Papers by Keyword: Tooth

Abstract: Bone tissue is a calcium deposit and supporting structure of the human body, it is exposed to several pathologies that modify its mineral content. To determine these changes, different diagnostic procedures are performed with techniques using invasive ionizing radiation, which are limited by the negative effects in the long term on human health. A methodology is explored that could be applicable in the diagnosis of pathologic variations in bone mineral density, using structural monitoring tools. The proposed technique estimates changes in bone conditions by applying impedance spectroscopy with a tooth-borne piezo-device. Bone-tooth samples were prepared to simulate a section of maxillary bone and subsequently treated with chemical agents, simulating pathologic decalcification. The piezo-device is inserted in the slot of an orthodontic bracket, previously bonded to the crown of the tooth, in order to transmit vibration to surrounding bone. The variations in bone micro-architecture were computed by image processing analyzed with samples prepared in transparent resin, allowing the measurement of morphometry before and after the induced changes in mineral content. Using vibrational bone response, impedance measurements allowed to observe the variations in bone mass as the samples were progressively decalcified. In the 5-50kHz spectrum, it was demonstrated the sensitivity of the electro-mechanical impedance during the bone alteration procedure since the electrical resistance signals of the piezo-device consistently changed in the frequency spectrum (5-50kHz). The piezo-device shows to be sensitive to the changes produced by the bone alterations, which were caused by the stiffness variations made in the sample during the decalcifying. These changes were statistically correlated to demonstrate that in a less invasive way, bone alterations could be monitored from the teeth. This result opens the door to search for a new way to diagnose bone density changes in real applications.

Abstract: The paper presents an original solution for the mathematical modeling and simulation of an orthodontic process. The orthodontic process is treated as a distributed parameter, its model being expressed using a partial differential equation, respectively the tooth movement is represented as the approximating analytical solution which verifies the mentioned equation. In order to prove the model usability, some interesting simulations are shown in the paper. The obtained model can be numerically simulated using a software application and the simulation results can be used in order to assist the dentist to establish the orthodontic treatment parameters (at the start of the treatment and during the treatment, too; for example the initial force which has to be applied, respectively its ulterior value adjustments).

Abstract: The 3D printing method for the human tooth is a possible and good solution in the manufacture. However, the shrinkage is the most challenging problem to manufacture the tooth. In this paper, CAE analysis and experimental design are applied to predict the shrinkage of different dentures shape. Then the CAD model of the dentures can be reverse amplified before the sintering process. The product will be close to the patients’ requirements with precise dentures shape. It also avoids the complicated procedure of CNC machining and reduces dentists finishing time. The dental bridge is the main research objective investigated in this paper to verify the CAE simulation developed by the authors.

Abstract: Outlined in this study is an analytical solution of the problem of dynamic excitation of two-mass elastic system by parametric change in the stiffness of teeth during the meshing process with consideration of the compliance of shafts. It is shown that the main source of excitation in a gear system is the central pinion gear. Introduction of an optimal level of multi-pitch in the gear wheel lowers vibrations to minimum.

Abstract: This paper can be used as acar key toothed recognition and detection technology and computer vision, imageprocessing technology combined with interdisciplinary applications. Car lockassembly complicated procedures, identification and car keys tooth detection isone of the key aspects of automotive lock assembly, lock a direct impact on theefficiency of the assembly process. The system can effectively improve theexisting car key tooth detection technology to reduce the cost of car keystooth detection recognition, while also rapid and accurate identification, sothat the entire lock assembly process much more efficient.

Abstract: Gear teeth are deformed due to the load. Recently, at ever faster evolving computer technology and the available literature, we can encounter modern numerical methods, such as finite element method (FEM), which can serve as methods for the determination of deflection gearing. This paper deals with stiffness and deformation of teeth of spur gears solution by finite element method.

Abstract: Jaw deformities from tooth removal can be prevented and repaired by a procedure called socket preservation. Socket preservation can greatly improve the smile’s appearance and increase the chances for successful dental implants for years to come. The procedure begins with atraumatic tooth extraction. Every attempt is made to preserve the surrounding bone and soft tissue, with an emphasis on being careful not to fracture the delicate buccal plate. There are a number of techniques and instruments that aid in this process. In general, one never wants to elevate so that force is directed toward the buccal plate. Once the tooth is extracted, all the granulation tissue is removed from the socket. It is important that good bleeding is established in the socket. Next, a bone graft material is placed into the socket.Various materials are used in modern dental and maxillofacial surgery for bone tissue substitution and reconstruction. All osteoplastic materials can be divided into four groups by origin: autogenic, allogenic, xenogenic and synthetic. The development of new medical technologies enables use of achievements in material science, biochemistry, molecular biology and genetic engineering while creating new combined synthetic materials for bone grafting. Mineralized cancellous bone is appropriate for most socket preservation cases.Synthetic resorbable materials were intended as an inexpensive substitute for natural hydroxyapatite. Synthetic graft materials include various types of calcium phosphate ceramics: tribasic calcium phosphate; bioglass; hydroxyapatite and its compositions with collagen, sulphated glycosaminoglycans such as keratan and chrondroitin sulphate as well as with sulphate and calcium phosphate.After the graft material is placed in the socket, it is then covered with a resorbable or non-resorbable membrane and sutured. Primary flap closure is not ideal. Most importantly, socket preservation helps to maintain the alveolar architecture. Socket preservation significantly reduces the loss of ridge width and height following tooth removal.

Abstract: Among the processing methods by cold flow, toothing by intermittent blow is one of the most widespread. The gear-cutting by cold generation by intermittent blow is a processing method which extended continuously especially in the last 30 years. This enabled on the one hand, a better knowledge of the properties of toothed surfaces, and on the other hand the emphasis of the relationships between the superficial characteristics and the exploitation (use) properties of these products (frictional, fatigue etc.), as well as of the optimization of the technological processing parameters of these surfaces. The present paper presents a determination study on the depth of the hammer-hardened coat in the cold teething process by intermittent blow for a tooth of the generated teeth.

Abstract: The powder particles with a flat-screen multi-tooth cutter blade design. This tool structure is used to glue particles fell legitimate work . Processing tool blade tines arranged in a staggered structure . The tool is a gap in the working conditions . Install the tool in the tool axis rotation is strip knives.Friction surface of the tool can be used strip surface design class . Rotating shaft mounted knives role is to bring people powder particles processing zones . After extrusion and promote the formation of frustration legitimate work . Friction surface knives biggest advantage is the use of a long time. Fixed on a movable carriage mounted flat-screen multi-tooth cutter blade . Fixedly mounted on a movable tool holder . Cutter with carbide knife block . Knives replaceable assembly structure can be used . Mobile holder for the tool replacement and gap adjustment .

Abstract: The review of researches of stress concentration in elastic bodies with loaded ledges, which are carried out with separate analysis of each of the force factors, is provided. The known results of using of such an approach are shown for example, the effects of geometrical concentrators curvature are revealed, and on their base principally new nonpole gear systems are developed. The recommendations for significant refinement of the known method are given.