Cone-beam computed tomography analysis of the apical third of curved roots after mechanical preparation with different automated systems

The present study evaluated by cone-beam computed tomography (CBCT) the apical canal transportation and centralizing ability of different automated systems after root canal preparation. The mesiobuccal canals of maxillary first molars (n=10 per group) were prepared with: GI - reciprocating system with K-Flexofile; GII - reciprocating system with NiTiFlex files; GIII - rotary system with K3 instruments; GIV - rotary system with RaCe instruments. CBCT scans were taken before and after biomechanical preparation up to a #40.02 diameter. Canal transportation was determined by measuring the smallest distance between the inner canal walls and the mesial and distal sides of the root. The centralization ability corresponded to the difference between the measurements from transportation evaluation, using the linear voxel to voxel method of analysis. The mean transportation was 0.06 ± 0.14 mm, with a tendency to deviate to the mesial side of the root (n=22), with no statistically significant difference among the groups (p=0.4153). The mean centralization index was 0.15 ± 0.65 also without statistically significant difference among the groups (p=0.0881). It may be concluded that apical canal transportation and centralization ability were not influenced by the type of mechanical movement and instruments used.

Assessment of the apical seal of root canals using different filling techniques.

The aim of this study was to investigate the apical leakage of roots filled by three different gutta-percha techniques: lateral condensation, Tagger's hybrid and E&Q Master. Forty-two extracted single-rooted teeth were used. The coronal part of each tooth was removed and the root received biomechanical preparation using a 60-K file. The roots were randomly divided into three groups according to the technique of filling the root canal: Group I, lateral condensation; Group II, Tagger's hybrid; Group III, E&Q Master. The roots were submitted to dye leakage test with Rhodamine B for 7 days, using vacuum during the initial 30 min. The teeth were sectioned longitudinally and the leakage was measured in a linear fashion from apex to crown. Statistical analysis indicated that lateral condensation and E&Q Master techniques showed lower leakage than Tagger's technique (P = 0.0016). However, statistically no difference was found between lateral condensation and E&Q Master system techniques.

Limpeza do forame e extrusão apical de raspas de dentina em dentes unirradiculares submetidos ao procedimento de patência apical

Objective: To verify the cleaning of the apical foramen and apical extrusion of dentin chips in single-rooted teeth instrumented with two techniques, one of which including the apical patency procedure. Method: Thirty teeth were internally stained with Indian ink, divided in two groups, of which only group I was subjected to apical patency. The dentin chips extruded through the apical foramen were collected in a glass receptacle and quantified. The apical foramen region was divided in quadrants and analyzed with a stereomicroscope to verify the action of the instrument on the cemental canal walls. The teeth were scored 0 4 according to the number of clean walls (without Indian ink), 0 corresponding to no clean wall. Results: In group I, there was no dentin plug, but only 1 tooth was scored 4. In group II, 10 teeth presented dentin plug and all of them were scored 0. There was no statistically significant difference between groups I and II regarding the extruded dentin mass (Scheffé test; p<0.05). Conclusion: The use of the apical patency procedure in single-rooted teeth does not modify the amount of dentin chips extruded through the apical foramen, does not produce an adequate cleaning of the cemental canal walls, but remove the plug of dentin chips from the cemental canal.

Influence of apical enlargement in cleaning and extrusion in canals with mild and moderate curvatures

Optical microscopy and morphometric analysis were used in this study to evaluate, in vitro, the cleaning of the apical region in root canals with mild or moderate curvatures subjected to biomechanical preparation with a rotary system, as well as to assess the amount of extruded material to the periapical area. Lateral incisors (n = 32), 16 with curvature angles smaller or equal to 10° (GI) and 16 between 11° and 25° angles (GII) were submitted to Hero 642 rotary instrumentation with different surgical diameters: (A) 30.02 and (B) 45.02. Irrigation was performed at each change of instrument with 5 mL of ultrapure Milli-Q water and the extruded material through the apical foramen was collected. Root cross-sections were subjected to histological analysis by optical microscopy (×40) and the images were evaluated morphometrically using the Image Tool software. Quantification of the extruded material was performed by weighing after liquid evaporation. ANOVA showed no statistically significant differences (p>0.05) among the groups with respect to the procedures used to clean the apical region. Considering the amount of extruded material, the Tukey's HSD showed that canals with mild curvature prepared with the 45.02 surgical diameter showed significantly higher values (p<0.05) that those of the other groups, which were similar between themselves (p>0.05). In conclusion, the effect of cleaning the apical region did not differ in the groups, considering root curvature and the surgical diameter of instruments used for apical preparation. The amount of extruded material was greater in canals with mild curvature that were prepared with the 45.02 surgical instrument diameter.

Nd:YAG Laser Irradiation effect on apical intracanal dentin-a microleakage and SEM evaluation

The purpose of this in vitro study was to evaluate the effect of neodymium:yttrium-aluminum-garnet (Nd:YAG) laser irradiation on intracanal dentin surface by SEM analysis and its interference in the apical seal of filled canals. After endodontic treatment procedures, 34 maxillary human incisors were randomly assigned to 2 groups. In the negative control group (n=17), no additional treatment was performed and teeth were filled with vertically condensed gutta-percha; in the laser-treated group (n=17), the root canals were irradiated with Nd:YAG laser (1.5 W, 100 mJ, 15 Hz) before filling as described for the control group. Two specimens of each group were prepared for SEM analysis to evaluate the presence and extent of morphological changes and removal of debris; the other specimens were immersed in 0.5% methylene blue dye (pH 7.2) for 24 h for evaluation of the linear dye leakage at the apical third. SEM analysis of the laser-treated group showed dentin fusion and resolidification without smear layer or debris. The Student's t-test showed that the laser-treated group had significantly less leakage in apical third than the control group. Within the limitations of this study, it may be concluded that the morphological changes on the apical intraradicular dentin surface caused by Nd:YAG laser resulted in less linear dye apical leakage.

Apical ballooning syndrome (Takotsubo Syndrome): Case report

Introduction. The apical ballooning syndrome (ABS) is a single reversible cardiomyopathy often triggered by a stressful event. We aimed to present a case report regarding this disorder. Case presentation. Here we present the case of a 77-year-old female hypertensive patient, sedentary and non-smoker, diagnosed with apical ballooning syndrome. We describe the clinical signs and symptoms, changes in markers of myocardial necrosis and changes in the electrocardiogram and coronary angiography. Conclusion: The course of events patient showed clinical improvement with treatment and support was not necessary to administer specific medications or interventions to reverse the situation. After hemodynamic stabilization coronary angiography showed no obstructive lesions and left ventricle with akinesia of the apex and the middle portion of the left ventricle. © 2013 do Nascimento et al.; licensee BioMed Central Ltd.

Efficacy of four irrigation needles in cleaning the apical third of root canals

This study aimed to evaluate the influence of irrigation needle gauge and design, and the final root canal diameter on the apical cleaning efficacy. Twelve human mandibular incisors were used. At different stages of root canal widening (sizes 20, 30 and 40 K-files), root canals were filled with radiopaque contrast medium. Four different needles were evaluated: 23G with side opening, 22G with apical opening, 30G with side opening and 30G with apical opening. Irrigation was carried out with 2 mL distilled water. The same tooth was radiographed with a digital system several times to assess the four types of needle in those three stages of canal widening. Pre-irrigation (canals filled with contrast) and post-irrigation (canals with remaining contrast) images were submitted to digital subtraction using the Adobe Photoshop CS4 program. Pre-irrigation (filled with contrast) and subtracted (cleaned by irrigation) areas were outlined by a trained and blinded operator using the Image Tool 3.0 software. Their ratio was calculated to express the percentage of apical cleaning in each stage of canal widening (sizes 20, 30 and 40 K-files) with each of the four needles. Data obtained were subjected to one-way ANOVA and Tukey's tests. The 30G needles with side and apical opening promoted better apical cleaning at all stages of root canal widening (p<0.05). In conclusion, smaller diameter needles were more efficacious in cleaning the apical third of the root canals, regardless of their design.

Flexibility, torque and kick performance in soccer: Effect of dominance

Aim: The aim of this study was to evaluate the knee flexor and extensor torques in isometric contractions, comparing the H:Q ratios, flexibility and maximal kick between dominant (DL) and non-dominant (NDL) limb of soccer players (SG) and active people (AG)Methods: Subjects performed maximal instep kicks with each limb, flexibility tests and maximal isometric voluntary contractions of the knee flexion and extension at 45° and 90° to determine peak torque of the DL and NDLKnee flexion torque was divided by the knee extension torque to calculate torque ratios (H:Q ratio)Results: The flexibility and maximal kick in SG was significantly higher than in AG for both the DL and NDL (P<0.05)The maximal kick of DL was significantly higher than in NDL in SG (P<0.01)Knee flexion torque in SG was significantly higher than in AG in the DL (P<0.05), and the H:Q ratio was similar between AG and SGConclusion: Dominance related differences were evident in the flexor torque and maximal kick for SG, probably related to the asymmetric demand in trainings, which present no effect on the flexibility© 2013 Elsevier Masson SAS.

Leaf anatomical traits are correlated with tree dominance in a Neotropical deciduous forest

Deciduous forests from the neotropics are one of the most endangered forest types in the world due to the exploitation of their natural resources by mankind. Many aspects of these ecosystems have been studied; however, there is a lack of information about leaf structure and the effects of tree dominance on their structural leaf patterns. In this article, we examine leaf anatomy and specific leaf areas (SLA) in 13 tree species differing in their dominance in a Dry Forest site in Central Brazil, relating leaf anatomical traits with phytosociological aspects. Leaf anatomical traits differed according to tree dominance: greater leaf thickness (achieved through greater thickness of the mesophyll), low values of SLA and bigger stomata were found for the most dominant species, whereas the less dominant species showed thinner leaves with high SLA, as well as numerous and small stomata. These responses suggest that tree dominance is an important indirect effect associated with vertical light availability in the forest. These strategies are probably related to the accomplishment of a high performance in carbon gain and water economy, given the distinction in irradiance that the leaves of different species are subject to in the dry forest. © 2013 Copyright The Royal Society of New Zealand.

Histologic Characterization of Engineered Tissues in the Canal Space of Closed-apex Teeth with Apical Periodontitis

Introduction: The aim of this study was to investigate the capacity of endodontic regenerative procedures combining an induced blood clot, platelet-rich plasma (PRP), and bone marrow aspirate (BMA) to regenerate dental pulp in canine closed-apex necrotic teeth. Methods: Apical periodontitis was induced in 20 upper and lower premolars of 2 dogs. After biomechanical preparation, enlargement to a #60 file, and disinfection with a triantibiotic paste for 28 days, the roots were randomly assigned to 4 treatment groups: blood clot (BC), BC + PRP gel, BC + BMA gel, and BC + BMA/PRP gel. Negative controls were also included. After a 3-month follow-up period, the animals were killed. Results: Histologic analysis showed the presence of newly formed vital tissues (connective, cement-like, and bone-like tissue) in 23 of the 32 treated roots (71.87%). There was no statistically significant difference between the treatment groups. Conclusions: New vital tissues were formed and characterized as connective, cementum-like, or bone-like, but not as pulp-like tissue; PRP and/or BMA did not improve the tissue ingrowth. © 2013 American Association of Endodontists.

Reimplante dentário após obturação do canal com pasta de hidróxido de cálcio associado ao plug apical de MTA: estudo histomorfométrico em ratos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ação de medicações intracanal sobre biofilme microbiano localizado em áreas de reabsorção apical de dentes humanos extraídos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sistema adesivo na obturação de canais radiculares: biocompatibilidade e infiltração coronária (reparação apical e periapical em dentes de cães)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influência dos corantes Azul de Metileno a 2% e Rodamina B a 2% na determinação da capacidade seladora apical de diferentes cimentos endodônticos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da infiltração bacteriana corono-apical de canais radiculares obturados com diferentes tipos de cimentos endodônticos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)