Original Article

Antibacterial Activity of Diode Laser and Sodium Hypochlorite in Enterococcus Faecalis-Contaminated Root Canals

Khosrow Sohrabi, Aidin Sooratgar, Kaveh Zolfagharnasab, Mohammad Javad Kharazi Fard, Farzaneh Afkhami

Iranian Endodontic Journal, Vol. 11 No. 1 (2016), 1 January 2016, Page 8-12

Introduction: The aim of the present in vitro study was to evaluate the disinfection ability of 980-nm diode laser in comparison with sodium hypochlorite (NaOCl) as a common root canal irrigant in canals infected with Enterococcus faecalis (E. faecalis). Methods and Materials: The root canals of 18 extracted single-rooted premolars were prepared by rotary system. After decoronation, the roots were autoclaved. One specimen was chosen for the negative control, and the remaining teeth were incubated with E. faecalis suspension for two weeks. Subsequently, one specimen was selected as the positive control and the remaining samples were divided into two groups (n=8). The samples of the first group were irrigated with 5.25% NaOCl and the second group were treated with a 980-nm diode laser. Microbial samples were taken from the root canals and bacterial cultivation was carried out. The average value and the standard deviation of colony-forming units (CFU) of each specimen were measured using descriptive statistics. The student’s t-test was used to compare the reduction in CFU in each group. The equality of variance of CFU was measured by the Levene’s test. Results: NaOCl resulted in 99.87% removal of the bacteria and showed significantly more antibacterial effect  compared to the 980-nm diode laser which led to 96.56% bacterial reduction (P<0.05). Conclusion: Although 5.25% NaOCl seems to reduce E. faecalis more effectively, the diode laser also reduced the bacterial count. Therefore a 980-nm diode laser could be considered as a complementary disinfection method in root canal treatment.

Keywords: Diode Laser; Enterococcus faecalis; Root Canal Disinfection; Root Canal Irrigant

Tissue Reaction and Biocompatibility of Implanted Mineral Trioxide Aggregate with Silver Nanoparticles in a Rat Model

Vahid Zand, Mehrdad Lotfi, Amirala Aghbali, Mehran Mesgariabbasi, Maryam Janani, Hadi Mokhtari, Pardis Tehranchi, Seyyed Mahdi Vahid Pakdel

Iranian Endodontic Journal, Vol. 11 No. 1 (2016), 1 January 2016, Page 13-16

Introduction: Biocompatibility and antimicrobial activity of endodontic materials are of utmost importance. Considering the extensive applications of mineral trioxide aggregate (MTA) in dentistry and antimicrobial properties of silver nanoparticles, this study aimed to evaluate the subcutaneous inflammatory reaction of rat connective tissues to white MTA with and without nanosilver (NS) particles. Methods and Materials: Polyethylene tubes (1.1×8 mm) containing experimental materials (MTA and MTA+NS and empty control tubes) were implanted in subcutaneous tissues of seventy-five male rats. Animals were divided into five groups (n=15) according to the time of evaluation: group 1; after 7 days, group 2; after 15 days, group 3; after 30 days, group 4; after 60 days and group 5; after 90 days. The inflammatory reaction was graded and data was analyzed using the Kruskal-Wallis and Mann-Whitney U tests. Statistical significance was defined at 0.05. Results: Comparison of cumulative inflammatory reaction at all intervals revealed that the mean grade of inflammatory reaction to MTA, MTA+NS and control samples were 3, 2 and 2, respectively. According to the Mann-Whitney analysis there were no significant differences between MTA+NS and MTA (P=0.42). Conclusion: Incorporation of 1% nanosilver to MTA does not affect the inflammatory reaction of subcutaneous tissue in rat models.

Keywords: Biocompatibility; Mineral Trioxide Aggregate; Nanosilver; Silver Nanoparticle

Cytotoxicity of Various Endodontic Materials on Stem Cells of Human Apical Papilla

Eshagh Ali Saberi, Hamed Karkehabadi, Narges Farhad Mollashahi

Iranian Endodontic Journal, Vol. 11 No. 1 (2016), 1 January 2016, Page 17-22

Introduction: This in vitro study assessed and compared the cytotoxicity of mineral trioxide aggregate (MTA), calcium-enriched mixture (CEM) cement, Biodentine (BD) and octacalcium phosphate (OCP) on stem cells of the human apical papilla (SCAP). Methods and Materials: SCAPs were isolated from two semi-impacted third molars. The cells were cultured in wells of an insert 24-well plate and were then incubated. The plates were then removed from the incubator and randomly divided into four experimental groups that were exposed to 1-mm discs of set MTA, CEM, BD or OCP, and one untreated control group. After 24, 48 and 168 h, the plates were removed from the incubator and 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) solution was added to each well. Data were analyzed at different time points using the repeated measures ANOVA followed by Bonferroni test and the level of significance was set at 0.05. Results: Cytotoxicity of the four materials was not significantly different from that of the control group at 24, 48 and 168 h (P>0.05). Two-by-two comparison revealed that cytotoxicity of MTA and CEM cement was significantly different from each other at 168 h (P<0.05) although the cytotoxicity of CEM was less than MTA. Cytotoxicity of OCP and MTA was also significantly different from each other at 48 h and OCP had more favorable biocompatibility than MTA (P<0.05). Conclusion: CEM, OCP, BD and MTA showed acceptable biocompatibility when exposed to SCAP. Over time, CEM showed the least cytotoxicity among the materials under study.

Keywords: Biodentine; Calcium-Enriched Mixture; Cytotoxicity; Endodontic Biomaterials; Mineral Trioxide Aggregate; MTT Assay; Stem Cells of Apical Papilla

Coronal Discoloration Induced by Calcium-Enriched Mixture, Mineral Trioxide Aggregate and Calcium Hydroxide: A Spectrophotometric Analysis

Behnaz Esmaeili, Homayoun Alaghehmand, Tavoos Kordafshari, Ghazaleh Daryakenari, Maryam Ehsani, Ali Bijani

Iranian Endodontic Journal, Vol. 11 No. 1 (2016), 1 January 2016, Page 23-28

Introduction: The aim of this study was to compare the discoloration potential of calcium-enriched mixture (CEM) cement, white mineral trioxide aggregate (WMTA) and calcium hydroxide (CH), after placement in pulp chamber. Methods and Materials: Access cavities were prepared in 40 intact maxillary central incisors. Then, a 2×2 mm box was prepared on the middle third of the inner surface on the buccal wall of the access cavity. The specimens were randomly assigned into four groups; the boxes in the control group were left empty, in groups 1 to 3, the boxes were filled with CH, WMTA and CEM cement, respectively. The access cavities and the apical openings were sealed using resin modified glass ionomer (RMGI). The color measurement was performed with a spectrophotometer at the following intervals: before (T0), immediately after placement of the filling material (T1), one week (T2), 1 month (T3), 3 months (T4) and 5 months (T5) after filling of the box and finally immediately after removing the material from the boxes (T6). Color change (ΔE) values were calculated using the sample Kolmogorov-Smirnov test to determine the normal distribution of data, followed by ANOVA, repeated measured ANOVA and post-hoc Tukey’s tests. Results: All materials led to clinically perceptible crown discoloration after 1 week. The highest ΔE value belonged to WMTA group. Discoloration induced by CEM cement was not significantly different from CH or the control group (P>0.05). Conclusion: CEM cement may be the material of choice in the esthetic region, specifically pertaining to its lower color changing potential compared to WMTA.

Keywords: Calcium-Enriched Mixture Cement; Mineral Trioxide Aggregate; Spectrophotometry; Tooth Discoloration

Effect of Autoclave Cycles on Surface Characteristics of S-File Evaluated by Scanning Electron Microscopy

Hamid Razavian, Pedram Iranmanesh, Hamid Mojtahedi, Rahman Nazeri

Iranian Endodontic Journal, Vol. 11 No. 1 (2016), 1 January 2016, Page 29-32

Introduction: Presence of surface defects in endodontic instruments can lead to unwanted complications such as instrument fracture and incomplete preparation of the canal. The current study was conducted to evaluate the effect of autoclave cycles on surface characteristics of S-File by scanning electron microscopy (SEM). Methods and Materials: In this experimental study, 17 brand new S-Files (#30) were used. The surface characteristics of the files were examined in four steps (without autoclave, 1 autoclave cycle, 5 autoclave cycles and 10 autoclave cycles) by SEM under 200× and 1000× magnifications. Data were analyzed using the SPSS software and the paired sample t-test, independent sample t-test and multifactorial repeated measures ANOVA. The level of significance was set at 0.05. Results: New files had debris and pitting on their surfaces. When the autoclave cycles were increased, the mean of surface roughness also increased at both magnifications (P<0.05). Moreover, under 1000× magnification the multifactorial repeated measures ANOVA showed more surface roughness (P<0.001). Conclusion: Sterilization by autoclave increased the surface roughness of the files and this had was directly related to the number of autoclave cycles.

Keywords: Autoclave; Endodontic Instruments; Root Canal Therapy; Scanning Electron Microscopy; Surface Characteristic

Effects of Glide Path on the Centering Ability and Preparation Time of Two Reciprocating Instruments

Marcelo Santos Coelho, Carlos Eduardo Fontana, Augusto Shoji Kato, Alexandre Sigrist de Martin, Carlos Eduardo da Silveira Bueno

Iranian Endodontic Journal, Vol. 11 No. 1 (2016), 1 January 2016, Page 33-37

Introduction: The aim of this in vitro study was to evaluate the effects of establishing glide path on the centering ability and preparation time of two single-file reciprocating systems in mesial root canals of mandibular molars. Methods and Materials: Sixty extracted mandibular molars with curvatures of 25-39 degrees and separate foramina for the mesiobuccal and mesiolingual canals, were divided into four groups (n=15); WaveOne+glide path; WaveOne; Reciproc+glide path and Reciproc. Non-patent canals were excluded and only one canal in each tooth was instrumented. A manual glide path was established in first and third groups with #10, 15 and 20 hand K-files. Preparation was performed with reciprocating in-and-out motion, with a 3-4 mm amplitude and slight apical pressure. Initial and final radiographs were taken to analyze the amount of dentin removed in the instrumented canals. The radiographs were superimposed with an image editing software and examined to assess discrepancies at 3-, 6- and 9-mm distances from the apex. The Kruskal-Wallis test was used for statistical analysis. The level of significance was set at 0.05. Results: Preparation in groups without glide paths was swifter than the other groups (P=0.001). However, no difference was observed regarding centering ability. Conclusion: Establishing a glide path increased the total instrumentation time for preparing curved canals with WaveOne and Reciproc instruments. Glide path had no influence on the centering ability of these systems.

Keywords: Centering Ability; Glide Path; Reciproc; Root Canal Preparation; Single-File Instrumentation; WaveOne

Postoperative Pain after Endodontic Treatment of Asymptomatic Teeth Using Rotary Instruments: A Randomized Clinical Trial

Shahriar Shahi, Vahideh Asghari, Saeed Rahimi, Mehrdad Lotfi, Mohammad Samiei, Hamidreza Yavari, Sahar Shakouie, Saeed Nezafati

Iranian Endodontic Journal, Vol. 11 No. 1 (2016), 1 January 2016, Page 38-43

Introduction: The aim of the present study was to compare the effect of two different rotary instruments on postoperative pain in teeth with asymptomatic irreversible pulpitis. Methods and Materials: A total of 78 mandibular first and second molars were divided into two groups (n=39) and their root canal preparation was carried out with either RaCe or ProTaper rotary instruments. All the subjects underwent one-visit root canal treatment and the severity of postoperative pain was evaluated using visual analog scale (VAS) at 4-, 12-, 24-, 48- and 72-h and 1-week intervals. In addition, the need for taking analgesics was recorded. Data were analyzed with the repeated-measures ANOVA and the Mann-Whitney U test was used for two-by-two comparison. Statistical significance was set at 0.05. Results: Comparison of mean pain severity between the two groups at various postoperative intervals did not reveal any significant differences (P=0.10). The difference in amount of analgesics taken by each groups was not statistically significant (P=0.25). Conclusion: There were no significant differences in the postoperative pain reported between the two groups; which indicates the clinical acceptability of both systems.

Keywords: Irreversible Pulpitis; Flare-Up; Postoperative Pain; ProTaper; RaCe; Root Canal Treatment  

Antimicrobial and Cytotoxic Activity of Cuminum Cyminum as an Intracanal Medicament Compared to Chlorhexidine Gel

Abbas Abbaszadegan, Ahmad Gholami, Yasamin Ghahramani, Razieh Ghareghan, Marzieh Ghareghan, Aboozar Kazemi, Aida Iraji, Younes Ghasemi

Iranian Endodontic Journal, Vol. 11 No. 1 (2016), 1 January 2016, Page 44-50

Introduction: The aims of this study were i) to define the chemical constituents of Cuminum cyminum (cumin) essential oil, ii) to compare the antimicrobial activity of this oil to that of chlorhexidine (CHX) and co-trimoxazole on planktonic and biofilm forms of bacteria isolated from the teeth with persistent endodontic infection and iii) to compare the cytotoxicity of these medicaments on L929 fibroblasts. Methods and Materials: Three groups of microorganisms [aerobic bacterial mixture, anaerobic bacterial mixture and Enterococcus faecalis (E .faecalis)] were isolated from the teeth with persistent apical periodontitis. Zone of inhibition (ZOI), minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC) and time-kill tests were performed to assess the antimicrobial efficacy of the medicaments. Further, a cytocompatibility analysis of the medicaments was performed on L929 fibroblasts. The results obtained from disc diffusion test and mean cell viability values of the experimental medicaments were analyzed using two-way and one-way analysis of variance (ANOVA). Results: Seventeen constituents were recognized in cumin oil (predominantly cumin aldehyde and γ-terpinene). Co-trimoxazole showed the greatest ZOI followed by cumin and CHX. The smallest MIC and MBC belonged to co-trimoxazole followed by cumin and CHX for all groups of bacteria except for E. faecalis for which the MBC of cumin was smaller than co-trimoxazole. The results of time-kill assay revealed that all medicaments totally inhibited the bacterial growth in all groups after 24 h. CHX was the most cytotoxic solution while there were no significant differences between the cytocompatibility of different concentrations of cumin essential oil and co-trimoxazole. Conclusion: Cumin exhibited a strong antimicrobial efficiency against the microbial flora of the teeth with failed endodontic treatments and it was biocompatible for L929 mouse fibroblasts.

Keywords: Antibacterial Activity; Chlorhexidine; Co-trimoxazole; Cuminum Cyminum; Cytotoxicity; Intracanal Medicament

Diagnostic Accuracy of Cone-Beam Computed Tomography and Periapical Radiography in Internal Root Resorption

Zahrasadat Madani, Ehsan Moudi, Ali Bijani, Elham Mahmoudi

Iranian Endodontic Journal, Vol. 11 No. 1 (2016), 1 January 2016, Page 51-56

Introduction: The aim of this study was to compare the diagnostic value of cone-beam computed tomography (CBCT) and periapical (PA) radiography in detecting internal root resorption. Methods and Materials: Eighty single rooted human teeth with visible pulps in PA radiography were split mesiodistally along the coronal plane. Internal resorption like lesions were created in three areas (cervical, middle and apical) in labial wall of the canals in different diameters. PA radiography and CBCT images were taken from each tooth. Two observers examined the radiographs and CBCT images to evaluate the presence of resorption cavities. The data were statistically analyzed and degree of agreement was calculated using Cohen’s kappa (k) values. Results: The mean±SD of agreement coefficient of kappa between the two observers of the CBCT images was calculated to be 0.681±0.047. The coefficients for the direct, mesial and distal PA radiography were 0.405±0.059, 0.421±0.060 and 0.432±0.056, respectively (P=0.001). The differences in the diagnostic accuracy of resorption of different sizes were statistically significant (P<0.05); however, the PA radiography and CBCT, had no statistically significant differences in detection of internal resorption lesions in the cervical, middle and apical regions. Conclusion: Though, CBCT has a higher sensitivity, specificity, positive predictive value and negative predictive value in comparison with conventional radiography, this difference was not significant.

Keywords: Cone-Beam Computed Tomography; Periapical Radiography; Root Resorption

Effect of Premedication with Indomethacin and Ibuprofen on Postoperative Endodontic Pain: A Clinical Trial

Fatemeh Mokhtari, Kamal Yazdi, Amir Mohammad Mahabadi, Seyed Jalil Modaresi, Zeinab Hamzeheil

Iranian Endodontic Journal, Vol. 11 No. 1 (2016), 1 January 2016, Page 57-62

Introduction: Post-endodontic pain is one of the main problems for both patients and dentists. The purpose of this study was to compare the effectiveness of premedication with indomethacin and ibuprofen for management of postoperative endodontic pain. Methods and Materials: In this clinical trial, mandibular molars with irreversible pulpitis were endodontically treated in 66 patients. The medicines were prepared similarly in the form of capsules containing 400 mg ibuprofen (group A), 25 mg indomethacin (group B) and placebo (group C). The patients were given one capsule 1 h before the start of treatment. Patients recorded their pain measured by a visual analogue scale (VAS) at medication time, during treatment and 8, 12 and 24 h after treatment. The data were analyzed using the chi-square, repeated measures ANOVA, paired t-test, Tamhane and Pearson correlation coefficient. Results: Ibuprofen and indomethacin significantly reduced the postoperative pain in comparison with placebo during treatment and 8 h after treatment; however, there were no significant differences between them 12 and 24 h after treatment. Conclusion: Premedication with ibuprofen and indomethacin can effectively control short term post-operative pain; the lower incidence of side effects and greater analgesic power of ibuprofen make it a superior choice.

Keywords: Ibuprofen; Indomethacin; Irreversible Pulpitis; Non-Steroidal Anti-Inflammatory Drugs; Post-Endodontic Pain

The Impact of Apical Patency in the Success of Endodontic Treatment of Necrotic Teeth with Apical Periodontitis: A Brief Review

Ricardo Machado, Carlos Henrique Ferrari, Eduardo Back, Daniel Comparin, Luiz Fernando Tomazinho, Luiz Pascoal Vansan

Iranian Endodontic Journal, Vol. 11 No. 1 (2016), 1 January 2016, Page 63-66

Accumulation of soft tissue or dentinal remnants in the apical region is a common event that can cause blockage of root canals. This event can be avoided if apical patency is performed during the root canal shaping procedures. However, there is no consensus on the role of apical patency in relation to the success of endodontic treatment of necrotic teeth with apical periodontitis. Therefore, the purpose of this paper was to conduct a brief review on the role of apical patency in guaranteeing the success of endodontic treatments of necrotic teeth with apical periodontitis considering two other key points; the root canal anatomy and microbiology.

Keywords: Apical Patency; Endodontic Success; Periradicular Disease; Root Canal Therapy

Case Report

Bisphosphonate-Induced Osteonecrosis of the Maxilla Resembling a Persistent Endodontic Lesion

Hossain Mosaferi, Mahta Fazlyab, Sanaz Sharifi, Sepideh Rahimian

Iranian Endodontic Journal, Vol. 11 No. 1 (2016), 1 January 2016, Page 67-70

A 52-year-old Caucasian woman suffering from pain in the anterior maxillary region, presented to the clinic. Examination revealed a draining sinus tract in the buccal vestibule of the maxilla in the left anterior segment and expansion in the middle of palate. On conventional radiographic examination the lesion was initially assumed to be a periapical problem related to the incisors but subsequently it was diagnosed to be a bisphosphonate osteonecrosis. Conclusion: Acquiring a comprehensive medical history from the patients, conducting the clinical vitality tests and most importantly being familiar with the non-odontogenic lesions that can be side effects of specific medications are important requirements for reaching a correct diagnosis.

Keywords: Bisphosphonate; Breast Cancer; Osteonecrosis; Periapical Pathosis

Interdisciplinary Approach for Management of Iatrogenic Internal Root Resorption: A Case Report

Mohsen Ramazani, Saeed Asgary, Nafiseh Zarenejad, Javad Mehrani

Iranian Endodontic Journal, Vol. 11 No. 1 (2016), 1 January 2016, Page 71-74

For management of a symptomatic maxillary lateral incisor with dull pain on chewing, suppurative sinus tract, defective metal-ceramic crown and iatrogenic internal root resorption, an interdisciplinary approach was taken. Two-visit nonsurgical treatment with calcium-enriched mixture (CEM) cement, replacement of metal-ceramic crown with all-ceramic crown and corrective periodontal plastic surgery were included in the treatment plan. Six-month and one-year follow-ups revealed complete resolution of signs and symptoms and radiographic healing. This case report highlights the importance of adequate cooling during crown preparation to preserve the pulp vitality and prevent internal resorptive lesions and also the profound sealing ability and biocompatibility of CEM cement.

Keywords: Calcium-Enriched Mixture; Interdisciplinary Treatment; Internal Root Resorption

Miniature Pulpotomy of Symptomatic Mature Permanent Teeth: A Report of Two Cases

Saeed Asgary, Mahdieh Nourzadeh, Mohammad Jafar Eghbal

Iranian Endodontic Journal, Vol. 11 No. 1 (2016), 1 January 2016, Page 75-78

Human dental pulp inflammation can progress to periapical lesion formation and conventional root canal treatment (RCT) has been the traditional method for disease management. This observational study presents two cases of vital pulp therapy in mature molars diagnosed with irreversible pulpitis and associated with apical periodontitis. In these two clinical cases, the involved teeth had deep carious lesions with a history of spontaneous/lingering pain and radiographic examinations revealed the presence of apical radiolucencies. A conservative miniature pulpotomy (MP) using calcium-enriched mixture (CEM) was performed and the teeth were permanently restored with amalgam. Clinical evaluations indicated resolution of pain 24 hours after treatment; the teeth showed normal vitality, remained asymptomatic and maintained normal function after recall examinations. Furthermore, the 18-month radiographic evaluation showed healing of the apical lesions. Vital pulp therapy using the MP technique with CEM appeared successful in avoiding RCT intervention. These two reports of case outcome suggest that simple MP using a CEM bioregenerative technique may provide a favorable outcome for permanent teeth diagnosed with irreversible pulpitis and associated with apical periodontitis.

Keywords: Calcium-Enriched Mixture, CEM cement, Endodontic, Miniature pulpotomy, Irreversible pulpitis

Review Article

Management of Root Resorption Using Chemical Agents: A Review

Zahed Mohammadi, Zafer C Cehreli, Sousan Shalavi, Luciano Giardino, Flavio Palazzi, Saeed Asgary

Iranian Endodontic Journal, Vol. 11 No. 1 (2016), 1 January 2016, Page 1-7

Root resorption (RR) is defined as the loss of dental hard tissues because of clastic activity inside or outside of tooth the root. In the permanent dentition, RR is a pathologic event; if untreated, it might result in the premature loss of the affected tooth. Several hypotheses have been suggested as the mechanisms of root resorption such as absence of the remnants of Hertwig's epithelial root sheath (HERS) and the absence of some intrinsic factors in cementum and predentin such as amelogenin or osteoprotegerin (OPG). It seems that a barrier is formed by the less-calcified intermediate cementum or the cementodentin junction that prevents external RR. There are several chemical strategies to manage root resorption. The purpose of this paper was to review several chemical agents to manage RR such as tetracycline, sodium hypochlorite, acids (citric acid, phosphoric acid, ascorbic acid and hydrochloric acid), acetazolamide, calcitonin, alendronate, fluoride, Ledermix and Emdogain.

Keywords: Alendronate; Calcitonin; Citric Acid; Emdogain; Fluoride; Osteoclast; Root Resorption; Tetracycline