotomy and apical resection of teeth #13, #14, #23 and #24. The root-ends were retro-prepared and sealed with putty bioceramic sealer. The patient was completely asymptomatic at the 12 months follow up visit and CBCT revealed complete tissue healing of the involved teeth. The protocol demonstrated to be reliable and reproducible. Its applicability can be extended to other anatomical complex scenarios. The reproducibility of the technique would encourage the maintenance of teeth in patients with indication to multiple endodontic surgery and permitted the conclusion of this case with precision and comfort to both patient and operator.

Management of a Large Periapical Lesion Using Decompression: A Case Report with Three-year Follow-up

Soheil Niavarzi, Faranak Noori, Mohsen Aminsobhani, Naghmeh Meraji

Iranian Endodontic Journal, Vol. 16 No. 3 (2021), 1 July 2021, Page 205-209

Large radicular lesions should be treated initially by orthograde root canal therapy. When the signs and symptoms of the infection (e.g. persistent purulent drainage) do not resolve after this treatment, then surgical approaches should be considered. In the cases of large radicular cysts, total enucleation of the cyst can endanger adjacent structures and teeth. Therefore, decompression or marsupialization techniques are recommended in order to decrease the size of the lesion. In this case report, a 55-year-old woman with previously initiated therapy was referred to endodontic department for management of a sinus tract associated with tooth #7. Root canal treatment was performed and intracanal irrigant (5.25% sodium hypochlorite) activated using passive ultrasonic application, various intracanal medicament (calcium hydroxide, double antibiotic paste) was used in multiple sessions, but intracanal purulent drainage was not resolved. After this, decompression was performed using needle cap to maintain the opening of the cyst and remained for three months. During this period the cavity was kept clean and rinsed by the patient with 0.2% chlorhexidine mouthwash. After three-year follow-up, radiographic examination revealed substantial osseous repair of the defect and clinical signs and symptoms were absent.