共查询到20条相似文献，搜索用时 31 毫秒
1.
Roserin Ratanajirasut Anchana Panichuttra Soontra Panmekiate 《Journal of endodontics》2018,44(1):56-61
Introduction
Understanding tooth anatomy is crucial for effective endodontic treatment. This study investigated the roots and root canal morphology of maxillary first and second permanent molars in a Thai population using cone-beam computed tomographic (CBCT) imaging.Methods
This study evaluated 476 maxillary first molars and 457 maxillary second molars receiving CBCT examination and determined the number of roots and canal morphology according to Vertucci's classification, and the prevalence of a second mesiobuccal (MB2) canal in the mesiobuccal (MB) root was correlated with sex, age, and tooth side.Results
Three roots were most commonly found in maxillary first and second molars. MB2 canals in the MB root were found in 63.6% and 29.4% of first and second molars, respectively. The most common canal morphology in the first molar MB roots was type I (36.4%) followed by type II (28.8%), and type IV (25.3%). The most common canal morphology in the second molar MB roots was type I (70.6%) followed by type II (14.6%) and type IV (7.5%). Bilateral MB2 canals in the MB roots were present in 80.93% and 82.59% of the first and second molars, respectively. There was a significant correlation between males and the prevalence of MB2 canals in first molars (P < .05).Conclusions
CBCT imaging is useful to determine root canal morphology. The prevalence of MB2 canals is approximately 60% and 30% in first and second molars, respectively. Furthermore, bilateral MB2 canals were commonly found. Our results can help endodontists to improve endodontic treatment outcomes. 相似文献2.
Yu-Chiao Wu Wan-Chien Cheng Pei-Wei Weng Ming-Pang Chung Chi-Chun Su Ho-Sheng Chiang Yi-Wen Cathy Tsai Chi-Hsiang Chung Yi-Shing Shieh Ren-Yeong Huang 《Journal of endodontics》2018,44(5):711-716.e1
Introduction
The aim of this study was to assess the prevalence of complicated root canals in permanent mandibular central incisors (PMCIs) and its correlation with the presence of a distolingual root (DLR) in permanent mandibular first molars (PMFMs) using cone-beam computed tomographic imaging in a Taiwanese population.Methods
A total of 400 patients (800 pairs of PMCIs and PMFMs) were qualified for further analysis. The prevalence of DLRs in PMFMs along with root canal configurations of PMCIs were assessed at subject and tooth levels. Multivariable logistic regression analysis was used to evaluate the correlation between the root canal configurations of PMCIs with the existence of DLRs in PMFMs.Results
The prevalence of PMFMs with DLRs and complicated root canal configurations in PMCIs was 23.0% and 15.6%, respectively. A significant difference in age (<50 years vs ≥50 years) was found for complicated root canal configurations in PMCIs. The most prevalent root canal system in PMCIs was Vertucci type I (84.4%) followed by type III (13.5%). A positive correlation between the presence of DLRs in PMFMs and complicated root canal configurations in PMCIs was noted. After adjusting for categoric variables including sex, age, and side, the odds ratios for the occurrence of complicated root canal configurations of PMCIs in the unilateral DLR group and the bilateral DLR group compared with the non-DLR group were 2.13 and 2.53, respectively.Conclusions
The concurrent appearance of DLRs in PMFMs and complicated root canal morphology in PMCIs is prominent in Taiwanese individuals. 相似文献3.
Introduction
Long-term studies examining the treatment outcomes of “cracked teeth” that received orthograde root canal treatment in the United States do not exist. The purpose of the present study was to examine the distribution and 1-year treatment outcomes of cracked teeth receiving orthograde root canal treatment in 1 private endodontic practice over a 25-year period.Methods
A total of 3038 cracked teeth were initially examined, and data from 2086 unique patients were analyzed. Pulpal and periapical diagnoses, year of treatment, tooth type, restorative material, and number of restored surfaces at the time of examination were recorded for all patients. Periodontal probing depths were also recorded. The patients’ age and sex were added retrospectively for all patients whose data were available. Univariate frequency distributions for all collected variables were evaluated. Bivariate associations were analyzed between explanatory variables and the success of the root canal therapy.Results
Of the 2086 cracked teeth observed among unique patients, the most common were mandibular second molars (36%) followed by mandibular first molars (27%) and maxillary first molars (18%). Among the 363 teeth eligible for multivariable regression analysis, 296 (82%) were deemed successes after 1 year. There were no statistically significant differences in success based on pulpal diagnosis (irreversible pulpitis, 85%; necrosis, 80%; previously treated, 74%), patients’ age, sex, year of treatment, tooth type, restorative material, or number of restored surfaces at the time of examination. The 3 factors most significant in bivariate analyses were pocket depth, distal marginal ridge crack, and periapical diagnosis, which were used to generate a prognostic index for success of orthograde root canal therapy in cracked teeth called the Iowa Staging Index.Conclusions
The results of this study suggest that cracked teeth that received root canal treatment can have prognoses at higher success rates than previously reported. The Iowa Staging Index may prove to be useful in clinical treatment decision making. 相似文献4.
Yu-Chiao Wu Wan-Chien Cheng Ming-Pang Chung Chi-Chun Su Pei-Wei Weng Yi-Wen Cathy Tsai Ho-Sheng Chiang Hsiao-Wen Yeh Chi-Hsiang Chung Yi-Shing Shieh Ren-Yeong Huang 《Journal of endodontics》2018,44(1):73-79.e1
Introduction
The aim of this study was to assess the root canal configurations in permanent mandibular lateral incisors (PMLIs) and the correlation between the root canal configurations of PMLIs with the appearance of a distolingual root (DLR) in permanent mandibular first molars (PMFMs) using cone-beam computed tomographic (CBCT) imaging.Methods
A total of 1200 CBCT images (300 patients) of PMFMs and PMLIs were investigated. The frequency and distribution of DLRs in PMFMs along with root canal configurations of PMLIs were assessed ipsilaterally and contralaterally. Multivariable logistic regression analysis was used to evaluate the correlation between the root canal configurations of PMLIs with the appearance of a DLR in PMFMs.Results
The prevalence of PMFMs with a DLR was 24.3%, and the incidence of complicated root canal configurations in PMLIs was 25.0%. The most prevalent root canal systems of PMLIs were Vertucci types I (75%) and III (23.0%). The incidence of complicated root canal configurations in PMLIs was 19.5% in the non-DLR group (ie, no DLR was found on either side of the PMFMs), 33.3% in the unilateral DLR (Uni-DLR) group (ie, a DLR was found in 1 of the PMFMs [the left or right side] and a DLR was not found on the other PMFM), and 39.8% in the bilateral DLR (Bil-DLR) group (ie, a DLR was found in both the right and left PMFMs). After adjusting for categoric variables including sex, age, and side, the odds ratios for the frequency of complicated root canal configurations of PMLIs in the Uni-DLR and Bil-DLR groups compared with the non-DLR group were 2.12 (P = .003) and 2.707 (P < .001), respectively.Conclusions
The simultaneous appearance of DLRs in PMFMs and complicated root canal configurations in PMLIs is prominent in Taiwanese individuals. Clinicians should be aware of the correlation between the anatomic variants of PMFMs and PMLIs, which are important before endodontic treatment. 相似文献5.
Introduction
The present study aimed to anatomically assess mandibular posterior teeth using cone-beam computed tomographic (CBCT) imaging for endodontic surgery.Methods
A total of 170 CBCT scans were evaluated for anatomic variations of mandibular posterior teeth. All the scans were obtained using a Planmeca Promax CBCT unit (Planmeca, Helsinki, Finland) with exposure settings of 90 kVp, 12 mA, 12 seconds, and 0.3-mm resolution. All CBCT images were reconstructed by Romexis Viewer 3.8.2. software (Planmeca) on a 16-inch LCD monitor (22MP47HQ; LG, Seoul, South Korea), and axial, coronal and sagittal views were evaluated.Results
The thickest buccal cortical plate was observed over the distal root of second molars (12.30 mm) among the molar teeth and over the second premolar root (5.41 mm) among the premolar teeth. The thinnest buccal cortical plate was observed over both the first and second premolar roots (0.42 mm) and over the mesial root of the first molar (0.62 mm) tooth. A 20.38-mm section was removed for surgical access during buccal resection of the distal root of the left second molar, and the closest distance from the apex to the inferior alveolar canal was 0 mm.Conclusions
Adequate knowledge of the anatomic dimensions of teeth and their surrounding structures is imperative for endodontic surgery. Information concerning the root thickness of mandibular posterior teeth at the site of root resection (apical 3 mm), buccal cortical plate thickness, and the distance from the apex of each tooth to the inferior alveolar canal and mental foramen can guide the surgeon before and during surgery. 相似文献6.
Carlos Estrela Gabriela Soares Couto Mike R. Bueno Kelvin G. Bueno Lucas R.A. Estrela Olavo César Lyra Porto Anibal Diogenes 《Journal of endodontics》2018,44(11):1741-1748
Introduction
The purpose of this study was to determine the position of the apical foramen (AF) in relation to root surfaces of human permanent teeth using cone-beam computed tomographic (CBCT) imaging and novel advanced imaging analysis software (e-Vol DX; CDT Software, Bauru, SP, Brazil).Methods
The AF position was determined on CBCT scans viewed and analyzed using e-Vol DX of 1400 teeth (422 patients) according to the root surface as follows: buccal, mesiobuccal, mesial, mesiolingual/palatal, lingual/palatal, distolingual/palatal, distal, distobuccal, and central. Categoric variables were described as frequencies and percentages. Frequencies were reported with their confidence intervals (95%). Categoric variables were analyzed using the chi-square test with Yates correction. The level of significance was set at α = 0.05.Results
The most frequent AF position in maxillary anterior teeth was central (46%–60%). The AF in mandibular central incisors was buccal in 44% of the cases. In maxillary first and second premolars, 39.98% and 42.56% of all AFs were central. In maxillary first and second molars, 46.12% and 57.49% of all AFs were central. The most frequent AF position in mandibular first and second premolars was central (42.85% and 50.98%). In mandibular first molars, 48.72% of all AFs were central.Conclusions
The AF position in human permanent teeth was central in 48.95% and 42.08% of the maxillary and mandibular teeth. CBCT images analyzed by e-Vol DX can be used to determine the true anatomic position of the AF and can be a useful tool for the treatment planning of nonsurgical and surgical endodontic treatments. 相似文献7.
Domenico Ricucci Simona Loghin Lucio S. Gonçalves Isabela N. Rôças José F. Siqueira 《Journal of endodontics》2018,44(3):405-413
Introduction
This histobacteriologic study described the pattern of intraradicular and extraradicular infections in teeth with sinus tracts and chronic apical abscesses.Methods
The material comprised biopsy specimens from 24 (8 untreated and 16 treated) roots of teeth associated with apical periodontitis and a sinus tract. Specimens were obtained by periradicular surgery or extraction and were processed for histobacteriologic and histopathologic methods.Results
Bacteria were found in the apical root canal system of all specimens, in the main root canal (22 teeth) and within ramifications (17 teeth). Four cases showed no extraradicular infection. Extraradicular bacteria occurred as a biofilm attached to the outer root surface in 17 teeth (5 untreated and 12 treated teeth), as actinomycotic colonies in 2 lesions, and as planktonic cells in 2 lesions. Extraradicular calculus formation (mineralized biofilm) was evident in 10 teeth.Conclusions
Teeth with chronic apical abscesses and sinus tracts showed a very complex infectious pattern in the apical root canal system and periapical lesion, with a predominance of biofilms. 相似文献8.
Introduction
The purpose of this study was to evaluate the number of roots and canal morphology of maxillary permanent first molars in a North American population.Methods
Three hundred seventeen cases with bilateral maxillary first molars were included. All images from cone-beam computed tomography were carefully reviewed by 2 endodontists. Frequency of number of roots, presence of an additional mesiobuccal canal (MB2), and Vertucci canal type for each root were tabulated. Age, gender, and ethnicity differences were calculated with the χ2 test. The intra-rater reliability was assessed by using the Cohen kappa statistic.Results
The fused root rate was 0.9%. The occurrence of 3-rooted maxillary first molars differed between left and right sides (P = .03). MB2 occurrence only showed statistically significant differences among age groups (P = .005). In the mesiobuccal roots, the most common Vertucci classifications of canal types were type IV (2-2, 41.9%), type I (1, 28.3%), and type II (2-1, 26.3%). There was a statistically significant difference in Vertucci classification of canal type among 5 ethnic groups (African American, Asian, Hispanic, Other, and Non-Hispanic white, P < .001).Conclusions
Cone-beam computed tomography facilitates the identification of root and canal configuration. The information gained about the tooth anatomy and canal morphology before treatment could potentially facilitate root canal therapy. 相似文献9.
Introduction
Maxillary premolars are among the teeth most susceptible to vertical root fracture (VRF) from lateral condensation of gutta-percha. These teeth are distinguished by a complex anatomy of the buccal root including a large depression in the dentin wall facing the bifurcation. It is hypothesized that tooth sectioning coupled with 2-dimensional fracture analysis is instrumental in understanding VRF in such teeth. VRF was examined by tooth sectioning following the development of a fracture mechanics analysis to predict VRF in such roots.Methods
The fracture morphology in teeth extracted from patients because of VRFs was examined from a series of horizontal cross sections. 2-dimensional fracture mechanics analysis in conjunction with the finite element technique was developed to evaluate VRF caused by canal pressure (q). As in our previous single-rooted tooth model, the apical obturation force (F) was related to q using a simple formula.Results
Fracture was mostly limited to the buccal root, exhibiting some competing modes including fracture from the depression peak to the canal surface and the canal surface to the root surface, which may occur either along straight lines or curved trajectories resembling the depression outline. The analysis predicted clinical fractures well, yielding VRF force values in the upper range used by clinicians during lateral condensation of gutta-percha.Conclusions
The main etiology for VRF is stress concentration resulting from the combined effect of wedgelike canal depression and the flexibility of periodontal ligament tissue joining the root and bone. This drawback can be alleviated by minimizing canal enlargement and apical condensation force during root canal therapy. 相似文献10.
Michael R. Shapiro Neville J. McDonald Richard J. Gardner Mathilde C. Peters Tatiana M. Botero 《Journal of endodontics》2018,44(4):523-528
Introduction
Profound pulpal anesthesia is difficult to achieve in mandibular molars with irreversible pulpitis (IP). However, there are no published randomized controlled clinical trials comparing the success of supplemental buccal infiltration (BI) in mandibular first versus second molars with IP. The purpose of this prospective, randomized, double-blind study was to compare the efficacy of 4% articaine with 2% lidocaine for supplemental BIs in mandibular first versus second molars with IP after a failed inferior alveolar nerve block (IANB). This study's sample was combined with data from a previous trial.Methods
One hundred ninety-nine emergency subjects diagnosed with IP of a mandibular molar were selected and received an IANB with 4% articaine. Subjects who failed to achieve profound pulpal anesthesia, determined by a positive response to cold or pain upon access, randomly received 4% articaine or 2% lidocaine as a supplemental BI. Endodontic access was begun 5 minutes after infiltration. Success was defined as less than mild pain during endodontic access and instrumentation on the Heft-Parker visual analog scale.Results
There was a 25% IANB success rate with 4% articaine. The success rate for articaine supplemental BI in first molars was 61% versus 63% for second molars (P > .05). The success of lidocaine in first molars was 66%, but for second molars it was 32% (P = .004).Conclusions
The success rate for IANB with 4% articaine was 25%. Articaine and lidocaine had similar success rates for supplemental infiltration in first molars, whereas articaine was significantly more successful for second molars. However, because BI often did not provide profound pulpal anesthesia, additional techniques including intraosseous anesthesia may still be required. 相似文献11.
Aim
To compare and evaluate the clinical and radiographic success of four different zinc-oxide integrated root canal obturating materials.Materials and method
120 grossly decayed primary molars of children, aged 4 to 9 years were selected with signs or symptoms of irreversibly inflamed pulp tissue and randomly assigned to one of the four groups: zinc oxide eugenol, zinc oxide powder with 10% sodium fluoride, zinc oxide powder with Aloe vera, and Endoflas. Single sitting pulpectomy was carried out in all teeth and subsequently restored with a preformed crown in next sitting. Teeth were assessed clinically and radiographically for 3, 6, 9 and 12 months interval.Results
90 out of 120 treated molars completed 12-month evaluations. Overall clinical and radiographic success rates were highest for endoflas, followed by zinc oxide-sodium fluoride, zinc oxide-aloe vera and least for zinc oxide eugenol. However, no significant differences between success rates were observed amongst the four study groups (P>0.05).Conclusions
These results suggest that the sodium fluoride and aloe vera may be considered as suitable alternative root canal obturating materials for primary teeth with low cost to achieve acceptable therapeutic results. 相似文献12.
Brent M. Hiebert Kenneth Abramovitch Dwight Rice Mahmoud Torabinejad 《Journal of endodontics》2017,43(10):1711-1715
Introduction
The purpose of this study was to determine the prevalence of the second mesiobuccal canal (MB2) in 100 maxillary first molars using 3 independent methods and a combination method.Methods
One hundred extracted human maxillary first molars were collected. The teeth were mounted in the maxillary first molar extraction sockets of a human cadaver head. A cone-beam computed tomographic (CBCT) scan was taken of each tooth. Two radiology faculty independently evaluated the CBCT volume for the presence of an MB2 canal. Additionally, teeth were accessed. If a canal was not found, a preoperative CBCT scan was viewed followed by a second attempt to locate an MB2 canal. Lastly, the mesiobuccal root was dissected by grinding in a coronal plane.Results
A review of CBCT volumes found the presence of an MB2 canal 69% of the time. Accessing the tooth led to an MB2 detection of 78%. When a CBCT scan was viewed, this brought the access detection rate up to 87%. Coronal plane root grinding had an MB2 canal detection rate of 92%. Differences between each method were statistically significant.Conclusions
The results of this study show that an MB2 canal is present up to 92% of the time. Direct access of teeth found statistically significant more MB2 canals than viewing CBCT volumes alone (P = .032). Therefore, exposing every patient to a preoperative CBCT scan may not be appropriate. However, taking a CBCT scan when an MB2 canal is not found clinically can significantly increase the chances of finding an MB2 canal (P < .001). 相似文献13.
Yu-Chiao Wu Yi-Wen Cathy Tsai Wan-Chien Cheng Pei-Wei Weng Chi-Chun Su Ho-Sheng Chiang Ming-Pang Chung Chi-Hsiang Chung Yi-Shing Shieh Ren-Yeong Huang 《Journal of endodontics》2018,44(10):1492-1499.e1
Introduction
The aim of this study was to determine the prevalence of C-shaped canal configurations (CSs) and radicular grooves (RGs) in permanent mandibular first premolars (MPs) and to investigate the relevance of such complexities with the presence of distolingual roots (DLRs) in permanent mandibular first molars (MMs).Methods
A total of 800 pairs of MPs and MMs were investigated using a cone-beam computed tomographic system (NewTom 5G; QR srl, Verona, Italy). The frequency and symmetry of DLRs in MMs along with the occurrence of RGs and CSs in examined MPs were evaluated. Multivariable logistic regression analysis was applied to examine the correlation between the CSs of MPs with the appearance of DLRs in MMs.Results
In the examined teeth, 23.0% of MMs had a DLR, whereas 16.6% of MPs had RGs and 12.5% of MPs had C-shaped canals. Although the most common canal configuration in MPs is the single canal (74.1%), the other 25.9% still possess complicated root canals. Of these MPs that have different canal configurations, 54.6% had 2 canals, whereas 44.4% had CSs. Specifically, the CS showed a high prevalence of C3 morphologies at 98.9% followed by C1 at 1.1%. A corresponding and increasing frequency was noted in CSs and RGs of MPs and MMs with DLRs (P < .001). After adjusting for related categoric variables, the adjusted odds ratios for CSs of MPs in the bilateral DLR group compared with the non-DLR group was 3.294 (P < .001).Conclusions
This study showed an increased appearance of CSs in MPs when DLRs were present in MMs in the Taiwanese population. 相似文献14.
Introduction
Conventional endodontic treatment includes instrumentation of the canals in most cases to size #25/.06 or larger, which changes the original canal wall anatomy. In recent years, energy-driven equipment, such as photon-induced photoacoustic streaming (Fotona LLC, Dallas, TX) and a multisonic GentleWave system (Sonendo Inc, Laguna Hills, CA), have been introduced to facilitate cleaning of minimally instrumented canals or even uninstrumented canals. The purpose of this study was to examine root canal wall anatomy in premolar teeth cleaned by a noninstrumentation method after #10 K-file patency examination.Methods
Twenty-four freshly extracted human premolars were accessed, and patency was established by a #10 K-file. Seventeen teeth were treated by the GentleWave system using 3% sodium hypochlorite, and 7 untreated teeth served as negative controls. The dentin surface in the coronal, middle, and apical thirds of the root canal was examined by scanning electron microscopy after tooth splitting. The canal wall structures were assessed using a predefined scale of 4 parameters: calcospherites, surface irregularities, dentinal tubule openings, and tissue debris.Results
A clean surface of mineralized dentin was exposed with no organic tissue remnants or debris left in the root canal system, including the isthmus areas between the 2 canals. The uninstrumented root canals showed an irregular dentin structure in many areas, including previously unreported fingerlike projections. The isthmus areas had no or only a few dentinal tubule openings. The dentin structures were well preserved in the test group, whereas in the untreated control teeth tissue debris covered most of the dentin surface.Conclusions
Root canal wall dentin in premolars cleaned with a noninstrumentation method showed a wide structural variety, especially in the middle and apical region. No organic tissue remnants or dentin debris were detected. 相似文献15.
Sabrina C. Brasil Marília F. Marceliano-Alves Márcia L. Marques João P. Grillo Mariane F.L.S. Lacerda Flávio R.F. Alves José F. Siqueira José C. Provenzano 《Journal of endodontics》2017,43(10):1683-1687
Introduction
This study compared the shaping ability of ProTaper Next (Dentsply Sirona, Tulsa, OK) and BT-RaCe (FKG Dentaire, La Chaux-de-Fonds, Switzerland) instrument systems in the mesial canals of mandibular molars using micro–computed tomographic (micro-CT) imaging.Methods
A total of 17 type IV mesial roots of extracted first mandibular molars were scanned using micro-CT imaging before and after root canal preparation with the 2 instrument systems. Both systems were used in the same root but alternating the mesial canals from root to root. The following parameters were analyzed: root canal volume, surface area, unprepared surface areas, transportation, canal/root width ratio, and preparation time.Results
There were no statistically significant differences between the 2 systems for all evaluated parameters (P > .05). The unprepared surface areas for the full canal length and the apical 5-mm segment were 33% and 14% for BT-RaCe and 31% and 14% for ProTaper Next, respectively. After preparation, all root canals had a diameter that was not larger than 35% of the root diameter at the coronal and middle segments.Conclusions
The 2 systems showed no differences in any of the evaluated shaping parameters. None of the tested systems put the roots at risk of fracture because of excessive dentin removal. 相似文献16.
Indre Graunaite Neringa Skucaite Greta Lodiene Indre Agentiene Vita Machiulskiene 《Journal of endodontics》2018,44(5):689-693
Introduction
The aim of this study was to compare the effect of resin-based and bioceramic root canal sealers on the occurrence and intensity of postoperative pain in patients with asymptomatic apical periodontitis (AAP).Methods
Patients presenting with AAP in previously endodontically treated teeth were included in this split-mouth blinded randomized controlled trial. For each patient, 2 single-rooted teeth were retreated and obturated using the warm vertical condensation technique and different obturation materials (ie, a gutta-percha point with resin-based sealer and a bioceramic-coated gutta-percha point with bioceramic sealer). Treatment of 1 root canal was performed in a single visit. Postoperative pain was recorded by a visual analog scale (VAS) at 24 hours, 48 hours, 72 hours, and 7 days after obturation.Results
Of the 61 included patients, 57 individuals presenting 114 teeth completed the study. There was no statistically significant difference between the tested root canal sealers regarding postoperative pain at any time points assessed (P > .05). In total, 20 (35%) patients perceived pain. Only 1 patient reported severe pain. VAS scores of 80 and 70 were reported in the AH Plus (Dentsply Maillefer, Ballaigues, Switzerland) and Total Fill (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) groups, respectively. Pain intensity decreased about 2-fold in both groups at 48 hours after treatment. There were no reports of pain since 72 hours after obturation. The odds ratio for pain occurrence in the lower premolars was 7.2 (95% confidence interval, 1.708–30.352) compared with the upper front teeth.Conclusions
AH Plus and Total Fill perform similarly in terms of the occurrence and intensity of postoperative pain in teeth with AAP with no material extrusion beyond the apex. 相似文献17.
Introduction
Root fusion is an anatomic variation in maxillary second molars (MSMs); however, the nature of this canal morphology as it relates to its root anatomy has not been fully clarified. The purpose of this study was to investigate the relationship between features of fused roots and root canal anatomy in MSMs using micro–computed tomographic imaging.Methods
One hundred eighty-seven extracted MSMs were scanned with the μCT50 (Scanco Medical, Bassersdorf, Switzerland), and their root and canal morphology was classified and analyzed using the classifications proposed by Yang and Vertucci. The number and position of canals that merged were recorded and compared among different root fusion types.Results
One hundred eight (57.75%) MSMs had 3 separate roots, and 79 (42.25%) had fused roots. Of the 79 fused roots, 22 showed partial canal merging, and 6 had complete canal merging. Canal merging was found with teeth with 3-root fusion more often than in those with 2-root fusion (P < .05). Of 28 merged canals, 16 occurred between mesiobuccal and distobuccal canals and 9 among mesiobuccal, distobuccal, and palatal canals.Conclusions
MSMs with fused roots may present a complicated root canal system as a result of canal merging. 相似文献18.
Peter Z. Tawil Elisa K. Arnarsdottir Ceib Phillips Sigurdur R. Saemundsson 《Journal of endodontics》2018,44(10):1487-1491
Introduction
This microsurgical clinical study evaluated if teeth that have undergone endodontic retreatment are associated with more dentinal defects than primary root canal–treated teeth.Methods
One hundred fifty-five patients who underwent periapical microsurgery treatment in a private practice setting were evaluated. The root ends were resected, and the roots were inspected for the presence of dentinal defects through the surgical operating microscope with the help of a 0.8-mm-diameter light-emitting diode probe light and methylene blue dye. The root canal treatment history (primary vs retreatment) of the teeth was documented and related to the presence or absence of dentinal defects. Bivariate analysis was performed using the chi-square test, and a multivariate analysis was performed using logistic regression to evaluate possible confounding effects of patient age, sex, and tooth location on the association between treatment and the presence of dentinal defects.Results
Of the 155 treated teeth, 33 were excluded (3 fractured and 30 missing treatment history). Of the remaining 122 included teeth, 73 (59.8%) had undergone primary root canal treatment and 49 (40.2%) retreatment. Sixteen teeth (22.5%) of the primary root canal group versus 33 (64.7%) of the retreatment group had dentinal defects. The proportion of retreated teeth with dentinal defects compared with primary treatment was statistically significant (P < .001) with a higher proportion of retreated teeth having dentinal defects. In the multivariate analysis, only the type of treatment was statistically significant (P < .001).Conclusions
This clinical study showed that root canal–retreated teeth are associated with more dentinal defects than primary root canal–treated teeth. 相似文献19.
Mohammad Sabeti Majid Kazem Omid Dianat Nazanin Bahrololumi Amirreza Beglou Kasra Rahimipour Farshad Dehnavi 《Journal of endodontics》2018,44(9):1402-1406
Introduction
The susceptibility of endodontically treated teeth (ETT) to fracture is mainly associated with the loss of tooth structure. This study evaluated the effect of the access cavity design and taper preparation of root canals on ETT fracture resistance of maxillary molars.Methods
For tapering assessment, 30 sound distobuccal roots of maxillary molars were randomly assigned to 1 of 3 groups (n = 10): a .04 taper, a .06 taper, or a .08 taper. Endodontic canal preparations were performed using the Twisted Files rotary system (Kerr Co, Glendora, CA). In addition, 48 intact maxillary first and second molars were randomly assigned to 1 of 3 groups (n = 16) for cavity preparation approaches: intact teeth, traditional access cavity (TAC), or conservative access cavity (CAC). Fracture resistance was tested using a universal testing machine. For statistical analysis, the level of significance was P ≤ .05.Results
The .04 taper instrumentation had the highest fracture resistance (259.61 ± 52.06), and the .08 taper had the lowest (168.43 ± 59.63). The .04 and .06 groups did not differ significantly (P > .05); however, these groups differed significantly from the .08 group (P ≤ .05). Regarding the cavity preparation approaches, the 3 groups of intact teeth, CAC, and TAC showed fracture resistance mean values of 2118.85 ± 336.97, 1705.69 ± 591.51, and 1471.11 ± 435.34, respectively, with no significant difference between the CAC and TAC groups (P > .05).Conclusions
Increasing the taper of the root canal preparation can reduce fracture resistance. Moreover, access cavity preparation can reduce resistance; however, CAC in comparison with TAC had no significant impact. 相似文献20.
Shinji Yoshii Masataka Fujimoto Masahiro Okuda Chiaki Kitamura 《Journal of endodontics》2018,44(12):1856-1861