Isolation and Cytotoxic Potency of Endophytic Fungi Associated with Dysosma difformis, a Study for the Novel Resources of Podophyllotoxin

Endophytic fungi are promising sources for the production of podophyllotoxin-an important anticancer compound, replacing depleted medical plants. In this study, the endophytes associated with Dysosma difformis-an ethnomedicinal plant species were isolated to explore novel sources of podophyllotoxin. Fifty-three endophytic fungi were isolated and identified by morphological observation and ITS-based rDNA sequencing, assigning them to 27 genera in 3 divisions. Fusarium was found the most prevalent genus with a colonization frequency of 11.11%, followed by Trametes (9.26%) and Penicillium (7.41%). Phylogenetic trees were constructed for the endophytic fungi community in two collection sites, Ha Giang and Lai Chau, revealing the adaptation of the species to the specific tissues and habitats. Cytotoxic activity of endophytic fungal extracts was investigated on cancer cell lines such as SK-LU-1, HL-60, and HepG2, demonstrating strong anti-cancer activity of six isolates belonging to Penicillium, Trametes, Purpureocillium, Aspergillus, and Ganoderma with IC 50 value of lower than 10 10 µg/mL. The presence of podophyllotoxin was indicated in Penicillium, Trametes, Aspergillus and for the first time in Purpureocillium and Ganoderma via high-performance liquid chromatography, which implied them as a potential source of this anticancer compound.

Coexisting Spine Lesions on Whole Spine T2 Sagittal MRI in Evaluating Spinal Degenerative Disease

Background@#Studies have reported on the usefulness of whole spine magnetic resonance imaging (MRI) in evaluating specific diseases such as spinal tuberculosis, spinal trauma, spondyloarthropathies, and multiple myeloma. In studies concerning degenerative spinal disease, sample sizes were small and some did not provide information on how symptomatic coexisting lesions were treated. We evaluated the types and prevalence of coexisting spine lesions found on whole spine T2 sagittal screening performed at the time of routine cervical and lumbar spine MRI and evaluated the efficacy of such screening in degenerative diseases of the cervical and lumbar spine. @*Methods@#We reviewed 1,757 and 2,266 consecutive cases where whole spine T2 sagittal screening had been performed with routine cervical and lumbar spine MRI, respectively, in patients with cervical and lumbar spinal degenerative diseases. Coexisting spine lesions were documented and statistical analysis was performed to investigate significant differences according to sex, age, and initial diagnosis. Electronic medical records were reviewed to determine whether additional interventions were necessary following such findings. @*Results@#We reviewed 1,252 and 1,689 consecutive cases of routine cervical and lumbar spine MRI respectively, with whole spine T2 sagittal screening. Of the 1,252, 419 (33.5%) patients with cervical spinal degenerative disease had coexisting lesions in the thoracolumbar spine.Patients with ligament ossification disease of the cervical spine showed a higher prevalence of coexisting spine lesions. Sixty of the 419 (14.3%) patients with coexisting spine lesions warranted additional intervention or surgical treatment. Four hundred and eighty-one of 1,689 (28.5%) patients with lumbar degenerative disease had coexisting spine lesions in the cervicothoracic spine. Forty-eight of the 481 (10.0%) patients with coexisting spine lesions warranted additional intervention. In both patient groups, older patients showed a significantly higher prevalence of coexisting spine lesions than younger patients. @*Conclusion@#Considering the minimal extra time and cost in performing whole spine screening, its application to routine spine MRI can be considered in evaluating cervical and lumbar spinal degenerative diseases.

Coexisting Spine Lesions on Whole Spine T2 Sagittal MRI in Evaluating Spinal Degenerative Disease

Background@#Studies have reported on the usefulness of whole spine magnetic resonance imaging (MRI) in evaluating specific diseases such as spinal tuberculosis, spinal trauma, spondyloarthropathies, and multiple myeloma. In studies concerning degenerative spinal disease, sample sizes were small and some did not provide information on how symptomatic coexisting lesions were treated. We evaluated the types and prevalence of coexisting spine lesions found on whole spine T2 sagittal screening performed at the time of routine cervical and lumbar spine MRI and evaluated the efficacy of such screening in degenerative diseases of the cervical and lumbar spine. @*Methods@#We reviewed 1,757 and 2,266 consecutive cases where whole spine T2 sagittal screening had been performed with routine cervical and lumbar spine MRI, respectively, in patients with cervical and lumbar spinal degenerative diseases. Coexisting spine lesions were documented and statistical analysis was performed to investigate significant differences according to sex, age, and initial diagnosis. Electronic medical records were reviewed to determine whether additional interventions were necessary following such findings. @*Results@#We reviewed 1,252 and 1,689 consecutive cases of routine cervical and lumbar spine MRI respectively, with whole spine T2 sagittal screening. Of the 1,252, 419 (33.5%) patients with cervical spinal degenerative disease had coexisting lesions in the thoracolumbar spine.Patients with ligament ossification disease of the cervical spine showed a higher prevalence of coexisting spine lesions. Sixty of the 419 (14.3%) patients with coexisting spine lesions warranted additional intervention or surgical treatment. Four hundred and eighty-one of 1,689 (28.5%) patients with lumbar degenerative disease had coexisting spine lesions in the cervicothoracic spine. Forty-eight of the 481 (10.0%) patients with coexisting spine lesions warranted additional intervention. In both patient groups, older patients showed a significantly higher prevalence of coexisting spine lesions than younger patients. @*Conclusion@#Considering the minimal extra time and cost in performing whole spine screening, its application to routine spine MRI can be considered in evaluating cervical and lumbar spinal degenerative diseases.

Implications of specific gene expression patterns in enamel knot in tooth development

Enamel knot (EK)—a signaling center—refers to a transient morphological structure comprising epithelial tissue. EK is believed to regulate tooth development in early organogenesis without its own cellular alterations, including proliferation and differentiation. EKs show a very simple but conserved structure and share functions with teeth of recently evolved vertebrates, suggesting conserved signaling in certain organs, such as functional teeth, through the course of evolution. In this study, we examined the expression patterns of key EK-specific genes including Dusp26 , Fat4, Meis2, Sln , and Zpld1 during mice embryogenesis. Expression patterns of these genes may reveal putative differentiation mechanisms underlying tooth morphogenesis.

Ultrastructure of Substance P Immunopositive Axons in the Human Dental Pulp

There exists very little information on the ultrastructure of substance P immunopositive (+) fibers in the human dental pulp, which may help in understanding the mechanism for substance P associated pulpal inflammatory pain. To address this issue, we investigated the presence of substance P+ fibers in the human dental pulp by light- and electron-microscopic immunohistochemistry. Light microscopy revealed that substance P+ fibers ran within neurovascular bundles in the radicular pulp and in the core of coronal pulp. They were also frequently present in the peripheral pulp. Substance P+ fibers showed beads like swellings interconnected by thin axonal strand, in a manner similar to bouton en passants and interconnecting axonal strand in the spinal cord. Electron microscopy revealed that almost all the substance P+ axons were unmyelinated. The axonal swellings of the substance P+ contained numerous clear round vesicles (40–50 nm in diameter) and many large dense-cored vesicles (80–110 nm in diameter) as well as many mitochondria. The vesicles and mitochondria were rarely observed in the thin axonal strand interconnecting the swellings. Intimate interrelationship or synaptic structure between the swellings of substance P+ axon and nearby pulpal cells or axons was not found. These findings suggest co-release of substance P and glutamate from the substance P+ pulpal axons and its action on nearby structures in a paracrine manner.

The Spinal Instability Neoplastic Score (SINS) as a Surgical Decision-Making Tool for the Treatment of Spine Metastasis / 대한척추외과학회지

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To investigate the potential clinical use of the spinal instability neoplastic score (SINS) for determining the surgical strategy, especially regarding the need for anterior support. SUMMARY OF LITERATURE REVIEW: The SINS seems to enable an improved qualitative and quantitative assessment of spinal instability in patients with spinal metastasis. MATERIALS AND METHODS: We retrospectively reviewed 69 consecutive patients who underwent surgical treatment for spinal metastasis. We assessed the patients' preoperative status with respect to each component of the SINS. Multiple logistic regression was performed to calculate odds ratios (ORs) representing the associations among SINS, age, Eastern Cooperative Oncology Group performance status, modified Tokuhashi score, as well as the preoperative Nurick grade variables and reconstruction of the anterior spinal column. RESULTS: Among the 6 items in the SINS, those indicating the degree of collapse and alignment had significantly higher scores in those who underwent corpectomy and anterior support (p<0.001). Multiple logistic regression revealed that the total SINS was the only factor significantly associated with predicting whether anterior support should be performed (adjusted OR=1.595). Receiver operating characteristic (ROC) curve analysis suggested that a cut-off value of 10 points on the SINS scale could be used to decide whether anterior support following corpectomy should be performed (AUC=0.706). CONCLUSIONS: The SINS, insofar as it assesses the degree of collapse and alignment, is a potentially useful tool for determining the surgical strategy in patients with spinal metastasis, especially for deciding upon the necessity of additional anterior support procedures.

Prognosis of Single Spinal Metastatic Tumors: Predictive Value of the Spinal Instability Neoplastic Score System for Spinal Adverse Events

STUDY DESIGN: This was a retrospective cohort study. PURPOSE: We evaluated the predictive value of the Spinal Instability Neoplastic Score (SINS) system for spinal adverse events (SAEs) in patients with single spinal metastatic tumor. OVERVIEW OF LITERATURE: The SINS system was developed to assess spinal instability in patients with single metastatic spinal tumor. However, the system’s potential predictive value for SAEs has been partially studied. METHODS: This system was applied to a retrospective cohort of 78 patients with single spinal metastatic tumors. The patients underwent surgical treatment and were postoperatively followed up for at least 2 years or until death. The attribution of each score and total SINS to SAE (vertebral compression fracture [VCF] and spinal cord compression [SCC]) occurrence was assessed using the Cox proportional hazards model. RESULTS: SAEs occurred on average 7 months after diagnosis of spinal metastasis. The mean survival rate post diagnosis was 43 months. Multivariate analysis using the Cox proportional hazards model revealed that the pain (p=0.029) and spinal alignment (p=0.001) scores were significantly related to VCF occurrence, whereas the pain (p=0.008) and posterolateral involvement (p=0.009) scores were related to SCC occurrence. CONCLUSIONS: Among the components of the SINS system, while pain and spinal alignment showed a significant association with VCF occurrence, pain and posterolateral involvement showed association with SCC occurrence.

The Spinal Instability Neoplastic Score (SINS) as a Surgical Decision-Making Tool for the Treatment of Spine Metastasis

OBJECTIVES@#To investigate the potential clinical use of the spinal instability neoplastic score (SINS) for determining the surgical strategy, especially regarding the need for anterior support.SUMMARY OF LITERATURE REVIEW: The SINS seems to enable an improved qualitative and quantitative assessment of spinal instability in patients with spinal metastasis.@*MATERIALS AND METHODS@#We retrospectively reviewed 69 consecutive patients who underwent surgical treatment for spinal metastasis. We assessed the patients' preoperative status with respect to each component of the SINS. Multiple logistic regression was performed to calculate odds ratios (ORs) representing the associations among SINS, age, Eastern Cooperative Oncology Group performance status, modified Tokuhashi score, as well as the preoperative Nurick grade variables and reconstruction of the anterior spinal column.@*RESULTS@#Among the 6 items in the SINS, those indicating the degree of collapse and alignment had significantly higher scores in those who underwent corpectomy and anterior support (p<0.001). Multiple logistic regression revealed that the total SINS was the only factor significantly associated with predicting whether anterior support should be performed (adjusted OR=1.595). Receiver operating characteristic (ROC) curve analysis suggested that a cut-off value of 10 points on the SINS scale could be used to decide whether anterior support following corpectomy should be performed (AUC=0.706).@*CONCLUSIONS@#The SINS, insofar as it assesses the degree of collapse and alignment, is a potentially useful tool for determining the surgical strategy in patients with spinal metastasis, especially for deciding upon the necessity of additional anterior support procedures.

Esthetic enhancement of a traumatized anterior tooth with a combination of forced eruption and tooth alignment: a case report

Exposing sound structure of a subgingivally fractured tooth using orthodontic extrusion is considered to be a conservative way to re-establish biologic width without sacrificing esthetics or jeopardizing periodontal support of neighboring teeth. When a misaligned tooth is traumatically involved, a more comprehensive approach combining tooth extrusion and re-alignment may be necessary for a successful restorative outcome. This case report describes a successful esthetic management of a patient with complicated crown-root fracture on the maxillary right central incisor and pre-existing malocclusion in the maxillary anterior region. Forced eruption along with re-alignment of teeth by orthodontic movement seems to allow re-positioning of the fracture line to a favorable position and correction of crowding, providing a better esthetic result.

Screw-in forces during instrumentation by various file systems

OBJECTIVES: The purpose of this study was to compare the maximum screw-in forces generated during the movement of various Nickel-Titanium (NiTi) file systems. MATERIALS AND METHODS: Forty simulated canals in resin blocks were randomly divided into 4 groups for the following instruments: Mtwo size 25/0.07 (MTW, VDW GmbH), Reciproc R25 (RPR, VDW GmbH), ProTaper Universal F2 (PTU, Dentsply Maillefer), and ProTaper Next X2 (PTN, Dentsply Maillefer, n = 10). All the artificial canals were prepared to obtain a standardized lumen by using ProTaper Universal F1. Screw-in forces were measured using a custom-made experimental device (AEndoS-k, DMJ system) during instrumentation with each NiTi file system using the designated movement. The rotation speed was set at 350 rpm with an automatic 4 mm pecking motion at a speed of 1 mm/sec. The pecking depth was increased by 1 mm for each pecking motion until the file reach the working length. Forces were recorded during file movement, and the maximum force was extracted from the data. Maximum screw-in forces were analyzed by one-way ANOVA and Tukey's post hoc comparison at a significance level of 95%. RESULTS: Reciproc and ProTaper Universal files generated the highest maximum screw-in forces among all the instruments while M-two and ProTaper Next showed the lowest (p < 0.05). CONCLUSIONS: Geometrical differences rather than shaping motion and alloys may affect the screw-in force during canal instrumentation. To reduce screw-in forces, the use of NiTi files with smaller cross-sectional area for higher flexibility is recommended.

Preference of undergraduate students after first experience on nickel-titanium endodontic instruments

OBJECTIVES: This study aimed to compare two nickel-titanium systems (rotary vs. reciprocating) for their acceptance by undergraduate students who experienced nickel-titanium (NiTi) instruments for the first time. MATERIALS AND METHODS: Eighty-one sophomore dental students were first taught on manual root canal preparation with stainless-steel files. After that, they were instructed on the use of ProTaper Universal system (PTU, Dentsply Maillefer), then the WaveOne (WO, Dentsply Maillefer). They practiced with each system on 2 extracted molars, before using those files to shape the buccal or mesial canals of additional first molars. A questionnaire was completed after using each file system, seeking students' perception about 'Ease of use', 'Flexibility', 'Cutting-efficiency', 'Screwing-effect', 'Feeling-safety', and 'Instrumentation-time' of the NiTi files, relative to stainless-steel instrumentation, on a 5-point Likert-type scale. They were also requested to indicate their preference between the two systems. Data was compared between groups using t-test, and with Chi-square test for correlation of each perception value with the preferred choice (p = 0.05). RESULTS: Among the 81 students, 55 indicated their preferred file system as WO and 22 as PTU. All scores were greater than 4 (better) for both systems, compared with stainless-steel files, except for 'Screwing-effect' for PTU. The scores for WO in the categories of 'Flexibility', 'Screwing-effect', and 'Feeling-safety' were significantly higher scores than those of PTU. A significant association between the 'Screwing-effect' and students' preference for WO was observed. CONCLUSIONS: Novice operators preferred nickel-titanium instruments to stainless-steel, and majority of them opted for reciprocating file instead of continuous rotating system.

Proximity of the mandibular molar root apex from the buccal bone surface: a cone-beam computed tomographic study

OBJECTIVES: The purpose of this study was to evaluate the proximity of the mandibular molar apex to the buccal bone surface in order to provide anatomic information for apical surgery. MATERIALS AND METHODS: Cone-beam computed tomography (CBCT) images of 127 mandibular first molars and 153 mandibular second molars were analyzed from 160 patients' records. The distance was measured from the buccal bone surface to the root apex and the apical 3.0 mm on the cross-sectional view of CBCT. RESULTS: The second molar apex and apical 3 mm were located significantly deeper relative to the buccal bone surface compared with the first molar (p < 0.01). For the mandibular second molars, the distance from the buccal bone surface to the root apex was significantly shorter in patients over 70 years of age (p < 0.05). Furthermore, this distance was significantly shorter when the first molar was missing compared to nonmissing cases (p < 0.05). For the mandibular first molars, the distance to the distal root apex of one distal-rooted tooth was significantly greater than the distance to the disto-buccal root apex (p < 0.01). In mandibular second molar, the distance to the apex of C-shaped roots was significantly greater than the distance to the mesial root apex of non-C-shaped roots (p < 0.01). CONCLUSIONS: For apical surgery in mandibular molars, the distance from the buccal bone surface to the apex and apical 3 mm is significantly affected by the location, patient age, an adjacent missing anterior tooth, and root configuration.

Heterotopic Ossification of the Elbow after Medial Epicondylectomy / 대한정형외과학회잡지

Postoperative heterotopic ossification of the elbow after surgery for treatment of acute trauma such as fractures and ligament/tendon ruptures has been well-documented. However, literature concerning heterotopic ossification after medial epicondylectomy is scarce. We report on two cases of heterotopic ossification that occurred following medial epicondylectomy for medial epicondylitis and for cubital tunnel syndrome. Preoperatively, calcifications around the medial epicondyle were observed in both patients. These cases suggest that medial epicondylectomy, in the presence of pre-existing calcifications, may pose an increased risk of postoperative heterotopic ossification of the elbow.

Safe root canal preparation using reciprocating nickel-titanium instruments

No abstract available.

Effect of repetitive pecking at working length for glide path preparation using G-file

OBJECTIVES: Glide path preparation is recommended to reduce torsional failure of nickel-titanium (NiTi) rotary instruments and to prevent root canal transportation. This study evaluated whether the repetitive insertions of G-files to the working length maintain the apical size as well as provide sufficient lumen as a glide path for subsequent instrumentation. MATERIALS AND METHODS: The G-file system (Micro-Mega) composed of G1 and G2 files for glide path preparation was used with the J-shaped, simulated resin canals. After inserting a G1 file twice, a G2 file was inserted to the working length 1, 4, 7, or 10 times for four each experimental group, respectively (n = 10). Then the canals were cleaned by copious irrigation, and lubricated with a separating gel medium. Canal replicas were made using silicone impression material, and the diameter of the replicas was measured at working length (D0) and 1 mm level (D1) under a scanning electron microscope. Data was analysed by one-way ANOVA and post-hoc tests (p = 0.05). RESULTS: The diameter at D0 level did not show any significant difference between the 1, 2, 4, and 10 times of repetitive pecking insertions of G2 files at working length. However, 10 times of pecking motion with G2 file resulted in significantly larger canal diameter at D1 (p < 0.05). CONCLUSIONS: Under the limitations of this study, the repetitive insertion of a G2 file up to 10 times at working length created an adequate lumen for subsequent apical shaping with other rotary files bigger than International Organization for Standardization (ISO) size 20, without apical transportation at D0 level.

Effect of repetitive pecking at working length for glide path preparation using G-file

OBJECTIVES: Glide path preparation is recommended to reduce torsional failure of nickel-titanium (NiTi) rotary instruments and to prevent root canal transportation. This study evaluated whether the repetitive insertions of G-files to the working length maintain the apical size as well as provide sufficient lumen as a glide path for subsequent instrumentation. MATERIALS AND METHODS: The G-file system (Micro-Mega) composed of G1 and G2 files for glide path preparation was used with the J-shaped, simulated resin canals. After inserting a G1 file twice, a G2 file was inserted to the working length 1, 4, 7, or 10 times for four each experimental group, respectively (n = 10). Then the canals were cleaned by copious irrigation, and lubricated with a separating gel medium. Canal replicas were made using silicone impression material, and the diameter of the replicas was measured at working length (D0) and 1 mm level (D1) under a scanning electron microscope. Data was analysed by one-way ANOVA and post-hoc tests (p = 0.05). RESULTS: The diameter at D0 level did not show any significant difference between the 1, 2, 4, and 10 times of repetitive pecking insertions of G2 files at working length. However, 10 times of pecking motion with G2 file resulted in significantly larger canal diameter at D1 (p < 0.05). CONCLUSIONS: Under the limitations of this study, the repetitive insertion of a G2 file up to 10 times at working length created an adequate lumen for subsequent apical shaping with other rotary files bigger than International Organization for Standardization (ISO) size 20, without apical transportation at D0 level.

Buckling resistance, bending stiffness, and torsional resistance of various instruments for canal exploration and glide path preparation

OBJECTIVES: This study compared the mechanical properties of various instruments for canal exploration and glide-path preparations. MATERIALS AND METHODS: The buckling resistance, bending stiffness, ultimate torsional strength, and fracture angle under torsional load were compared for C+ file (CP, Dentsply Maillefer), M access K-file (MA, Dentsply Maillefer), Mani K-file (MN, Mani), and NiTiFlex K-file (NT, Dentsply Maillefer). The files of ISO size #15 and a shaft length of 25 mm were selected. For measuring buckling resistance (n = 10), the files were loaded in the axial direction of the shaft, and the maximum load was measured during the files' deflection. The files (n = 10) were fixed at 3-mm from the tip and then bent 45degrees with respect to their long axis, while the bending force was recorded by a load cell. For measuring the torsional properties, the files (n = 10) were also fixed at 3-mm, and clockwise rotations (2-rpm) were applied to the files in a straight state. The torsional load and the distortion angle were recorded until the files succumbed to the torque. RESULTS: The CP was shown to require the highest load to buckle and bend the files, and the NT showed the least. While MA and MN showed similar buckling resistances, MN showed higher bending stiffness than MA. The NT had the lowest bending stiffness and ultimate torsional strength (p < 0.05). CONCLUSIONS: The tested instruments showed different mechanical properties depending on the evaluated parameters. CP and NT files were revealed to be the stiffest and the most flexible instruments, respectively.

Buddy Taping: Is It a Safe Method for Treatment of Finger and Toe Injuries?

BACKGROUND: Buddy taping is a well known and useful method for treating sprains, dislocations, and other injuries of the fingers or toes. However, the authors have often seen complications associated with buddy taping such as necrosis of the skin, infections, loss of fixation, and limited joint motion. To our knowledge, there are no studies regarding the complications of buddy taping. The purpose of this study was to report the current consensus on treating finger and toe injuries and complications of buddy taping by using a specifically designed questionnaire. METHODS: A questionnaire was designed for this study, which was regarding whether the subjects were prescribed buddy taping to treat finger and toe injuries, reasons for not using it, in what step of injury treatment it was use, indications, complications, kinds of tape for fixation, and special methods for preventing skin injury. Fifty-five surgeons agreed to participate in the study and the survey was performed in a direct interview manner at the annual meetings of the Korean Pediatric Orthopedic Association and Korean Society for Surgery of the Hand, in 2012. RESULTS: Forty-eight surgeons (87%) used buddy taping to treat finger and toe injuries, especially proximal interphalangeal (PIP) injuries of the hand, finger fractures, toe fractures, metacarpophalangeal injuries of the hand, and PIP injuries of the foot. Sixty-five percent of the surgeons experienced low compliance. Forty-five percent of the surgeons observed skin injuries on the adhesive area of the tape, and skin injuries between the injured finger and healthy finger were observed by 45% of the surgeons. CONCLUSIONS: This study sheds light on the current consensus and complications of buddy taping among physicians. Low compliance and skin injury should be considered when the clinician treats finger and toe injuries by using buddy taping.

Cyclic fatigue resistance tests of Nickel-Titanium rotary files using simulated canal and weight loading conditions

OBJECTIVES: This study compared the cyclic fatigue resistance of nickel-titanium (NiTi) files obtained in a conventional test using a simulated canal with a newly developed method that allows the application of constant fatigue load conditions. MATERIALS AND METHODS: ProFile and K3 files of #25/.06, #30/.06, and #40/.04 were selected. Two types of testing devices were built to test their fatigue performance. The first (conventional) device prescribed curvature inside a simulated canal (C-test), the second new device exerted a constant load (L-test) whilst allowing any resulting curvature. Ten new instruments of each size and brand were tested with each device. The files were rotated until fracture and the number of cycles to failure (NCF) was determined. The NCF were subjected to one-way ANOVA and Duncan's post-hoc test for each method. Spearman's rank correlation coefficient was computed to examine any association between methods. RESULTS: Spearman's rank correlation coefficient (rho = -0.905) showed a significant negative correlation between methods. Groups with significant difference after the L-test divided into 4 clusters, whilst the C-test gave just 2 clusters. From the L-test, considering the negative correlation of NCF, K3 gave a significantly lower fatigue resistance than ProFile as in the C-test. K3 #30/.06 showed a lower fatigue resistance than K3 #25/.06, which was not found by the C-test. Variation in fatigue test methodology resulted in different cyclic fatigue resistance rankings for various NiTi files. CONCLUSIONS: The new methodology standardized the load during fatigue testing, allowing determination fatigue behavior under constant load conditions.

Endodontic treatment of maxillary lateral incisors with anatomical variations

Maxillary lateral incisors usually exhibit a single root with a single canal. However, maxillary lateral incisor teeth with unusual morphology of root canal system are frequently reported. These cases of variable root canal anatomy can be treated well by nonsurgical endodontic methods. A detailed description of root canal morphology is fundamental for successful endodontic treatment. Treatment using an operating microscope, radiographs from different angles, and cone-beam computerized tomography (CBCT) can produce more predictable endodontic outcomes.