Payam Paymanpour - Academia.edu (original) (raw)
Papers by Payam Paymanpour
Journal of Dental Rehabilitation and Applied Science, 2014
Aberrant anatomy of mandibular premolars is very rare in Korean, but aberration can contribute th... more Aberrant anatomy of mandibular premolars is very rare in Korean, but aberration can contribute the endodontic failure as it makes difficult to remove the irritants during cleaning and shaping procedure. This case report describes the successful root canal treatment of a rare mandibular first premolar with C-shaped root canal as using a cone-beam computed tomography to understand the internal shape of root canal system and a dental operating microscope to improve the magnification and illumination.
Confluent middle mesial root canals in mandibular first molar: A case report
Knowledge of both normal and abnormal anatomy of the root canal system can directly affect the ou... more Knowledge of both normal and abnormal anatomy of the root canal system can directly affect the outcome of the endodontic therapy. This paper describes the nonsurgical endodontic management of the rare anatomical configuration middle mesial canal in previously treated mandibular first molar. After coronal access, the gutta-percha was eliminated. In precise examination of groove between two mesial canals, the middle mesial orifice was revealed. All root canals prepared chemo mechanically and obturated. After 6 months follow up, the tooth was asymptomatic and functional and apical lesion was healed.
Iranian endodontic journal, 2015
The aim of this study was to compare the changes that occur in the danger zone (DZ) after prepara... more The aim of this study was to compare the changes that occur in the danger zone (DZ) after preparation of curved mesiobuccal (MB) canals of mandibular first molars with WaveOne instruments in two different movements [reciprocation (RCP) and counter-clockwise rotation (CCWR)] by means of cone-beam computed tomography (CBCT). MB canals of 30 mandibular molars were randomly divided into 2 groups (n=15); WaveOne/RCP and WaveOne/CCWR. Pre- and post-instrumentation CBCT images were assessed for changes in the dentin thickness in DZ (2 and 4 mm below the highest point of the root furcation) in both groups. Data was analyzed using the repeated measures ANOVA test. There was no statistically significant difference between two experimental groups in terms of remaining dentin thickness at 2 and 4 mm levels below the highest point of the furcation (P>0.05). The efficacy of WaveOne instrument on changes of the dentin thickness in the DZ was not affected by different file movements.
Journal of Research in Dental and Maxillofacial Sciences, 2020
Background and Aim: Different methods have been proposed for rapid disinfection of gutta-percha (... more Background and Aim: Different methods have been proposed for rapid disinfection of gutta-percha (GP) cones. This study aimed to assess the efficacy of low-pressure radiofrequency cold plasma (LRFCP) in disinfection of GP cones compared to three chemical disinfectants. Materials and Methods: Seventy GP cones were allocated to seven groups of 10 each. All samples were initially sterilized with ethylene oxide (EO) and subsequently inoculated with Staphylococcus aureus (S. aureus), except for the negative control group (n=10). In the experimental groups (n=50), samples were subjected to oneminute chemical disinfection [5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and 10% Deconex® 53 PLUS) or LRFCP (30 seconds or one minute). The effectiveness of disinfection was evaluated by counting the colony-forming units (CFUs). Data were analyzed using Kruskal-Wallis test (P=0.05). Result: All experimental groups effectively eliminated S. aureus. LRFCP and 5.25% NaOCl were the most effective agents in disinfection of GP cones. In addition, 2% CHX was significantly weaker than the other agents (P<0.05). Although Deconex® 53 PLUS was less potent than LRFCP groups and NaOCl (P>0.05), it showed higher antibacterial activity than 2% CHX (P>0.05). Conclusion: LRFCP can be assumed as a noninvasive and efficient method for disinfection of GP cones.
Copyright © 2013 Hengameh Ashraf et al. This is an open access article distributed under the Crea... more Copyright © 2013 Hengameh Ashraf et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Long-term success of endodontic treatment is strictly dependent on proper shaping and cleaning of the root canal system followed by obturation of entire prepared space. Anatomical variations should be considered during radiographic and clinical evaluation as parts of endodontic treatment. A mandibular premolar with three canals is quite rare and such a tooth requires special canal preparation and obturation techniques. An astute clinician should identify different canal configurations and treat them endodontically well, because presence of an untreated canal could be a reason for failure of endodontic treatment. This paper describes the conventional orthograde endodontic therapy on an unusual mandibular first premolar with three roo...
Dental Research Journal, 2016
Background: The aim of this study was to evaluate apical transportation and centering ability of ... more Background: The aim of this study was to evaluate apical transportation and centering ability of single-file instruments, WaveOne primary, with full rotation versus reciprocation movement using cone-beam computed tomography (CBCT) analysis in curved mesiobuccal (MB) root canal of human mandibular molars. Materials and Methods: Thirty MB canals of mandibular molars were randomly divided into two groups according to the instrument motion (n = 15): Group 1, reciprocation/WaveOne primary; Group 2, continuous rotation/WaveOne primary. After preparation, the amount of apical transportation and centering ability were assessed by evaluating pre-and post-instrumentation CBCT scans in three section (1, 3, and 5 mm from apical foramen). Statistical analysis of the data was performed using Mann-Whitney U-test and Friedman test (α = 0.05). Results: There was no statistically significant difference between two experimental groups in terms of apical transportation and centering ratio at 1, 3, and 5 mm from apical foramen (P > 0.05). Conclusion: Apical transportation and centering ability of WaveOne primary reciprocating instrument did not significantly differ between two motion patterns.
Long-term success of endodontic treatment is strictly dependent on proper shaping and cleaning of... more Long-term success of endodontic treatment is strictly dependent on proper shaping and cleaning of the root canal system followed by obturation of entire prepared space. Anatomical variations should be considered during radiographic and clinical evaluation as parts of endodontic treatment. A mandibular premolar with three canals is quite rare and such a tooth requires special canal preparation and obturation techniques. An astute clinician should identify different canal configurations and treat them endodontically well, because presence of an untreated canal could be a reason for failure of endodontic treatment. This paper describes the conventional orthograde endodontic therapy on an unusual mandibular first premolar with three root canals.
Iranian endodontic journal, Oct 7, 2014
A healthy female was referred to Endodontic Department. The referral letter from her dentist expr... more A healthy female was referred to Endodontic Department. The referral letter from her dentist expressed that an emergency pulpotomy of tooth #27 had been carried out with probable perforation of the chamber floor which was due to the unusual anatomy of the chamber. Cone-beam computed tomography (CBCT) revealed that the tooth had two mesial and two distal canals. Perforation site was repaired and endodontic treatment was completed. At 24-month follow-up, patient was asymptomatic and clinical and radiographic examinations showed successful outcomes.
IEJ Iranian Endodontic Journal 2015;10(3): 156-161 Alterations of the Danger Zone after Preparation of Curved Root Canals Using WaveOne with Reverse Rotation or Reciprocation Movements
Introduction: The aim of this study was to compare the changes that occur in the danger zone (DZ)... more Introduction: The aim of this study was to compare the changes that occur in the danger zone (DZ) after preparation of curved mesiobuccal (MB) canals of mandibular first molars with WaveOne instruments in two different movements [reciprocation (RCP) and counter-clockwise rotation (CCWR)] by means of cone-beam computed tomography (CBCT). Methods and Materials: MB canals of 30 mandibular molars were randomly divided into 2 groups (n=15);
Sealing Ability of Resilon and MTA as Root-end Filling Materials: A Bacterial and Dye Leakage Study
Iranian Endodontic Journal, 2017
Introduction: Gutta-percha (GP), is a neutral and non-toxic material. The aim of this animal stud... more Introduction: Gutta-percha (GP), is a neutral and non-toxic material. The aim of this animal study was to compare the biocompatibility of nanosilver coated GP (NS-GP) with conventional GP in subcutaneous tissues in a rat model. Methods and Materials: Conventional GP and NS-GP were subcutaneously implanted in the backs of 20 male Wistar rats (n=10). A control animal was assigned for each trial period. Ten animals were sacrificed after 7 and 30 days and light microscopic evaluation of tissue reaction to NS-GP (n=20) and conventional GP (n=20) was accomplished. The Mann-Whitney U, Wilcoxon Signed Ranks, Fisher Exact, and McNemar tests were used for statistical analysis of the data. Results: After 7 days, inflammation was moderate and mild for NS-GP and conventional GP, respectively (P<0.001). After 30 days, no inflammation was discernible in conventional GP. However, mild inflammation was reported for NS-GP (P<0.001). Regarding inflammatory cell type, there was a significant diff...
Background: During endodontic procedures, the smear layer is formed as a result of mechanical ins... more Background: During endodontic procedures, the smear layer is formed as a result of mechanical instrumentation of the canal. Combination of ethylenediamine tetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) is widely used for removal of the smear layer. Application of Mixture of tetracycline, acid, and detergent (MTAD) as final irrigant subsequent to initial irrigation of 1.35% NaOCl has been proposed to increase clinical efficiency, biocompatibility and prolonged intra-canal antibacterial activity. Considering the importance of adhesion of endodontic sealers to the dentin walls of a prepared root canal, the present study evaluated push-out bond strength of AH26 sealer using final irrigation of MTAD and EDTA + NaOCl. Materials and Methods: Sixty five single-rooted teeth were prepared endodontically with the same chemomechanical technique and were randomly divided into three groups based on their final irrigation regimen: 17% EDTA + 5.25% NaOCl group (n =30), MTAD group (n =30) a...
Paresthesia of the inferior alveolar nerve (IAN) as the result of preapical inflammation or endod... more Paresthesia of the inferior alveolar nerve (IAN) as the result of preapical inflammation or endodontic treatment is a rare but serious occurrence. The following case report describes the diagnosis and management of paresthesia related to an endodontic periodical lesion of a mandibular third molar.
Journal of Lasers in Medical Sciences, 2016
Introduction: Root canal therapy as a routine dental procedure has resulted in retention of milli... more Introduction: Root canal therapy as a routine dental procedure has resulted in retention of millions of teeth that would otherwise be lost. Unfortunately, successful outcomes are not always achievable within initial endodontic treatments, and that necessitates further treatment. Nonsurgical retreatment is the first choice in most clinical situations. The aim of this clinical pilot study was to assess the effect of additional photodynamic therapy (PDT) on intraradicular bacterial load following retreatment of failed previously root treated teeth. Methods: Thirty single-rooted/canalled endodontically treated matured teeth (in 27 healthy patients) accompanied by apical periodontitis (AP) were selected for this study. Standard protocol was followed for nonsurgical retreatment of each tooth. Microbiological samples were taken after establishment of apical patency, finished cleaning/shaping procedure, and PDT (665 nm, 1 W, 240 seconds). All samples were cultured for 72 hours and colonyforming unit (CFU) was counted. McNemar test was used for statistical analysis of the data. The level of significance was set at 0.001. Results: Routine cleaning and shaping resulted in twenty four negative (80%) out of 30 cultures. Four additional negative results were obtained after additional PDT (93.3%). The addition of PDT to routine procedures significantly enhanced the number of bacteria-free samples (P < 0.001). Conclusion: Regarding elimination of intraradicular microbiota, additional PDT may increase the effectiveness of conventional chemomechanical preparation in previously root filled teeth accompanied by AP. Well controlled randomized clinical trials should be planned for future.
Endodontic repair in immature dogs’ teeth with apical periodontitis: blood clot versus plasma rich in growth factors scaffold
Dental Traumatology, 2016
BACKGROUND/AIM Different types of scaffolds have been suggested for endodontic repair procedures.... more BACKGROUND/AIM Different types of scaffolds have been suggested for endodontic repair procedures. The aim of this study was to compare the outcome of procedures using blood clot vs plasma rich in growth factors (PRGF) scaffold in immature teeth with apical periodontitis in dogs. MATERIALS AND METHODS In this in vivo animal study, 20 teeth (30 canals) with open apices were divided into two groups (n = 12): (1) blood clot and (2) PRGF. Two positive and negative control groups were also selected randomly. After exposing the pulp and inducing periapical inflammation by placing a sponge soaked in a suspension of dental plaque, the root canals of both groups were flushed with sodium hypochlorite and filled with triple antibiotic paste. After 28 days, the antibiotic mixture was removed, bleeding was induced through the apical foramen, and mineral trioxide aggregate was placed over the blood clot in group one and PRGF scaffold in group two. Access cavities were then filled with composite resin. The radiographic and histological findings were compared immediately after the procedure, as well as after 3 and 6 months of follow-up. RESULTS There was no statistically significant difference between the two experimental groups with regard to the radiographic or histological results (P > 0.05). The incidence of healed periapical radiolucency was 60% and 53.33% in groups one and two, respectively. Apical closure was noted in 60% of samples in both experimental groups. New cementum-like tissue formation was detected along the walls of the canals, and bone-like islands within the canals were also observed. CONCLUSIONS Plasma rich in growth factors scaffold showed no advantage over blood clots regarding healing of the periapical radiolucency, radiographic apical closure and type of the newly formed soft and hard tissues.
Background and Aim: Different methods have been proposed for rapid disinfection of gutta-percha (... more Background and Aim: Different methods have been proposed for rapid disinfection of gutta-percha (GP) cones. This study aimed to assess the efficacy of low-pressure radiofrequency cold plasma (LRFCP) in disinfection of GP cones compared to three chemical disinfectants. Materials and Methods: Seventy GP cones were allocated to seven groups of 10 each. All samples were initially sterilized with ethylene oxide (EO) and subsequently inoculated with Staphylococcus aureus (S. aureus), except for the negative control group (n=10). In the experimental groups (n=50), samples were subjected to oneminute chemical disinfection [5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and 10% Deconex® 53 PLUS) or LRFCP (30 seconds or one minute). The effectiveness of disinfection was evaluated by counting the colony-forming units (CFUs). Data were analyzed using Kruskal-Wallis test (P=0.05). Result: All experimental groups effectively eliminated S. aureus. LRFCP and 5.25% NaOCl were the most effective agents in disinfection of GP cones. In addition, 2% CHX was significantly weaker than the other agents (P<0.05). Although Deconex® 53 PLUS was less potent than LRFCP groups and NaOCl (P>0.05), it showed higher antibacterial activity than 2% CHX (P>0.05). Conclusion: LRFCP can be assumed as a noninvasive and efficient method for disinfection of GP cones.
Human Pulp Response to Direct Pulp Capping and Miniature Pulpotomy with MTA after Application of Topical Dexamethasone: A Randomized Clinical Trial
Iranian endodontic journal, 2016
The aim of this randomized clinical trial was to compare the histologic pulp tissue response to o... more The aim of this randomized clinical trial was to compare the histologic pulp tissue response to one-step direct pulp capping (DPC) and miniature pulpotomy (MP) with mineral trioxide aggregate (MTA) after application of dexamethasone in healthy human premolars. Forty intact premolars from 10 orthodontic patients, were randomly chosen for DPC (n=20) or MP (n=20). In 10 teeth from each group, after exposure of the buccal pulp horn, topical dexamethasone was applied over the pulp. In all teeth the exposed/miniaturely resected pulp tissue was covered with MTA and cavities were restored with glass ionomer. Teeth vitality was evaluated during the next 7, 21, 42, and 60 days. Signs and/or symptoms of irreversible pulpitis or pulp necrosis were considered as failure. According to the orthodontic schedule, after 60 days the teeth were extracted and submitted for histological examination. The Kruskal-Wallis and Fisher's exact tests were used for statistical analysis of the data (P=0.05). A...
Influence of motion pattern on apical transportation and centering ability of WaveOne single-file technique in curved root canals
Dental Research Journal, 2016
The aim of this study was to evaluate apical transportation and centering ability of single-file ... more The aim of this study was to evaluate apical transportation and centering ability of single-file instruments, WaveOne primary, with full rotation versus reciprocation movement using cone-beam computed tomography (CBCT) analysis in curved mesiobuccal (MB) root canal of human mandibular molars. Thirty MB canals of mandibular molars were randomly divided into two groups according to the instrument motion (n = 15): Group 1, reciprocation/WaveOne primary; Group 2, continuous rotation/WaveOne primary. After preparation, the amount of apical transportation and centering ability were assessed by evaluating pre- and post-instrumentation CBCT scans in three section (1, 3, and 5 mm from apical foramen). Statistical analysis of the data was performed using Mann-Whitney U-test and Friedman test (α = 0.05). There was no statistically significant difference between two experimental groups in terms of apical transportation and centering ratio at 1, 3, and 5 mm from apical foramen (P &amp;amp;amp;amp;amp;gt; 0.05). Apical transportation and centering ability of WaveOne primary reciprocating instrument did not significantly differ between two motion patterns.
Alterations of the Danger Zone after Preparation of Curved Root Canals Using WaveOne with Reverse Rotation or Reciprocation Movements
Iranian endodontic journal, 2015
The aim of this study was to compare the changes that occur in the danger zone (DZ) after prepara... more The aim of this study was to compare the changes that occur in the danger zone (DZ) after preparation of curved mesiobuccal (MB) canals of mandibular first molars with WaveOne instruments in two different movements [reciprocation (RCP) and counter-clockwise rotation (CCWR)] by means of cone-beam computed tomography (CBCT). MB canals of 30 mandibular molars were randomly divided into 2 groups (n=15); WaveOne/RCP and WaveOne/CCWR. Pre- and post-instrumentation CBCT images were assessed for changes in the dentin thickness in DZ (2 and 4 mm below the highest point of the root furcation) in both groups. Data was analyzed using the repeated measures ANOVA test. There was no statistically significant difference between two experimental groups in terms of remaining dentin thickness at 2 and 4 mm levels below the highest point of the furcation (P>0.05). The efficacy of WaveOne instrument on changes of the dentin thickness in the DZ was not affected by different file movements.
Effects of Reciproc, Mtwo and ProTaper Instruments on Formation of Root Fracture
Iranian endodontic journal, 2015
The aim of this study was to compare the formation of dentinal crack and craze lines in the root ... more The aim of this study was to compare the formation of dentinal crack and craze lines in the root dentin during root canal preparation with three different NiTi endodontic systems, naming Reciproc (RCP), ProTaper Universal (PTU) and Mtwo. One hundred extracted mandibular premolars with single canals were selected and decoronated. The teeth were randomly divided into four groups of 25 each (n=25). In groups 1, 2 and 3 the teeth were prepared using Mtwo, PTU and RCP, respectively. While in group 4 (control group) the samples were left unprepared. After preparation, all specimens were sectioned perpendicular to the long axis of root at 3, 5 and 9-mm distances from the apex. The sections were then individually observed under 12× magnification using stereomicroscope. The data was analyzed using the chi-square and Fisher's exact tests. The level of significance was set at 0.05. No cracks were observed in the control group. All engine-driven systems caused dentinal cracks. Mtwo and PTU ...
Journal of Dental Rehabilitation and Applied Science, 2014
Aberrant anatomy of mandibular premolars is very rare in Korean, but aberration can contribute th... more Aberrant anatomy of mandibular premolars is very rare in Korean, but aberration can contribute the endodontic failure as it makes difficult to remove the irritants during cleaning and shaping procedure. This case report describes the successful root canal treatment of a rare mandibular first premolar with C-shaped root canal as using a cone-beam computed tomography to understand the internal shape of root canal system and a dental operating microscope to improve the magnification and illumination.
Confluent middle mesial root canals in mandibular first molar: A case report
Knowledge of both normal and abnormal anatomy of the root canal system can directly affect the ou... more Knowledge of both normal and abnormal anatomy of the root canal system can directly affect the outcome of the endodontic therapy. This paper describes the nonsurgical endodontic management of the rare anatomical configuration middle mesial canal in previously treated mandibular first molar. After coronal access, the gutta-percha was eliminated. In precise examination of groove between two mesial canals, the middle mesial orifice was revealed. All root canals prepared chemo mechanically and obturated. After 6 months follow up, the tooth was asymptomatic and functional and apical lesion was healed.
Iranian endodontic journal, 2015
The aim of this study was to compare the changes that occur in the danger zone (DZ) after prepara... more The aim of this study was to compare the changes that occur in the danger zone (DZ) after preparation of curved mesiobuccal (MB) canals of mandibular first molars with WaveOne instruments in two different movements [reciprocation (RCP) and counter-clockwise rotation (CCWR)] by means of cone-beam computed tomography (CBCT). MB canals of 30 mandibular molars were randomly divided into 2 groups (n=15); WaveOne/RCP and WaveOne/CCWR. Pre- and post-instrumentation CBCT images were assessed for changes in the dentin thickness in DZ (2 and 4 mm below the highest point of the root furcation) in both groups. Data was analyzed using the repeated measures ANOVA test. There was no statistically significant difference between two experimental groups in terms of remaining dentin thickness at 2 and 4 mm levels below the highest point of the furcation (P>0.05). The efficacy of WaveOne instrument on changes of the dentin thickness in the DZ was not affected by different file movements.
Journal of Research in Dental and Maxillofacial Sciences, 2020
Background and Aim: Different methods have been proposed for rapid disinfection of gutta-percha (... more Background and Aim: Different methods have been proposed for rapid disinfection of gutta-percha (GP) cones. This study aimed to assess the efficacy of low-pressure radiofrequency cold plasma (LRFCP) in disinfection of GP cones compared to three chemical disinfectants. Materials and Methods: Seventy GP cones were allocated to seven groups of 10 each. All samples were initially sterilized with ethylene oxide (EO) and subsequently inoculated with Staphylococcus aureus (S. aureus), except for the negative control group (n=10). In the experimental groups (n=50), samples were subjected to oneminute chemical disinfection [5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and 10% Deconex® 53 PLUS) or LRFCP (30 seconds or one minute). The effectiveness of disinfection was evaluated by counting the colony-forming units (CFUs). Data were analyzed using Kruskal-Wallis test (P=0.05). Result: All experimental groups effectively eliminated S. aureus. LRFCP and 5.25% NaOCl were the most effective agents in disinfection of GP cones. In addition, 2% CHX was significantly weaker than the other agents (P<0.05). Although Deconex® 53 PLUS was less potent than LRFCP groups and NaOCl (P>0.05), it showed higher antibacterial activity than 2% CHX (P>0.05). Conclusion: LRFCP can be assumed as a noninvasive and efficient method for disinfection of GP cones.
Copyright © 2013 Hengameh Ashraf et al. This is an open access article distributed under the Crea... more Copyright © 2013 Hengameh Ashraf et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Long-term success of endodontic treatment is strictly dependent on proper shaping and cleaning of the root canal system followed by obturation of entire prepared space. Anatomical variations should be considered during radiographic and clinical evaluation as parts of endodontic treatment. A mandibular premolar with three canals is quite rare and such a tooth requires special canal preparation and obturation techniques. An astute clinician should identify different canal configurations and treat them endodontically well, because presence of an untreated canal could be a reason for failure of endodontic treatment. This paper describes the conventional orthograde endodontic therapy on an unusual mandibular first premolar with three roo...
Dental Research Journal, 2016
Background: The aim of this study was to evaluate apical transportation and centering ability of ... more Background: The aim of this study was to evaluate apical transportation and centering ability of single-file instruments, WaveOne primary, with full rotation versus reciprocation movement using cone-beam computed tomography (CBCT) analysis in curved mesiobuccal (MB) root canal of human mandibular molars. Materials and Methods: Thirty MB canals of mandibular molars were randomly divided into two groups according to the instrument motion (n = 15): Group 1, reciprocation/WaveOne primary; Group 2, continuous rotation/WaveOne primary. After preparation, the amount of apical transportation and centering ability were assessed by evaluating pre-and post-instrumentation CBCT scans in three section (1, 3, and 5 mm from apical foramen). Statistical analysis of the data was performed using Mann-Whitney U-test and Friedman test (α = 0.05). Results: There was no statistically significant difference between two experimental groups in terms of apical transportation and centering ratio at 1, 3, and 5 mm from apical foramen (P > 0.05). Conclusion: Apical transportation and centering ability of WaveOne primary reciprocating instrument did not significantly differ between two motion patterns.
Long-term success of endodontic treatment is strictly dependent on proper shaping and cleaning of... more Long-term success of endodontic treatment is strictly dependent on proper shaping and cleaning of the root canal system followed by obturation of entire prepared space. Anatomical variations should be considered during radiographic and clinical evaluation as parts of endodontic treatment. A mandibular premolar with three canals is quite rare and such a tooth requires special canal preparation and obturation techniques. An astute clinician should identify different canal configurations and treat them endodontically well, because presence of an untreated canal could be a reason for failure of endodontic treatment. This paper describes the conventional orthograde endodontic therapy on an unusual mandibular first premolar with three root canals.
Iranian endodontic journal, Oct 7, 2014
A healthy female was referred to Endodontic Department. The referral letter from her dentist expr... more A healthy female was referred to Endodontic Department. The referral letter from her dentist expressed that an emergency pulpotomy of tooth #27 had been carried out with probable perforation of the chamber floor which was due to the unusual anatomy of the chamber. Cone-beam computed tomography (CBCT) revealed that the tooth had two mesial and two distal canals. Perforation site was repaired and endodontic treatment was completed. At 24-month follow-up, patient was asymptomatic and clinical and radiographic examinations showed successful outcomes.
IEJ Iranian Endodontic Journal 2015;10(3): 156-161 Alterations of the Danger Zone after Preparation of Curved Root Canals Using WaveOne with Reverse Rotation or Reciprocation Movements
Introduction: The aim of this study was to compare the changes that occur in the danger zone (DZ)... more Introduction: The aim of this study was to compare the changes that occur in the danger zone (DZ) after preparation of curved mesiobuccal (MB) canals of mandibular first molars with WaveOne instruments in two different movements [reciprocation (RCP) and counter-clockwise rotation (CCWR)] by means of cone-beam computed tomography (CBCT). Methods and Materials: MB canals of 30 mandibular molars were randomly divided into 2 groups (n=15);
Sealing Ability of Resilon and MTA as Root-end Filling Materials: A Bacterial and Dye Leakage Study
Iranian Endodontic Journal, 2017
Introduction: Gutta-percha (GP), is a neutral and non-toxic material. The aim of this animal stud... more Introduction: Gutta-percha (GP), is a neutral and non-toxic material. The aim of this animal study was to compare the biocompatibility of nanosilver coated GP (NS-GP) with conventional GP in subcutaneous tissues in a rat model. Methods and Materials: Conventional GP and NS-GP were subcutaneously implanted in the backs of 20 male Wistar rats (n=10). A control animal was assigned for each trial period. Ten animals were sacrificed after 7 and 30 days and light microscopic evaluation of tissue reaction to NS-GP (n=20) and conventional GP (n=20) was accomplished. The Mann-Whitney U, Wilcoxon Signed Ranks, Fisher Exact, and McNemar tests were used for statistical analysis of the data. Results: After 7 days, inflammation was moderate and mild for NS-GP and conventional GP, respectively (P<0.001). After 30 days, no inflammation was discernible in conventional GP. However, mild inflammation was reported for NS-GP (P<0.001). Regarding inflammatory cell type, there was a significant diff...
Background: During endodontic procedures, the smear layer is formed as a result of mechanical ins... more Background: During endodontic procedures, the smear layer is formed as a result of mechanical instrumentation of the canal. Combination of ethylenediamine tetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) is widely used for removal of the smear layer. Application of Mixture of tetracycline, acid, and detergent (MTAD) as final irrigant subsequent to initial irrigation of 1.35% NaOCl has been proposed to increase clinical efficiency, biocompatibility and prolonged intra-canal antibacterial activity. Considering the importance of adhesion of endodontic sealers to the dentin walls of a prepared root canal, the present study evaluated push-out bond strength of AH26 sealer using final irrigation of MTAD and EDTA + NaOCl. Materials and Methods: Sixty five single-rooted teeth were prepared endodontically with the same chemomechanical technique and were randomly divided into three groups based on their final irrigation regimen: 17% EDTA + 5.25% NaOCl group (n =30), MTAD group (n =30) a...
Paresthesia of the inferior alveolar nerve (IAN) as the result of preapical inflammation or endod... more Paresthesia of the inferior alveolar nerve (IAN) as the result of preapical inflammation or endodontic treatment is a rare but serious occurrence. The following case report describes the diagnosis and management of paresthesia related to an endodontic periodical lesion of a mandibular third molar.
Journal of Lasers in Medical Sciences, 2016
Introduction: Root canal therapy as a routine dental procedure has resulted in retention of milli... more Introduction: Root canal therapy as a routine dental procedure has resulted in retention of millions of teeth that would otherwise be lost. Unfortunately, successful outcomes are not always achievable within initial endodontic treatments, and that necessitates further treatment. Nonsurgical retreatment is the first choice in most clinical situations. The aim of this clinical pilot study was to assess the effect of additional photodynamic therapy (PDT) on intraradicular bacterial load following retreatment of failed previously root treated teeth. Methods: Thirty single-rooted/canalled endodontically treated matured teeth (in 27 healthy patients) accompanied by apical periodontitis (AP) were selected for this study. Standard protocol was followed for nonsurgical retreatment of each tooth. Microbiological samples were taken after establishment of apical patency, finished cleaning/shaping procedure, and PDT (665 nm, 1 W, 240 seconds). All samples were cultured for 72 hours and colonyforming unit (CFU) was counted. McNemar test was used for statistical analysis of the data. The level of significance was set at 0.001. Results: Routine cleaning and shaping resulted in twenty four negative (80%) out of 30 cultures. Four additional negative results were obtained after additional PDT (93.3%). The addition of PDT to routine procedures significantly enhanced the number of bacteria-free samples (P < 0.001). Conclusion: Regarding elimination of intraradicular microbiota, additional PDT may increase the effectiveness of conventional chemomechanical preparation in previously root filled teeth accompanied by AP. Well controlled randomized clinical trials should be planned for future.
Endodontic repair in immature dogs’ teeth with apical periodontitis: blood clot versus plasma rich in growth factors scaffold
Dental Traumatology, 2016
BACKGROUND/AIM Different types of scaffolds have been suggested for endodontic repair procedures.... more BACKGROUND/AIM Different types of scaffolds have been suggested for endodontic repair procedures. The aim of this study was to compare the outcome of procedures using blood clot vs plasma rich in growth factors (PRGF) scaffold in immature teeth with apical periodontitis in dogs. MATERIALS AND METHODS In this in vivo animal study, 20 teeth (30 canals) with open apices were divided into two groups (n = 12): (1) blood clot and (2) PRGF. Two positive and negative control groups were also selected randomly. After exposing the pulp and inducing periapical inflammation by placing a sponge soaked in a suspension of dental plaque, the root canals of both groups were flushed with sodium hypochlorite and filled with triple antibiotic paste. After 28 days, the antibiotic mixture was removed, bleeding was induced through the apical foramen, and mineral trioxide aggregate was placed over the blood clot in group one and PRGF scaffold in group two. Access cavities were then filled with composite resin. The radiographic and histological findings were compared immediately after the procedure, as well as after 3 and 6 months of follow-up. RESULTS There was no statistically significant difference between the two experimental groups with regard to the radiographic or histological results (P > 0.05). The incidence of healed periapical radiolucency was 60% and 53.33% in groups one and two, respectively. Apical closure was noted in 60% of samples in both experimental groups. New cementum-like tissue formation was detected along the walls of the canals, and bone-like islands within the canals were also observed. CONCLUSIONS Plasma rich in growth factors scaffold showed no advantage over blood clots regarding healing of the periapical radiolucency, radiographic apical closure and type of the newly formed soft and hard tissues.
Background and Aim: Different methods have been proposed for rapid disinfection of gutta-percha (... more Background and Aim: Different methods have been proposed for rapid disinfection of gutta-percha (GP) cones. This study aimed to assess the efficacy of low-pressure radiofrequency cold plasma (LRFCP) in disinfection of GP cones compared to three chemical disinfectants. Materials and Methods: Seventy GP cones were allocated to seven groups of 10 each. All samples were initially sterilized with ethylene oxide (EO) and subsequently inoculated with Staphylococcus aureus (S. aureus), except for the negative control group (n=10). In the experimental groups (n=50), samples were subjected to oneminute chemical disinfection [5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and 10% Deconex® 53 PLUS) or LRFCP (30 seconds or one minute). The effectiveness of disinfection was evaluated by counting the colony-forming units (CFUs). Data were analyzed using Kruskal-Wallis test (P=0.05). Result: All experimental groups effectively eliminated S. aureus. LRFCP and 5.25% NaOCl were the most effective agents in disinfection of GP cones. In addition, 2% CHX was significantly weaker than the other agents (P<0.05). Although Deconex® 53 PLUS was less potent than LRFCP groups and NaOCl (P>0.05), it showed higher antibacterial activity than 2% CHX (P>0.05). Conclusion: LRFCP can be assumed as a noninvasive and efficient method for disinfection of GP cones.
Human Pulp Response to Direct Pulp Capping and Miniature Pulpotomy with MTA after Application of Topical Dexamethasone: A Randomized Clinical Trial
Iranian endodontic journal, 2016
The aim of this randomized clinical trial was to compare the histologic pulp tissue response to o... more The aim of this randomized clinical trial was to compare the histologic pulp tissue response to one-step direct pulp capping (DPC) and miniature pulpotomy (MP) with mineral trioxide aggregate (MTA) after application of dexamethasone in healthy human premolars. Forty intact premolars from 10 orthodontic patients, were randomly chosen for DPC (n=20) or MP (n=20). In 10 teeth from each group, after exposure of the buccal pulp horn, topical dexamethasone was applied over the pulp. In all teeth the exposed/miniaturely resected pulp tissue was covered with MTA and cavities were restored with glass ionomer. Teeth vitality was evaluated during the next 7, 21, 42, and 60 days. Signs and/or symptoms of irreversible pulpitis or pulp necrosis were considered as failure. According to the orthodontic schedule, after 60 days the teeth were extracted and submitted for histological examination. The Kruskal-Wallis and Fisher's exact tests were used for statistical analysis of the data (P=0.05). A...
Influence of motion pattern on apical transportation and centering ability of WaveOne single-file technique in curved root canals
Dental Research Journal, 2016
The aim of this study was to evaluate apical transportation and centering ability of single-file ... more The aim of this study was to evaluate apical transportation and centering ability of single-file instruments, WaveOne primary, with full rotation versus reciprocation movement using cone-beam computed tomography (CBCT) analysis in curved mesiobuccal (MB) root canal of human mandibular molars. Thirty MB canals of mandibular molars were randomly divided into two groups according to the instrument motion (n = 15): Group 1, reciprocation/WaveOne primary; Group 2, continuous rotation/WaveOne primary. After preparation, the amount of apical transportation and centering ability were assessed by evaluating pre- and post-instrumentation CBCT scans in three section (1, 3, and 5 mm from apical foramen). Statistical analysis of the data was performed using Mann-Whitney U-test and Friedman test (α = 0.05). There was no statistically significant difference between two experimental groups in terms of apical transportation and centering ratio at 1, 3, and 5 mm from apical foramen (P &amp;amp;amp;amp;amp;gt; 0.05). Apical transportation and centering ability of WaveOne primary reciprocating instrument did not significantly differ between two motion patterns.
Alterations of the Danger Zone after Preparation of Curved Root Canals Using WaveOne with Reverse Rotation or Reciprocation Movements
Iranian endodontic journal, 2015
The aim of this study was to compare the changes that occur in the danger zone (DZ) after prepara... more The aim of this study was to compare the changes that occur in the danger zone (DZ) after preparation of curved mesiobuccal (MB) canals of mandibular first molars with WaveOne instruments in two different movements [reciprocation (RCP) and counter-clockwise rotation (CCWR)] by means of cone-beam computed tomography (CBCT). MB canals of 30 mandibular molars were randomly divided into 2 groups (n=15); WaveOne/RCP and WaveOne/CCWR. Pre- and post-instrumentation CBCT images were assessed for changes in the dentin thickness in DZ (2 and 4 mm below the highest point of the root furcation) in both groups. Data was analyzed using the repeated measures ANOVA test. There was no statistically significant difference between two experimental groups in terms of remaining dentin thickness at 2 and 4 mm levels below the highest point of the furcation (P>0.05). The efficacy of WaveOne instrument on changes of the dentin thickness in the DZ was not affected by different file movements.
Effects of Reciproc, Mtwo and ProTaper Instruments on Formation of Root Fracture
Iranian endodontic journal, 2015
The aim of this study was to compare the formation of dentinal crack and craze lines in the root ... more The aim of this study was to compare the formation of dentinal crack and craze lines in the root dentin during root canal preparation with three different NiTi endodontic systems, naming Reciproc (RCP), ProTaper Universal (PTU) and Mtwo. One hundred extracted mandibular premolars with single canals were selected and decoronated. The teeth were randomly divided into four groups of 25 each (n=25). In groups 1, 2 and 3 the teeth were prepared using Mtwo, PTU and RCP, respectively. While in group 4 (control group) the samples were left unprepared. After preparation, all specimens were sectioned perpendicular to the long axis of root at 3, 5 and 9-mm distances from the apex. The sections were then individually observed under 12× magnification using stereomicroscope. The data was analyzed using the chi-square and Fisher's exact tests. The level of significance was set at 0.05. No cracks were observed in the control group. All engine-driven systems caused dentinal cracks. Mtwo and PTU ...