• Computers and Concrete
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• v.31 no.2
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• pp.163-171
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• 2023

Face gear transmission is widely used in aerospace shunt-confluence transmission system. Tooth wear is one of the main factors affecting its bearing transmission performance. Furthermore, the installation errors of face gear are inevitable. In order to study the wear mechanism of face gear tooth surface with installation errors, based on tooth contact analysis numerical method and Archard wear theory, the UMESHMOTION subroutine in ABAQUS is developed.Combining with Arbitrary Lagrangian-Eulerian adaptive mesh technology, the finite element mesh wear model of abraded face gear pair is established.The preprocessing conditions are set to generate the inp files.Then,the inp files for each corner are imported and batch processed in ABAQUS.The loading tooth contact problem at each rotation angle is solved and the load distribution coefficient among gear tooth, tooth root bending stress, tooth surface contact stress and loaded transmission error are obtained. Results show that the tooth root wear is the most serious and the wear at the pitch cone is close to 0.The wear law of tooth surface along tooth width direction is convex parabola and the wear law along tooth height direction is concave parabola.

• Tribology and Lubricants
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• v.16 no.5
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• pp.357-364
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• 2000

In this study, the sliding wear in spur gears, using Archard's wear model, is analyzed. Formulas of tooth sliding wear depth along the line of action are derived. The tooth profile is modified Id make a smooth transmission of the normal loads and the cylinder profile for reducing the pressure spike is suggested. The sliding wear rate is calculated with these profiling results. We expect these modification methods to contribute to the reduction of sliding wear not only in the root, but the tip of tooth and tooth edge.

• The Journal of the Korean dental association
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• v.55 no.5
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• pp.358-364
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• 2017

Nowadays, there has been an increasing interest in the preservation of natural dentition and the proper occlusion related to tooth wear for quality of life. Tooth wear means the loss of tooth enamel structure. This is happened by many causes which is the combined effects of many mechanisms. For keeping proper occlusion, dentists should check tooth wear status with acceptable methods and tools for the proper diagnosis. Until now, there have been many traditional qualitative ways to measure tooth wear which are intuitive, rapid, and simple. On the contrast, they are not objective nor reproducible. With the development of related technique, new quantitative methods using CAD and 3d scanners. This article aimed to introduce qualitative and quantitative methods for tooth wear measurements.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.11
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• pp.1720-1729
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• 2001

Wear characteristics of Nylon and acetal pinions against steel gears for different pitch line velocities was studied with a power circulating gear test rig under unlubricated condition. Specific wear rate was measured as a function of tooth number, module, tooth width and total revolution. The worn tooth surfaces were examined with a profile projector. The Nylon pinion showed lower specific wear rate than the acetal pinion. However, the Nylon pinion was fractured at high tooth loads, whereas the acetal pinion exhibited a steady wear behavior. The wear characteristics of Nylon pinion varied significantly with the Pitch line velocity. Wear occurred most severely at the tooth tip and the region immediately below the pitch line of pinion. The dominant wear mechanisms were adhesion and abrasion.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.3
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• pp.137-146
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• 2018

Tooth wear is a multifactorial condition, leading to the loss of dental hard tissues. While for many years, tooth wear was a condition of little interest in daily clinical practice, nowadays this is changed. Tooth wear is becoming increasingly significant in maintaining the long-term health of the dentition. This becomes especially important when the dentition is kept relatively intact in the contemporary ageing population, and edentulism is decreasing. There is also evidence that the prevalence of tooth wear is growing. It is a natural consequence of the unidirectionality of tooth wear that it is frequently used as a means of individual age estimation. Tooth wear was very serious in ancient populations up to the medieval period. Tooth wear is thus studied in a wide variety of areas. The purpose of this paper is to summarize and analyze the many issues surrounding tooth wear through recent studies in various fields and to search for future research direction.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.25-34
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• 1999

In this study, the sliding wear in spur gears, using Archard's wear model, is analyzed. Formulas of tooth sliding wear depth along the line of action are derived. The tooth profile is modified Id make a smooth transmission of the normal loads and the cylinder profile for reducing the pressure spike is suggested. The sliding wear rate is calculated with these profiling results. We expect these modification methods to contribute to the reduction of sliding wear in the root and the tip of tooth and tooth edge.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.1
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• pp.1-10
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• 2004

Statement of problem : Tooth wear is physiological phenomenon. Ninety-seven percent of normal people have tooth wear and about 7% has pathologic teeth wear. If we know the amount of tooth surface loss caused by pathologic tooth wear, we may restore it ideally Purpose : Recently measurement of tooth wear by using 3D scan has been increasing. Therefore, we need to know how accurate 3D scan is. Past accuracy test on 3D scan was about linear change, but as we know that tooth wear is volume change. Thus, the purpose of this study is to know how accurate 3D scan is. Material and Methods : For accuracy test of 3D scanner volume values measured by 3D scanner and micro-balance were compared. For test I, preliminary, 3 ball samples and 3 circular cones were made with pattern resin. For test II, 10 teeth shape rubber samples were used. Results and Conclusion : 1. The result of the accuracy test on 3D scan with 3 ball samples and 3 circular cones made of pattern resin has no significant difference(p<0.05). 2. The result of the accuracy test on 3D scan with 10 samples of tooth shape rubber has no significant difference (p<0.05). As a result, we may concluded the analysis of quantifying tooth wear used by 3D scan is useful in the clinic.

• Journal of Korean society of Dental Hygiene
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• v.22 no.4
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• pp.225-230
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• 2022

Objectives: Patients with excessive tooth wear should first be diagnosed for the etiology of the tooth wear. Causes of tooth wear include bruxism, clenching, and taking medications for systemic diseases. After identifying the cause of tooth attrition, the final prosthesis should be restored with an appropriate vertical dimension. Methods: A 79-year-old man with worn out teeth desired a whole dental treatment. He was on medications for high blood pressure and asthma. The treatment proceeded with a consultation with a medical doctor. The medications for asthma evoked multiple teeth wear and a loss of the vertical dimension. After recovery of 3 mm of vertical dimension, 2 months of evaluation was followed by an interim prosthesis. Results: The increased vertical dimension caused no problem in function and esthetics, and the final restoration was performed with a full monolithic zirconia crown. Group function, adequate anterior guidance, and the occlusal plane were determined. Conclusions: After the final restoration, the patient was both esthetically and functionally satisfied, and a night guard splint was delivered to prevent prosthesis fracture. The patient was informed about the potential tooth wear associated with asthma drugs and educated to visit the clinic regularly.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.3
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• pp.113-122
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• 2019

Tooth wear is gradually increasing with increasing life expectancy. In particular, it is important to establish a treatment plan in the early stages so that it does not proceed to moderate or severe wear stages. It is essential to diagnose tooth wear accurately in order to plan a treatment for it. There are many risk factors including age, diet, and drugs which affects tooth wear. For the diagnosis of a tooth wear, appropriate index and evaluation method should be used. There were various tooth wear indices such as TWI, Lussi index, BEWE, and TWES. The evaluation method includes clinical examination, dental cast examination and clinical photographs. Recently, a 3D scanner is being used to assess tooth wear. The risk factors, tooth wear evaluation system, the methods of measuring tooth wear, and related literature were reviewed. The strengths and weaknesses of each index and evaluation methods were compared to derive a proper way to diagnose tooth wear.

• Journal of Embryo Transfer
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• v.25 no.3
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• pp.201-206
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• 2010

Two male reticulated giraffes (Giraffa camelopardalis reticulata), 21-year-old, died of nutritional deficiency that primarily caused by serious tooth wear at Seoul Zoo in winter. A 970 kg-weighed giraffe showed tooth wear of premolars, molars and incisors at necropsy. A foreign body in the rumen, congestion and ulcer of abomasum and duodenum were also observed. Mild appearance of serous fat atrophy in pericardial sac suggests that lack of nutritional intake caused by tooth wear can become harmful enough to threat life. At the necropsy of a 1,290 kg-weighed giraffe, a large quantity of sandy soil were found in the rumen which would stuck the pathway of well-fermented ruminal contents at esophageal groove. Nutritional deficiency could be suspected to urge this giraffe to graze grass on the ground along with sandy soil. Secondarily, the soil damaged teeth and become a culprit making irregular tooth wear and mild serous fat atrophy. Nutritionally good care of geriatric animals is needed especially for browsing animals like giraffes and critically in winter season.