Introduction: The configuration of C-shaped root canals, root canal wall thickness and orientatio... more Introduction: The configuration of C-shaped root canals, root canal wall thickness and orientation of the thinnest area using CBCT in mandibular second molars were assessed. Methods and materials: Seventy five CBCT scans were evaluated. Axial sections were evaluated to determine the configuration of C-shaped canals in the coronal, middle and apical regions. The root canal path from the orifice to the apex, the thinnest root canal wall and its orientation were all determined. Data were analyzed using one-way ANOVA and post hoc Tukey's test. Results: The most common configurations were Melton's type I in the coronal and middle and types I and IV in the apical region. The mean thicknesses of the thinnest root canal wall were 1.94±0.43, 1.42±0.57 and 1.10±0.52 mm in the coronal, middle and apical regions, respectively. The lingual wall was the thinnest wall in the coronal, middle and apical regions and it was thinner in the apical than in the middle and coronal regions. The lingual wall was thinner in the middle third of the mesial root compared to the distal root (P<0.05). Conclusion: The lingual wall was the thinnest in C-shaped root canals of mandibular second molars of an Iranian population. Type, number and pathway of canals may vary from the orifice to the apex.
Introduction: The configuration of C-shaped root canals, root canal wall thickness and orientatio... more Introduction: The configuration of C-shaped root canals, root canal wall thickness and orientation of the thinnest area using CBCT in mandibular second molars were assessed. Methods and Materials: Seventy five CBCT scans were evaluated. Axial sections were evaluated to determine the configuration of C-shaped canals in the coronal, middle and apical regions. The root canal path from the orifice to the apex, the thinnest root canal wall and its orientation were all determined. Data were analyzed using one-way ANOVA and post hoc Tukey’s test. Results: The most common configurations were Melton's type I in the coronal and middle and types I and IV in the apical region. The mean thicknesses of the thinnest root canal wall were 1.94±0.43, 1.42±0.57 and 1.10±0.52 mm in the coronal, middle and apical regions, respectively. The lingual wall was the thinnest wall in the coronal, middle and apical regions and it was thinner in the apical than in the middle and coronal regions. The lingual...
The root fracture resistance (RFR) of premolars extracted from diabetic patients and the effect o... more The root fracture resistance (RFR) of premolars extracted from diabetic patients and the effect of biomaterials: white mineral trioxide aggregate (WMTA) and WMTA+Na2HPO4 as an additive, on enhancing RFR were evaluated. Diabetic and non‐diabetic teeth were divided into 4 subgroups (n = 5): root canals were obturated with WMTA, WMTA+Na2HPO4, gutta‐percha and one unfilled (control). A plunger (1 mm diameter) applied a downward compressive load with crosshead speed of 1 mm min−1 on the specimens mounted on resin blocks, and the ultimate force to fracture was measured. The mean RFR values of diabetic specimens were significantly lower. The lowest and highest means of RFR were recorded in the control and WMTA, in normal group and the control and WMTA+Na2HPO4 in the diabetic group, respectively. The RFR in diabetic patients was significantly lower, indicating their higher susceptibility to fracture under vertical forces. The use of WMTA (with or without Na2HPO4) for obturation enhances the...
INTRODUCTION Endodontic sealers play a vital role in the obturation of root canal space. The aim ... more INTRODUCTION Endodontic sealers play a vital role in the obturation of root canal space. The aim of this study was to evaluate the utility of a recently developed Polyurethane Expandable Sealer (PES), along with its cytotoxicity and dimensional changes. METHODS L929 fibroblasts and an MTS assay were used to determine the cytotoxicity of dental sealers (AH Plus, Sure-Seal Root™, and the PES) at 24, 48, 72, and 96 hours. An advanced choroidal neovascularization (CNV) model was used to assess the effect of these sealers on angiogenesis. Thirty-six extracted single-rooted human teeth were prepared and randomly divided into three groups (n=12). Obturation was performed with gutta-percha and a sealer using lateral compaction: group 1 - AH Plus, group 2 - Sure-Seal, and group 3 - PES. The average depth of sealer penetration into dentinal tubules was measured with an SEM. Data were analyzed using one-way ANOVA and Post-hoc Tukey tests (level of significance, P <0.05). RESULTS The values of MTS, CNV, and penetration depth of PES were significantly higher than in other experimental groups (P <0.05). The lowest values were seen in specimens of AH Plus, while the highest were detected in PES groups. CONCLUSIONS PES showed promising results in terms of biocompatibility and dentinal tubules adaptation and penetration.
INTRODUCTION This study investigated the fatigue and fracture modes of RaCe and ProTaper rotary i... more INTRODUCTION This study investigated the fatigue and fracture modes of RaCe and ProTaper rotary instruments. MATERIALS AND METHODS Fatigue resistance was evaluated by rotating the files 30° or 60° and with 2 or 5mm radius of curvature. RaCe taper 06 size 25 and ProTaper F1 files (n=40) were used. The number of rotations to failure was analyzed by two-way ANOVA and independent sample t-test. Fracture surfaces were examined under a scanning electron microscope. RESULTS Both files exhibited significantly more resistance to fracture when angle severity was reduced and increase in curvature radius (P=0.000). ProTaper demonstrated higher number of cycle of failure (P=0.0029) in one group (r=5mm, 60º). SEM observation revealed fatigue mark/features in 17 specimens, shear characteristics in 37 samples, and tensile overload in 26 samples. CONCLUSION Radius of curvature was the main factor in torsional and fatigue failures.
INTRODUCTION Adequate root canal seal following retreatment is essential for a successful outcome... more INTRODUCTION Adequate root canal seal following retreatment is essential for a successful outcome. Resilon/Epiphany (R/E) obturation system has been introduced as a substitute for conventional gutta-percha/sealer method. This in vitro study compared the amount of apical microleakage of R/E with gutta-percha/AH26 (GP/AH26) sealer as secondary root canal filling following retreatment in human teeth. MATERIALS AND METHODS Fifty human single-rooted lower premolar teeth were selected. After preparing them with ProTaper rotary NiTi instruments, all the canals were obturated using GP/AH26 sealer. After 10 days, all the samples were retreated using the same rotary NiTi instruments. The samples were divided randomly into two experimental groups A and B (n=20) and positive and negative control groups (n=5). In group A, all canals were obturated using GP/AH26 sealer and in group B all canals were obturated using R/E. After one week incubation in 37˚C with 100% humidity, the amount of apical mi...
OBJECTIVES This study aimed to determine the success rate of retromolar canal (RMC) infiltration ... more OBJECTIVES This study aimed to determine the success rate of retromolar canal (RMC) infiltration following the failure of inferior alveolar nerve block (IANB) injections for the anesthesia of mandibular first molars with acute irreversible pulpitis. MATERIALS AND METHODS An IANB injection was administered for 50 patients with acute irreversible pulpitis. Lip numbness was set as the sign of anesthesia and further evaluated and confirmed with pulp sensibility tests after 10-15 min. Access cavity preparation was commenced unless the patient felt any pain; in this case, an RMC infiltration injection was given. The success rate was determined through the patients' recording of the presence, absence, or reduction of pain severity during access cavity preparation using the Heft-Parker visual analog scale. RESULTS Seven patients (14%) did not experience any pain by pulp sensibility tests and during access cavity preparation after IANB injection. Twenty-five (58.1%) of the remaining 43 patients who had the RMC infiltration injection had reduced pain, and four patients (9.3%) experienced no pain after the RMC infiltration. Fourteen patients (32.5%) experienced no change in pain. Chi-squared test results revealed that the percentage of patients with reduced pain was higher than that of other patients (P < 0.001). CONCLUSIONS RMC infiltration, along with IANB, significantly reduced the pain felt by patients and increased the success of the anesthetic technique for root canal treatment of mandibular first molars with acute irreversible pulpitis. CLINICAL RELEVANCE The administration of RMC infiltration can enhance the success of the IANB technique for anesthetizing mandibular first molars exhibiting acute irreversible pulpitis.
Surface alterations of instruments were investigated after single and multiple uses in the root c... more Surface alterations of instruments were investigated after single and multiple uses in the root canals. XP‐endo Shaper (n = 5) and WaveOne GOLD (n = 5) files were used until the separation of the instruments occurred. The apical 3‐mm and separated fragments were analysed by SEM to determine the changes in the instruments and the cross‐sections of the separated fragments. Each group was divided into five subgroups: control, first, second, third and fourth molar. The results were reported descriptively for each group. In the XP‐endo Shaper group, microcracks started to appear after the second use, and pitting and galvanic corrosion occurred after the third use. During the fourth use, microcracks propagated, resulting in ductile fracture while it happened after the third use in the second group. The single use of XP‐endo Shaper and WaveOne GOLD was safe without any major changes on their surfaces. Reciprocating motion was not necessarily superior to full rotation motion.
Gutta-percha must be removed from the root canal space during retreatment to ensure a more favora... more Gutta-percha must be removed from the root canal space during retreatment to ensure a more favorable outcome. The aim of this study was to compare the efficacy of hand instruments, RaCe and RaCe plus XP-endo finisher instruments in removal of gutta-percha from root canal walls during retreatment. Thirty single-rooted premolars were prepared, obturated, and divided into three groups according to retreatment method; in group 1, retreatment was carried out by hand instruments, while in groups 2 and 3 retreatment was done using RaCe rotary files alone or accompanied by XP-endo finisher instruments, respectively. After retreatment, teeth were sectioned longitudinally and photographic images were taken. The amount of remaining gutta-percha in coronal, middle and apical thirds was quantified using Image J software. The two-way ANOVA and post hoc Tukey's tests were used to analyze data. The level of significance was set at 0.05. RaCe cleaned the apical third significantly better than ha...
Photodiagnosis and photodynamic therapy, Jan 26, 2016
The treatment of periodontal disease focuses on eradication or suppression of the pathogenic micr... more The treatment of periodontal disease focuses on eradication or suppression of the pathogenic microbiota within the periodontal pocket. There are some mechanical and chemical ways, and recently antimicrobial photodynamic therapy to eliminate the bacteria. The aim of this in vitro study was to compare the effects of 2% chlorhexidine gel, 2% metronidazole in Orabase, antimicrobial photodynamic therapy with Emundo solution and Emundo solution on P. gingivalis. The antibacterial activities of 2% CHX gel, 2% Metronidazole in Orabase, Emundo+Laser (an infra-red laser diode of 810nm, 300mW, continuous mode radiation, 30s and energy density of 11.5J/cm2), and Emundo against P. gingivalis were tested in vitro using two different methods; (1) Counting CFU/mL and (2) agar diffusion test (ADT). Data of CFU/mL were analyzed using one way ANOVA and Post hoc Tukey test (p<0.05). Data obtained from ADT test were analyzed using Kruskal-Wallis. The percentage of colony-forming units reduction was (...
Quintessence international (Berlin, Germany : 1985), 2012
To compare the efficacy of ProFile File cleaner and a nanostructured foam in removing debris from... more To compare the efficacy of ProFile File cleaner and a nanostructured foam in removing debris from two rotary nickel-titanium instruments during and after instrumentation. Twenty mandibular premolars were decoronated and instrumented up to either no. 40.04 RaCe (no. 40.04) or K3 (no. 40.04) instruments (n = 10). Each group of files was randomly divided into two groups: ProFile File cleaner and Nano Foam cleaner. The instruments were examined under a scanning electron microscope (SEM) before and after placement into the canals. Subsequently, instruments were introduced into each cleaner and examined again under SEM. The amount of debris removal from the instruments was determined by ImageJ software. Data were subjected to Kruskal-Wallis and Mann-Whitney tests at a .05 level of significance. The amount of debris removal was significantly different between the groups (P = .002). The amount of debris removed was significantly higher in K3 with Nano Foam cleaner than ProFile File cleaner ...
Introduction: The configuration of C-shaped root canals, root canal wall thickness and orientatio... more Introduction: The configuration of C-shaped root canals, root canal wall thickness and orientation of the thinnest area using CBCT in mandibular second molars were assessed. Methods and materials: Seventy five CBCT scans were evaluated. Axial sections were evaluated to determine the configuration of C-shaped canals in the coronal, middle and apical regions. The root canal path from the orifice to the apex, the thinnest root canal wall and its orientation were all determined. Data were analyzed using one-way ANOVA and post hoc Tukey's test. Results: The most common configurations were Melton's type I in the coronal and middle and types I and IV in the apical region. The mean thicknesses of the thinnest root canal wall were 1.94±0.43, 1.42±0.57 and 1.10±0.52 mm in the coronal, middle and apical regions, respectively. The lingual wall was the thinnest wall in the coronal, middle and apical regions and it was thinner in the apical than in the middle and coronal regions. The lingual wall was thinner in the middle third of the mesial root compared to the distal root (P<0.05). Conclusion: The lingual wall was the thinnest in C-shaped root canals of mandibular second molars of an Iranian population. Type, number and pathway of canals may vary from the orifice to the apex.
Introduction: The configuration of C-shaped root canals, root canal wall thickness and orientatio... more Introduction: The configuration of C-shaped root canals, root canal wall thickness and orientation of the thinnest area using CBCT in mandibular second molars were assessed. Methods and Materials: Seventy five CBCT scans were evaluated. Axial sections were evaluated to determine the configuration of C-shaped canals in the coronal, middle and apical regions. The root canal path from the orifice to the apex, the thinnest root canal wall and its orientation were all determined. Data were analyzed using one-way ANOVA and post hoc Tukey’s test. Results: The most common configurations were Melton's type I in the coronal and middle and types I and IV in the apical region. The mean thicknesses of the thinnest root canal wall were 1.94±0.43, 1.42±0.57 and 1.10±0.52 mm in the coronal, middle and apical regions, respectively. The lingual wall was the thinnest wall in the coronal, middle and apical regions and it was thinner in the apical than in the middle and coronal regions. The lingual...
The root fracture resistance (RFR) of premolars extracted from diabetic patients and the effect o... more The root fracture resistance (RFR) of premolars extracted from diabetic patients and the effect of biomaterials: white mineral trioxide aggregate (WMTA) and WMTA+Na2HPO4 as an additive, on enhancing RFR were evaluated. Diabetic and non‐diabetic teeth were divided into 4 subgroups (n = 5): root canals were obturated with WMTA, WMTA+Na2HPO4, gutta‐percha and one unfilled (control). A plunger (1 mm diameter) applied a downward compressive load with crosshead speed of 1 mm min−1 on the specimens mounted on resin blocks, and the ultimate force to fracture was measured. The mean RFR values of diabetic specimens were significantly lower. The lowest and highest means of RFR were recorded in the control and WMTA, in normal group and the control and WMTA+Na2HPO4 in the diabetic group, respectively. The RFR in diabetic patients was significantly lower, indicating their higher susceptibility to fracture under vertical forces. The use of WMTA (with or without Na2HPO4) for obturation enhances the...
INTRODUCTION Endodontic sealers play a vital role in the obturation of root canal space. The aim ... more INTRODUCTION Endodontic sealers play a vital role in the obturation of root canal space. The aim of this study was to evaluate the utility of a recently developed Polyurethane Expandable Sealer (PES), along with its cytotoxicity and dimensional changes. METHODS L929 fibroblasts and an MTS assay were used to determine the cytotoxicity of dental sealers (AH Plus, Sure-Seal Root™, and the PES) at 24, 48, 72, and 96 hours. An advanced choroidal neovascularization (CNV) model was used to assess the effect of these sealers on angiogenesis. Thirty-six extracted single-rooted human teeth were prepared and randomly divided into three groups (n=12). Obturation was performed with gutta-percha and a sealer using lateral compaction: group 1 - AH Plus, group 2 - Sure-Seal, and group 3 - PES. The average depth of sealer penetration into dentinal tubules was measured with an SEM. Data were analyzed using one-way ANOVA and Post-hoc Tukey tests (level of significance, P <0.05). RESULTS The values of MTS, CNV, and penetration depth of PES were significantly higher than in other experimental groups (P <0.05). The lowest values were seen in specimens of AH Plus, while the highest were detected in PES groups. CONCLUSIONS PES showed promising results in terms of biocompatibility and dentinal tubules adaptation and penetration.
INTRODUCTION This study investigated the fatigue and fracture modes of RaCe and ProTaper rotary i... more INTRODUCTION This study investigated the fatigue and fracture modes of RaCe and ProTaper rotary instruments. MATERIALS AND METHODS Fatigue resistance was evaluated by rotating the files 30° or 60° and with 2 or 5mm radius of curvature. RaCe taper 06 size 25 and ProTaper F1 files (n=40) were used. The number of rotations to failure was analyzed by two-way ANOVA and independent sample t-test. Fracture surfaces were examined under a scanning electron microscope. RESULTS Both files exhibited significantly more resistance to fracture when angle severity was reduced and increase in curvature radius (P=0.000). ProTaper demonstrated higher number of cycle of failure (P=0.0029) in one group (r=5mm, 60º). SEM observation revealed fatigue mark/features in 17 specimens, shear characteristics in 37 samples, and tensile overload in 26 samples. CONCLUSION Radius of curvature was the main factor in torsional and fatigue failures.
INTRODUCTION Adequate root canal seal following retreatment is essential for a successful outcome... more INTRODUCTION Adequate root canal seal following retreatment is essential for a successful outcome. Resilon/Epiphany (R/E) obturation system has been introduced as a substitute for conventional gutta-percha/sealer method. This in vitro study compared the amount of apical microleakage of R/E with gutta-percha/AH26 (GP/AH26) sealer as secondary root canal filling following retreatment in human teeth. MATERIALS AND METHODS Fifty human single-rooted lower premolar teeth were selected. After preparing them with ProTaper rotary NiTi instruments, all the canals were obturated using GP/AH26 sealer. After 10 days, all the samples were retreated using the same rotary NiTi instruments. The samples were divided randomly into two experimental groups A and B (n=20) and positive and negative control groups (n=5). In group A, all canals were obturated using GP/AH26 sealer and in group B all canals were obturated using R/E. After one week incubation in 37˚C with 100% humidity, the amount of apical mi...
OBJECTIVES This study aimed to determine the success rate of retromolar canal (RMC) infiltration ... more OBJECTIVES This study aimed to determine the success rate of retromolar canal (RMC) infiltration following the failure of inferior alveolar nerve block (IANB) injections for the anesthesia of mandibular first molars with acute irreversible pulpitis. MATERIALS AND METHODS An IANB injection was administered for 50 patients with acute irreversible pulpitis. Lip numbness was set as the sign of anesthesia and further evaluated and confirmed with pulp sensibility tests after 10-15 min. Access cavity preparation was commenced unless the patient felt any pain; in this case, an RMC infiltration injection was given. The success rate was determined through the patients' recording of the presence, absence, or reduction of pain severity during access cavity preparation using the Heft-Parker visual analog scale. RESULTS Seven patients (14%) did not experience any pain by pulp sensibility tests and during access cavity preparation after IANB injection. Twenty-five (58.1%) of the remaining 43 patients who had the RMC infiltration injection had reduced pain, and four patients (9.3%) experienced no pain after the RMC infiltration. Fourteen patients (32.5%) experienced no change in pain. Chi-squared test results revealed that the percentage of patients with reduced pain was higher than that of other patients (P < 0.001). CONCLUSIONS RMC infiltration, along with IANB, significantly reduced the pain felt by patients and increased the success of the anesthetic technique for root canal treatment of mandibular first molars with acute irreversible pulpitis. CLINICAL RELEVANCE The administration of RMC infiltration can enhance the success of the IANB technique for anesthetizing mandibular first molars exhibiting acute irreversible pulpitis.
Surface alterations of instruments were investigated after single and multiple uses in the root c... more Surface alterations of instruments were investigated after single and multiple uses in the root canals. XP‐endo Shaper (n = 5) and WaveOne GOLD (n = 5) files were used until the separation of the instruments occurred. The apical 3‐mm and separated fragments were analysed by SEM to determine the changes in the instruments and the cross‐sections of the separated fragments. Each group was divided into five subgroups: control, first, second, third and fourth molar. The results were reported descriptively for each group. In the XP‐endo Shaper group, microcracks started to appear after the second use, and pitting and galvanic corrosion occurred after the third use. During the fourth use, microcracks propagated, resulting in ductile fracture while it happened after the third use in the second group. The single use of XP‐endo Shaper and WaveOne GOLD was safe without any major changes on their surfaces. Reciprocating motion was not necessarily superior to full rotation motion.
Gutta-percha must be removed from the root canal space during retreatment to ensure a more favora... more Gutta-percha must be removed from the root canal space during retreatment to ensure a more favorable outcome. The aim of this study was to compare the efficacy of hand instruments, RaCe and RaCe plus XP-endo finisher instruments in removal of gutta-percha from root canal walls during retreatment. Thirty single-rooted premolars were prepared, obturated, and divided into three groups according to retreatment method; in group 1, retreatment was carried out by hand instruments, while in groups 2 and 3 retreatment was done using RaCe rotary files alone or accompanied by XP-endo finisher instruments, respectively. After retreatment, teeth were sectioned longitudinally and photographic images were taken. The amount of remaining gutta-percha in coronal, middle and apical thirds was quantified using Image J software. The two-way ANOVA and post hoc Tukey's tests were used to analyze data. The level of significance was set at 0.05. RaCe cleaned the apical third significantly better than ha...
Photodiagnosis and photodynamic therapy, Jan 26, 2016
The treatment of periodontal disease focuses on eradication or suppression of the pathogenic micr... more The treatment of periodontal disease focuses on eradication or suppression of the pathogenic microbiota within the periodontal pocket. There are some mechanical and chemical ways, and recently antimicrobial photodynamic therapy to eliminate the bacteria. The aim of this in vitro study was to compare the effects of 2% chlorhexidine gel, 2% metronidazole in Orabase, antimicrobial photodynamic therapy with Emundo solution and Emundo solution on P. gingivalis. The antibacterial activities of 2% CHX gel, 2% Metronidazole in Orabase, Emundo+Laser (an infra-red laser diode of 810nm, 300mW, continuous mode radiation, 30s and energy density of 11.5J/cm2), and Emundo against P. gingivalis were tested in vitro using two different methods; (1) Counting CFU/mL and (2) agar diffusion test (ADT). Data of CFU/mL were analyzed using one way ANOVA and Post hoc Tukey test (p<0.05). Data obtained from ADT test were analyzed using Kruskal-Wallis. The percentage of colony-forming units reduction was (...
Quintessence international (Berlin, Germany : 1985), 2012
To compare the efficacy of ProFile File cleaner and a nanostructured foam in removing debris from... more To compare the efficacy of ProFile File cleaner and a nanostructured foam in removing debris from two rotary nickel-titanium instruments during and after instrumentation. Twenty mandibular premolars were decoronated and instrumented up to either no. 40.04 RaCe (no. 40.04) or K3 (no. 40.04) instruments (n = 10). Each group of files was randomly divided into two groups: ProFile File cleaner and Nano Foam cleaner. The instruments were examined under a scanning electron microscope (SEM) before and after placement into the canals. Subsequently, instruments were introduced into each cleaner and examined again under SEM. The amount of debris removal from the instruments was determined by ImageJ software. Data were subjected to Kruskal-Wallis and Mann-Whitney tests at a .05 level of significance. The amount of debris removal was significantly different between the groups (P = .002). The amount of debris removed was significantly higher in K3 with Nano Foam cleaner than ProFile File cleaner ...
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