Original Article

Efficacy of IANB and Gow-Gates Techniques in Mandibular Molars with Symptomatic Irreversible Pulpitis: A Prospective Randomized Double Blind Clinical Study

Jamileh Ghoddusi, Mohammad Hasan Zarrabi, Farzaneh Daneshvar, Neda Naghavi

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 143-148

Introduction: The aim of the present study was to compare the efficacy of the inferior alveolar nerve block (IANB) and Gow-Gates techniques in mandibular molars with symptomatic irreversible pulpitis. Methods and Materials: In this randomised, double-blind clinical trial, 80 patients referred to Mashhad Dental School, were randomly divided into two groups: IANB and Gow-Gates anaesthetic techniques using 2% lidocaine with 1:100000 epinephrine. After injection, if pain during caries/dentin removal and access cavity preparation was reported in each group, the patients once again were randomly allocated to receive buccal or lingual supplementary infiltration. Pain severity was evaluated using a visual analogue scale. The rates of positive aspiration and changes in heart rate were compared between the IANB and Gow-Gates. Paired and individual t-tests and the Mann-Whitney U-test were used to compare the reduction in pain severity. The level of significance was set at 0.05. Results: The success rates of anaesthesia in the Gow-Gates and IANB techniques were 50% and 42.5%, respectively with no significant difference (P=0.562). Supplementary infiltrations significantly reduced pain severity in all subgroups (P<0.05). Lingual infiltration resulted in a significantly greater reduction in pain severity in the IANB group than in the Gow-Gates group (P<0.05). No significant difference in heart rate or positive aspiration results was observed between groups (P>0.05). Conclusions: In the present study, the efficacy of the IANB and Gow-Gates techniques was comparable in mandibular molars with symptomatic irreversible pulpitis. Supplementary buccal and lingual infiltration significantly reduced pain severity.

Keywords: Buccal Infiltration; Gow-Gates Technique; Inferior Alveolar Nerve Block; Irreversible Pulpitis; Lingual Infiltration

Introduction: The aim of this study was to compare the quality of root canal treatment provided by undergraduate dental students in relation to the number of dental visits. Methods and Materials: Root canal treatments done by 77 dental students were observed. For each student, one tooth treated in a single visit was matched and compared with a tooth treated in multiple visits. The effect of preoperative conditions on the quality of root canal treatment and the number of visits were analyzed. The quality of root canal treatment was determined by the following criteria: obturation length, density, taper, and presence of procedural errors. The data were statistically analyzed using an exact conditional logistic regression test, and the level of significance was set at 0.05. Results: There was no statistically significant association between single- and multiple-visit root canal treatment in terms of obturation length (P=0.263), obturation density (P=0.625), and obturation taper (P=1.00). The incidence of procedural errors in teeth which required a single visit (7.8%) was less but not significantly different from those treated in multiple visits (16.9%). The presence of preoperative conditions was not significantly associated with multiple-visit treatment. Conclusion: Within the limitations of the study, multiple-visit treatment was not associated with a better quality of root canal treatment compared to single-visit treatment.

Keywords: Case Control; Endodontic Treatment; Multiple Visits; Radiographic Evaluation; Single Visit

Correlation between the Periapical Index and Lesion Volume in Cone-Beam Computed Tomography Images

Etevaldo Matos Maia Filho, Amanda Martins Calisto, Rudys Rodolfo de Jesus Tavarez, Raquel Assed Bezerra Segato, Lea Assed Bezerra da Silva

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 155-158

Introduction: The study aimed to correlate the Periapical Index (PAI), obtained by way of periapical radiographs, with the volume of chronic periapical lesion, obtained through cone-beam computed tomography (CBCT), in the permanent teeth. Methods and Materials: Radiographs and CBCT images were selected from 35 single-rooted permanent teeth, with fully formed apices, with a diagnosis of pulp necrosis and chronic apical periodontitis that was radiographically visible. Two independent raters evaluated the radiographs on two separate occasions and classified the periapical lesions in accordance with Ørstavik’s PAI. The periapical lesion volume was calculated in the CBCT images. The correlation between the PAI and the lesion volume was calculated using Spearman’s correlation test. Results: There was a positive, moderate correlation between the PAI and the volume (rs=0.596; P<0.001) where rs2 is equal to 0.355, showing that only 35% of the PAI variation was dependent upon the variation in periapical lesion volume. Conclusion: The radiographic evaluation of the periapical lesion does not reflect the lesion’s volumetric characteristics as the volume had a moderate effect on the choice of PAI score.

Keywords: Apical Periodontitis; Cone-Beam Computed Tomography; Endodontics; Periapical Radiography

Diameter Variability of Rotary Files and Their Corresponding Gutta-Percha Cones Using Laser Scan Micrometre

Hesam Mirmohammadi, Monika Sitarz, Hagay Shemesh

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 159-162

Introduction: Manufacturers offer gutta-percha (GP) cones matched with different sizes of endodontic files as an attempt to simplify the obturation process and create a tight seal in the canal. The purpose of this study was to evaluate whether intra-manufacture GP diameters matched the diameters of their corresponding files at different levels using laser micrometre. Methods and Materials: Twenty files and corresponding GP master cones of Reciproc R40 (40/0.06) (VDW, Munich, Germany), WaveOne Large (40/0.08) (Dentsply Maillefer, Ballaigues, Switzerland), ProTaper F3 (30/0.09) (Dentsply Maillefer, Ballaigues, Switzerland), and Mtwo 40/0.06 (VDW, Munich, Germany) were examined using laser micrometre (LSM 6000 by Mitutoyo, Japan) with accuracy of 1 nm to establish their actual diameter at D0, D1, D3 and D6. The data was analysed using the independent t-test. The differences were considered at 0.05. Results: The diameter of GP master cones was significantly larger than that of the corresponding files at all levels in all brands. ProTaper GP diameter was closest to the file diameter at D1 (GP=0.35, File=0.35 mm), and D3 (GP=0.48, File=0.49). Conclusion: Within the same manufacturer, GP cone diameters do not match the diameters of their corresponding files. Clinicians are advised to use a GP gauge to cut the tip so as to appropriate the diameter from a smaller sized GP cone.

Keywords: Diameter; Gutta-Percha; Root Canal; Rotary File; Size 


The Effect of Canal Preparation with Four Different Rotary Systems on Formation of Dentinal Cracks: An In Vitro Evaluation

Elham Khoshbin, Zakyeh Donyavi, Erfan Abbasi Atibeh, Ghodratollah Roshanaei, Faranak Amani

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 163-168

Introduction: Endodontic rotary systems may result in dentinal cracks. They may propagate to vertical root fracture that compromises the outcome of endodontic treatment. This study aimed to compare Neolix and Reciproc (single-file systems), Mtwo and ProTaper (conventional rotary systems) in terms of dentinal crack formation in root canal walls. Methods and Materials: This in vitro study was conducted on 110 extracted human single-rooted teeth. The teeth were randomly divided into four experimental groups (n=25) for root canal preparation with Neolix, Reciproc, Mtwo and ProTaper systems and two control groups (n=5). The first control group underwent root canal instrumentation with hand files while the second control group received no preparation and was only irrigated. After instrumentation, root canals were horizontally sectioned at 3, 6 and 9 mm from the apex and inspected under a stereomicroscope under 12× magnification for detection of cracks. The data were analyzed using chi-square, GEE test and Bonferroni tests (P<0.05). Results: No crack was found in the control groups. All rotary systems caused dentinal cracks. ProTaper, Reciproc, Mtwo and Neolix caused cracks in 92%, 80%, 68% and 48% of samples. ProTaper caused significantly more cracks than Neolix and Mtwo (P<0.05). No significant differences were noted between other groups (P>0.05). Conclusion: All rotary systems cause dentinal cracks and it is significantly different in apical, middle and coronal third of the root. Neolix appears to be a suitable alternative to other rotary systems since use of this single-file system saves time and cost and minimizes trauma to dentinal walls.

Keywords: Dentinal Crack; Endodontics; Root Canal Preparation; Rotary System

Extrusion of Irrigant in Open Apex Teeth with Periapical Lesions Following Laser-Activated Irrigation and Passive Ultrasonic Irrigation

Harry Huiz Peeters, Ketut Suardita, Latief Mooduto, Norbert Gutknecht

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 169-175

Introduction: Sodium hypochlorite (NaOCl) irrigation is critical for the success of endodontic treatment and several agitation techniques have been developed to improve the efficacy of this irrigation. Using a combination of contrast medium and radiographic examination, this study evaluated NaOCl extrusion during agitation of irrigant. Development of pressure, which may result in apical extrusion of the irrigant, has been described during laser-activated irrigation (LAI) and passive ultrasonic irrigation (PUI). Methods and Materials: We examined 40 single root canals categorized as having open apices with apical lesions in 40 patients. For the final irrigation, the teeth were irrigated with a mixture of radiopaque contrast medium and 2.5% NaOCl in solution. The solution was activated for 60 sec in both groups [the Er, Cr: YSGG laser group (n=20) and the ultrasonic group (n=20)]. The teeth were imaged subsequently using radiography for the evaluation of contrast extrusion. Results: Radiopaque contrast medium was absent from the periapical tissues in all cases. Conclusion: Use of LAI or PUI appears to be safe as used currently in endodontic treatment.

Keywords: Endodontics; Er, Cr: YSGG Laser; Open Apex; Periapical Lesion 

Bacterial Reduction after Gutta-Percha Removal with Single vs. Multiple Instrument Systems

Felipe Xavier, Giselle Nevares, Luciana Gominho, Renata Rodrigues, Marcelly Cassimiro Kaline Romeiro, Kaline Romeiro

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 176-180

Introduction: The aim of this study was to evaluate the effectiveness of a reciprocating single-instrument system (Reciproc-REC) compared with combined continuously rotating multiple-instrument systems [D-Race (DR) and BioRace (BR)] in reducing Enterococcus faecalis (E.f.) after gutta-percha removal. Methods and Materials: Forty-six extracted human maxillary incisors were prepared and contaminated with E.f. strain (ATCC 29212) for 30 days. The samples were obturated and randomly divided into two experimental groups for gutta-percha removal (n=23): a REC group (R50) and a DR/BR group (DR1, DR2 and BR6). A standardized irrigation with 0.9% saline solution was performed. Root canal samples were taken with paper points before (S1) and after (S2) the removal of gutta-percha to establish bacterial quantification by culture. The time required for gutta-percha removal was also recorded. Positive and negative control groups (n=6) were used to test bacterial viability and control asepsis, respectively. Data were analysed using t-Student and one-way ANOVA tests (5% margin of error). Results: The mean percentage of bacterial reduction was significantly higher in DR/BR group (84.2%) than in REC group (72.3%) (P<0.05). The mean time for obturation removal was 74.00 sec in REC group and 107.53 sec in DR/BR group (P<0.05). Conclusion: The combined continuously rotating multiple-instrument system was more effective in reducing bacteria after the removal of gutta-percha than the single-instrument system. None of the tested systems was able to completely eliminate root canal infection after gutta-percha removal. Thus, additional techniques should be considered.

Keywords: Endodontics; Enterococcus faecalis; Instrumentation; Retreatment; Root Canal Instrumentation

Accuracy of Cone-beam Computed Tomography in Comparing with Clearing and Staining Method in Evaluating the Root Canal Morphology: An In Vitro Study

Zahra Dalili Kajan, Mehran Taramsari, Negar Khosravi Fard, Mohsen Kanani

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 181-187

Introduction: In order to successfully perform root canal treatment, thorough knowledge of the root canal anatomy is essential. Cone-beam computed tomography (CBCT) has the ability to improve our understanding of the root canal system. The goal of the present study was to compare the accuracy of CBCT in revealing the number and form of the root canals of different maxillary and mandibular teeth with clearing and staining method. Methods and Materials: CBCT images were taken from 80 extracted human teeth fixed in agar arch models. The number and configuration of the root canals of each tooth were determined by the two observers. Then the teeth were cleared and stained. Two endodontists evaluated the number and forms of the root canals. The accuracy of CBCT was determined and compared with clearing and staining by Fisher’s exact test. The agreement of two methods in detection of the number and form of the root canals were evaluated by Kappa test, P≤0.05. Results: CBCT accurately detected the number of root canals in 129 (92.1%) of 140 roots and the form of the canals in 119 (85%) of the roots. There was no significant difference between the accuracy of CBCT in the detection of the number (P=0.13) and forms (P=0.4) of root canals of maxillary and mandibular teeth. The agreement between CBCT, and tooth clearing and staining in detection of the number of root canals was excellent in the maxilla (kappa=0.88±0.05) and good in the mandible (kappa=0.720±0.097). The agreement between the two methods in demonstration of the form of root canals was good in both maxillary (kappa=0.73±0.07) and mandibular (kappa=0.67±0.09) teeth. Conclusion: CBCT provides accurate information about root canal morphology. Application of this technique could result in more successful endodontic treatments.

Keywords: Anatomy; Cone-beam Computed Tomography; Root Canals

The Effect of Resection Angle on Stress Distribution after Root-End Surgery

Jaiane Bandoli Monteiro, Amanda Maria Oliveira Dal Piva, João Paulo Mendes Tribst, Alexandre Luiz Souto Borges, Rubens Nisie Tango

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 188-194

Introduction: This study aimed to investigate the influence of the resection angle on the stress distribution of retrograde endodontic treated maxillary incisors under oblique-load application.  Methods and Materials: A maxillary central incisor which was endodontically treated and restored with a fiber glass post was obtained in a 3-dimensional numerical model and distributed into three groups according to type of resection: control; restored with fiber post without retrograde obturation, R45 and R90 with 45º and 90º resection from tooth axial axis, respectively and restored with Fuji II LC (GC America). The numerical models received a 45º occlusal load of 200 N/cm2 on the middle of lingual surface. All materials and structures were considered linear elastic, homogeneous and isotropic. Numerical models were plotted and meshed with isoparametric elements, and the results were analyzed using maximum principal stress (MPS). Results: MPS showed greater stress values in the bone tissue for control group than the other groups. Groups with apicectomy showed acceptable stress distribution on the fiber post, cement layer and root dentin, presenting more improved values than control group. Conclusion: Apicectomy at 90º promotes more homogeneity on stress distribution on the fiber post, cement layer and root dentin, which suggests less probability of failure. However, due to its facility and stress distribution also being better than control group, apicectomy at 45° could be a good choice for clinicians.

Keywords: Apicectomy; Cut Angle; Dental Stress Analysis; Endodontics; Finite Element Analysis; Resection Angle

Thermal Scanning of Dental Pulp Chamber by Thermocouple System and Infrared Camera during Photo Curing of Resin Composites

Faeze Hamze, Seyed Abdolreza Ganjalikhan Nasab, Ali Eskandarizade, Arash Shahravan, Fatemeh Akhavan Fard, Neda Sinaee

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 195-199

Introduction: Due to thermal hazard in composite restorations, this study was designed to scan the pulp temperature by thermocouple and infrared camera during photo polymerizing different composites. Methods and Materials: A mesio-occlso-distal (MOD) cavity was prepared in an extracted tooth and the K-type thermocouple was fixed in its pulp chamber. Subsequently, 1 mm increment of each composites were inserted (four composite types were incorporated) and photo polymerized employing either LED or QTH systems for 60 sec while the temperature was recorded with 10 sec intervals. Ultimately, the same tooth was hemisected bucco-lingually and the amalgam was removed. The same composite curing procedure was repeated while the thermogram was recorded using an infrared camera. Thereafter, the data was analyzed by repeated measured ANOVA followed by Tukey’s HSD Post Hoc test for multiple comparisons (α=0.05). Results: The pulp temperature was significantly increased (repeated measures) during photo polymerization (P=0.000) while there was no significant difference among the results recorded by thermocouple comparing to infrared camera (P>0.05). Moreover, different composite materials and LCUs lead to similar outcomes (P>0.05). Conclusion: Although various composites have significant different chemical compositions, they lead to similar pulp thermal changes. Moreover, both the infrared camera and the thermocouple would record parallel results of dental pulp temperature.

Keywords:Exothermic Reaction; Infrared Camera; Light Curing Unit; Pulp Temperature; Resin Composite; Thermocouple


Effect of the Bone Graft on the Surface Microhardness of Endodontic Biomaterials

Shahriar Shahi, Saeed Rahimi, Hamid Reza Yavari, Negin Ghasemi, Yashar Rezaie, Samira Mirzapour

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 200-203

Introduction: During periapical surgery, using of bone products in large endodontic lesions, is a treatment option that could affect the properties of the retro-filling endodontic material. The aim of present study was to evaluate the effect of Osteon II bone powder on the surface microhardness of calcium-enriched mixture (CEM) and mineral trioxide aggregate (MTA). Methods and Materials: Each material was mixed and carried into 40 sterile custom-made plastic cylinders. Half of the samples in each group were exposed to Osteon II. All cylinders were submerged in simulated tissue fluid and incubated at 37°C and 100% relative humidity for 7 days. Surface microhardness values of each study group was attained using Vickers microhardness test. The data were analyzed statistically using two-way ANOVA and independent t-test at a significance level of 0.05. Results: The highest and lowest microhardness values were recorded in the MTA/without Osteon and MTA/with Osteon groups, respectively. Irrespective of the presence or absence of bone powder, the overall microhardness of CEM cement and MTA was not significantly different. In the MTA group, the presence of the powder resulted in a significant decrease (P<0.05) of the microhardness; however, its effect on CEM cement was not significant (P>0.05). Conclusion: Under the limitations of the present in vitro study, the presence of Osteon bone powder had no negative effect on the microhardness of CEM cement, contrary to its effect on MTA.

Keywords: Bone Graft; Calcium-enriched Mixture; Hardness; Mineral Trioxide Aggregate

Diagnostic Efficacy of Four Methods for Locating the Second Canal of the Mesiobuccal Root of Maxillary Molars

Mariana De Carlo Bello, Camilla Tibúrcio-Machado, Clacir Dotto Londero, Fernando Branco Barletta, Carlos Heitor Cunha Moreira

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 204-208

Introduction: The major cause for failure of root canal therapy is the inability to recognize the presence of all canals of the root canal system. Auxiliary tools, such as magnifying loupe, operative microscope and computed tomography (CT) images are used to facilitate the location of canals. The objective of the present survey was to evaluate the diagnostic efficacy of four methods for detecting the second canal of mesiobuccal roots (MB2) of permanent maxillary molars. Methods and Material: A total of 147 extracted human maxillary molars were assessed. The floor of the pulp chamber was inspected by an endodontist to find MB2 canals. Analyses were performed without magnification (direct visual method), using a loupe (with 3.5× magnification), and using a microscope (with 16× magnification). A fourth analysis was conducted using cone-beam computed tomography (CBCT) images. Teeth were sectioned horizontally into three parts (cervical, medial and apical thirds) to confirm the presence of MB2 canals (reference standard method). Sensitivity, specificity, and positive/negative predictive values were calculated for each method. Results: No statistically significant differences were observed in the frequency of MB2 found between the microscope and the reference standard or between CBCT and the reference standard. CBCT had higher sensitivity (0.88), specificity (0.88), positive (0.84) and negative (0.91) predictive value than the other three methods. Conclusion: CBCT was the most accurate method for detecting the MB2 and it had a diagnostic efficacy similar to that of the reference standard method.

Keywords: Cone-beam Computed Tomography; Diagnosis; Data Accuracy; Endodontic; Root Canal Therapy

Effects of Different Irrigation Solutions and Protocols on Mineral Content and Ultrastructure of Root Canal Dentine

Brenna Magdalena Lima Nogueira, Thais Isabele da Costa Pereira, Victor Feliz Pedrinha, Patrícia de Almeida Rodrigues

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 209-215

Introduction: The aim of this study was to evaluate the effect of different irrigating solutions and irrigation protocols on the chemical and physical structure of root dentin. Materials and Methods: Thirty extracted single-rooted human teeth were selected and then distributed into the following treatment groups (n=10): G1, saline solution (0.9% NaCl); G2, 2.5% NaOCl + 17% EDTA + 2.5% NaOCl; G3, 2.5% NaOCl + 9% Etidronate (HEBP) + 2.5% NaOCl; G4, mixture of 5% NaOCl + 18% HEBP; G5, 2.5% NaOCl + 17% EDTA + 0.9% NaCl, and G6, 2.5% NaOCl + 9% HEBP + 0.9% NaCl. The ultrastructure of dentin was characterized through scanning electron microscopy (SEM) and energy dispersive x-ray spectrometry (EDS) determined the chemical composition in terms of the calcium (Ca), phosphorus (P), magnesium (Mg) and potassium (K) content and the Ca/P ratio; and the crystalline phase was analyzed by x-ray diffraction (XRD). A descriptive analysis was performed on the ultrastructure and the crystallography data of dentin. Data analysis included a chemical composition analysis of variance (one-way ANOVA) and a subsequent multiple comparison test (Tukey’s test). Results: Except for the control group, all groups showed morphological changes upon visualization with SEM. For EDS, G2 and G5 showed significant mineral loss and changes in the Ca/P ratio (P<0.05); the highest values of Ca and P were observed in G3, G4 and G6. Conclusion: All the irrigating solutions and irrigation protocols tested promoted changes in the morphology and physical and chemical composition of the dentin. However, no significant differences were observed crystallographically.

Keywords: Chelating agent; Dentin; Root Canal Irrigant; Surface Properties

Efficacy of Pre-Medication with Ibuprofen on Post-Operative Pain after Pulpotomy in Primary Molars

Lili Shafie, Sara Esmaili, Masoud Parirokh, Abbas Pardakhti, Nouzar Nakhaeee, Paul V. Abbott, Hamide Barghi

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 216-220

Introduction: Pain management following dental procedures, particularly pulpotomies and extraction, is of great importance in pediatric dentistry. The aim of this study was to investigate the efficacy of pre-treatment with ibuprofen on post-operative pain following pulpotomy of primary molars. Methods and Materials: In a split mouth double-blinded randomized clinical trial, 49 children aging between 6-10 years old were given either ibuprofen or a placebo 45 min prior to the treatment. After pulpotomy and placement of a stainless steel crown (SSC), the pain level was evaluated using the Wong-Baker face visual analogue scale for up to 7 days post-treatment. McNemar and Wilcoxon tests were used for data analysis. Results: Forty-five patients were eligible to participate in this study. Pre-medication with ibuprofen significantly reduced pain during the first 24 h post-treatment (P=0.032). However, there was no significant difference in the pain levels between placebo and ibuprofen groups at 48 and 72 h post-treatment (P=0.154 and P=0.197, respectively). The number of times patients needed analgesics in ibuprofen group was significantly lower compared to that in the placebo group (P=0.008). Conclusion: Pre-medication with ibuprofen resulted in less pain following pulpotomy and SSC placement in primary teeth.

Keywords:Ibuprofen; Pre-Medication; Primary Molar; Pulpotomy; Visual Analogue Scale; Wong Baker


Micro-CT Evaluation of Gutta-Percha Removal by Two Retreatment Systems

Gustavo Alberto Rubino, George Táccio de Miranda Candeiro, Elaine Faga Iglecias, Érico de Mello Lemos, Celso Luiz Caldeira, Giulio Gavini

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 221-227

Introduction: The aim of the present ex vivo research was to compare the remaining filling material and the volumes of dentine removed after retreatment of curved canals with two rotary systems naming ProTaper Universal Retreatment and Mani NRT-GPR using micro-computed tomography (micro-CT). Material and Methods: Forty mandibular molars containing two completely separated canals, with curvature angle of 25-35° and a curvature radius <10 mm were prepared to the Mtwo instrument 35/0.04 and filled with warm gutta-percha and AH-Plus sealer. The teeth were randomly divided into 2 groups (n=20), according to the retreatment system evaluated: ProTaper Universal Retreatment (PR group) or Mani NRT-GPR (MR group). Retreatment was considered complete when the working length was reached and when smooth dentinal walls were observed, with no evidence of filling material adhered to instruments or in the irrigating solution. Preoperative and postoperative micro-CT images were obtained with an isotropic voxel size of 11.88 µm to observe the volume of residual filling material in the canals and dentine removed after retreatment. Statistical analysis was performed by Student’s t-test (P<0.05). Results: The mean percentage of remaining filling material was 12.96% for PR group and 24.26% for MR group (P=0.0056). The percentage of dentin removal was greater in the PR group (5.02%) than MR group (1.36%) (P=0.0028). Both systems failed to completely remove the filling material from the canals. Conclusion: ProTaper Universal Retreatment system was more effective than Mani NRT-GPR system regarding removal of root filling material and also removed significantly more dentine after retreatment of curved mesial root canals of mandibular molars.

Keywords: Dental Instruments; Endodontics; Gutta-Percha; Endodontic Retreatment 

Effects of Reciproc, ProTaper Next and WaveOne Gold on Root Canal Walls: A Stereomicroscope Analysis

Marcely Cassimiro, Kaline Romeiro, Luciana Gominho, Andressa de Almeida, Lívia Belo, Diana Albuquerque

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 228-233

Introduction: The aim of this study was to analyse the potential occurrence of dentinal defects after root canal preparation using three engine-driven instruments. Methods and Materials: Eighty permanent mandibular incisors were selected. Twenty teeth did not undergo preparation, and the remaining teeth were divided into three groups (n=20): Reciproc (REC), ProTaper Next (PTN) and WaveOne Gold (WOG). The samples were dyed with methylene blue, sectioned perpendicularly to the long axis in 3-, 6- and 9-mm slices and were finally observed under a stereomicroscope (under 25×). The absence/presence of dentinal defects was documented by two blind observers. The data were analysed using Pearson’s chi-squared test with a confidence level of 95% (P=0.05). The time to prepare the samples was recorded, and the groups were compared using F-test (ANOVA). Results: The control group did not present any defects, and the differences between the control and experimental groups were statistically significant (P<0.05). WOG, PTN and REC caused microcracks on 60%, 33.33% and 18.33% of the samples, respectively. No significant differences between the groups in the 3-mm sections (P=0.126) were observed. There were significant differences in the 6-mm (P=0.042) and 9-mm sections (P<0.001). When WOG and PTN were used to perform root canal preparation, a significant difference was found in the average time (P=0.047). Conclusion: All the used instruments caused dentinal defects in the root dentin. All the instruments were used to perform the preparation with a similar average time.

Keywords: Dentinal Defects; Microcracks; Nickel-Titanium Instruments; Root Canal Preparation

Introduction: the aim of this in vitro study was to compare the antifungal effect of propolis as an endodontic irrigant agent with a mixture of doxycycline, citric acid, and a detergent (MTAD), 2% chlorhexidine (CHX) and 3% sodium hypochlorite (NaOCl) against Candida albicans in presence and absence of smear layer. Methods and Materials: Extracted teeth with single canals (n=104) were prepared and randomly distributed into four experimental groups; 30% propolis, MTAD, 2% CHX and 3% NaOCl. Each group had two subgroups; with and without smear layer. The antifungal effectiveness was evaluated. The Kruskal-Wallis and Mann-Whitney tests were used to compare the overall effectiveness of different treatments at significance level of 0.05. Results: Propolis, CHX and NaOCl had similar levels of effectiveness to each other against C. albicans, and these levels were not affected by the presence or absence of the smear layer. Each irrigant was significantly more effective than MTAD or saline solution. MTAD was less effective in the presence of the smear layer than in its absence. Conclusions: Propolis irrigation can produce root canals that are free of C. albicans, even in the presence of the smear layer.

Keywords: Candida albicans; Chlorhexidine; Irrigating Solution; Propolis; Smear Layer; Sodium Hypochlorite

Canal Transportation and Centering Ability of ProTaper and SafeSider in Preparation of Curved Root Canals: A CBCT Evaluation

Negar Delgoshayi, Mansoure Abbasi, Hengameh Bakhtiar, Shirin Sakhdari, Setareh Ghannad, Mohammad Reza Ellini

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 240-245

Introduction: Maintaining the original central canal path is an important parameter in efficient root canal preparation. Instruments causing minimal changes in original canal path are preferred for this purpose. This study sought to compare canal transportation and centering ability of ProTaper and SafeSider instruments in curved mesiobuccal root canals of mandibular first molars using cone beam computed tomography (CBCT). Materials and Methods: In this experimental study, 30 mesiobuccal root canals of extracted human mandibular first molars with 20° to 40° curvature were randomly divided into two groups (n=15). After mounting in putty, preoperative CBCT scans were obtained of teeth. Root canals in group A were shaped using S1, S2, F1 and F2 of ProTaper system. Root canals in group B were instrumented to size 25 using SafeSider system according to the manufacturers’ instructions. Postoperative CBCT scans were then obtained. The distance between the external root surface and internal canal wall was measured at the mesial and distal at 1, 3 and 7 mm from the apex. The values measured on primary and secondary CBCT scans were compared to assess possible changes in original central canal path and canal transportation. Data were compared using the t-test and repeated measure ANOVA. Results: ProTaper and SafeSider were significantly different in terms of canal transportation and centering ability, and ProTaper was significantly superior to SafeSider in this respect (P<0.001). Conclusion: ProTaper (in contrast to SafeSider) is well capable of maintaining the original central canal path with the least amount of transportation.

Keywords: Canal Transportation; Cone-beam Computed Tomography; ProTaper; Root Canal Preparation; SafeSider

How the Prevalence of Pulp Stone in a Population Predicts the Risk for Kidney Stone

Najmeh Movahhedian, Abdolaziz Haghnegahdar, Fatemeh Owji

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 246-250

Introduction: Conflicting researches exist on relationship between pulp stones and systemic disorders. Nephrolithiasis is a common disease with severe pain and discomfort with increasing prevalence worldwide. The purpose of this study is to evaluate the correlation between pulp and kidney stones to help find a method for early detection of kidney stones. Methods and Materials: the sample of this case-control study comprised of 154 subjects (77 patients with and 77 patients without kidney stone approved by sonographic examination). Two oral and maxillofacial radiologists evaluated their panoramic images for the presence of pulpal stones. Results: A total of 42.9% of subjects showed pulp stones. Most of the teeth with pulp stone in case and control groups were molars (86.30% and 72.97%, respectively). In the group with kidney stones, pulp stones were detected in 38 patients (49.4%), while in the control group, they were detected in 28 subjects (36.4%). Although there was not a significant relationship between the presence/absence of pulp stone and kidney stone (P=0.143), there was statistically significant association between number of teeth with pulp stone in a patient and the presence of kidney stone (P<0.013). The chance of having kidney stone is 5.78 times higher in the subjects having pulp stone in three teeth or more (≥ 3 teeth). Conclusion: Although there is not a correlation between the presence of pulp and kidney stone, the chance of having kidney stone is 5.78 times higher in the subjects with ≥ 3 teeth having pulp stone. Thus, the number of teeth with pulp stone can serve as a predictor for possibility of having kidney stone.

Keywords: Dental Pulp Stone; Kidney Stone; Nephrolithiasis; Pulp Calcification; Radiography

Anatomy of Permanent‎ ‎Mandibular‎ First‎ Molars in a Selected Iranian Population Using ‎Cone-beam Computed Tomography

Aria Choupani Dastgerdi ‎, Manije Navabi, Ladan Hafezi ‎, Zohre Khalilak ‎, Vahid Rakhshan ‎

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 251-256

Introduction: Knowledge of radicular anatomy has a crucial impact on endodontic practices. Since some anatomic features such as modifications of Vertucci are not evaluated adequately, this study was conducted. Methods and Materials: In this in vivo study, cone-beam computed tomography (CBCT) images of‎ 312‎ intact bilateral first‎ molars‎ from‎ 156‎ patients‎ (‎79‎ ‎males‎ and‎ 77‎ females with an average age of ‎35.58‎±‎11.17‎ years‎)‎ were‎ investigated by a trained dentist in terms of number‎ of‎ roots,‎ number‎ of‎ canals‎ in‎ each‎ root‎ and‎ in‎ ‎each‎ tooth,‎ and shapes‎ of‎ canals‎ according‎ to‎ Vertucci’s‎ classification‎ and‎ its‎ modifications.‎ Groups were compared using the Chi-square test. The level of significance was set at 0.05. Results: Of all teeth, 5.2%‎ had‎ 3‎ roots.‎‎ ‎Mesial‎ roots‎ had‎ mostly‎ 2‎ canals‎ while distal roots had a similar frequency of 1 and 2 canals.‎ ‎Of‎ all‎ teeth,‎ ‎‎39.7%‎ had‎ 3‎ canals,‎ 45.2%‎ had‎ 4‎ canals,‎ 13.8%‎ had‎ 5‎ canals,‎ and‎ 1.3%‎ had‎ 6‎ canals.‎ There were no significant differences between males and females, ‎in terms of number of roots (P=0.137), number of canals in mesial (P=0.453) or distal roots (P‎‎=0.328), and total number of canals (P=0.138).‎ The most frequent Vertucci classes in mesial and distal roots were IV ‎‎followed‎ by‎ II and I‎, respectively. There were no significant differences between males and females in terms of Vertucci classes of mesial (P=0.211) or distal (P=0.205) roots. Conclusion: In this population, there were 3 to 6 canals per tooth (mostly 4 and 3 canals).‎ Males and female’s ‎might be similar regarding the number of roots, or number of canals in each root, number of ‎canals in each tooth, or the predominant canal shape in each root.

Keywords: Anatomy;‎ Cone-beam Computed Tomography; Endodontics;‎ Root Anatomy

Cytotoxicity of Two Experimental Epoxy Resin-Based Sealers

Hengameh Ashraf, Farhood Najafi, Soolmaz Heidari, Zahra Yadegary, Saeede Zadsirjan

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 257-262

Introduction: Many endodontic sealers are available, but search for the ideal sealer continues. This study aimed to assess the cytotoxicity of two experimental endodontic sealers in comparison with AH-26 resin sealer. Methods and Materials: This in vitro study was conducted on conventional and experimental root canal sealers: AH-26, an epoxy resin experimental sealer A (ES-A) composed of calcium tungstate, zirconium oxide, aerosil, bismuth oxide, titanium oxide, hexamine and an epoxy resin and experimental sealer B (ES-B) with compositions similar to ES-A except for the presence of imidazoline as a catalyst. The experimental sealers containing nano-particles were mixed with 37.5% of an epoxy resin. The extraction of five samples of each experimental sealer (A, B) and AH-26 sealer were subjected to MTT assay in the form of set and fresh at 1, 24 and 72 h with 1, 10, 100% dilution according to the International Standard ISO:10993-2012. Data were analyzed using the one-way ANOVA. Results: The set ES-A had the least cytotoxicity from the first hour but the cytotoxicity of ES-B and AH-26 extraction decreased over time. In fresh form, except for 100% concentration, ES-A showed the least cytotoxicity compared to the other two sealers. Conclusion: All three sealers had high cytotoxicity in 100% concentration but had low cytotoxicity in 10% and 1% concentrations.

Keywords: Cytotoxicity; Endodontics; Epoxy Resin; Sealer

Case Report

Endodontic Treatment of Complex Dens Invaginatus Teeth with Long Term Follow-Up Periods

Natália Gomes de Oliveira, Marina Torreão da Silveira, Shirley Machado Batista, Sirley Raiane Mamede Veloso, Marianne de Vasconcelos Carvalho, Rosana Maria Coelho Travassos

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 263-266

Dens invaginatus is characterized by invagination of enamel and dentin in the dental papilla prior to tissue calcification. This malformation commonly occurs in the maxillary lateral incisors. The present study reports two complex endodontic treatments in Oehlers’ type II and III dens invaginatus, with periapical lesion and presence of bone resorption. In the reported cases, conventional endodontic therapy was successful and sufficient enough to eliminate the infectious process, allowing periapical bone neoformation and absence of symptomatology. Dens invaginatus is a relatively easy-to-diagnose dental malformation. However, it is necessary to know its radiographic aspects. The treatment results demonstrated that, although the cases of dens invaginatus of high complexity are challenging, an accurate diagnosis accompanied with proper endodontic treatment can avoid unnecessary surgical intervention and allow great chances of favorable prognosis in long term.

Keywords: Anomalies; Classification; Dens Invaginatus; Root Canal Therapy

Autotransplantation, Surgical Repositioning of Retained Canine, and Apical Filling of Two Incisors with Root Resorption

Norberto Juarez Broon, Cuauhtemoc Bello Hernandez, Oscar Ivan Ruiz Montañez, Elizabeth Diaz Rosales, Jaime Padron Santana, Alejandra Zulema Calderon Escamilla

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 267-270

The purpose is to show the autotransplantation and surgical repositioning of a retained canine, and the apical filling of central and lateral resorbed incisors from a 12-year-old female patient, healthy and with clinical absence of left maxillary canine. Radiographically, the retained canine between the resorbed central and lateral incisors was observed. Root canal treatment of the canine was performed after 8 weeks; apical curettage and placement of bovine graft in inter-incisal zone was done after 4 months. During 6 months, orthodontic traction of the canine was carried out with no positive results, and 12 months after the autotransplantation, surgical repositioning was performed. Clinical-radiographic control at 30 days and 24 months showed absence of inflammation, restoration and integration of the tooth-supporting structures. Autotransplantation combined with surgical repositioning of the retained canine and the apical filling of two incisors achieved the harmonious, aesthetic, functional, dental and psychological preservation of the patient.

Keywords: Autotransplantation; Endodontics; Endodontic Surgery; Root Resorption; Surgical Repositioning

Surgical Endodontics vs Regenerative Periodontal Surgery for Management of a Large Periradicular Lesion

Saeed Asgary, Leyla Roghanizadeh, Ali Haeri

Iranian Endodontic Journal, Vol. 13 No. 2 (2018), 9 April 2018 , Page 271-276

Treatment success of periodontal-endodontic lesions is dependent on the elimination of both disease causative factors, whether they exist separately or concurrently. This report presents successful endodontic management of a misdiagnosed large periradicular pathology, which had not resolved after a previous periodontal regenerative surgery. A patient complaining of discomfort in the left maxillary region was referred. He had undergone regenerative surgery for treatment of a large periradicular defect; however, there was no further amelioration of the clinical signs/symptoms. Radiographically, a large periradicular lesion filled with bone substitute materials was detected around tooth #25. The endodontic treatment of the tooth was imperfect; therefore, surgical endodontic retreatment was planned. During root-end surgery, the biopsy containing bone substitute materials was obtained. Root-end filling/sealing using calcium-enriched mixture cement was completed. The histopathological examination showed granulation tissues enclosing exogenous materials. In two-year radiographic evaluation, resolving lesion and complete bone healing was observed. The first fundamental step in the management of periradicular lesions is correct diagnosis of the lesion origin and set-by step of the treatment plan according to the main causative factor. Regenerative periodonttal surgery, without considering the defective apical seal, will only cause a painful procedure for the patient without any positive benefit. Following appropriate apical seal, the endodontic lesion healing can be anticipated.

Keywords: Apical Periodontitis; Apical Seal; Calcium-Enriched Mixture; CEM Cement;  Diagnostic Errors; Endodontic-Periodontal Lesions; Endodontic Surgery