Vertical Root Research Articles

Impact of different instruments metallurgy on Apical extrusion of debris and fracture resistance: A comparative invitro study

Abstract: The purpose of this research was to compare apical debris extrusion and fracture resistance of teeth prepared with OneCurve, WaveOne Gold, or ProTaper Universal. Materials and Methods: Mandibular premolars were prepared with OneCurve, WaveOne Gold, or ProTaper Universal. In the experimental model, debris was recovered by apical section of the root washing with distilled water. The Eppendorf tubes were weighed after 15 days of storage to establish the overall weight of the tubes, including the extruded debris. The dry weight of the ejected material was then computed. After root canal obturation, the apical root ends were trapped in the acrylic up to 2 mm below the cementoenamel junction. The fracture force was calculated and given in Newtons. A one-way ANOVA test was used to compare more than two groups, followed by a Tukey post hoc test. The significance level was set at P≤ 0.05. Results: The results revealed a statistically significant difference in extruded debris between OneCurve, WaveOne Gold, and ProTaper Universal (P <0.05), as well as a statistically significant difference in the load required for vertical root fracture between the negative control and OneCurve, WaveOne Gold, and ProTaper Universal (P <0.05). Conclusion WaveOne Gold had the lowest weight value of debris extrusion, whereas ProTaper Universal had the most. Negative control had the highest load, followed by WaveOne gold and One Curve, and finally ProTaper Universal.

Formation of Optical Images with Synchrotron Radiation Flux of Relativistic Electrons in the X-Ray Generator "Nestor"

When setting up physical experiments involving the use of the polarization properties of synchrotron radiation (SR) or a monoenergetic photon beam, detailed calculation of the spectral angular distribution of SR and its polarization components is of interest. Consideration of the electron beam size shows that in real conditions the radiation propagating in the plane of the equilibrium orbit will not be completely polarized, and the shape and dimensions of the angular distribution of radiation will be distorted. The motion of electrons in the uniform magnetic field and SR of the beam of relativistic particles in the storage ring of "NESTOR" are considered. The effect of the size of the electron beam with the energy of E=225 MeV in the 6-dimensional space on the formation of images of the flux of quanta of SR is analyzed. It is shown that the main contribution to the formation of images is made by the two-dimensional distribution of particles along the vertical direction axis and vertical oscillations. A software simulation code has been developed, the use of which made it possible to simulate the process of optical image formations by the flux of SR quanta (Этого предложения нет в русской аннотации). The formation of images of the radiation of electrons with an energy of E=225 MeV with change in the longitudinal distance L to the registration plane is considered. It is determined that at small longitudinal distances the main contribution to the image is made by the vertical distribution of particles in the beam. With an increase in the basic distance L, the contribution of the distribution of particles over vertical oscillations increases, which becomes decisive for large L value. Numerical simulation of image formation has been carried out. For the base distance of 300 cm and beam parameters with the vertical root mean square size of 0.2 mm and a vertical root mean square size of 0.15 mrad, the family of angular distributions is presented in the form of two-dimensional histograms for wavelengths , , , where , is the critical wavelength of SR. The dimensions of the optical window are obtained, the size of which makes it possible to reliably register the entire flux of SR quanta for the indicated registration characteristics.

Cone beam CT optimisation for detection of vertical root fracture with metal in the field of view or the exomass

Dose optimisation has been revisited in the literature due to the frequent use of cone beam computed tomography (CBCT). Although the reduction of the field-of-view (FOV) size has shown to be an effective strategy, this indirectly increases the negative effect from the exomass. The aim of this study was to evaluate the diagnostic accuracy of an optimised CBCT protocol in the detection of simulated vertical root fracture (VRF) in the presence of metal in the exomass and/or inside the FOV. Twenty teeth were endodontically instrumented and VRF was induced in half of them. All teeth were individually placed in a human mandible covered with a soft tissue equivalent material, metallic materials were placed at different dispositions in the exomass and/or endomass, and CBCT scans were obtained at two dose protocols: standard and optimised. Five radiologists evaluated the images and indicated the presence of VRF using a 5-point scale. Area under the ROC curve (AUC), sensitivity, and specificity were calculated and compared using ANOVA (α = 0.05). Overall, AUC, sensitivity, and specificity did not differ significantly (p > 0.05) between the dose protocols. In conclusion, optimised dose protocols should be considered in the detection of simulated VRF irrespective of the occurrence of artefacts from metallic materials in the exomass and/or inside the FOV.

Influence of Root Canal Sealers and Obturation Techniques on Vertical Root Fracture Resistance. An In Vitro Experiment

The aim of the present study was to determine the vertical root fracture (VRF) resistance of roots obturated with TotalFill BC Sealer and AH Plus sealer using lateral condensation and single cone techniques in comparison to untreated controls. Sixty single rooted mandibular premolars were sectioned and divided into six groups. Ten teeth were left untreated (positive control-Gp 1) and fifty teeth were cleaned and shaped. Ten root specimens were left unfilled (negative control-Gp 2) and the remaining roots were divided into 4 groups. Gp 3, GP and AH Plus sealer (AH Plus) using the cold lateral compaction (LC) technique; Gp 4, GP and AH Plus using the Single Cone (SC) technique; Gp 5: TotalFill GP and TotalFill BC sealer using the LC technique; Gp 6: TotalFill GP and TotalFill BC sealer with SC. VRF was performed for all specimens using a universal testing machine. Analysis of variance (ANOVA) and Tukeys post-hoc multiple comparison test was used to compare the means among tested study groups. Group 1 (positive control) displayed the highest fracture resistance (946.61 ± 166.465 N); however, the lowest fracture strength was demonstrated by the specimens in group 2 (negative control) (433.31 ± 129.350 N). Specimens treated with AH plus using different obturation techniques (group 3 and 4) showed comparable outcomes (p &gt; 0.05). Similarly, specimens treated with TotalFill BC sealer with different obturation techniques showed statistically similar outcomes (p &gt; 0.05). It was also observed that specimens in groups 3, 4, 5 and 6 demonstrated comparable outcomes of fracture strength (p &gt; 0.05). The use of TotalFill-BC sealer showed similar vertical root fracture resistance as AH plus sealer in root canal treated teeth. Use of total fill-BC and AH Plus sealer in root canal treatment showed vertical root fracture resistance comparable to untreated natural teeth (positive controls).

Detection of vertical root fractures in the presence of artefacts by digital radiography and cone beam computed tomography

The correct diagnosis of vertical root fractures (VRF) in the presence of artifacts is a challenge for clinicians and endodontists. Moreover, there is controversy about which imaging technique is best for this purpose. In an in vitro model, we evaluated the diagnosis of VRF in teeth treated endodontically with and without intraradicular metal posts, using the Clark technique and cone beam computed tomography (CBCT), as well as the interference of artifacts with the diagnosis. Twenty-two first or second maxillary or mandibular premolars were included. Teeth were randomly allocated to three groups: G1 (two teeth without fracture with endodontic treatment and one with an intraradicular metal post); G2 (10 fractured teeth with endodontic treatment); and G3 (10 fractured teeth with endodontic treatment plus a metal post). The examiners recorded the presence or absence of fracture and its location and classified its type. There was no statistically significant difference between image acquisition systems. When differentiating the teeth (first vs. second premolars), there was a statistically significant difference among the examiners (p=0.020). However, when comparing the values obtained by the examiners regarding the visualization of the fracture site as well as the presence of fracture correlated with the presence of a metal post and angulation, there were no statistically significant differences (p&gt;0.05). Digital radiographs and CBCT were similar for the diagnosis of VRF. High sensitivity was observed by CBCT image reconstructions. Therefore, the presence of metal posts generated artifacts, resulting in low sensitivity, specificity and accuracy.

CEMENTAL TEAR: REAL OR FICTION? A REVIEW OF THE LITERATURE AND THREE CASES

<h3>BACKGROUND</h3> Cemental tears are a form of root surface fracture caused by partial or total separation of cementum from the root surface.^1-4 Common clinical findings include deep periodontal pockets, gingival swelling, and pain. Owing to the overlapping clinical signs and symptoms with apical periodontitis, vertical root fracture, and periodontitis, cemental tears are often misdiagnosed and inappropriately treated. Their true prevalence remains unknown; however, many suspect that they occur more commonly than previously thought. <h3>CASE REPORT</h3> We report 3 patients examined at the University of Toronto. Two patients presented with draining fistulas and deep probing depths, and the third patient presented with a buccal vestibular swelling. Imaging examinations revealed a well-defined, linear, radiopaque/high-attenuation focus partially attached to or within close proximity to the adjacent root surface. The radiologic differential interpretation of the radiopaque/high-attenuation focus include dystrophic calcification, displaced bone or root fragments, or a cemental tear.^1-5 Owing to the linear nature of the radiopaque/high-attenuation entities and their positions parallel to the adjacent root surfaces, cemental tears were suspected. There was visual confirmation of sloughing cementum in 1 of the reported cases. <h3>DISCUSSION/CONCLUSIONS</h3> Cemental tears tend to be underreported, and this may be due to diagnostic difficulties. Definitive treatment via complete removal of the torn cemental fragment allows for successful healing and prolonged retention of the tooth. A review of the literature is also provided that summarizes the common radiographic presentations of histologically or visually verified cases of cemental tears.

Tomato root senses horizontal/vertical mechanical impedance and correspondingly modulates root/shoot metabolome

Plant root encounters coarse environs right after emergence from the seed. Little is known about the metabolic changes enabling the root to overcome the soil impedance. It is also not known whether roots respond differently to soil hardness when grown in the horizontal and vertical orientation.We grew tomato (Solanum lycopersicum) seedlings vertically or horizontally on agarose with increasing hardness (0.2 % → 1.2 %). We examined the morphology of roots and shoots of the seedling and also profiled phytohormones, primary metabolite levels, and transcript levels of related genes from the respective organs.Tomato seedlings grown vertically or horizontally, on agarose with increasing hardness, exhibited lateral roots proliferation, shorter hypocotyl, and primary root. In primary root tip, hardness increase elicited loss of amyloplast staining; induced reactive oxygen species, and nitric oxide accumulation. The level of indole butyric acid, zeatin, jasmonates, and salicylic acid markedly differed in root and shoot exposed to increasing hardness. Increasing hardness lowered indole acetic acid and elevated abscisic acid level, while increased ethylene emission was confined to the horizontally-impeded seedling. The trajectories of metabolomic shift distinctly differed between vertically/horizontally-impeded root/shoot. In the horizontal root, amino acids were the major affected group, while in the vertical root, sugars were the major group. Commonly affected metabolites in root and shoot, trehalose, dopamine, caffeoylquinic acid, and suberic acid, hallmarked the signature for hardness. Increasing hardness lowered Snf1-related protein kinase1a (SnRK1a) expression in root/shoot implying regulation of metabolic homeostasis by the SnRK1 signalling module. The lower E2Fa expression may lead to growth inhibition by reduced meristematic activity.Our study highlights the importance of metabolic homeostasis in facilitating root ramification in the soil. Though hardness is a common denominator, root distinguishes the horizontal/vertical orientation and correspondingly modulates metabolites level. Altogether, the data uncovers ABA, E2Fa, and SnRK1 as key regulators of hardness-induced growth inhibition of tomato seedlings.

Effect of Different Heat-treated Nickel-Titanium Files on Vertical Root Fracture Resistance

Effect of Different Heat-treated Nickel-Titanium Files on Vertical Root Fracture Resistance

Vertical root fracture resistance and dentinal crack formation of root canal-treated teeth instrumented with different nickel-titanium rotary systems: an in-vitro study.

To compare the vertical root fracture (VRF) resistance of root canal-treated teeth instrumented with four different nickel-titanium (NiTi) rotary file systems and examine the dentinal crack pattern and direction using a new classification. Eighty mature mandibular premolars were selected and decoronated, leaving 13mm of the root. The root samples were mounted in acrylic resin and divided randomly into five groups of different NiTi file systems: Group 1-control, Group 2-T-Pro, Group 3-HyFlex CM, Group 4-TG6 and lastly Group 5-ZenFlex. Samples in Group 2 and Group 3 were instrumented up to size 25/0.04, whereas Group 4 and Group 5 were instrumented up to size 25/0.06. Obturation was performed with AH Plus sealer and gutta-percha using single cone technique. Subsequently, all samples were subjected to occlusal compressive force until they were fractured. The force (N) needed to cause root fracture was recorded. The crack patterns and directions were also inspected under magnification and classified using a new and simple classification. The highest (VRF) resistance was noted in the control group (453.15 ± 92.23N), followed by T-Pro (387.43 ± 76.81N), HyFlex CM (381.88 ± 52.73N), ZenFlex (369.15 ± 89.41N) and finally TG6 (346.05 ± 72.08N), but there was no significant difference between T-Pro and HyFlex (P = 0.438). A significantly higher prevalence (P = 0.001) of Type 1 crack pattern was observed, especially in samples instrumented with TG6. Majority of the cracks ran buccolingually except in some samples instrumented with ZenFlex (P = 0.898). Smaller file taper increased the VRF resistance of root canal-treated teeth. Majority of the dentinal crack exhibited Type 1 pattern and ran buccolingually.

Agreement between Scheimpflug Camera and the Swept-source Optical Coherence Tomography Measurements in Keratometry and Higher-order Aberrations.

PurposeTo evaluate the compatibility of corneal curvature and astigmatism, and higher-order aberrations (HOAs) measured by the Scheimpflug camera Pentacam HR and the swept-source optical coherence tomography ANTERION.MethodsThis prospective study included normal subjects with no ophthalmic history. Steep keratometry (K), flat K, astigmatism and its axis of the anterior and posterior surfaces, total corneal power, and HOAs using the two instruments were compared. To compare the mean values of the measurements, a paired t-test was used. Bland-Altman analysis was applied to assess the agreement between the two devices.ResultsFifty-three eyes of 53 subjects were evaluated. There were statistically significant differences for steep K, astigmatism, and vector J0, J45 in the anterior surface and total corneal power between the two devices (p < 0.05). There were also significant differences in the most of the keratometric values of the posterior corneal surface (p < 0.05) except J0 (p = 0.410). Both devices showed strong positive correlations in steep K, flat K, astigmatism (r > 0.81, p < 0.001) with wide ranges of a 95% limit of agreement. Vectoral components were significantly correlated (r > 0.78, p < 0.001) with narrow 95% limit of agreement, except J45 of the posterior surface (r = 0.39, p = 0.004). In the corneal HOAs, there were statistically significant differences in the vertical coma, horizontal trefoil, spherical aberration, and root mean square of each fifth- and sixth-order Zernike coefficient (p = 0.043, p = 0.041, p < 0.001, p < 0.001, and p < 0.001, respectively). Other HOAs showed moderate to strong positive correlations (r > 0.37, p < 0.05). Most HOAs, except for the horizontal trefoil, showed clinically acceptable agreements. The total root mean square of HOAs was not significantly different between the two devices (p = 0.122).ConclusionsMost of the keratometric values cannot be used interchangeably. However, the vectoral component of astigmatism showed clinically good agreement. Several HOAs have statistically significant differences; however, almost all HOAs showed acceptable agreements, except for the horizontal trefoil.

Limited evidence of vertical fine-root segregation in a subtropical forest.

Vertical root segregation and the resulting niche partitioning can be a key underpinning of species coexistence. This could result from substantial interspecific variations in root profiles and rooting plasticity in response to soil heterogeneity and neighbours, but they remain largely untested in forest communities. In a diverse forest in subtropical China, we randomly sampled >4000 root samples from 625 0-30cm soil profiles. Using morphological and DNA-based methods, we identified 109 woody plant species, determined the degree of vertical fine-root segregation, and examined rooting plasticity in response to soil heterogeneity and neighbour structure. We found no evidence of vertical fine-root segregation among cooccurring species. By contrast, root abundance of different species tended to be positively correlated within soil zones. Underlying these findings was a lack of interspecific variation in fine-root profiles with over 90% of species concentrated in the 0-10cm soil zone with only one species dominating in the 10-20cm soil zone. Root profiles exhibited low responsiveness to root neighbours but tended to be shallow in soils with low phosphorus and copper content. These findings suggest that if there is niche differentiation leading to coexistence in this diverse forest, it would be occurring by mechanisms other than vertical fine-root segregation.

Influence of metal artefact reduction tool on the detection of vertical root fractures involving teeth with intracanal materials in cone beam computed tomography images: A systematic review and meta-analysis.

The effectiveness of the metal artefact reduction (MAR) tool for the detection of vertical root fracture (VRF) by cone beam computed tomography (CBCT) images is controversial. To evaluate the effectiveness of the MAR tool on VRF detection involving teeth with intracanal materials in CBCT images. In September 2019, an electronic search was performed in six databases (PubMed, Scopus, Web of Science, Cochrane, Lilacs and Embase). The electronic search was updated in May 2020 through searches in Google Scholar and references of included studies (embracing the electronic and gray literature searches). No language or year restrictions were applied. Independently, two reviewers examined titles, abstracts and full texts according to the eligibility criteria that were as follows: diagnostic studies that evaluated the effectiveness of the MAR tool on the diagnosis of VRF in human teeth (laboratory or in vivo studies) on CBCT images. The risk of bias was evaluated using the Quality Assessment Tool for Diagnostic of Accuracy Studies-2 (QUADAS-2). For conducting the meta-analysis, the values of sensitivity, specificity, diagnostic odds ratio (DOR) and area under the ROC curve (AUC) were obtained, considering the subgroups with and without MAR active. The Grading of Recommendation, Assessment, Development and Evaluation instrument was applied to assess the level of evidence across the studies using GRADEpro software. A total of 8 laboratory studies were included in both systematic review and meta-analysis. The values of sensitivity, specificity, DOR and AUC to VRF diagnosis with and without MAR active were, respectively, 0.586 and 0.603; 0.699 and 0.713, 3.037 and 3.767; 0.67 and 0.71. The quality of the evidence suggested low confidence in estimating the outcomes. The MAR tool decreased slightly the diagnostic values of VRF involving teeth with intracanal materials in laboratory studies. However, it is important to highlight that most studies had an uncertain risk of bias. Although a low level of evidence and high heterogeneity were observed in the included studies, the meta-analysis revealed better diagnosis values for VRF detection when the MAR was deactivated when analysing extracted teeth in a laboratory setting. PROSPERO-CRD42020145222. This study was financed in party by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES).

Mechanistic modeling of pesticide uptake with a 3D plant architecture model

Meaningful assessment of pesticide fate in soils and plants is based on fate models that represent all relevant processes. With mechanistic models, these processes can be simulated based on soil, substance, and plant properties. We present a mechanistic model that simulates pesticide uptake from soil and investigate how it is influenced, depending on the governing uptake process, by root and substance properties and by distributions of the substance and water in the soil profile. A new root solute uptake model based on a lumped version of the Trapp model (Trapp, 2000) was implemented in a coupled version of R-SWMS-ParTrace models for 3-D water flow and solute transport in soil and root systems. Solute uptake was modeled as two individual processes: advection with the transpiration stream and diffusion through the root membrane. We set up the model for a FOCUS scenario used in the European Union (EU) for pesticide registration. Considering a single vertical root and advective uptake only, the root hydraulic properties could be defined so that water and substance uptake and substance fate in soil showed a good agreement with the results of the 1D PEARL model, one of the reference models used in the EU for pesticide registration. Simulations with a complex root system and using root hydraulic parameters reported in the literature predicted larger water uptake from the upper root zone, leading to larger pesticide uptake when pesticides are concentrated in the upper root zone. Dilution of root water concentrations at the top root zone with water with low pesticide concentration taken up from the bottom of the root zone leads to larger uptake of solute when uptake was simulated as a diffusive process. This illustrates the importance of modeling uptake mechanistically and considering root and solute physical and chemical properties, especially when root-zone pesticide concentrations are non-uniform.

Drought adaptability of phreatophytes: insight from vertical root distribution in drylands of China

Abstract Aims The vertical distribution of plant roots is a comprehensive result of plant adaptation to the environment. Limited knowledge on fine vertical root distributions and complex interactions between roots and environmental variables hinders our ability to reliably predict climatic impacts on vegetation dynamics. This study attempts to understand the drought adaptability of plants in arid areas from the perspective of the relationship between vertical root distribution and surroundings. Methods By analyzing root profiles compiled from published studies, the root vertical profiles of two typical phreatophytes, Tamarix ramosissima and Populus euphratica, and their relationships with environmental factors were investigated. A conceptual model was adopted to link the parameter distribution frequency with plant drought adaptability. Important Findings The strong hydrotropism (groundwater-dependent) and flexible water-use strategy of T. ramosissima and P. euphratica help both species survive in hyperarid climates. The differences in the developmental environments between T. ramosissima and P. euphratica can be explained well by the different distribution characteristics of root profiles. That is, higher root plasticity helps T. ramosissima develop a more efficient water-use strategy and therefore survive in more diverse climatic and soil conditions than P. euphratica. We conclude that the higher variation in root profile characteristics of phreatophytes can have greater root adaptability to the surroundings and thus wider hydrological niches and stronger ecological resilience. The inadequacy of models in describing root plasticity limits the accuracy of predicting the future response of vegetation to climate change, which calls for developing process-based dynamic root schemes in Earth system models.

Evaluating the Performance of sUAS Photogrammetry with PPK Positioning for Infrastructure Mapping

Traditional acquisition methods for generating digital surface models (DSMs) of infrastructure are either low resolution and slow (total station-based methods) or expensive (LiDAR). By contrast, photogrammetric methods have recently received attention due to their ability to generate dense 3D models quickly for low cost. However, existing frameworks often utilize many manually measured control points, require a permanent RTK/PPK reference station, or yield a reconstruction accuracy too poor to be useful in many applications. In addition, the causes of inaccuracy in photogrammetric imagery are complex and sometimes not well understood. In this study, a small unmanned aerial system (sUAS) was used to rapidly image a relatively even, 1 ha ground surface. Model accuracy was investigated to determine the importance of ground control point (GCP) count and differential GNSS base station type. Results generally showed the best performance for tests using five or more GCPs or when a Continuously Operating Reference Station (CORS) was used, with vertical root mean square errors of 0.026 and 0.027 m in these cases. However, accuracy outputs generally met comparable published results in the literature, demonstrating the viability of analyses relying solely on a temporary local base with a one hour dwell time and no GCPs.

Tree species mixing reduces biomass but increases length of absorptive fine roots in European forests

Abstract Mixed‐species forests often enhance the provision of ecosystem functions, both above‐ and below‐ground. Several of these effects are mediated by the amount and spatial distribution of tree tissues. However, previous studies on tree diversity effects on fine‐root biomass (FRB) have returned inconsistent results and did not distinguish between absorptive and transport fine roots. Furthermore, owing to the lack of species‐specific data, it is not well understood whether complementarity or selection effects contribute more to these mixing effects. Here, we analysed tree species mixing effects on fine‐root traits while considering the respective tree species contributions and root functional types. Specifically, we tested whether tree species mixing increases FRB and root length density (RLD) and results in vertical root stratification. We quantified FRB and RLD in 30‐cm deep soil profiles for 13 tree species in mixed and pure stands across four widespread European forest types. The differentiation of different fine‐root species in mixtures allowed us to disentangle complementarity and selection effects. Across all sites, mixtures supported on average less FRB than pure stands, which was reflected in negative complementarity and selection effects. RLD of absorptive fine roots did not change across the soil profile and even increased in the topsoil, which was associated with positive complementarity effects. There was no evidence for vertical root stratification. Conifer proportion, which was mainly associated with selection effects, dampened net diversity effects. Root functional type further influenced tree species mixing effects. Synthesis. Despite the underyielding of FRB in mixtures, overall soil occupation by absorptive fine roots (RLD) did not decrease in mixtures, pointing to morphological root trait adaptations associated with higher resource‐use efficiency. Increased RLD in the most nutrient‐rich layer in mixtures further indicates complementary interactions among species and a greater resource uptake capacity. This work illustrates that considering only one aspect of trait‐functioning relationships, for example, root biomass, may not capture the full effect of plant diversity on ecosystem functioning. The integration of a larger range of relevant traits is required. Moreover, traditional classification of fine roots based on the 2‐mm diameter cut‐off may obscure responses of roots to environmental changes.

Diagnosis of cracked teeth using cone-beam computed tomography: literature review and clinical experience

Cone-beam computed tomography (CBCT) has been widely used in diagnosis of vertical root fractures (VRFs) in recent years. According to the American Association of Endodontists (AAE) classification, there are five types of cracked teeth and VRF is one of them. Due to the variability and overlapping of the cracks and fractures, some narrow fractures on the roots of VRFs could not be detected by CBCT, and some wide cracks on the crown of cracked teeth could be detected by CBCT. In this review, we firstly discussed the value of CBCT in the diagnosis of the AAE five types of cracked teeth and presented CBCT manifestations of some typical cases. Secondly, we summarized the factors influencing the diagnosis of cracks/fractures using CBCT, namely, CBCT device-related factors, patient-related factors, and evaluator-related factors. The possible strategies to improve the diagnostic accuracy in the clinic practice are also discussed in this part. Finally, we compared the differences of root fractures with lateral canals and external root resorption on CBCT images.

Radish cultivation with hydrogel doses combined with different water slides in drip irrigation system

Radish yield and quality are factors influenced by water stress that may occur during periods of drought or irrigation handled inappropriately, interfering negatively in plants development, producing radishes of inferior quality and in lesser quantity. In addition to irrigation, which makes water available in the system, it is important to maintain it with the use of water-retaining products such as hydrogel. The aim of this work was to evaluate radish yield, submitted to three different hydrogel doses combined with two water slides. The experimental design was in factorial scheme 3 x 2, with three water slides (50%, 75% and 100% Eto – reference evapotranspiration estimate) and two hydrogel doses (40 and 60 g m-2) with four replicates. Number of leaves, horizontal and vertical root diameter (mm), total and shoot length (cm), fresh mass of root and shoot (g), dry mass of shoot and root (g) and yield (t ha-1) were evaluated. The best results, regarding radish production and development, were obtained when using 50% of Eto with 60 g m-2 of hydrogel in combination. Thus, radish cultivation in oxisoil was influenced by the use of hydrogel, which provided a more efficient water level use.

Vertical root distribution in Himalayan trees: about half of roots occur below 30 cm, the generally sampled depth

Almost nothing is known about the vertical root distribution for Himalayan forest trees. By providing an analysis of vertical distribution of root density of ten important central Himalayan tree species (two evergreen conifers, five evergreen broadleaf species and three deciduous broadleaf species), this paper attempts to address this gap. We used trench profile method to measure tree root density, both of fine (≤ 3 mm diameter) and coarse (> 3 mm diameter) roots. Principal Component Analysis was performed to identify the major sources of variation among species in root distribution. In ten study tree species (eg., sal, oaks, pine and Cupressus torulosa) the rooting depth varied from 90 to 150 cm. On average across the study species, about 49% total roots (all diameter classes) occurred below 30 cm depth and 20.6% below 60 cm depth. These percentages are almost identical to that of tropical rain forest of Amazon. The tree species varied in root density (in entire soil column) from 26.04 ± 2.66 root/100 cm2 in Q. floribunda to 52.7 ± 4.96 root/100 cm2 in Machilus duthei. The ordination graph indicated that tree species of a growth form and even a genus did not form groups and differed markedly in root characters. Tree water status and roots were related only partially and in a complex way. The study has shown that (1) root density measured by digging trenches gives a reasonable estimate of proportional root distribution of trees, and (2) studies which consider only top 30 cm depth can grossly misrepresent root distribution and its consequence.

Combined Use of 2 Cone-beam Computed Tomography Scans in the Assessment of Vertical Root Fracture in Teeth with Intracanal Material

IntroductionThe purpose of this preliminary study was to evaluate the diagnostic accuracy of the combined use of 2 cone-beam computed tomographic (CBCT) volumes obtained with the tooth of interest positioned at different orientations in the detection of vertical root fracture (VRF). MethodsThirty single-rooted teeth were divided into 2 main groups (n = 15): control and with VRF. The teeth were individually placed in a phantom composed of a human skull and mandible, which was CBCT scanned in 2 spatial orientations: conventional (with the Frankfurt plane parallel to the floor) and angled acquisition (tilted 90° backward). Also, each tooth was scanned with gutta-percha, a metal post, and without any intracanal material. Three oral radiologists individually evaluated the images resulting from conventional acquisition and verified the presence or absence of VRF (conventional CBCT assessment), setting a score on a 5-point scale. Subsequently, the observers evaluated both images resulting from the conventional and angled acquisitions (combined CBCT assessment). The diagnostic values of the conventional and combined assessments were compared using 2-way analysis of variance with the post hoc Tukey test. The significance level was set at 5% (α = 0.05). ResultsThe combined CBCT assessment showed higher accuracy and sensitivity in the VRF diagnosis of teeth filled with gutta-percha (P < .05). In teeth with a metal post, all diagnostic values were higher in the combined CBCT assessment (P < .05). ConclusionsThis preliminary study suggests that the CBCT-based diagnosis of VRF in teeth with intracanal material was improved when the assessment combines images obtained at 2 orientations.