Kinds Of Teeth Research Articles

Influence of Seal Structure on the Motion Characteristics and Stability of a Steam Turbine Rotor

Sealing aerodynamic characteristics are affected by the seal structure, and thus the stability of the rotor system is affected too. A 1.5-stage, three-dimensional, full-cycle model of the high-pressure cylinder of a 1000 MW steam turbine was established. The high eccentricity whirl of the rotor was realized using mesh deformation technology and the multi-frequency whirl model. The nonlinear steam-flow-exciting force of different sealing structures was obtained using CFD/FLUENT, and the motion equations with a nonlinear steam-exciting force were solved using the Runge–Kutta method. The motion characteristics and stability of the rotor system with different sealing structures were obtained. The results show that there are “inverted bifurcation” and “double bifurcation” phenomena in the bifurcation diagrams of different tooth numbers, boss numbers, and tooth lengths, and a 1/2 power frequency of different sealing structures goes through the process of weakening, disappearing, reproducing, and evolving into a 1/3 power frequency and a 2/3 power frequency. With the increasing load, the steam-flow-exciting force becomes stronger, and the multi-frequency vibration and dense frequency phenomena are significant. Under some load conditions, the change curves of three kinds of teeth in 1/3 and 2/3 power frequency vibrations are highly similar, and the tooth number has little influence on the system stability. Under the high load condition, with the boss number increasing, the chaos phenomenon is weakened. Increasing the tooth length is beneficial to the stability of the rotor.

Denoised encoder-based residual U-net for precise teeth image segmentation and damage prediction on panoramic radiographs

ObjectivesThis research focuses on performing teeth segmentation with panoramic radiograph images using a denoised encoder-based residual U-Net model, which enhances segmentation techniques and has the capacity to adapt to predictions with different and new data in the dataset, making the proposed model more robust and assisting in the accurate identification of damages in individual teeth. MethodsThe effective segmentation starts with pre-processing the Tufts dataset to resize images to avoid computational complexities. Subsequently, the prediction of the defect in teeth is performed with the denoised encoder block in the residual U-Net model, in which a modified identity block is provided in the encoder section for finer segmentation on specific regions in images, and features are identified optimally. The denoised block aids in handling noisy ground truth images effectively. ResultsProposed module achieved greater values of mean dice and mean IoU with 98.90075 and 98.74147 ConclusionsProposed AI enabled model permitted a precise approach to segment the teeth on Tuffs dental dataset in spite of the existence of densed dental filling and the kind of tooth. Clinical SignificanceThe proposed model is pivotal for improved dental diagnostics, offering precise identification of dental anomalies. This could revolutionize clinical dental settings by facilitating more accurate treatments and safer examination processes with lower radiation exposure, thus enhancing overall patient care.

Golden proportion in smile design and maxillary anterior teeth: A review

The golden proportion is a well-known phenomenon and is considered a proportion often cited as frequently occurring in nature. It has been demonstrated by various artists, mathematicians, scientists and even philosophers. The golden proportion revolves around living beings and inactive creatures; even synthetic components and designs seem to follow the golden proportion. Human beings are genetically developed so that they can easily recognize the proportion as pleasurable because it demonstrates delicacy and is associated with the number science. The optimal proportion is associated directly with the golden proportion. The golden proportion is recognized as a standard rule for facial delicacy, and its application may aid in simplifying the diagnosis related to different dentofacial disorders. Various techniques were utilized to quantify the size and kind of teeth, such as the golden proportion. The primary aim of this review is to demonstrate the golden proportion phenomenon and evaluate the relationship between maxillary-anterior teeth and golden proportion.

Diagnosis of Vertical Root Fractures in Endodontically Treated Teeth by Cone-Beam Computed Tomography.

The purpose of this study was to investigate the characteristics and the detection ability of vertical root fractures in endodontically treated teeth by intraoral radiography and cone-beam computed tomography (CBCT). CBCT images of 50 patients with root fractures in endodontically treated teeth were reviewed, and 36 vertical root fractures were taken in this study. The cause of fracture, core construction, kind of teeth, and fracture direction (bucco-lingual and mesio-distal fractures) were investigated. Detection ability of vertical root fractures by intraoral radiography and CBCT was also examined. Statistical analyses concerning the characteristics were performed by χ2 test, and the detection ability was analyzed by cross-tabulation. All of the fractured teeth were nontraumatized teeth. The vertical root fracture occurrence was not differed by core construction. The vertical root fracture number was largest at the premolar teeth (p = 0.005), and the number of the bucco-lingual fracture was larger than the mesio-distal fracture (p = 0.046). Vertical root fractures were detectable using CBCT, while undetectable by intraoral radiography (p < 0.001). Vertical root fractures occurred easily in premolar teeth with bucco-lingual direction, and CBCT is an adequate radiographic method to diagnose vertical root fracture.

Three-Dimensional Dental Analysis for Sex Estimation in the Italian Population: A Pilot Study Based on a Geometric Morphometric and Artificial Neural Network Approach.

Dental dimorphism can be used for discriminating sex in forensic contexts. Geometric morphometric analysis (GMA) allows the evaluation of the shape and size, separately, of uneven 3D objects. This study presents experiments using a novel combination of GMA and an artificial neural network (ANN) for sex classification, applied to premolars of Caucasian Italian adults (50 females and 50 males). General Procrustes superimposition (GPS) and the partial least square (PLS) method were performed, respectively, to study the shape variance between sexes and to eliminate landmark variations. The “set-aside” approach was used to assess the accuracy of the proposed neural networks. As the main findings of the pilot study, the proposed method applied to the first upper premolar correctly classified 90% of females and 73% of males of the test sample. The accuracy was 0.84 and 0.80 for the training and test samples, respectively. The sexual dimorphism resulting from GMA was low, although statistically significant. GMA combined with the ANN demonstrated better sex classification ability than previous odontometric or dental morphometric methods. Future research could overcome some limitations by considering a larger sample of subjects and other kinds of teeth and experimenting with the use of computer vision for automatic landmark positioning.

The Effect of Two Kinds of Teeth Socked on Prognosis after Extraction of Impacted Teeth

The Effect of Two Kinds of Teeth Socked on Prognosis after Extraction of Impacted Teeth

Novel Approach to Tooth Chemistry. Quantification of the Dental-Enamel Junction.

The dentin-enamel junction (DEJ) is known for its special role in teeth. Several techniques were applied for the investigation of the DEJ in human sound molar teeth. The electron (EPMA) and proton (PIXE) microprobes gave consistent indications about the variability of elemental concentrations on this boundary. The locally increased and oscillating concentrations of Mg and Na were observed in the junction, in the layer adhering to the enamel and covering roughly half of the DEJ width. The chemical results were compared with the optical profiles of the junction. Our chemical and optical results were next compared with the micromechanical results (hardness, elastic modulus, friction coefficient) available in the world literature. A strong correlation of both result sets was proven, which testifies to the self-affinity of the junction structures for different locations and even for different kinds of teeth and techniques applied for studies. Energetic changes in tooth strictly connected with crystallographic transformations were calculated, and the minimum energetic status was discovered for DEJ zone. Modeling of both walls of the DEJ from optical data was demonstrated. Comparing the DEJ in human teeth with the same structure found in dinosaur, shark, and alligator teeth evidences the universality of dentin enamel junction in animal world. The paper makes a contribution to better understanding the joining of the different hard tissues.

English

A tooth can be broken due to many reasons, out of which deep cervical caries can be the one leading to destruction of the whole buccal surface of the tooth. So, to preserve such kind of tooth, root canal treatment is the ultimate treatment option followed by proper selection of the restorative means of such endodontically treated tooth. endodontically treated tooth (ETT) has loss of tooth structure and changes in physical characteristics. Therefore, proper selection of restoration for ETT is mandatory to maintain almost the same level of strength and regaining its functional abilities. The decision of doing restoration of endodontically treated teeth depends on many factors like the amount of tooth structure remaining, condition of the opposing tooth, etc. In cases of less than 50 % tooth structure remaining post and core followed by crown is the best treatment option. This article showcases a case report of treatment of anterior teeth with deep cervical caries. The posts used in these cases were fiber post which were luted and the core build up was done with ParaCore, which is a glassreinforced composite by Coltene. Deep cervical caries can lead to destruction of the whole buccal surface of the tooth. So, to preserve such kind of tooth, root canal treatment followed by proper selection of restoration for endodontically treated tooth is mandatory to maintain almost the same level of strength and to regain its functional abilities. This article showcases a case report of treatment of anterior teeth with deep cervical caries.

Diagnosis of root fractures using cone-beam computed tomography: difference of vertical and horizontal root fracture.

The aim of this study was to investigate the occurrence of vertical and horizontal root fractures using cone-beam computed tomography (CBCT). We reviewed the CBCT images of 51 patients who were examined by CBCT for the diagnosis of root fracture. The occurrences of vertical and horizontal root fractures were investigated concerning the pulpal vitality and the kind of tooth, and analyzed by cross-tabulation. The fracture direction of vertical root fracture and the fracture angle were also investigated, and analyzed by cross-tabulation and Kruskal-Wallis test, respectively. The occurrence of vertical and horizontal root fractures was statistically significantly different between vital tooth and non-vital tooth (p = 0.044). The occurrence of vertical and horizontal root fractures was also different among anterior, premolar, and molar teeth (p = 0.004). The kind of tooth on traumatized tooth was only anterior teeth and the number was larger on horizontal root fracture. The occurrence of vertical and horizontal root fractures on non-traumatized tooth was different among the kind of tooth (p = 0.007), and the number of vertical root fracture was larger than that of horizontal root fracture on premolar teeth. Fracture direction was not different, but the fracture angle was different among the kind of tooth on vertical root fracture (p = 0.027). The results suggested that the number of vertical root fracture was larger on non-vital tooth and that of horizontal root fracture was larger on vital tooth. The number of vertical root fracture was larger on premolar teeth.

Diagnosis of vertical root fractures using cone-beam computed tomography

Background/Aim: The aim of this study was to investigate the occurrence of vertical root fracture using cone-beam computed tomography (CBCT). Methods: We reviewed the CBCT images of 41 patients who were examined and verified vertical root fracture. The characteristics of root fractures (pulpal vitality, existence of injury, kind of tooth, and core construction) that were considered to influence the occurrence of root fracture were investigated. The position of the tooth and the fracture direction were also examined. Diagnostic propriety of root fractures between intraoral radiography and CBCT was examined. Statistical analyses of each characteristic and the fracture direction were performed by Chi-squared test. The position of the tooth and diagnostic propriety were analyzed by cross-tabulation. Results: The number of vertical root fracture was larger at nonvital tooth (P

CLINICAL AND ANATOMICAL RESTORATION OF THE MASTICATORY GROUP OF TEETH WITH A BURDENED GENERAL STATUS

Objective. The chewing group of teeth is intended for equally crusher of food and forming food lump. This group is presented by two kinds of teeth: premolars and molars, and more often affected by caries, because a lot of retention zones are contribute to the active delay of plaque and the appearance of carious cavities. It is happening before 18 years. In the absence of these teeth or badly damaged of the crown part, food is chewed badly and as a result, stomach contain extremely large pieces. But its size is impossible for physiological digestion by the gastrointestinal tract and as a consequence the occurrence of gastrointestinal diseases. According to modern data, to work with lesions of hard tissues of the teeth, namely the chewing group of teeth, it is advisable to use composite light-curing microhybrid materials, which are characterized by particles close to the spherical shape. The aim of this study is determination of the possibility using a budgetary aesthetic composite for restorative restoration of the masticatory group of teeth in patients with a burdened anamnesis. Material and methodology. Was examined 22 people with aesthetic and anatomical disorders of the vestibular and occlusal surface of the hard tissues of the chewing group of teeth (n=154), followed by their recovery. The stability of filling materials was assessed according to Ryge-criteria: color coincidence, discoloration of the marginal segment, marginal adaptation, anatomical shape integrity, restoration surface, secondary caries. Results. Clinical and dental examination showed all the above violations of existing restorations (according to Ryge classification) in patients before restoration manipulations. After 1 week after the restoration, the examination showed that both groups of composites completely restore the anatomical and aesthetic chewing group of teeth and meet all the criteria. After 3 months, the assessmen t of the restoration by the composite of group A and group B did not reveal evidence of secondary caries on the perimeter of the restorations. Clinical and dental examination after 6 months showed minor changes in the restorations of composites of both groups in assessing the stability of color (90.9% and 83.3% in groups A and B) and the stability of surface polishing (89.6% and 81.8%, respectively). Discussion. The main signs of the restoration, which are undergoing changes, are discoloration, as well as the preservation of the smoothness of the surface regardless of the cost and branding of the base material.

Investigation on impact toughness and wear resistance of nanocomposite Al2O3/WC-Co hammer bit teeth

Abstract The material of the hammer bit tooth is cemented carbide YG8, whose impact toughness and wear resistance are insufficient, leading to tooth fracture and wear. In this paper, cemented carbide YG8 teeth and nanocomposite teeth doped with Al 2 O 3 nanoparticles and VC inhibitors were fabricated through a series of processes. Cemented carbide YG8 teeth act as comparison. Two kinds of teeth were analyzed and compared using the scanning electron microscopy (SEM) and the MLD-10 dynamic impact-wear tester. SEM micrographs of samples show that Al 2 O 3 /WC-Co nanocomposite grains are finer and more uniform, which can improve impact-wear resistance. Impact-wear tests indicate that nanocomposite teeth had 3 to 5 times higher impact toughness and wear resistance than YG8 teeth. The fracture toughness can be significantly improved by adding the proper amount of Al 2 O 3 nanoparticles. Based on fracture morphology analysis, it is found that the fracture of the YG8 tooth under impact-wear condition is brittle fracture and the fracture of the nanocomposite tooth is ductile fracture.

Surface architecture of the oropharyngeal cavity and the digestive tract of Mulloidichthys flavolineatus from the red sea, Egypt: A scanning electron microscope study.

Surface architecture of the buccal cavity and the surface organization of the luminal mucosa of the oesophagus, stomach, and intestine of the carnivorous fish M. flavolineatus from the Red Sea were studied by using SEM. The results revealed that M. flavolineatus has four kinds of teeth; curved-blunt, wedge-shaped, flattened crowns, molariform and papilliform. Three types of taste buds (type I, II and III) were recorded in the oropharyngeal cavity. It was observed that taste buds and teeth are co-located in the pharyngeal region. Characteristic patterns of microridges of the surface cells in the oral cavity and oesophagus were observed. Mucous cells are distributed in the lining of the mouth cavity, oesophagus, stomach, and intestine. Characteristic patterns of mucosal folds throughout the alimentary canal, concerning oesophagus, stomach, and intestine were revealed. Numerous gastric pits, which represents the emergence of the gastric glands, were recorded in the anterior and middle regions of the stomach. Complex patterns of the folds and mucous cells were recorded in the intestinal mucosa. These results were discussed with other teleost fishes.

Determination of the Average Native Background and the Light-Induced EPR Signals and their Variation in the Teeth Enamel Based on Large-Scale Survey of the Population

The aim of the study is to determine the average intensity and variation of the native background signal amplitude (NSA) and of the solar light-induced signal amplitude (LSA) in electron paramagnetic resonance (EPR) spectra of tooth enamel for different kinds of teeth and different groups of people. These values are necessary for determination of the intensity of the radiation-induced signal amplitude (RSA) by subtraction of the expected NSA and LSA from the total signal amplitude measured in L-band for in vivo EPR dosimetry. Variation of these signals should be taken into account when estimating the uncertainty of the estimated RSA. A new analysis of several hundred EPR spectra that were measured earlier at X-band in a large-scale examination of the population of the Central Russia was performed. Based on this analysis, the average values and the variation (standard deviation, SD) of the amplitude of the NSA for the teeth from different positions, as well as LSA in outer enamel of the front teeth for different population groups, were determined. To convert data acquired at X-band to values corresponding to the conditions of measurement at L-band, the experimental dependencies of the intensities of the RSA, LSA and NSA on the m.w. power, measured at both X and L-band, were analysed. For the two central upper incisors, which are mainly used in in vivo dosimetry, the mean LSA annual rate induced only in the outer side enamel and its variation were obtained as 10±2 (SD =8) mGy y-1, the same for X- and L-bands (results are presented as the mean±error of mean). Mean NSA in enamel and its variation for theupper incisors was calculated at 2.0±0.2 (SD =0.5) Gy, relative to the calibrated RSA dose-response to gamma radiation measured under non-power saturation conditions at X-band. Assuming the same value for L-band under non-power saturating conditions, then for in vivo measurements at L-band at 25 mW (power saturation conditions), a mean NSA and its variation correspond to 4.0±0.4 (SD =1.0) Gy.

Gold Enamel Choumps – A Case report

Tooth jewellery has been practiced since time immemorial and has become an increasingly popular trend. This case report provides a brief insight into a kind of tooth adornment/a tooth tattoo on the enamel prevalent in parts of western Uttar Pradesh, India locally known as a ‘Choump’. A tooth tattooed with ‘Choumps’ has extremely low incidence and could be used as an identification trait. Tooth adornment with ‘Choumps’ has been reported in adults however, this is the first reported case of ‘Choumps’ in children.

Evaluation of polymerization shrinkage of dental composites by an optical method.

This study proposes an alternative methodology for evaluating polymerization shrinkage of dental composites using an advanced video extensometer (AVE) system. This equipment measures the displacement between two points drawn on a tooth's wall without requiring physical contact with the tooth. By doing so, the polymerization process was monitored by the cusp deflection. This technique was used in human and bovine teeth, where the cavities were prepared under controlled conditions so that the volume of the composite used was the same in both types of teeth. After the cavity preparation, the specimens were acid etched, washed and dried, and then the adhesive was applied and polymerized. The composite was then inserted into the cavity. Polymerization was performed with two different light polymerizing units (LD Max and Optilight Max - Gnatus do Brasil), and the displacement curve of the tooth cusp was recorded for a period of 400 s. After a statistical analysis, it was concluded that the technique was capable of evaluating shrinkage by the deflection from the cusps and that the human and bovine teeth do not react in a similar manner towards the polymerization shrinkage of composites.

MODERN CONCEPTS OF ETIOLOGY, PATHOGENESIS AND TREATMENT APPROACHES TO ENDO-PERIO LESIONS

A combination ofperiodontitis and pulp or periapical tissues inflammation in one tooth is known as endo-periodontal lesions. Such kind of lesion is serious problem of modern dentistry. It was found that pathogenic microflora of periodontal pocket and root canal of tooth with eno-perio lesion is almost the equal and consist of anaerobic microorganisms. Pathogenic effects have not only microorganisms but also their life products. Apical foramen, lateral and additional canals are physiological ways for pathogens migration. Inflammatory processes in these structures complicate each other. Lack of information among dentists about treatment possibilities of endo-perio lesions is a main reasons of extraction such kind of teeth. Simultaneous elimination of pathogens both from periodontal pocket and root canal is a key factor for effective treatment. Periodontal status is main factor for prognosis of tooth with endo-perio lesion, because of it treatment of endo-perio lesions should consist of two stages: infection elimination and regeneration of tooth-supported structures.

Techniques of dental DNA extraction: Some operative experiences

This study presents and discusses the possibility of multiple dental DNA extraction at different times using an endodontic technique. We chose a mixed sample of twenty teeth (decayed, filled, different kinds of teeth, etc.) and performed two different accesses to the pulp cavity to collect samples of dental tissue useful for DNA extraction. The Identifiler ® and Minifiler ® kits were used respectively for the first and second genetic analysis. The research's most relevant findings are the possibility of successfully repeating dental DNA extractions, and that a dental element can be considered as a DNA source that can be reused even after prolonged time elapses. The study's results document a simple and efficient methodology for dental identification based on the choice of dental elements, endodontic techniques and the use of the Minifiler ® kit for genetic analysis.

Phlebotomus (Euphlebotomus) barguesae n. sp. from Thailand (Diptera – Psychodidae)

BackgroundA few studies have been carried out on the Phlebotomine sandflies from Thailand. Within the Phlebotomine sandflies, the genus Phlebotomus Rondani & Berté, 1840 contains the vectors of leishmaniases in Europe, Africa and Asia. It includes several subgenera. Among them the subgenus Euphlebotomus Theodor, 1948 contains at the present time 12 taxa. The type-species of this subgenus is P. argentipes Annandale & Brunetti, 1908, the vector of Leishmania donovani (Laveran & Mesnil, 1903) in India.ResultsA new species of sandfly, P. barguesae n. sp. is described from limestone caves in Thailand. The male-female gathering in the same species is based on ecological, morphological and molecular criteria (homology of mtDNA cytochrome c oxidase I sequences). The inclusion of P. barguesae n. sp. in the subgenus Euphlebotomus is justified on the basis of characters of the male genitalia (five spines on the style, bifurcated paramere, and no basal lobe on the coxite) and of female pharyngeal armature (two kinds of teeth). It well differenciated from another sympatric species: P. mascomai.ConclusionThe new species described in the present study has smooth spermathecae. This original morphology opens a discussion on the heterogeneity of this subgenus.

Review of Two Documentary Films from First Run/Icarus Films: How Happy Can You Be? and Teeth

How Happy Can You Be? and Teeth are two competently made, yet less than completely satisfying, documentary films distributed by First Run/Icarus Films in 2005 and 2007, respectively, that rely heavily on statistics to examine smiles from different perspectives. Teeth: An Investigation into Consumer Culture Identification and Good Smiles-a. 26-minute film by Alice Arnold-is less engaging of two both intrinsically and in its realization as documentary. Essentially an investigation into socio-cultural impetus driving 300% increase (from 1999 to 2004) in America's whitening market, Teeth provides considerable, but sometimes-suspect, statistical information while featuring interspliced interviews with psychoanalyst, three dentists, seven individuals who feel compelled for variety of reasons to consider cosmetic dentistry, and grill-wearer. These include frugal Leo, who does not like his because of missing initially fears he couldn't afford it, yet finally has all his replaced by dentures (the cheaper alternative to implants) only to discover that eating with is like having sex wearing condom; crooked-toothed, middle-aged Austrian immigrant who is surprised to be told to get braces, once in America, but attributes American obsession with to advertising . . . American corporate imagery is all white big smile; an Asian-American insecure his yellowish teeth; young woman who, told by her dentist to have her whitened to younger, resents to match current elevated of whiteness . . . of cleanliness, and feels that new phase of whitening, on top of straightening, is whole new level of beautification, and commodification; and Markus Wailand, handsome but gap-toothed actor who is advised by producers that those on TV need perfect looks, and that all anyone will remember him is his tooth gap. The dentists, one of whom quick-fixes of ordinary people who appear on Montel Williams Show, discuss procedures and expense of having whitened or repaired, note that people want their fixed because an smile is important to dating (84%), friendship (71%), getting job (74%), and succeeding at work (75%)-yet source of these statistics is an Invisaline Smile Survey. They conclude, Everybody wants to look good . . . . That's what our society is all about while acknowledging that attractive are as well as health issue. In this dentists agree with psychoanalyst Michael Moskowitz, who asserts that this false smile is unique to United States and that we've developed this norm for showing that is in other ways an expression of class and power, not only because Freud interprets dreams losing one's as representing loss of one's penis and thus a loss of power, but also because dentistry is expensive. While opining that dental economics makes quality of one's race issue as well as class issue, Moskowitz points out that hip-hop culture's preference for grills is rejection of the typical white man's attitude of allwhite teeth that nonetheless, in words of pleased grill-wearer, similarly signifies . . . I got more money . . . which means I got more power. (The best audio material in documentary is hip-hop song, Show Your Teeth, that accompanies this segment.) The documentary is visually unimaginative in merely running quotations and statistics across screen and in focusing excessively on talking (and reading) heads, but its primary flaw is that it is just too obvious: Its conclusion and central thesis, that there's an industry out there that profits from making people feel like they need certain kind of teeth, articulated by Moskowitz, does not go beyond what nearly everyone already knows. How Happy Can You Be?-a 52-minute film by Line Hatland-has advantage of examining far more elusive topic which there is considerably more that average person might want to know. …