• Title/Summary/Keyword: 심한 마모

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Wear and wear transition mechanism in SiC and SiC-TiB$_{2}$ Composites during sliding (SiC 및 SiC-TiB$_{2}$복합재료에서 미끄럼시의 마모 및 마모천이기구)

  • 조성재;엄창도;김석삼
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1995.06a
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    • pp.11-17
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    • 1995
  • 본 연구에서는 SiC 및 SiC-TiB$_{2}$복합재료의 마모 및 마모천이기구를 비교 실험한 결과 다음과 같은 결론을 얻었다. 두 재료의 마모천이현상은 각각의 하중이 200N(SiC)과 80N(SiC-TiB$_{2}$)이상에서 나타나게 되었다. 마모기구는 임계미끄럼시간에서 두 단계로 나뉘어진다. 소성변형에 의한 grooving과정과 잔류응력에 의한 grain pull-out과정들로써 미세 구조를 통해 관찰할 수 있었다. grain pull-out과정은 초기단계에서 부터 생성된 전위가 축적되어 잔류응력을 발생시키므로 일어난 과정이다. SiC에 TiB$_{2}$를 첨가하므로 마모는 더욱 심하게 일어나게 되었다. 입계의 강도를 더 약하게 하였기 때문이다. 그러나, 파괴인성은 입계강도가 약할수록 증가하였다. 결국 파괴인성이 큰 재료가 마모는 더 심하게 일어남으로 서로 상반된 관계를 갖고 있슴을 결론지을 수 있었다.

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Full mouth rehabilitation with extremely worn dentition (심한 치아 마모 환자의 전악보철 수복 증례)

  • Cha, Hwa-Ryun;Yeom, Kyeong-Yeon;Lee, Yong-Sang;Kim, Na-Hong
    • Journal of Dental Rehabilitation and Applied Science
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    • v.33 no.3
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    • pp.238-244
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    • 2017
  • Pathologic attrition leads to pathologic damage on occlusal plane, functional disorders, occlusal disharmony, esthetic problems, pulpal lesion, temporomandibular joint (TMJ) disorder. In this case, treatment plan should be considered for possibility of vertical dimension loss, occlusal pattern, esthetics, phonetics, amount of vertical dimension increase. This case report was a 71-year-old man who had severely worn dentition. Full mouth rehabilitation was carried out with vertical dimension increase due to limited space for prosthesis. After evaluation of provisional restorations for patient's compliance, final restorations were fabricated and routine clinical assessments were made. This case presents that a satisfactory clinical result was achieved by restoring the worn dentition.

윤활박막이 증착된 다이아몬드 박막의 트리보 거동

  • 나종주;이상로;이구현;남기석;백운승;허종서;백영준
    • Proceedings of the Korean Vacuum Society Conference
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    • 1999.07a
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    • pp.194-194
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    • 1999
  • 다이아몬드 박막은 결정립에 의해 심한 표면 거칠기를 나타낸다. 루비를 상대재료로 사용하여 하중 50g, 50rpm의 회전속도로 마모시험을 하였으며 마모 track의 직경은 100mm였다. 마찰계수는 0.5에서 계속 감소하며 0.1이하에서 안정한 상태를 유지하게 된다. 이 다이아몬드 박막위에 저마찰재료로 알려진 PTFE를 타겟으로 RF로 증착한 후 같은 조건으로 마모시험을 행하면 마찰계수가 초기부터 일정하게 유지할 수 있게 된다. 반면에 MoS2박막이 증착된 경우에는 완만한 마찰계수의 감소가 나타난다. 이러한 변화의 원인으로는 DLC 박막에서 보고되고 있는 바와 같이 다이아몬드의 sp3 결합구조가 마모시험중 흑연화하여 sp2 결합구조로 변하기 때문인 것인지 살펴보기 위하여 micro Raman을 통하여 마모 track을 분석하였고 AFM을 통하여 표면거칠기 변화와 표면 스크래치 발생 여부를 살펴보았다.

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Full mouth rehabilitation using removable partial denture in patient with loss of vertical dimension due to worn dentition (심한 치아 마모로 인해 수직 고경이 상실된 환자에서 국소 의치를 이용한 전악 수복 증례)

  • Shim, Eun-Young;Lee, Na-Young;Kang, Jeong-Kyung
    • The Journal of Korean Academy of Prosthodontics
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    • v.56 no.4
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    • pp.347-353
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    • 2018
  • Gradual attrition is a normal process of aging, but severe attrition causes occlusal disharmony, functional disorder and esthetic problems. The collapse of posterior support may cause attrition of anterior teeth, and loss of occlusal vertical dimension (OVD). And it induces the pathologic change of the TMJ, unaesthetic facial appearance and decreased masticatory function. In this case, 70 year-old male presented with decreased vertical dimension and esthetic problems due to worn dentition. Based on assessment of intraoral findings, diagnostic cast and radiographic examination, full-mouth rehabilitation with increase of OVD was planned. After 10 month follow-up, occlusal stability is maintained and through this procedure, satisfactory outcomes were achieved in esthetic and functional aspects.

Mouth rehabilitation of a patient with severely worn dentition with vertical dimension increase (심한 마모를 가진 환자에서 수직 고경 증가를 동반한 구강회복 증례)

  • Lee, Ki-Young;Kim, Chi-Yoon;Jung, Ji-Hye;Kim, Yu-Lee
    • The Journal of Korean Academy of Prosthodontics
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    • v.53 no.3
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    • pp.215-221
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    • 2015
  • Treating patients with severely worn dentition often requires comprehensive prosthetic treatments. Oral rehabilitation and long-term stability could be achieved by analyzing the cause of the wear and changing vertical dimension. The temporary restoration procedure is executed and patient's adaptation is evaluated by long-term observation when treatment is accompanied with increasing vertical dimension. In this case, 54 year-old male presented with worn dentition and esthetic dissatisfaction. In oral manifestations, severely worn dentition with attrition and erosion is diagnosed. To evaluate change of vertical dimension, interocclusal rest space, facial appearance, pronunciation, clinical crown length, distance from incisor edge to labial vestibule are evaluated. Consequently, 2.5 mm increase of vertical dimension that based on articulator incisal pin is determined. After 8 weeks stabilization period with temporary prostheses, definitive prostheses are fabricated. After 6 months follow up period, satisfactory outcomes were achieved both in functional and esthetic aspects through this procedure.

Full mouth rehabilitation using various digital tools in a patient with collapsed bite due to severe attrition (심한 마모로 인하여 교합이 붕괴된 환자의 다양한 디지털 도구를 이용한 완전 구강회복증례)

  • Moon, Sooin;Lee, Younghoo;Hong, Seoung-Jin;Noh, Kwantae;Pae, Ahran;Kim, Hyeong-Seob;Kwon, Kung-Rock;Paek, Janghyun
    • The Journal of Korean Academy of Prosthodontics
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    • v.60 no.4
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    • pp.320-329
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    • 2022
  • Physiological wear of occlusal surface is inevitable throughout the lifetime, and considered to be normal. Pathologic wear, however, may cause fatal damage to the occlusal surface and destroy esthetics and proper anterior guidance. In such cases, rehabilitation of occlusal wear should be followed by thorough evaluation and diagnosis. In this present case, severe occlusal wear was found in the labial surfaces of mandibular anterior teeth and palatal surfaces of maxillary anterior teeth. Occlusal vertical dimension was evaluated and decided to be regained due to insufficient amount of restorative space. After determining new occlusal vertical dimension, diagnostic wax-up is usually performed to continue prosthodontic treatment. In this case with collapsed occlusion and loss of occlusal vertical dimension, conventional diagnostic wax-up was replaced with various digital devices. Diagnostic wax-up was digitally performed in the software and provisional prosthesis was fabricated with digital tools. With verification with provisional prosthesis, the entire dentition was rehabilitated with newly set occlusal vertical dimension and proper anterior guidance.

Overdenture treatment in patient with severely worn dentition: a case report (심한 마모를 보이는 환자에서의 자연치 피개의치 수복증례)

  • Kim, Min-Ji;Kim, Jun-Yub;Yang, Hong-So;Lim, Hyun-Pil;Yun, Kwi-Dug;Park, Chan;Shin, Jin-Ho;Park, Sang-Won
    • Journal of Dental Rehabilitation and Applied Science
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    • v.32 no.4
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    • pp.307-313
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    • 2016
  • Overdenture is one of the methods of patients with severely worn dentition. Remaining natural teeth help preserve alveolar bone and proprioception and provide rigid support. Also, overdenture distributes the concentrated stress applied to the abutment tooth and denture supporting tissues. There is an advantage that it can provide long-term stability to denture. In this case, the patient with only a few teeth due to severe wear and caries was satisfied with good function and favorable esthetics by using overdenture.

Full mouth rehabilitation of the patient with severely worn dentition and limited vertical dimension (심한 치아 마모와 수복공간 부족을 보이는 환자에서의 완전 구강회복 증례)

  • Yang, Min-Seong;Kim, Seong-Kyun;Heo, Seong-Joo;Koak, Jai-Young;Park, Ji-Man;Yi, Yu-Seung
    • The Journal of Korean Academy of Prosthodontics
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    • v.60 no.1
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    • pp.91-99
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    • 2022
  • Severely worn dentition causes various complications such as loss of tooth structure, discoloration, pulp complications and loss of function and aesthetics. In this case, the patient showed particularly severe attrition in the anterior teeth and lack of space for restoration. The amount of vertical dimension was determined based on the diagnostic wax up, and the patient's adaptation was evaluated by using a removable occlusal splint for 6 weeks. Thereafter, the coordination of the muscular nervous system, aesthetics, temporomandibular joint were re-evaluated for 3 months by restoring the fixed provisional restoration. Through the above treatment process, the final restoration was completed with full mouth fixed prosthesis using monolithic zirconia, and functionally and aesthetically stable results were obtained.

Mandibular full-arch rehabilitation with increased vertical dimension of a patient with severe tooth wear (심한 치아 마모 환자의 수직 교합고경 증가를 동반한 하악 편악 수복 증례)

  • Kim, Hyun-Jin;Kim, Jong-Jin;Baik, Jin;Cha, Hyun-Suk;Lee, Joo-Hee
    • Journal of Dental Rehabilitation and Applied Science
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    • v.38 no.3
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    • pp.162-170
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    • 2022
  • In the case of patients with pathological tooth wear, it is necessary to evaluate the loss of the vertical dimension. Setting the appropriate vertical dimension is important to rehabilitate the patient's stable intermaxillary relationship. A 77-year-old female patient's chief complaint was the pain of the mandibular incisors and the lack of molars. At the first visit, pathologic tooth wear of the mandibular incisors were observed. After diagnosis and evaluation, loss of vertical dimension was not observed, but insufficient intermaxillary space for prosthetic restoration was confirmed. Mandibular rehabilitation was performed with vertical dimension increase and this showed satisfactory results both functionally and aesthetically.