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1.
Shinji Yoshii Masataka Fujimoto Masahiro Okuda Chiaki Kitamura 《Journal of endodontics》2018,44(12):1856-1861
Introduction
In straight root canals, intraradicular structures around the root canal orifice and apical foramen can be visualized with a dental operating microscope and commercially available root canal endoscopes. However, the root apex area, including the apical foramen, in a curved root canal cannot be visualized using these devices. In the present study, the potential of a newly developed root canal endoscope implementing an image fiber was examined in 3 types of root canal models and extracted teeth.Methods
A straight and 2 curved (10° and 30°) resin block models were prepared. A resolution chart was set at the outer surface of the apical foramen in each model. Using the microscope and the endoscope, the resolution chart was observed, and the captured images were analyzed quantitatively. Additionally, fracture lines in 20 extracted teeth were observed with both devices.Results
With the dental operating microscope, a resolution chart line was clearly observed in the straight canal model with 18.0 line pairs/mm resolution and an observing capability of 0.16 at 40 × magnification but not in the curved root canal models. With the root canal endoscope, resolution charts in all types of root canal models were visualized, and the resolution and observing capability were 16.0 line pairs/mm and 0.053, respectively. Fracture lines and the apical foramen of the extracted teeth were observed more clearly with the endoscope than the microscope.Conclusions
The newly developed root canal endoscope using an image fiber is useful for accurate visualization of the apex area of curved root canals. 相似文献2.
Introduction
The present study aimed to quantitatively analyze apical foramen deviations of mesial root canals of mandibular first molar teeth by means of micro–computed tomographic (micro-CT) imaging.Methods
Micro-CT images of the mesial roots of 109 mandibular first molar teeth with independent mesiobuccal (MB) and mesiolingual (ML) root canals were analyzed. The deviations of the apical foramina of the MB, ML, and middle mesial root canals from the anatomic apex were measured. The vertical distance between the apical foramina of each mesial root canal in relation to each other was also calculated.Results
The distances from the apical foramina of the MB, ML, and middle mesial root canals to the anatomic apex of the mesial root were up to 2.51 mm, 3.21 mm, and 5.67 mm, respectively. There was no significant difference between the deviations of MB and ML root canals from each other (P > .05). The middle mesial root canal showed the greatest deviation compared with the MB and ML canals (P < .05).Conclusions
The apical foramina of mesial root canals of mandibular first molar teeth showed greater variations from each other and anatomic apices than previously reported. Clinically, the use of electronic apex locators for the detection of minor apical foramen of each mesial root canal is of the utmost important. 相似文献3.
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4.
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5.
Introduction
Mandibular premolars that have rare and complex anatomies may have the highest failure rate in nonsurgical endodontic treatment. Awareness of rare and complex anatomies of mandibular second premolars would aid in better outcomes of the treatment. This study aimed to evaluate the success of nonsurgical root canal treatment of mandibular second premolar teeth with complex apical branching.Methods
Twenty-six mandibular second premolar teeth with complex apical branching treated with multiple-visit nonsurgical root canal treatment or nonsurgical retreatment were retrospectively evaluated.Results
For the clinical outcomes, 9 subjects had complete healing, 1 subject had functional healing, and no subject had no healing scores out of 10 root canal treatment subjects. Six subjects had complete healing, 8 subjects had functional healing, and 2 subjects had no healing scores out of 16 retreatment subjects. For the radiographic outcomes, 7 subjects had complete healing, 3 subjects had incomplete healing, and no subject had no healing scores out of 10 root canal treatment subjects. Six subjects had complete healing, 8 subjects had incomplete healing, and 2 subjects had no healing scores out of 16 retreatment subjects. The clinical outcome of root canal treatment subjects was significantly different than retreatment subjects (P < .05). Similarly, the radiographic outcome of root canal treatment subjects was also significantly different than retreatment cases (P < .05).Conclusions
The outcome of endodontic treatment of mandibular second premolars may be influenced by treatment type. 相似文献6.
Mahmoud Torabinejad Arin Alexander Seyed Aliakbar Vahdati Anupama Grandhi David Baylink Shahrokh Shabahang 《Journal of endodontics》2018,44(12):1796-1801
Introduction
Current pulp revascularization procedures in teeth with necrotic pulps and open apices have produced histologic evidence of connective tissue growth, cementum, and bone within the root canals of experimental animals. This study aims to investigate the effect of maintaining uninflamed residual apical pulp tissue on the histologic outcome of pulp-dentin complex regeneration after a revascularization procedure in immature ferret cuspid teeth.Methods
Twenty-eight cuspid teeth from 7 young male ferrets were used in this experiment. Seven teeth were reserved to serve as positive control samples without any treatment. In another 7 teeth, the pulp was completely extirpated (negative control), whereas the pulp of the remaining 14 teeth were removed to either 1–2 mm short of the apex (7 samples) or 2–4 mm short of the apex (7 samples). Blood clots were covered with mineral trioxide aggregate at the cementoenamel junction level of each tooth. Three months later, block sections were removed for histologic evaluations, and the data were statistically analyzed with the chi-square test (P < .05).Results
All teeth with complete pulp extirpation showed the presence of bone inside the root canal. In contrast, the root canals for most teeth with pulp amputation 1–4 mm from the radiographic apex were filled with normal pulp, which extended coronally to the mineral trioxide aggregate, where hard tissue bridges had formed.Conclusions
Based on these results, we concluded that regeneration of the pulp-dentin complex is possible when the apical 1–4 mm of the apical pulp remains intact in immature teeth. 相似文献7.
Ersan Çiçek Neslihan Yılmaz M. Murat Koçak Baran Can Sağlam Sibel Koçak Burcu Bilgin 《Journal of endodontics》2017,43(10):1697-1700
Introduction
The aim of this study was to compare the fracture resistance of simulated immature teeth after using different thicknesses of mineral trioxide aggregate (MTA) apical plugs.Methods
Fifty-two human maxillary anterior teeth were used. Five teeth were the positive control group; they were prepared using Peeso reamers to simulate immature teeth without any access cavity preparation. Access cavities of the 47 teeth were prepared, and the canals were instrumented with Peeso reamers. Five teeth served as the negative control; they were filled with calcium hydroxide. Forty-two teeth were divided into 3 groups; in groups 1, 2, and 3, MTA was placed into canals as a 3-mm and a 6-mm apical plug and a thorough canal length, respectively. The rest of the canals in groups 1 and 2 were filled with gutta-percha and AH Plus sealer (Dentsply DeTrey, Konstanz, Germany). After the storage period, the roots were covered with a polyether impression material and were embedded into self-curing resin blocks. Each specimen was then subjected to fracture testing using a universal testing machine. Data were analyzed using 1-way analysis of variance with the Tukey post hoc test for multiple comparisons.Results
The negative group showed the lowest fracture resistance compared with the other groups. The 3-mm apical plug group showed the highest fracture resistance (P < .05). No significant differences were found between the 3-mm and 6-mm apical plug groups (P > .05).Conclusions
MTA should be used as an apical plug instead of root canal filling material to increase the fracture resistance of immature teeth. 相似文献8.
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9.
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10.
Nastaran Meschi Mostafa EzEldeen Andres Eduardo Torres Garcia Reinhilde Jacobs Paul Lambrechts 《Journal of endodontics》2018,44(10):1517-1525
Introduction
A regenerative endodontic procedure (REP) is a biologically based treatment to functionally replace the pulp of infected immature permanent teeth. The purpose of this retrospective case series was to assess the outcome of REPs of infected immature permanent teeth in terms of periapical bone healing (PBH), root development (RD), and pulp vitality.Methods
Five patients (1 tooth/patient) who had undergone a REP based on the cell homing concept were recalled 3, 6, 12, 24, and 36 months postoperatively. At each recall session, clinical and periapical radiographic (PR) investigations were performed. Cone-beam computed tomographic (CBCT) imaging was taken before and 36 months after REPs. Qualitative and quantitative PR assessments were performed on the teeth that underwent REPs. Quantitative CBCT analyses were performed on the teeth that underwent REP and contralateral teeth.Results
At each recall session, all teeth were asymptomatic but reacted negatively on carbon dioxide snow and electrical pulp testing. All teeth that underwent a REP showed complete PBH and further RD on PR and CBCT assessments when comparing the baseline with the final recall radiographs. CBCT analyses indicated increases in root hard tissue volume and RL for all teeth that underwent a REP, but they were 5 and 3 times less, respectively, than the contralateral teeth. The postoperative CBCT images presented bone ingrowth inside the root canal, calcification, or nonuniform RD.Conclusions
Thirty-six months after the REPs (based on the cell homing concept), this RCS resulted radiographically and clinically in functional and asymptomatic teeth with complete PBH and continued reparative RD. CBCT quantitative measurements and qualitative root development observations are more reliable and accurate than PR analysis. 相似文献11.
Introduction
The aim of the present study was to evaluate the possibility of regaining pulp sensibility in mature necrotic teeth using modified regenerative endodontic procedures by inducing bleeding in root canals and using platelet-rich fibrin (PRF).Methods
Fifteen patients with necrotic pulp with symptomatic or asymptomatic apical periodontitis were included. At the first visit, the tooth was anesthetized, and an access cavity was performed. Mechanical preparation of root canals was performed using the standardized technique reaching apical canal preparation to K-file size #60–80. Double antibiotic paste was injected into the canal, and the cavity was temporarily sealed using glass ionomer cement. Three weeks from the first visit, regenerative endodontic procedures were performed by inducing bleeding, and a freshly prepared PRF membrane was placed in the canal. White mineral trioxide aggregate was placed directly over the PRF matrix, and the tooth was restored with a glass ionomer cement base and resin composite restoration. The electric pulp test was used to record if the teeth included in the study regained sensibility or not every 3 to 12 months follow-up. Readings at different times were compared as categoric qualitative data using the chi-square test and compared as means and standard deviations using the analysis of variance test.Results
Readings of tooth sensibility revealed a highly significant difference (P < .0001) between baseline and the 12-month follow-up period.Conclusions
The presence of sensibility is indicative of the formation of vital pulplike tissue. Reestablishing real pulp tissue after regenerative endodontic treatment is debatable and still needs high level of evidence with large-scale investigations. 相似文献12.
Jae M. Shin Ting Luo Kyu Han Lee Diogo Guerreiro Tatiana M. Botero Neville J. McDonald Alexander H. Rickard 《Journal of endodontics》2018,44(7):1080-1087
Introduction
Biofilms are present in more than 70% of endodontically diseased teeth. Through the advancements in the next-generation sequencing (NGS) technologies, microbiome research has granted a deeper analysis of the microbial communities living in human hosts. Here, we reviewed previous studies that used NGS to profile the microbial communities of root canals.Methods
A total of 12 peer-reviewed articles from PubMed were identified and critically reviewed. The study criteria were as follows: NGS platforms, sequenced bacterial hypervariable regions, teeth diagnosis with available patient information, sample characteristics, collection method, and microbial signatures.Results
The most common NGS platforms used were 454 pyrosequencing (Roche Diagnostic Corporation, Risch-Rotkreuz, Switzerland) and Illumina-based technology (Illumina Inc, San Diego, CA). The hypervariable regions sequenced were between the V1 and V6 regions. The patient and sample population ranged from ages 12–76 years and asymptomatic and symptomatic teeth diagnosed with pulp necrosis with or without apical periodontitis. Microbial sampling was conducted directly from the infected pulp or the extracted teeth. The most abundant phyla were Firmicutes, Actinobacteria, Bacteroidetes, Proteobacteria, and Fusobacteria. The most frequently detected genera were Prevotella, Fusobacterium, Porphyromonas, Parvimonas, and Streptococcus. Other notable microbial signatures at different taxa levels were identified but were widely variable between studies.Conclusions
Technologies based on high-throughput 16S ribosomal RNA NGS can aid in deciphering the complex bacterial communities of root canal biofilms. Thus far, only a few studies have been published with relatively small sample sizes, variable sample collection protocols, and community analyses methods. Future larger clinical studies are essential with validated standardized protocols for improved understanding of the pathogenic nature of bacterial biofilm communities in root canals. 相似文献13.
Sam L. Kahler Sowmya Shetty Frances M. Andreasen Bill Kahler 《Journal of endodontics》2018,44(3):464-469
Introduction
Calcium hydroxide has been widely used to treat immature teeth to achieve periodontal healing and to promote the formation of an apical barrier. However, retrospective clinical studies have shown a high incidence of cervical root fractures with long-term calcium hydroxide dressing. The alkalinity of calcium hydroxide has been suggested to weaken the root. In vitro studies using ovine teeth show conflicting results on fracture strength of dentine, although different commercial products may have influenced the results. The purpose of this study was to investigate the effects of 2 commercial products used in prior studies (Calasept Plus and UltraCal XS), as well as a new product (Calmix) that uses a nonaqueous vehicle that allows for a higher pH, on the fracture strength of dentine over time.Methods
A total of 330 lamb incisor teeth were collected and the canals prepared so that 3 commercial calcium hydroxide products as well as a positive control of pure calcium hydroxide slurry that filled the root canal from the open apex and a negative control of saline was tested. The teeth were loaded until fracture with a universal testing machine at time points 0, 3, 6, and 9 months and the force to fracture was calculated. The data were analyzed with Friedman analysis of variance and Mann-Whitney t tests.Results
No statistical differences were observed between the different calcium hydroxide products and the negative controls.Conclusions
Thin and fragile roots could be the cause of fracture rather than the calcium hydroxide dressing. 相似文献14.
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15.
Avi Shemesh Eitan Kavalerchik Avi Levin Joe Ben Itzhak Oleg Levinson Alex Lvovsky Michael Solomonov 《Journal of endodontics》2018,44(1):51-55
Introduction
Central and lateral mandibular incisors usually have 1 root canal. The purpose of this study was to investigate the prevalence of additional root canals in central and lateral mandibular incisors and to investigate the prevalence of oval and long oval canals in the cervical, middle, and apical thirds of cases with 1 root canal.Methods
A total of 1016 Israeli patients' cone-beam computed tomography scans were screened and evaluated. A total of 1472 central mandibular incisors and 1508 lateral mandibular incisors were examined. The root canal morphology and cross-sectional shape were recorded and analyzed.Results
The overall prevalence of more than 1 root canal in mandibular central and mandibular lateral respectively was 40.5% and 37.9%. The bilateral incidence of more than 1 root canal in mandibular central and mandibular lateral respectively was 69.8% and 68.7%. The root canal separation in type II to type V central and lateral mandibular incisors was found in the middle third of the root in 81.5% and 79.0%, respectively. The septum was smaller than 1 mm in 37% of central mandibular incisors and one-third of lateral mandibular incisors. In central and lateral incisors with 1 root canal, long oval canals were found in the middle third of the root of central and lateral mandibular incisors in 36.8% and 48.9%, respectively.Conclusion
The occurrence of more than 1 root canal in central and lateral mandibular incisors is approximately 40% (type III was the predominant canal type). In central and lateral incisors with 1 root canal, long oval canals are common. 相似文献16.
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17.
Mario Alovisi Damiano Pasqualini Edoardo Musso Elena Bobbio Carlotta Giuliano Davide Mancino Nicola Scotti Elio Berutti 《Journal of endodontics》2018,44(4):614-620
Introduction
Contracted endodontic cavities (CECs) have developed from the concept of minimally invasive dentistry and provide an alternative to traditional endodontic cavities (TECs). They have been designed in an effort to preserve the mechanical stability of teeth. The contracted cavity design preserves more of the dentin but may influence the geometric shaping parameters. The aim of this micro–computed tomographic study was to evaluate the influence of contracted endodontic cavities on the preservation of the original root canal anatomy after shaping with nickel-titanium rotary instruments.Methods
Thirty extracted human mandibular molars with fully formed apices and independent mesial canals were randomly assigned to group 1 (TEC) and group 2 (CEC). Each group was shaped using ProGlider (Dentsply Maillefer, Ballaigues, Switzerland) and WaveOne Gold (Dentsply Maillefer). Irrigation was performed with 10% EDTA and 5% sodium hypochlorite. Samples were scanned before and after canal shaping to match canal volumes (SkyScan; Bruker microCT, Kontich, Belgium [100 kV, 100 μA, and 15-μm resolution]), and images were analyzed to evaluate canal volumes, surface areas, and centroid shift on cross sections at ?1 mm and ?3 mm from the apex.Results
TECs showed a greater preservation of the original root canal anatomy with less apical transportation than CECs, possibly because of the absence of coronal interferences and, therefore, fewer pecking motions required to complete instrumentation.Conclusions
Within the limitations of this study, TECs may lead to a better preservation of the original canal anatomy during shaping compared with CECs, particularly at the apical level. 相似文献18.
19.
H. Melike Bayram Emre Bayram Mert Ocak M. Bora Uzuner Ferhat Geneci Hakan Hamdi Celik 《Journal of endodontics》2017,43(10):1736-1739
Introduction
The aim of the present study was to evaluate the frequency of dentinal microcracks observed after root canal preparation with HyFlex CM (Coltène/Whaledent, Altstätten, Switzerland), HyFlex EDM (Coltène/Whaledent), Vortex Blue (Dentsply Tulsa Dental Specialties, Tulsa, OK), and TRUShape (Dentsply Tulsa Dental Specialties) systems using micro–computed tomographic (micro-CT) analysis.Methods
Forty human mandibular incisors with 1 and straight root canals were randomly assigned to 4 experimental groups (n = 10) and 1 control group for root canal preparation: group 1, HyFlex CM; group 2, HyFlex EDM; group 3, Vortex Blue; and group 4, TRUShape. The specimens were scanned using high-resolution micro-CT imaging before and after root canal preparation. Afterward, preoperative and postoperative cross-sectional images of the teeth were screened to identify the presence of dentinal defects. The number of microcracks was determined as a percentage for each group.Results
Before and after canal preparation, 36,152 cross-sectional images were examined. Four thousand four hundred fifty-two (12.31%) dentinal defects were observed. No new microcracks were observed after root canal instrumentation with the tested systems.Conclusions
Root canal preparation with the HyFlex CM, HyFlex EDM, Vortex Blue, and TRUShape systems did not induce the formation of new dentinal microcracks on straight root canals of mandibular incisors. 相似文献20.