Middle-mesial canals in mandibular molars are present in the population depending on age, sex and ethnicity. However, limited literature alludes to its prevalence. Troughing procedures may enhance identification, clea...Middle-mesial canals in mandibular molars are present in the population depending on age, sex and ethnicity. However, limited literature alludes to its prevalence. Troughing procedures may enhance identification, cleaning and shaping. This case report expresses the recognition and management of middle-mesial canal in a mandibular second molar of 24 years old Hispanic-Latino male.展开更多
Background: The aim was to evaluate the nonsurgical Root Canal Treatment (nRCT) outcome, the restorative condition and the relationship between the coronal restoration quality and the outcome of teeth endodontic treat...Background: The aim was to evaluate the nonsurgical Root Canal Treatment (nRCT) outcome, the restorative condition and the relationship between the coronal restoration quality and the outcome of teeth endodontic treated by undergraduates at the University of Caxias do Sul School of Dentistry (UCS-SD), Brazil, between 2019 and 2021. Materials and Methods: Data from the endodontically treated cases were retrieved, and the patients were recalled for a follow-up appointment at the university. The endodontic diagnosis, radiographs, and the presence of definitive restorations were analyzed in the clinical records. During the follow-up appointment, endodontically treated teeth were classified as present or absent. The nRCT was classified as successful (complete or incomplete healing) or failure (uncertain or unsatisfactory healing). Coronal restoration was classified as absent or present. When it was present, it was classified as permanent or temporary, and its quality as adequate or inadequate restoration. The results were presented as percentages. Results: A total of 257 teeth were endodontically treated. The most prevalent diagnosis was Chronic Apical Periodontitis (33.33%) and the most commonly treated teeth were premolars (46.15%). A total of 52 (21%) treated teeth were clinically and radiographically reexamined. The success rate for the nRCT was 98.08%. About 61.54% of this sample had a definitive composite resin restoration. Conclusion: The nRCT success rate was high. Special attention should be given to the presence and quality of the definitive restoration. Clinical Implications: There was no statistically significant impact between the coronal restoration and the nRCT success (P > 0.05).展开更多
The aim of this study was to analyze the specific influence of root canal anatomy on the accessibility of working length during root canal therapy. Four hundred seventy-six root canal therapy cases （amounting to a to...The aim of this study was to analyze the specific influence of root canal anatomy on the accessibility of working length during root canal therapy. Four hundred seventy-six root canal therapy cases （amounting to a total of 1 005 root canals） were examined. The anatomy risk factors assessed in each case included： tooth type （tooth location）, root canal curvature, and root canal calcification, as well as endodontic retreatment. The investigation examined the correlation between each of these anatomic factors and the working length, with statistical analysis consisting of Chi-square tests and multiple logistic regression analysis. In an independent factor analysis, tooth type （tooth iocation）, root canal curvature, canal calcification, and endodontic retreatment were determined to be the primary risk factors. In a multiple-factor regression model, root curvature and canal calcification were found to most significantly influence root canal working length accessibility （P〈0.05）. Root canal anatomy increases the difficulty of root canal preparation. Appropriate consideration of tooth anatomy will assist in accurate determination of preparation difficulty before instrumentation. This study alerts clinical therapists to anatomical factors influencing the working length accessibility, and allows for a direct estimate of success rate given in situ measurements of tooth factors during the root canal treatment procedure.展开更多
To compare the efficacy of various irrigants(citric acid, ethylenediaminetetraacetic acid(EDTA) and Na OCl) and techniques in removing Ca(OH)2in two types of curved root canal systems, simulated root canals with speci...To compare the efficacy of various irrigants(citric acid, ethylenediaminetetraacetic acid(EDTA) and Na OCl) and techniques in removing Ca(OH)2in two types of curved root canal systems, simulated root canals with specific curvatures were used to investigate the effects of different irrigants and instruments on Ca(OH)2removal. The optimal methods were verified on extracted human teeth. Simulated root canals were assigned to one of two groups based on the irrigation solution: 10% citric acid or2.5% Na OCl. Each group was divided into four subgroups according to the technique used to remove Ca(OH)2. The percentage of Ca(OH)2removal in different sections of root canals was calculated. On the basis of the results obtained for the simulated canals, 10% citric acid and 17% EDTA were applied to remove Ca(OH)2from the extracted human teeth with curved root canal systems. The teeth were scanned by micro computed tomography to calculate the percentage of Ca(OH)2removal in the canals.In simulated root canals, we found that 10% citric acid removed more Ca(OH)2than 2.5% NaOCl in the 0–1 mm group from the apex level(Po0.05). Ultrasonic and Endo Activator activation significantly removed more Ca(OH)2than a size 30 K file in the apical third(Po0.05). However, there were no significant differences in any sections of the canals for 10% citric acid or 17%EDTA in removing Ca(OH)2in extracted human teeth. We concluded that it was effective to remove residual Ca(OH)2using the decalcifying solution with Endo Activator or Passive Ultrasonic Irrigation in a curved root canal system. A protocol for Ca(OH)2removal was provided based on the conclusions of this study and the methods recommended in previous studies.展开更多
The aims of the study were to investigate the incidence of C-shaped root canal systems in mandibular second molars in a native Chinese population using radiography and clinical examination under microscope and to comp...The aims of the study were to investigate the incidence of C-shaped root canal systems in mandibular second molars in a native Chinese population using radiography and clinical examination under microscope and to compare the relative efficacies of these methods. For the recognition of C-shaped root canal system, 1 146 mandibular second molars were selected and examined. Teeth with C-shaped canal systems were categorized by using the radiographic classification criteria and the modified Melton＇s method. C-shaped canals were identified in 397 （34.64%） mandibular second molars by radiography （type I, 31.23%; type II, 38.29%; type III, 30.48%）. Clinical examination showed that 449 （39.18%） cases exhibited C-shaped canal systems （C1, 22.94%; C2, 48.11%; C3a, 15.59%; C3b, 13.36%）. As for the result of the radiographic and clinical combined examination, C-shaped root canals were found in 473 （41.27%） mandibular second molars （C1, 21.78%; C2, 45.67%; C3a, 16.70%; C3b, 15.86%）. The incidence of C-shaped root canal diagnosed by radiographic method was statistically different from that by clinical examination and the combined examination （P〈O.05）. The study indicated a high incidence of C-shaped canal system in a Chinese population. The combination of microscopic and radiographic examination is an effective method in identifying the C-shaped root canal system.展开更多
This study was designed to compare the impact of post and core systems on resistance to fracture of endodontically treated anterior teeth with flared root canals and to assess their fracture pattern. Sixty central inc...This study was designed to compare the impact of post and core systems on resistance to fracture of endodontically treated anterior teeth with flared root canals and to assess their fracture pattern. Sixty central incisors were cut horizontally 2 mm coronal to the cementoenamel junction(CEJ). After root canal therapy, teeth were assigned into 6 groups(n = 10 each) based on a post system and used as follows: Group C, non-flared root received size #1 glass fiber posts(Control); Group AP, flared root restored with anatomical post; Group RC, flared root restored with size #1 fiber post and cemented with thick layer of resin cement; Group CR, flared root restored with size #1 and reinforced with composite resin; Group CM, cast post-core; Group CP, CAD/CAM polymer-infiltrated ceramic post and core.Following post cementation, core build-up and crown insertion, the specimens were thermo-cycled up to 10,000 cycles(5 C/55 C; 30 seconds dwell time, 6 seconds transition time) and then statically loaded at 1 mm/minute crosshead speed using a universal testing machine. One-way ANOVA and Tukey HSD post hoc test(α= 0.05) were used for data analysis. Group C recorded significantly higher resistance to fracture values [(826.9±39.1) N] followed by group CP [(793.8±55.6) N] while group RC yielded the lowest fracture resistance values [(586.7±51.4) N]. The resistance to fracture of wide root canals can be enhanced by using one-piece CAM/CAM post and core as an alternative to the use of either glass fiber post, relined with composite resin increasing the thickness of luting cement or the use of cast post and core system. However, this was an in vitro investigation and further in vivo studies are necessary.展开更多
Summary： This study was aimed to evaluate the effectiveness of solution form of 17% ethylenediaminetetraacetic acid （EDTA） on removing smear layer of root canals at different exposure time periods and to provide sc...Summary： This study was aimed to evaluate the effectiveness of solution form of 17% ethylenediaminetetraacetic acid （EDTA） on removing smear layer of root canals at different exposure time periods and to provide scientific basis for EDTA as a choice of root canal irrigation in clinical practice. Twenty-five single-rooted teeth were randomly divided into 5 groups： control group （group A） was given 2.5% NaOC1, and 4 experimental groups were given 2.5% NaOC1 and 17% EDTA, including groups B, C, D and E with exposure time of 1, 3, 5 and 7 min, respectively. After preparation of the root canals, the teeth were split along their longitudinal axis, and the root sections were examined under scanning elec- tron microscope for evaluation of smear layer removal and erosion on the surface of the root canal walls. The specimens in group B showed presence of smear layer on the walls of the root canal with no statistical difference from that in group A （P〉0.05）. In groups C and D, partial removal of smear layer was obtained, and there was no significant difference between the two groups （P〉0.05）, but there was significant difference in removal of smear layer between group C and group B （P〈0.05）. Root canal walls in group E specimens showed almost complete removal of smear layer, and the removal of smear layer was significantly different from that in group D （P〈0.01）. There was no significant change in the structure of the surface of root canal for each sample. It was concluded that combined irrigation with 17% EDTA and 2.5% NaOC1 could remove the smear layer with no significant alteration in dentinal structure when the chelating agent was applied for 7 min. At 3 and 5 min of application, partial removal of smear layer was observed and at 1 min negligible removal of smear layer was achieved.展开更多
The aim of this study was to investigate the root canal configuration, accessory canals and number of main foramina of 123 maxillary second molars by means of micro-computed tomography. The teeth were scanned and repr...The aim of this study was to investigate the root canal configuration, accessory canals and number of main foramina of 123 maxillary second molars by means of micro-computed tomography. The teeth were scanned and reproduced with 3D software imaging. The root canal configuration and number of main foramina were evaluated by means of a four-digit system. The morphological complexity of human maxillary second molars is depicted by the number of accessory and connecting canals. The most frequently observed root canal configurations in the mesiobuccal root were 2-2-2/2 （19.5%）, 2-2-1/1 （14.6%） and 2-1-1/1 （13.0%）. A 1-1-1/1 configuration was observed in 93.5% and in 96.7% in the distobuccal and palatal roots, respectively. The MB1 mot canal had one accessory canal （18.7%）, and 8.9% of the MB2 root canal had one or two accessory canals. The distobuccal （11.3%） and palatal （14.6%） root canals had at least one accessory canal, and connecting canals were observed in 16.3% of mesiobuccal roots. The MB1, MB2, distobuccal and palatal root canals had one main foramen in 99.2%, 43.1%, 98.4% and 99.2% of samples, respectively. In the mesiobuccal root, one accessory foramen was detected in 14.6%, two were detected in 7.3%, and three were detected in 5.7%. The distobuccal root showed one or two accessory foramina in 9.1% of samples. The root canal configuration of maxillary second molars is quite heterogeneous; the mesiobuccal root has predominantly two root canal entrances （58.4%, 1 in 41.1%） with one main foramen （54.4%）. Two main foramina were observed in 43.0%. Morphological variations, connecting and accessory canals were observed in all apical thirds.展开更多
BACKGROUND The complex anatomy of the maxillary first molars has always been a major challenge for complete root canal treatment in endodontic therapy. Here, we present two cases of maxillary first molars, each with o...BACKGROUND The complex anatomy of the maxillary first molars has always been a major challenge for complete root canal treatment in endodontic therapy. Here, we present two cases of maxillary first molars, each with only two root canals, which have been rarely reported. We also perform a literature review of maxillary first molar anatomy.CASE SUMMARY The two patients were referred to the hospital after 1) finding a cavity in their tooth with a color change and, 2) a toothache during mastication, respectively.Both of these cases were diagnosed as apical periodontitis by X-ray imaging and cone beam computed tomography(CBCT). Non-surgical endodontic therapy was performed with the assistance of a dental operating microscope(DOM). CBCT showed rare but accurate images of both patients, each with two root canals and two roots in their maxillary first molars. Both roots were located in the buccal in the palatal direction, and each root had only one clear root canal. In addition,each maxillary first molar in both patients was symmetrical to that on the opposing side with only two separate root canals. Non-surgical endodontic therapy was performed with the assistance of a DOM. Finally, the teeth were restored using composite resin and the patients were satisfied with the results.CONCLUSION Making full use of CBCT and DOM would contribute to helping dentists make correct diagnoses and successfully treat teeth with rare root canal morphologies.展开更多
文摘Middle-mesial canals in mandibular molars are present in the population depending on age, sex and ethnicity. However, limited literature alludes to its prevalence. Troughing procedures may enhance identification, cleaning and shaping. This case report expresses the recognition and management of middle-mesial canal in a mandibular second molar of 24 years old Hispanic-Latino male.
文摘Background: The aim was to evaluate the nonsurgical Root Canal Treatment (nRCT) outcome, the restorative condition and the relationship between the coronal restoration quality and the outcome of teeth endodontic treated by undergraduates at the University of Caxias do Sul School of Dentistry (UCS-SD), Brazil, between 2019 and 2021. Materials and Methods: Data from the endodontically treated cases were retrieved, and the patients were recalled for a follow-up appointment at the university. The endodontic diagnosis, radiographs, and the presence of definitive restorations were analyzed in the clinical records. During the follow-up appointment, endodontically treated teeth were classified as present or absent. The nRCT was classified as successful (complete or incomplete healing) or failure (uncertain or unsatisfactory healing). Coronal restoration was classified as absent or present. When it was present, it was classified as permanent or temporary, and its quality as adequate or inadequate restoration. The results were presented as percentages. Results: A total of 257 teeth were endodontically treated. The most prevalent diagnosis was Chronic Apical Periodontitis (33.33%) and the most commonly treated teeth were premolars (46.15%). A total of 52 (21%) treated teeth were clinically and radiographically reexamined. The success rate for the nRCT was 98.08%. About 61.54% of this sample had a definitive composite resin restoration. Conclusion: The nRCT success rate was high. Special attention should be given to the presence and quality of the definitive restoration. Clinical Implications: There was no statistically significant impact between the coronal restoration and the nRCT success (P > 0.05).
基金supported by State Key Laboratory of Oral Diseases and Department of Endodontics and Operative Dentistry, West China School of Stomatology, Sichuan Universitysupported by the Key Clinical Program of the Ministry of Health of China (2010)National Key Clinical Program of China (2010)
文摘The aim of this study was to analyze the specific influence of root canal anatomy on the accessibility of working length during root canal therapy. Four hundred seventy-six root canal therapy cases （amounting to a total of 1 005 root canals） were examined. The anatomy risk factors assessed in each case included： tooth type （tooth location）, root canal curvature, and root canal calcification, as well as endodontic retreatment. The investigation examined the correlation between each of these anatomic factors and the working length, with statistical analysis consisting of Chi-square tests and multiple logistic regression analysis. In an independent factor analysis, tooth type （tooth iocation）, root canal curvature, canal calcification, and endodontic retreatment were determined to be the primary risk factors. In a multiple-factor regression model, root curvature and canal calcification were found to most significantly influence root canal working length accessibility （P〈0.05）. Root canal anatomy increases the difficulty of root canal preparation. Appropriate consideration of tooth anatomy will assist in accurate determination of preparation difficulty before instrumentation. This study alerts clinical therapists to anatomical factors influencing the working length accessibility, and allows for a direct estimate of success rate given in situ measurements of tooth factors during the root canal treatment procedure.
基金supported by projects from the Sichuan Science and Technology Department(Grant No.2013JY0164)the National Nature Science Foundation of China(Grant No.81670980)
文摘To compare the efficacy of various irrigants(citric acid, ethylenediaminetetraacetic acid(EDTA) and Na OCl) and techniques in removing Ca(OH)2in two types of curved root canal systems, simulated root canals with specific curvatures were used to investigate the effects of different irrigants and instruments on Ca(OH)2removal. The optimal methods were verified on extracted human teeth. Simulated root canals were assigned to one of two groups based on the irrigation solution: 10% citric acid or2.5% Na OCl. Each group was divided into four subgroups according to the technique used to remove Ca(OH)2. The percentage of Ca(OH)2removal in different sections of root canals was calculated. On the basis of the results obtained for the simulated canals, 10% citric acid and 17% EDTA were applied to remove Ca(OH)2from the extracted human teeth with curved root canal systems. The teeth were scanned by micro computed tomography to calculate the percentage of Ca(OH)2removal in the canals.In simulated root canals, we found that 10% citric acid removed more Ca(OH)2than 2.5% NaOCl in the 0–1 mm group from the apex level(Po0.05). Ultrasonic and Endo Activator activation significantly removed more Ca(OH)2than a size 30 K file in the apical third(Po0.05). However, there were no significant differences in any sections of the canals for 10% citric acid or 17%EDTA in removing Ca(OH)2in extracted human teeth. We concluded that it was effective to remove residual Ca(OH)2using the decalcifying solution with Endo Activator or Passive Ultrasonic Irrigation in a curved root canal system. A protocol for Ca(OH)2removal was provided based on the conclusions of this study and the methods recommended in previous studies.
基金supported by the grant from the Independent Innovation Foundation of Shandong University of China (No. 2011JC019)the grant of Science and Technique Development Foundation of Shandong province(2010G0020230)
文摘The aims of the study were to investigate the incidence of C-shaped root canal systems in mandibular second molars in a native Chinese population using radiography and clinical examination under microscope and to compare the relative efficacies of these methods. For the recognition of C-shaped root canal system, 1 146 mandibular second molars were selected and examined. Teeth with C-shaped canal systems were categorized by using the radiographic classification criteria and the modified Melton＇s method. C-shaped canals were identified in 397 （34.64%） mandibular second molars by radiography （type I, 31.23%; type II, 38.29%; type III, 30.48%）. Clinical examination showed that 449 （39.18%） cases exhibited C-shaped canal systems （C1, 22.94%; C2, 48.11%; C3a, 15.59%; C3b, 13.36%）. As for the result of the radiographic and clinical combined examination, C-shaped root canals were found in 473 （41.27%） mandibular second molars （C1, 21.78%; C2, 45.67%; C3a, 16.70%; C3b, 15.86%）. The incidence of C-shaped root canal diagnosed by radiographic method was statistically different from that by clinical examination and the combined examination （P〈O.05）. The study indicated a high incidence of C-shaped canal system in a Chinese population. The combination of microscopic and radiographic examination is an effective method in identifying the C-shaped root canal system.
文摘This study was designed to compare the impact of post and core systems on resistance to fracture of endodontically treated anterior teeth with flared root canals and to assess their fracture pattern. Sixty central incisors were cut horizontally 2 mm coronal to the cementoenamel junction(CEJ). After root canal therapy, teeth were assigned into 6 groups(n = 10 each) based on a post system and used as follows: Group C, non-flared root received size #1 glass fiber posts(Control); Group AP, flared root restored with anatomical post; Group RC, flared root restored with size #1 fiber post and cemented with thick layer of resin cement; Group CR, flared root restored with size #1 and reinforced with composite resin; Group CM, cast post-core; Group CP, CAD/CAM polymer-infiltrated ceramic post and core.Following post cementation, core build-up and crown insertion, the specimens were thermo-cycled up to 10,000 cycles(5 C/55 C; 30 seconds dwell time, 6 seconds transition time) and then statically loaded at 1 mm/minute crosshead speed using a universal testing machine. One-way ANOVA and Tukey HSD post hoc test(α= 0.05) were used for data analysis. Group C recorded significantly higher resistance to fracture values [(826.9±39.1) N] followed by group CP [(793.8±55.6) N] while group RC yielded the lowest fracture resistance values [(586.7±51.4) N]. The resistance to fracture of wide root canals can be enhanced by using one-piece CAM/CAM post and core as an alternative to the use of either glass fiber post, relined with composite resin increasing the thickness of luting cement or the use of cast post and core system. However, this was an in vitro investigation and further in vivo studies are necessary.
基金supported by the Fundamental Research Funds for the Central Universities,China(No.2010JC030)
文摘Summary： This study was aimed to evaluate the effectiveness of solution form of 17% ethylenediaminetetraacetic acid （EDTA） on removing smear layer of root canals at different exposure time periods and to provide scientific basis for EDTA as a choice of root canal irrigation in clinical practice. Twenty-five single-rooted teeth were randomly divided into 5 groups： control group （group A） was given 2.5% NaOC1, and 4 experimental groups were given 2.5% NaOC1 and 17% EDTA, including groups B, C, D and E with exposure time of 1, 3, 5 and 7 min, respectively. After preparation of the root canals, the teeth were split along their longitudinal axis, and the root sections were examined under scanning elec- tron microscope for evaluation of smear layer removal and erosion on the surface of the root canal walls. The specimens in group B showed presence of smear layer on the walls of the root canal with no statistical difference from that in group A （P〉0.05）. In groups C and D, partial removal of smear layer was obtained, and there was no significant difference between the two groups （P〉0.05）, but there was significant difference in removal of smear layer between group C and group B （P〈0.05）. Root canal walls in group E specimens showed almost complete removal of smear layer, and the removal of smear layer was significantly different from that in group D （P〈0.01）. There was no significant change in the structure of the surface of root canal for each sample. It was concluded that combined irrigation with 17% EDTA and 2.5% NaOC1 could remove the smear layer with no significant alteration in dentinal structure when the chelating agent was applied for 7 min. At 3 and 5 min of application, partial removal of smear layer was observed and at 1 min negligible removal of smear layer was achieved.
文摘The aim of this study was to investigate the root canal configuration, accessory canals and number of main foramina of 123 maxillary second molars by means of micro-computed tomography. The teeth were scanned and reproduced with 3D software imaging. The root canal configuration and number of main foramina were evaluated by means of a four-digit system. The morphological complexity of human maxillary second molars is depicted by the number of accessory and connecting canals. The most frequently observed root canal configurations in the mesiobuccal root were 2-2-2/2 （19.5%）, 2-2-1/1 （14.6%） and 2-1-1/1 （13.0%）. A 1-1-1/1 configuration was observed in 93.5% and in 96.7% in the distobuccal and palatal roots, respectively. The MB1 mot canal had one accessory canal （18.7%）, and 8.9% of the MB2 root canal had one or two accessory canals. The distobuccal （11.3%） and palatal （14.6%） root canals had at least one accessory canal, and connecting canals were observed in 16.3% of mesiobuccal roots. The MB1, MB2, distobuccal and palatal root canals had one main foramen in 99.2%, 43.1%, 98.4% and 99.2% of samples, respectively. In the mesiobuccal root, one accessory foramen was detected in 14.6%, two were detected in 7.3%, and three were detected in 5.7%. The distobuccal root showed one or two accessory foramina in 9.1% of samples. The root canal configuration of maxillary second molars is quite heterogeneous; the mesiobuccal root has predominantly two root canal entrances （58.4%, 1 in 41.1%） with one main foramen （54.4%）. Two main foramina were observed in 43.0%. Morphological variations, connecting and accessory canals were observed in all apical thirds.
文摘BACKGROUND The complex anatomy of the maxillary first molars has always been a major challenge for complete root canal treatment in endodontic therapy. Here, we present two cases of maxillary first molars, each with only two root canals, which have been rarely reported. We also perform a literature review of maxillary first molar anatomy.CASE SUMMARY The two patients were referred to the hospital after 1) finding a cavity in their tooth with a color change and, 2) a toothache during mastication, respectively.Both of these cases were diagnosed as apical periodontitis by X-ray imaging and cone beam computed tomography(CBCT). Non-surgical endodontic therapy was performed with the assistance of a dental operating microscope(DOM). CBCT showed rare but accurate images of both patients, each with two root canals and two roots in their maxillary first molars. Both roots were located in the buccal in the palatal direction, and each root had only one clear root canal. In addition,each maxillary first molar in both patients was symmetrical to that on the opposing side with only two separate root canals. Non-surgical endodontic therapy was performed with the assistance of a DOM. Finally, the teeth were restored using composite resin and the patients were satisfied with the results.CONCLUSION Making full use of CBCT and DOM would contribute to helping dentists make correct diagnoses and successfully treat teeth with rare root canal morphologies.
