Search results for: dental calculus
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 423

Search results for: dental calculus

153 Stability Analysis of Tumor-Immune Fractional Order Model

Authors: Sadia Arshad, Yifa Tang, Dumitru Baleanu

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A fractional order mathematical model is proposed that incorporate CD8+ cells, natural killer cells, cytokines and tumor cells. The tumor cells growth in the absence of an immune response is modeled by logistic law as it was the simplest form for which predictions also agreed with the experimental data. Natural Killer Cells are our first line of defense. NK cells directly kill tumor cells through several mechanisms, including the release of cytoplasmic granules containing perforin and granzyme, expression of tumor necrosis factor (TNF) family members. The effect of the NK cells on the tumor cell population is expressed with the product term. Rational form is used to describe interaction between CD8+ cells and tumor cells. A number of cytokines are produced by NKs, including tumor necrosis factor TNF, IFN, and interleukin (IL-10). Source term for cytokines is modeled by Michaelis-Menten form to indicate the saturated effects of the immune response. Stability of the equilibrium points is discussed for biologically significant values of bifurcation parameters. We studied the treatment of fractional order system by investigating analytical conditions of tumor eradication. Numerical simulations are presented to illustrate the analytical results.

Keywords: cancer model, fractional calculus, numerical simulations, stability analysis

Procedia PDF Downloads 286
152 Experimental and Theoretical Analysis of the Electromagnetic Environment in the Vicinity of Two 220Kv Power Lines

Authors: Wafa Tourab, Abdessalem Babouri, Mohamed Nemamcha

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This work presents an experimental and theoretical characterization of electromagnetic environment in the vicinity of EL-HADJAR high voltage substation located in the eastern Algerian within a very high populated zone. There have been analyses on the effects of electromagnetic fields emanating from coupled multi-lines power systems on the health of the workers and people living in proximity of substations. An experimental investigation has been conducted around a circuit of two 220Kv lines running in parallel. The experimental results are validated by a flexible code of calculus developed in the environment Matlab. The implications of the results are discussed and are in very good agreement with the ICNIRP reference levels for occupational and non-occupational exposures. In a case of study, the separation between the two structures “S” is varied to demonstrate its influence on the electric and magnetic charges quantities generated by the circuit of lines proposed. It is found that increasing S decreases the electric and magnetic fields which occur at the center of the structure then reduces the coupling between lines. We concluded that the evaluation of the spacing between the phase conductors is of paramount interest in the preparation of the line’s implantation inside the electrical posts to reduce them radiations in the environment.

Keywords: low frequency, electromagnetic fields, electromagnetic coupling, high voltage power lines

Procedia PDF Downloads 367
151 An Empirical Examination of Ethnic Differences in the Use and Experience of Child Healthcare Services in New Zealand

Authors: Terryann Clark, Kabir Dasgupta, Sonia Lewycka, Gail Pacheco, Alexander Plum

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This paper focused on two main research aims using data from the Growing Up in New Zealand (GUINZ) birth cohort: 1. To examine ethnic differences in life-course trajectories in the use and experience of healthcare services in early childhood years (namely immunisation, dental checks and use of General Practitioners (GPs)) 2. To quantify the contribution of relevant explanatory factors to ethnic differences. Current policy in New Zealand indicates there should be, in terms of associated direct costs, equitable access by ethnicity for healthcare services. However, empirical evidence points to persistent ethnic gaps in several domains. For example, the data highlighted that Māori have the lowest immunisation rates, across a number of time points in early childhood – despite having a higher antenatal intention to immunise relative to NZ European. Further to that, NZ European are much more likely to have their first-choice lead maternity caregiver (LMC) and use child dental services compared to all ethnicities. Method: This research explored the underlying mechanisms behind ethnic differences in the use and experience of child healthcare services. First, a multivariate regression analysis was used to adjust raw ethnic gaps in child health care utilisation by relevant covariates. This included a range of factors, encompassing mobility, socio-economic status, mother and child characteristics, household characteristics and other social aspects. Second, a decomposition analysis was used to assess the proportion of each ethnic gap that can be explained, as well as the main drivers behind the explained component. The analysis for both econometric approaches was repeated for each data time point available, which included antenatal, 9 months, 2 years and 4 years post-birth. Results: The following findings emerged: There is consistent evidence that Asian and Pacific peoples have a higher likelihood of child immunisation relative to NZ Europeans and Māori. This was evident at all time points except one. Pacific peoples had a lower rate relative to NZ European for receiving all first-year immunisations on time. For a number of potential individual and household predictors of healthcare service utilisation, the association is time-variant across early childhood. For example, socio-economic status appears highly relevant for timely immunisations in a child’s first year, but is then insignificant for the 15 month immunisations and those at age 4. Social factors play a key role. This included discouragement or encouragement regarding child immunisation. When broken down by source, discouragement by family has the largest marginal effect, followed by health professionals; whereas for encouragement, medical professionals have the largest positive influence. Perceived ethnically motivated discrimination by a health professional was significant with respect to both reducing the likelihood of achieving first choice LMC, and also satisfaction levels with child’s GP. Some ethnic gaps were largely unexplained, despite the wealth of factors employed as independent variables in our analysis. This included understanding why Pacific mothers are much less likely to achieve their first choice LMC compared to NZ Europeans; and also the ethnic gaps for both Māori and Pacific peoples relative to NZ Europeans concerning dental service use.

Keywords: child health, cohort analysis, ethnic disparities, primary healthcare

Procedia PDF Downloads 127
150 Dentofacial-Targeted Bullying: A Review

Authors: Mai Ashraf Talaat

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Bullying is an aggressive behavior and a serious issue that should be addressed by everyone and should be avoided at all costs. It is very common among adolescents and schoolchildren and the effects can be devastating and long-lasting. Students are most commonly bullied about physical appearance, race, gender, disability, ethnicity, religion, and sexual orientation. Appearance-targeted bullying is a form of bullying that targets an aspect of a person's appearance, which includes facial and dental features. Deviation from accepted dentofacial aesthetics leads to elevated incidences of bullying in schoolchildren. The aim of this review article is to assess the prevalence of bullying due to dentofacial characteristics and evaluate the importance of dentofacial appearance on perceived social attractiveness based on multiple studies.

Keywords: dentofacial features, orthodontics, malocclusion, adolescents, bullying

Procedia PDF Downloads 44
149 Machine Learning Analysis of Student Success in Introductory Calculus Based Physics I Course

Authors: Chandra Prayaga, Aaron Wade, Lakshmi Prayaga, Gopi Shankar Mallu

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This paper presents the use of machine learning algorithms to predict the success of students in an introductory physics course. Data having 140 rows pertaining to the performance of two batches of students was used. The lack of sufficient data to train robust machine learning models was compensated for by generating synthetic data similar to the real data. CTGAN and CTGAN with Gaussian Copula (Gaussian) were used to generate synthetic data, with the real data as input. To check the similarity between the real data and each synthetic dataset, pair plots were made. The synthetic data was used to train machine learning models using the PyCaret package. For the CTGAN data, the Ada Boost Classifier (ADA) was found to be the ML model with the best fit, whereas the CTGAN with Gaussian Copula yielded Logistic Regression (LR) as the best model. Both models were then tested for accuracy with the real data. ROC-AUC analysis was performed for all the ten classes of the target variable (Grades A, A-, B+, B, B-, C+, C, C-, D, F). The ADA model with CTGAN data showed a mean AUC score of 0.4377, but the LR model with the Gaussian data showed a mean AUC score of 0.6149. ROC-AUC plots were obtained for each Grade value separately. The LR model with Gaussian data showed consistently better AUC scores compared to the ADA model with CTGAN data, except in two cases of the Grade value, C- and A-.

Keywords: machine learning, student success, physics course, grades, synthetic data, CTGAN, gaussian copula CTGAN

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148 Merging Appeal to Ignorance, Composition, and Division Argument Schemes with Bayesian Networks

Authors: Kong Ngai Pei

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The argument scheme approach to argumentation has two components. One is to identify the recurrent patterns of inferences used in everyday discourse. The second is to devise critical questions to evaluate the inferences in these patterns. Although this approach is intuitive and contains many insightful ideas, it has been noted to be not free of problems. One is that due to its disavowing the probability calculus, it cannot give the exact strength of an inference. In order to tackle this problem, thereby paving the way to a more complete normative account of argument strength, it has been proposed, the most promising way is to combine the scheme-based approach with Bayesian networks (BNs). This paper pursues this line of thought, attempting to combine three common schemes, Appeal to Ignorance, Composition, and Division, with BNs. In the first part, it is argued that most (if not all) formulations of the critical questions corresponding to these schemes in the current argumentation literature are incomplete and not very informative. To remedy these flaws, more thorough and precise formulations of these questions are provided. In the second part, how to use graphical idioms (e.g. measurement and synthesis idioms) to translate the schemes as well as their corresponding critical questions to graphical structure of BNs, and how to define probability tables of the nodes using functions of various sorts are shown. In the final part, it is argued that many misuses of these schemes, traditionally called fallacies with the same names as the schemes, can indeed be adequately accounted for by the BN models proposed in this paper.

Keywords: appeal to ignorance, argument schemes, Bayesian networks, composition, division

Procedia PDF Downloads 253
147 Scope of Lasers in Periodontics

Authors: Atmaja Patel

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Since the development of lasers in 1951, the first medical application was reported by Goldman in 1962. In 1960, T.H. Maiman produced the first Ruby laser and was used in cardiovascular surgery by McGuff in 1963. After a long time of investigations and new developments in laser technology first clinical applications were performed by Choy and Ginsburg in 1983. Introduction of the first true dental laser was in 1989. This paper is to highlight the various treatments and prevention of periodontal diseases. Lasers have become more predictable and effective form of treatment for periodontal diseases. The advantages of lasers include reduced use of anaesthesia, coagulation that yields a dry surgical field and hence better visibility, reduced need of sutures, minimal swelling and scarring, less pain and medication, faster healing and increased patient acceptance.

Keywords: lasers, periodontal surgery, diode laser, healing

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146 New Variational Approach for Contrast Enhancement of Color Image

Authors: Wanhyun Cho, Seongchae Seo, Soonja Kang

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In this work, we propose a variational technique for image contrast enhancement which utilizes global and local information around each pixel. The energy functional is defined by a weighted linear combination of three terms which are called on a local, a global contrast term and dispersion term. The first one is a local contrast term that can lead to improve the contrast of an input image by increasing the grey-level differences between each pixel and its neighboring to utilize contextual information around each pixel. The second one is global contrast term, which can lead to enhance a contrast of image by minimizing the difference between its empirical distribution function and a cumulative distribution function to make the probability distribution of pixel values becoming a symmetric distribution about median. The third one is a dispersion term that controls the departure between new pixel value and pixel value of original image while preserving original image characteristics as well as possible. Second, we derive the Euler-Lagrange equation for true image that can achieve the minimum of a proposed functional by using the fundamental lemma for the calculus of variations. And, we considered the procedure that this equation can be solved by using a gradient decent method, which is one of the dynamic approximation techniques. Finally, by conducting various experiments, we can demonstrate that the proposed method can enhance the contrast of colour images better than existing techniques.

Keywords: color image, contrast enhancement technique, variational approach, Euler-Lagrang equation, dynamic approximation method, EME measure

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145 Numerical Solution of Space Fractional Order Linear/Nonlinear Reaction-Advection Diffusion Equation Using Jacobi Polynomial

Authors: Shubham Jaiswal

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During modelling of many physical problems and engineering processes, fractional calculus plays an important role. Those are greatly described by fractional differential equations (FDEs). So a reliable and efficient technique to solve such types of FDEs is needed. In this article, a numerical solution of a class of fractional differential equations namely space fractional order reaction-advection dispersion equations subject to initial and boundary conditions is derived. In the proposed approach shifted Jacobi polynomials are used to approximate the solutions together with shifted Jacobi operational matrix of fractional order and spectral collocation method. The main advantage of this approach is that it converts such problems in the systems of algebraic equations which are easier to be solved. The proposed approach is effective to solve the linear as well as non-linear FDEs. To show the reliability, validity and high accuracy of proposed approach, the numerical results of some illustrative examples are reported, which are compared with the existing analytical results already reported in the literature. The error analysis for each case exhibited through graphs and tables confirms the exponential convergence rate of the proposed method.

Keywords: space fractional order linear/nonlinear reaction-advection diffusion equation, shifted Jacobi polynomials, operational matrix, collocation method, Caputo derivative

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144 Regulation of Water Balance of the Plant from the Different Geo-Environmental Locations

Authors: Astghik R. Sukiasyan

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Under the drought stress condition, the plants would grow slower. Temperature is one of the most important abiotic factors which suppress the germination processes. However, the processes of transpiration are regulated directly by the cell water, which followed to an increase in volume of vacuoles. During stretching under the influence of water pressure, the cell goes into the state of turgor. In our experiments, lines of the semi-dental sweet maize of Armenian population from various zones of growth under mild and severe drought stress were tested. According to results, the value of the water balance of the plant cells may reflect the ability of plants to adapt to drought stress. It can be assumed that the turgor allows evaluating the number of received dissolved substance in cell.

Keywords: turgor, drought stress, plant growth, Armenian Zea Maize Semidentata

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143 Improving the Teaching of Mathematics at University Using the Inverted Classroom Model: A Case in Greece

Authors: G. S. Androulakis, G. Deli, M. Kaisari, N. Mihos

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Teaching practices at the university level have changed and developed during the last decade. Implementation of inverted classroom method in secondary education consists of a well-formed basis for academic teachers. On the other hand, distance learning is a well-known field in education research and widespread as a method of teaching. Nonetheless, the new pandemic found many Universities all over the world unprepared, which made adaptations to new methods of teaching a necessity. In this paper, we analyze a model of an inverted university classroom in a distance learning context. Thus, the main purpose of our research is to investigate students’ difficulties as they transit to a new style of teaching and explore their learning development during a semester totally different from others. Our teaching experiment took place at the Business Administration department of the University of Patras, in the context of two courses: Calculus, a course aimed at first-year students, and Statistics, a course aimed at second-year students. Second-year students had the opportunity to attend courses in the university classroom. First-year students started their semester with distance learning. Using a comparative study of these two groups, we explored significant differences in students’ learning procedures. Focused group interviews, written tests, analyses of students’ dialogues were used in a mixed quantity and quality research. Our analysis reveals students’ skills, capabilities but also a difficulty in following, non-traditional style of teaching. The inverted classroom model, according to our findings, offers benefits in the educational procedure, even in a distance learning environment.

Keywords: distance learning, higher education, inverted classroom, mathematics teaching

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142 Cavitas Sensors into Human Cavities: Soft-Contact Lens and Mouthguard Sensors

Authors: Kohji Mitsubayashi, Takahiro Arakawa, Kohji Mitsubayashi

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‘Cavitas sensors’ attached to human body cavities such as a contact lens type and a mouthguard (‘no implantable', ‘no wearable’) attracted attention as self-detachable devices for daily medicine. In this contribution, the soft contact lens glucose sensor for tear sugar monitoring will be introduced. And the mouthguard sensor with dental materials integrated with Bluetooth low energy (BLE) wireless module for real-time monitoring of saliva glucose would also be demonstrated. In the near future, those self-detachable cavitas sensors are expected to improve quality of life in view of the aging of society.

Keywords: cavitas sensor, biosensor, contact lens, mouthguard

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141 Comparative Study and Parallel Implementation of Stochastic Models for Pricing of European Options Portfolios using Monte Carlo Methods

Authors: Vinayak Bassi, Rajpreet Singh

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Over the years, with the emergence of sophisticated computers and algorithms, finance has been quantified using computational prowess. Asset valuation has been one of the key components of quantitative finance. In fact, it has become one of the embryonic steps in determining risk related to a portfolio, the main goal of quantitative finance. This study comprises a drawing comparison between valuation output generated by two stochastic dynamic models, namely Black-Scholes and Dupire’s bi-dimensionality model. Both of these models are formulated for computing the valuation function for a portfolio of European options using Monte Carlo simulation methods. Although Monte Carlo algorithms have a slower convergence rate than calculus-based simulation techniques (like FDM), they work quite effectively over high-dimensional dynamic models. A fidelity gap is analyzed between the static (historical) and stochastic inputs for a sample portfolio of underlying assets. In order to enhance the performance efficiency of the model, the study emphasized the use of variable reduction methods and customizing random number generators to implement parallelization. An attempt has been made to further implement the Dupire’s model on a GPU to achieve higher computational performance. Furthermore, ideas have been discussed around the performance enhancement and bottleneck identification related to the implementation of options-pricing models on GPUs.

Keywords: monte carlo, stochastic models, computational finance, parallel programming, scientific computing

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140 Antimicrobial and Antibiofilm Properties of Fatty Acids Against Streptococcus Mutans

Authors: A. Mulry, C. Kealey, D. B. Brady

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Planktonic bacteria can form biofilms which are microbial aggregates embedded within a matrix of extracellular polymeric substances (EPS). They can be found attached to abiotic or biotic surfaces. Biofilms are responsible for oral diseases such as dental caries, gingivitis and the progression of periodontal disease. Biofilms can resist 500 to 1000 times the concentration of biocides and antibiotics used to kill planktonic bacteria. Biofilm development on oral surfaces involves four stages, initial attachment, early development, maturation and dispersal of planktonic cells. The Minimum Inhibitory Concentration (MIC) was determined using a range of saturated and unsaturated fatty acids using the resazurin assay, followed by serial dilution and spot plating on BHI agar plates to establish the Minimum Bactericidal Concentration (MBC). Log reduction of bacteria was also evaluated for each fatty acid. The Minimum Biofilm Inhibition Concentration (MBIC) was determined using crystal violet assay in 96 well plates on forming and pre-formed S. mutans biofilms using BHI supplemented with 1% sucrose. Saturated medium-chain fatty acids Octanoic (C8.0), Decanoic (C10.0) and Undecanoic acid (C11.0) do not display strong antibiofilm properties; however, Lauric (C12.0) and Myristic (C14.0) display moderate antibiofilm properties with 97.83% and 97.5% biofilm inhibition with 1000 µM respectively. Monounsaturated, Oleic acid (C18.1) and polyunsaturated large chain fatty acids, Linoleic acid (C18.2) display potent antibiofilm properties with biofilm inhibition of 99.73% at 125 µM and 100% at 65.5 µM, respectively. Long-chain polyunsaturated Omega-3 fatty acids α-Linoleic (C18.3), Eicosapentaenoic Acid (EPA) (C20.5), Docosahexaenoic Acid (DHA) (C22.6) have displayed strong antibiofilm efficacy from concentrations ranging from 31.25-250µg/ml. DHA is the most promising antibiofilm agent with an MBIC of 99.73% with 15.625µg/ml. This may be due to the presence of six double bonds and the structural orientation of the fatty acid. To conclude, fatty acids displaying the most antimicrobial activity appear to be medium or long-chain unsaturated fatty acids containing one or more double bonds. Most promising agents include Omega-3-fatty acids Linoleic, α-Linoleic, EPA and DHA, as well as Omega-9 fatty acid Oleic acid. These results indicate that fatty acids have the potential to be used as antimicrobials and antibiofilm agents against S. mutans. Future work involves further screening of the most potent fatty acids against a range of bacteria, including Gram-positive and Gram-negative oral pathogens. Future work will involve incorporating the most effective fatty acids onto dental implant devices to prevent biofilm formation.

Keywords: antibiofilm, biofilm, fatty acids, S. mutans

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139 Conservative and Surgical Treatment of Antiresorptive Drug-Related Osteonecrosis of the Jaw with Ultrasonic Piezoelectric Bone Surgery under Polyvinylpyrrolidone Iodine Irrigation: A Case Series of 13 Treated Sites

Authors: Esra Yuce, Isil D. S. Yamaner, Murude Yazan

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Aims and objective: Antiresorptive agents including bisphosphonates and denosumab as strong suppressors of osteoclasts are the most commonly used antiresorptive medications for the treatment of osteoporosis which counteract the negative quantitative alteration of trabecular and cortical bone by inhibition of bone turnover. Oral bisphosphonate therapy for the treatment of osteopenia, osteoporosis or Paget's disease is associated with the low-grade risk of osteonecrosis of the jaw, while higher-grade risk is associated with receiving intravenous bisphosphonates therapy in the treatment of multiple myeloma and bone metastases. On the other hand, there has been a remarkable increase in incidences of antiresorptive related osteonecrosis of the jaw (ARONJ) in oral bisphosphonate users. This clinical presentation will evaluate the healing outcomes via piezoelectric bone surgery under the irrigation of PVP-I solution irrigation in patients received bisphosphonate therapy. Material-Method: The study involved 8 female and 5 male patients that have been treated for ARONJ. Among 13 necrotic sites, 9 were in the mandible and 4 were in the maxilla. All of these 13 patients treated with surgical debridement via piezoelectric bone surgery under irrigation by solution with 3% PVP-I concentration in combination with long-term antibiotic therapy and 5 also underwent removal of mobile segments of bony sequestrum. All removable prosthesis in 8 patients were relined with soft liners during the healing periods in order to eliminate chronic minor traumas. Results: All patients were on oral bisphosphonate therapy for at least 2 years and 5 of which had received intravenous bisphosphonates up to 1 year before therapy with oral bisphosphonates was started. According to the AAOMS staging system, four cases were stage II, eight cases were stage I, and one case was stage III. The majority of lesions were identified at sites of dental prostheses (38%) and dental extractions (62%). All patients diagnosed with ARONJ stage I had used unadjusted removable prostheses. No recurrence of the symptoms was observed during the present follow-up (9–37 months). Conclusion: Despite their confirmed effectiveness, the prevention and treatment of osteonecrosis of the jaw secondary to oral bisphosphonate therapy remain major medical challenges. Treatment with piezoelectric bone surgery with irrigation of povidone-iodine solution was effective for management of bisphosphonate-related osteonecrosis of the jaw. Taking precautions for patients treated with oral bisphosphonates, especially also denture users, may allow for a reduction in the rate of developing osteonecrosis of the maxillofacial region.

Keywords: antiresorptive drug related osteonecrosis, bisphosphonate therapy, piezoelectric bone surgery, povidone iodine

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138 Non Linear Stability of Non Newtonian Thin Liquid Film Flowing down an Incline

Authors: Lamia Bourdache, Amar Djema

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The effect of non-Newtonian property (power law index n) on traveling waves of thin layer of power law fluid flowing over an inclined plane is investigated. For this, a simplified second-order two-equation model (SM) is used. The complete model is second-order four-equation (CM). It is derived by combining the weighted residual integral method and the lubrication theory. This is due to the fact that at the beginning of the instability waves, a very small number of waves is observed. Using a suitable set of test functions, second order terms are eliminated from the calculus so that the model is still accurate to the second order approximation. Linear, spatial, and temporal stabilities are studied. For travelling waves, a particular type of wave form that is steady in a moving frame, i.e., that travels at a constant celerity without changing its shape is studied. This type of solutions which are characterized by their celerity exists under suitable conditions, when the widening due to dispersion is balanced exactly by the narrowing effect due to the nonlinearity. Changing the parameter of celerity in some range allows exploring the entire spectrum of asymptotic behavior of these traveling waves. The (SM) model is converted into a three dimensional dynamical system. The result is that the model exhibits bifurcation scenarios such as heteroclinic, homoclinic, Hopf, and period-doubling bifurcations for different values of the power law index n. The influence of the non-Newtonian parameter on the nonlinear development of these travelling waves is discussed. It is found at the end that the qualitative characters of bifurcation scenarios are insensitive to the variation of the power law index.

Keywords: inclined plane, nonlinear stability, non-Newtonian, thin film

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137 Damping and Stability Evaluation for the Dynamical Hunting Motion of the Bullet Train Wheel Axle Equipped with Cylindrical Wheel Treads

Authors: Barenten Suciu

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Classical matrix calculus and Routh-Hurwitz stability conditions, applied to the snake-like motion of the conical wheel axle, lead to the conclusion that the hunting mode is inherently unstable, and its natural frequency is a complex number. In order to analytically solve such a complicated vibration model, either the inertia terms were neglected, in the model designated as geometrical, or restrictions on the creep coefficients and yawing diameter were imposed, in the so-called dynamical model. Here, an alternative solution is proposed to solve the hunting mode, based on the observation that the bullet train wheel axle is equipped with cylindrical wheels. One argues that for such wheel treads, the geometrical hunting is irrelevant, since its natural frequency becomes nil, but the dynamical hunting is significant since its natural frequency reduces to a real number. Moreover, one illustrates that the geometrical simplification of the wheel causes the stabilization of the hunting mode, since the characteristic quartic equation, derived for conical wheels, reduces to a quadratic equation of positive coefficients, for cylindrical wheels. Quite simple analytical expressions for the damping ratio and natural frequency are obtained, without applying restrictions into the model of contact. Graphs of the time-depending hunting lateral perturbation, including the maximal and inflexion points, are presented both for the critically-damped and the over-damped wheel axles.

Keywords: bullet train, creep, cylindrical wheels, damping, dynamical hunting, stability, vibration analysis

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136 “SockGEL/PLUG” Injectable Smart/Intelligent and Bio-Inspired Sol-Gel Nanomaterials for Simple and Complex Oro-Dental and Cranio-Maxillo-Facial Interventional Applications

Authors: Ziyad S. Haidar

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Millions of teeth are removed annually, and dental extraction is one of the most commonly performed surgical procedures globally. Whether due to caries, periodontal disease or trauma, exodontia and the ensuing wound healing and bone remodeling processes of the resultant socket (hole in the jaw bone) usually result in serious deformities of the residual alveolar osseous ridge and surrounding soft tissues (reduced height/width). Such voluminous changes render the placement of a proper conventional bridge, denture or even an implant-supported prosthesis extremely challenging. Further, most extractions continue to be performed with no regard for preventing the onset of alveolar osteitis (also known as dry socket, a painful and difficult-to-treat/-manage condition post-exodontia). Hence, such serious resorptive morphological changes often result in significant facial deformities and a negative impact on the overall Quality of Life (QoL) of patients (and oral health-related QoL), alarming, particularly for the geriatric with compromised healing and in light of the thriving longevity statistics. Opportunity: Despite advances in tissue/wound grafting, serious limitations continue to exist, including efficacy and clinical outcome predictability, cost, treatment time, expertise and risk of immune reactions. For cases of dry sockets, specifically, the commercially-available and often-prescribed home remedies are highly lacking. Indeed, most are not recommended for use anymore. Alveogyl is a fine example. Hence, there is a great market demand and need for alternative solutions. Solution: Herein, SockGEL/PLUG (patent pending), an all-natural, drug-free and injectable stimuli-responsive hydrogel, was designed, formulated, characterized and evaluated as an osteogenic, angiogenic, anti-microbial and pain-soothing suture-free intra-alveolar dressing, safe and efficacious for use in several oro-dental and cranio-maxillo-facial interventional applications; for example: in fresh dental extraction sockets, immediately post-exodontia. It is composed of FDA-approved, biocompatible and biodegradable polymers, self-assembled electro-statically to formulate a scaffolding matrix to (a) prevent the onset of alveolar osteitis via securing the fibrin-clot in situ and protecting/sealing the socket from contamination/infection; and (b) endogenously promote/accelerate wound healing and bone remodeling to preserve the volume of the alveolus. Findings: The intrinsic properties of the SockGEL/PLUG hydrogel were evaluated physico-chemico-mechanically for safety (cell viability), viscosity, rheology, bio-distribution and essentially, capacity to induce wound healing and osteogenesis (small defect, in vivo) without any signaling cues from exogenous cells, growth factors or drugs. The performed animal model of cranial critical-sized and non-vascularized bone defects shall provide vitally critical insights into the role and mechanism of the employed natural bio-polymer blend and gel product in endogenous reparative regeneration of soft tissues and bone morphogenesis. Alongside, the fine-tuning of our modified formulation method will further tackle appropriateness, reproducibility, scalability, ease and speed in producing stable, biodegradable and sterilizable stimuli (thermo-sensitive and photo-responsive) matrices (3-dimensional interpenetrating yet porous polymeric network) suitable for an intra-socket application, and beyond. Conclusions and Perspective: Findings are anticipated to provide sufficient evidence to translate into pilot clinical trials and validate the bionanomaterial before engaging the market for feasibility, acceptance and cost-effectiveness studies. The SockGEL/PLUG platform is patent pending: SockGEL is a bio-inspired drug-free hydrogel; SockPLUG is a drug-loaded hydrogel designed for complex indications.

Keywords: hydrogel, injectable, dentistry, craniomaxillofacial complex, bioinspired, nanobiotechnology, biopolymer, sol-gel, stimuli-responsive, matrix, tissue engineering, regenerative medicine

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135 Hydroxyapatite Based Porous Scaffold for Tooth Tissue Engineering

Authors: Pakize Neslihan Taslı, Alev Cumbul, Gul Merve Yalcın, Fikrettin Sahin

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A key experimental trial in the regeneration of large oral and craniofacial defects is the neogenesis of osseous and ligamentous interfacial structures. Currently, oral regenerative medicine strategies are unpredictable for repair of tooth supporting tissues destroyed as a consequence of trauma, chronic infection or surgical resection. A different approach combining the gel-casting method with Hydroxy Apatite HA-based scaffold and different cell lineages as a hybrid system leads to successively mimic the early stage of tooth development, in vitro. HA is widely accepted as a bioactive material for guided bone and tooth regeneration. In this study, it was reported that, HA porous scaffold preparation, characterization and evaluation of structural and chemical properties. HA is the main factor that exists in tooth and it is in harmony with structural, biological, and mechanical characteristics. Here, this study shows mimicking immature tooth at the late bell stage design and construction of HA scaffolds for cell transplantation of human Adipose Stem Cells (hASCs), human Bone Marrow Stem Cells (hBMSCs) and Gingival Epitelial cells for the formation of human tooth dentin-pulp-enamel complexes in vitro. Scaffold characterization was demonstrated by SEM, FTIR and pore size and density measurements. The biological contraction of dental tissues against each other was demonstrated by mRNA gene expressions, histopatologic observations and protein release profile by ELISA tecnique. The tooth shaped constructs with a pore size ranging from 150 to 300 µm arranged by gathering right amounts of materials provide interconnected macro-porous structure. The newly formed tissue like structures that grow and integrate within the HA designed constructs forming tooth cementum like tissue, pulp and bone structures. These findings are important as they emphasize the potential biological effect of the hybrid scaffold system. In conclusion, this in vitro study clearly demonstrates that designed 3D scaffolds shaped as a immature tooth at the late bell stage were essential to form enamel-dentin-pulp interfaces with an appropriate cell and biodegradable material combination. The biomimetic architecture achieved here is providing a promising platform for dental tissue engineering.

Keywords: tooth regeneration, tissue engineering, adipose stem cells, hydroxyapatite tooth engineering, porous scaffold

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134 Correction of Skeletal Deformity by Surgical Approach – A Case Report

Authors: Davender Kumar, Virender Singh, Rekha Sharma

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Correction of skeletal deformities in adult patients with orthodontics is limited. In adult severe cases, the combined approach, orthodontic and orthognathic surgery, is always the treatment of choice, and the results obtained usually ensure a better esthetic, functional, and stable results Orthognathic surgery is the best option for cases when camouflage treatment is questionable and growth modulation is not possible. This case report illustrates the benefit of the team approach in correcting mandible retrusion along with class II skeletal deformity with 100% deep bite. Correction was achieved by anterior repositioning of mandible osteotomy along with orthodontic treatment. The patient's facial appearance was markedly improved along with functional and stable occlusion.

Keywords: camouflage, skeletal, orthognathic, dental

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133 Initial Periodontal Therapy and Follow-up in a Periodontitis Patient: A Case Report

Authors: Yasir Karabacak

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Objective: The aim of periodontal therapy is to control and eliminate inflammation in order halt disease progression. The initial periodontal therapy (IPT) including scaling and root planing (SRP) can control periodontal disease in most cases of periodontitis; also maintaining good oral hygiene by the patient is fundamental. The aim of this case report is to present IPT and to present 3-month follow-up results in a patient with periodontitis. Materials and Methods IPT of a 63-year-old non-smoker male with generalized periodontitis is presented. The patient had no history of systemic disease. The intraoral examination reveals marked gingival inflammation as well as plaque accumulation and significant calculus deposits. On radiographic examination, severe bone loss was evident. The patient was diagnosed with generalized advanced periodontitis. Initial periodontal therapy including oral hygiene instructions and quadrant-based SRP under local anesthesia was performed using hand and ultrasonic instruments. No antibiotics were prescribed. The patient was recalled 4 weeks after IPT. Results Favorable clinical improvement was obtained. Gingival inflammation was resolved significantly. A reduction of the mean probing depth from 2.4 mm at baseline to 1.9 mm was observed. The patient presented with a good standard of oral hygiene. The plaque scores decreased from 54.0% at baseline to 17.0%. In addition, the percentage of sites with bleeding on probing decreased from 80.0% at baseline to 44.0%. The patient was scheduled for maintenance therapy every three months. Conclusion: The level of oral hygiene has a great impact on periodontal treatment outcome and supports periodontal therapy properly.

Keywords: initial periodontal, therapy and follow-up in a periodontitis, patient, a case report

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132 Evaluation of Salivary Nickel Level During Orthodontic Treatment

Authors: Mudafara S. Bengleil, Juma M. Orfi, Iman Abdelgader

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Since nickel is a known toxic and carcinogenic metal, the present study was designed to evaluate the level of nickel released into the saliva of orthodontic patients. Non-stimulated saliva was collected from 18 patients attending The Orthodontic Clinic of Dental Faculty of Benghazi University. Patients were divided into two groups and level of nickel was determined by atomic absorption spectrophotometry. Nickel concentration values (mg/L) in first group prior to starting treatment was 0.097± 0.071. An increase in level of nickel was followed by decrease 4 and 8 weeks after applying the arch wire (0.208± 0.112) and (0.077±0.056 mg/L) respectively. Nickel levels in saliva of the second group were showed minimal variation and ranged from 0.061± 0.044mg/L to 0.083±0.054 throughout period of study. It may be concluded that there could be a release of nickel from the appliance used in first group but it doesn't reach toxic level in saliva.

Keywords: atomic absorption spectrophotometry, nickel, orthodontic treatment, saliva, toxicity

Procedia PDF Downloads 322
131 Fluid–Structure Interaction Modeling of Wind Turbines

Authors: Andre F. A. Cyrino

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Knowing that the technological advance is the focus on the efficient extraction of energy from wind, and therefore in the design of wind turbine structures, this work aims the study of the fluid-structure interaction of an idealized wind turbine. The blade was studied as a beam attached to a cylindrical Hub with rotation axis pointing the air flow that passes through the rotor. Using the calculus of variations and the finite difference method the blade will be simulated by a discrete number of nodes and the aerodynamic forces were evaluated. The study presented here was written on Matlab and performs a numeric simulation of a simplified model of windmill containing a Hub and three blades modeled as Euler-Bernoulli beams for small strains and under the constant and uniform wind. The mathematical approach is done by Hamilton’s Extended Principle with the aerodynamic loads applied on the nodes considering the local relative wind speed, angle of attack and aerodynamic lift and drag coefficients. Due to the wide range of angles of attack, a wind turbine blade operates, the airfoil used on the model was NREL SERI S809 which allowed obtaining equations for Cl and Cd as functions of the angle of attack, based on a NASA study. Tridimensional flow effects were no taken in part, as well as torsion of the beam, which only bends. The results showed the dynamic response of the system in terms of displacement and rotational speed as the turbine reached the final speed. Although the results were not compared to real windmills or more complete models, the resulting values were consistent with the size of the system and wind speed.

Keywords: blade aerodynamics, fluid–structure interaction, wind turbine aerodynamics, wind turbine blade

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130 [Keynote Talk]: Applying p-Balanced Energy Technique to Solve Liouville-Type Problems in Calculus

Authors: Lina Wu, Ye Li, Jia Liu

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We are interested in solving Liouville-type problems to explore constancy properties for maps or differential forms on Riemannian manifolds. Geometric structures on manifolds, the existence of constancy properties for maps or differential forms, and energy growth for maps or differential forms are intertwined. In this article, we concentrate on discovery of solutions to Liouville-type problems where manifolds are Euclidean spaces (i.e. flat Riemannian manifolds) and maps become real-valued functions. Liouville-type results of vanishing properties for functions are obtained. The original work in our research findings is to extend the q-energy for a function from finite in Lq space to infinite in non-Lq space by applying p-balanced technique where q = p = 2. Calculation skills such as Hölder's Inequality and Tests for Series have been used to evaluate limits and integrations for function energy. Calculation ideas and computational techniques for solving Liouville-type problems shown in this article, which are utilized in Euclidean spaces, can be universalized as a successful algorithm, which works for both maps and differential forms on Riemannian manifolds. This innovative algorithm has a far-reaching impact on research work of solving Liouville-type problems in the general settings involved with infinite energy. The p-balanced technique in this algorithm provides a clue to success on the road of q-energy extension from finite to infinite.

Keywords: differential forms, holder inequality, Liouville-type problems, p-balanced growth, p-harmonic maps, q-energy growth, tests for series

Procedia PDF Downloads 208
129 Effect of Different Local Anesthetic Agents on Physiological Parameters and Vital Signs during Extraction in Children

Authors: Rasha F. Sharaf

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Administration of local anesthesia for a child is considered a painful procedure, which affects his vital signs, physiological parameters, and his further attitude in the dental clinic. During the extraction of mandibular molars, the nerve block technique is the most commonly used for the administration of local anesthesia; however, this technique requires deep penetration of the needle, which causes pain and discomfort for the child. Therefore, the inferior alveolar nerve block technique can be substituted with an infiltration technique which is not painful if a potent anesthetic solutions will be used. In the current study, the effect of Articaine 4% will be compared to Mepivacaine 2%, and their influence on the vital signs of the child, as well as their ability to control pain during extraction, will be assessed.

Keywords: anesthesia, articaine, pain control, extraction

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128 Analysis of the Outcome of the Treatment of Osteoradionecrosis in Patients after Radiotherapy for Head and Neck Cancer

Authors: Petr Daniel Kovarik, Matt Kennedy, James Adams, Ajay Wilson, Andy Burns, Charles Kelly, Malcolm Jackson, Rahul Patil, Shahid Iqbal

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Introduction: Osteoradionecrosis (ORN) is a recognised toxicity of radiotherapy (RT) for head and neck cancer (HNC). Existing literature lacks any generally accepted definition and staging system for this toxicity. Objective: The objective is to analyse the outcome of the surgical and nonsurgical treatments of ORN. Material and Method: Data on 2303 patients treated for HNC with radical or adjuvant RT or RT-chemotherapy from January 2010 - December 2021 were retrospectively analysed. Median follow-up to the whole group of patients was 37 months (range 0–148 months). Results: ORN developed in 185 patients (8.1%). The location of ORN was as follows; mandible=170, maxilla=10, and extra oral cavity=5. Multiple ORNs developed in 7 patients. 5 patients with extra oral cavity ORN were excluded from treatment analysis as the management is different. In 180 patients with oral cavity ORN, median follow-up was 59 months (range 5–148 months). ORN healed in 106 patients, treatment failed in 74 patients (improving=10, stable=43, and deteriorating=21). Median healing time was 14 months (range 3-86 months). Notani staging is available in 158 patients with jaw ORN with no previous surgery to the mandible (Notani class I=56, Notani class II=27, and Notani class III=76). 28 ORN (mandible=27, maxilla=1; Notani class I=23, Notani II=3, Notani III=1) healed spontaneously with a median healing time 7 months (range 3–46 months). In 20 patients, ORN developed after dental extraction, in 1 patient in the neomandible after radical surgery as a part of the primary treatment. In 7 patients, ORN developed and spontaneously healed in irradiated bone with no previous surgical/dental intervention. Radical resection of the ORN (segmentectomy, hemi-mandibulectomy with fibula flap) was performed in 43 patients (all mandible; Notani II=1, Notani III=39, Notani class was not established in 3 patients as ORN developed in the neomandible). 27 patients healed (63%); 15 patients failed (improving=2, stable=5, deteriorating=8). The median time from resection to healing was 6 months (range 2–30 months). 109 patients (mandible=100, maxilla=9; Notani I=3, Notani II=23, Notani III=35, Notani class was not established in 9 patients as ORN developed in the maxilla/neomandible) were treated conservatively using a combination of debridement, antibiotics and Pentoclo. 50 patients healed (46%) with a median healing time 14 months (range 3–70 months), 59 patients are recorded with persistent ORN (improving=8, stable=38, deteriorating=13). Out of 109 patients treated conservatively, 13 patients were treated with Pentoclo only (all mandible; Notani I=6, Notani II=3, Notani III=3, 1 patient with neomandible). In total, 8 patients healed (61.5%), treatment failed in 5 patients (stable=4, deteriorating=1). Median healing time was 14 months (range 4–24 months). Extra orally (n=5), 3 cases of ORN were in the auditory canal and 2 in mastoid. ORN healed in one patient (auditory canal after 32 months. Treatment failed in 4 patients (improving=3, stable=1). Conclusion: The outcome of the treatment of ORN remains in general, poor. Every effort should therefore be made to minimise the risk of development of this devastating toxicity.

Keywords: head and neck cancer, radiotherapy, osteoradionecrosis, treatment outcome

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127 Comparison of Safety and Efficacy between Thulium Fibre Laser and Holmium YAG Laser for Retrograde Intrarenal Surgery

Authors: Sujeet Poudyal

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Introduction: After Holmium:yttrium-aluminum-garnet (Ho: YAG) laser has revolutionized the management of urolithiasis, the introduction of Thulium fibre laser (TFL) has already challenged Ho:YAG laser due to its multiple commendable properties. Nevertheless, there are only few studies comparing TFL and holmium laser in Retrograde Intrarenal Surgery(RIRS). Therefore, this study was carried out to compare the efficacy and safety of thulium fiber laser (TFL) and holmium laser in RIRS. Methods: This prospective comparative study, which included all patients undergoing laser lithotripsy (RIRS) for proximal ureteric calculus and nephrolithiasis from March 2022 to March 2023, consisted of 63 patients in Ho:YAG laser group and 65 patients in TFL group. Stone free rate, operative time, laser utilization time, energy used, and complications were analysed between the two groups. Results: Mean stone size was comparable in TFL (14.23±4.1 mm) and Ho:YAG (13.88±3.28 mm) group, p-0.48. Similarly, mean stone density in TFL (1269±262 HU) was comparable to Ho:YAG (1189±212 HU), p-0.48. There was significant difference in lasing time between TFL (12.69±7.41 mins) and Ho:YAG (20.44±14 mins), p-0.012). TFL group had operative time of 43.47± 16.8 mins which was shorter than Ho:YAG group (58±26.3 mins),p-0.005. Both TFL and Ho:YAG groups had comparable total energy used(11.4±6.2 vs 12±8 respectively, p-0.758). Stone free rate was 87%for TFL, whereas it was 79.5% for Ho:YAG, p-0.25). Two cases of sepsis and one ureteric stricture were encountered in TFL, whereas three cases suffered from sepsis apart from one ureteric stricture in Ho:YAG group, p-0.62). Conclusion: Thulium Fibre Laser has similar efficacy as Holmium: YAG Laser in terms of safety and stone free rate. However, due to better stone ablation rate in TFL, it can become the game changer in management of urolithiasis in the coming days.

Keywords: retrograde intrarenal surgery, thulium fibre laser, holmium:yttrium-aluminum-garnet (ho:yag) laser, nephrolithiasis

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126 Probabilistic Analysis of Bearing Capacity of Isolated Footing using Monte Carlo Simulation

Authors: Sameer Jung Karki, Gokhan Saygili

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The allowable bearing capacity of foundation systems is determined by applying a factor of safety to the ultimate bearing capacity. Conventional ultimate bearing capacity calculations routines are based on deterministic input parameters where the nonuniformity and inhomogeneity of soil and site properties are not accounted for. Hence, the laws of mathematics like probability calculus and statistical analysis cannot be directly applied to foundation engineering. It’s assumed that the Factor of Safety, typically as high as 3.0, incorporates the uncertainty of the input parameters. This factor of safety is estimated based on subjective judgement rather than objective facts. It is an ambiguous term. Hence, a probabilistic analysis of the bearing capacity of an isolated footing on a clayey soil is carried out by using the Monte Carlo Simulation method. This simulated model was compared with the traditional discrete model. It was found out that the bearing capacity of soil was found higher for the simulated model compared with the discrete model. This was verified by doing the sensitivity analysis. As the number of simulations was increased, there was a significant % increase of the bearing capacity compared with discrete bearing capacity. The bearing capacity values obtained by simulation was found to follow a normal distribution. While using the traditional value of Factor of safety 3, the allowable bearing capacity had lower probability (0.03717) of occurring in the field compared to a higher probability (0.15866), while using the simulation derived factor of safety of 1.5. This means the traditional factor of safety is giving us bearing capacity that is less likely occurring/available in the field. This shows the subjective nature of factor of safety, and hence probability method is suggested to address the variability of the input parameters in bearing capacity equations.

Keywords: bearing capacity, factor of safety, isolated footing, montecarlo simulation

Procedia PDF Downloads 155
125 Prevalence of Dens Evaginatus in Adolescent Population of Melaka: A Retrospective Study

Authors: Preethy Mary Donald, Renjith George Pallivathukal

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Dens evaginatus (DE) is a rare developmental anomaly characterized by a slender enamel-covered tubercle which projects from the occlusal surface of an otherwise normal premolar. DE can often interfere normal occlusion and can lead to complications like sensitivity, pulpal exposure and temporo mandibular joint problems. The orthopantomographs (OPGs) and dental records of patients under the age of 20 who attended the faculty of dentistry, Melaka-Manipal Medical College were examined for DE. Results: The prevalence of DE was 23% among the study group. Males presented with a higher prevalence of 67% and females with 33%. The prevalence of Dens evaginatus was distributed as 28% in maxillary central incisor, 52% in maxillary lateral incisors, 12% in mandibular second premolars. Prevalence in permanent dentitions appeared to be higher than deciduous dentition. The bilateral occurrence of Dens evaginatus is an interesting phenomenon. 57% of the cases of the DE were bilateral.

Keywords: deciduous dentition, dens evaginatus, permanent dentition, prevalence

Procedia PDF Downloads 278
124 Damage to LCP by the Ratcheting Phenomenon Under Cyclic Motion in Oligocyclic Fatigue

Authors: Aboussalih Amira, Zarza Tahar, Fedaoui Kamel, Baroura Lazhar, Hammoudi Salah

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316 L steel is a stainless steel frequently used in orthopedic surgery; in the design of implants (hip, knee, shoulder, ankle, etc.), in dental surgery, cardiology, ophthalmology. Before any use, it is essential to predict the macroscopic phenomenological behavior of the material, and to analyze its response. The behavior of 316 L steel in low cycle fatigue, under uniaxial cyclic loading of tension/compression, producing significant plastic deformations leading to material damage. This investigation allowed us to characterize the behavior of the 316L steel employed in the locking of the compression plates (LCP), of which they are generally used in orthopedics to stabilize the fractured bone parts. And to perceive the phenomenon of Ratcheting leading to the damage of LCP by an excess of plastic deformation under nonsymmetrical alternated imposed constraint in low cycle fatigue.

Keywords: 316L SS, locking compression plate, low cycle fatigue, ratcheting

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