• 대한치과의사협회지
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• 제48권2호
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• pp.140-145
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• 2010

True vertical root fracture (VRF) in nonendodontically treated teeth confined to the root surface (fatigue root fracture; FRF) is apparently uncommon, the few documented reports being Chinese. The aim of this study is to analyze the cases of a fatigue root fracture and to find out the characteristic features of teeth with a FRF. A total of 21 consecutive cases of fatigue root fracture occurring in 16 patients were reviewed. In terms of the occlusion, the presence of restorations, the location, the age and gender, each tooth and patient were analyzed. The prevalent age was in those over 50 years of age (75%) and FRFs were more frequent in male patients (69%). Fatigue root fractures occurred most frequently in the mandibular molars (61.9%; 42.9% in first molar, 19% in second molar). Fatigue root fractures were observed most frequently in the teeth with no restorations (85.7%) and in the patients with occlusal problems (94%). FRFs seem to occur frequently and may represent an undiagnosed clinical entity deserving of our attention.

• 대한소아치과학회지
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• 제45권1호
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• pp.10-20
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• 2018

본 연구는 미성숙 영구치에서 치근 파절 시 치수와 치근 치유에 영향을 주는 요인을 평가하기 위해 치근 파절위치, 치근단공의 크기, 파절편 간격을 측정하였고, 치수와 치근 치유 양상과의 연관성을 통계적으로 분석하여 치근 파절시 예후를 알아보고자 하였다. 51개의 상악 전치부 치근 파절 증례를 대상으로 치근 파절위치, 치근단공의 크기, 파절편 간격을 방사선 사진에서 길이를 측정하였다. 측정된 수치는 독립 T검증, 로지스틱 회귀분석을 통해 평가하였다. 본 연구의 결과, 치근 파절의 위치에 따른 치수 치유의 예후의 차이는 없었다. 그러나 치근 파절의 위치가 치근단에 위치할수록 치근 치유는 잘 일어났으며(p < 0.05), 정복 후 파절편 간격이 좁을수록 치수 치유가 잘 일어남을 확인하였다(p < 0.05).

• 대한구강악안면병리학회지
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• 제42권5호
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• pp.153-158
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• 2018

Complicated crown-root fractures are considered rare occurrences in young permanent dentition; however, they often present complicated and unpredictable treatment options. The most common treatment option for crown-root fractured teeth is reattachment of fractured segment, but if it is thought impossible to maintain, it should be extracted. However, when unfavorable crown-root fracture occurs in the adolescents, extraction of fractured teeth is expected to be poor due to excessive resorption of alveolar and prosthetic replacement cannot be performed immediately, various treatment options should be considered. This report suggests root submergence in the complex crown-root fracture in growing patients is performed and the functional and aesthetic results including preservation of the alveolar bone are obtained.

• 대한소아치과학회지
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• 제27권2호
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• pp.256-261
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• 2000

파절의 종류는 치관파절 치근파절, 동시에 나타난 치관-치근파절이 있고 치수노출에 따라 단순파절과 복잡파절로 나뉜다. 치아파절이 치은 연하로 침범하여 치아장축을 따라 나타난 경우나 치근의 1/3 이상을 넘어선 경우 발치가 원칙이다. 그러나 치근쪽 파절편을 교정적으로 정출시켜서 수복시켜 주는 방법과 인위적으로 발치하여 적절하게 수복 가능한 위치로 재식 시켜주는 방법을 선택적으로 이용할 수 있다. 본 증례에선 치아외상으로 상악 중절치가 치관-치근 파절된 혼합치열기의 환아에서 의도적 재식술을 이용하여 발치 후 즉일 근관치료와 역충전 후 레진수복을 시행하여 치료하였기에 보고하는 바이다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1358-1361
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• 2003

In this study, intrinsic static/dynamic fracture toughness of Al 7175-T74 are evaluated from the apparent static/dynamic toughness of notched specimen. The notch/crack critical average stress fracture model is suggested to establish the relationship to predict the intrinsic fracture toughness from the apparent fracture toughness of a notched specimen. The notch/crack critical average stress fracture model is established using the relation between the notch root radius and the effective distance calculated by finite element analysis. It is conclude that the true fracture toughness can be estimated from test results of apparent fracture toughness measured by using a notched specimen. Also, critical notch root radius can be predicted by notch/crack critical average stress fracture model.

• Restorative Dentistry and Endodontics
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• 제39권2호
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• pp.126-131
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• 2014

Among dental traumas, horizontal root fractures are relatively uncommon injuries. Proper initial management and periodical evaluation is essential for the successful treatment of a root-fractured tooth. If pulpal necrosis develops, endodontic treatment is indicated, exclusively for the coronal fragment. Fragment diastases exert a great influence on healing at the fracture line and on pulpal necrosis. An adequately treated root-fractured tooth has a good prognosis. This case report describes the treatment and 2-yr follow up of 3 maxillary central incisors, first with horizontal root fracture, second with horizontal root fracture and avulsion, and third with horizontal root fracture and lateral luxation. All three cases were treated with mineral trioxide aggregate (ProRoot, Dentsply). During 2 yr of follow-up evaluation, the root-fractured teeth of the present patients were well retained in the arch, showing periodontal healing, even after endodontic treatment.

• 대한소아치과학회지
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• 제35권3호
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• pp.571-577
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• 2008

유치열에서의 치근파절은 유치열의 손상 유형 중 $2{\sim}7%$ 정도를 차지하고 생리적 치근흡수가 시작하는 $3{\sim}4$세 쯤 흔히 나타난다. 파절선의 위치에 따라 치근단 1/3, 중간 1/3, 치경부 1/3으로 분류되며 치경부 1/3에서의 치근파절이 예후가 가장 불량하다. 유치의 치근파절이 발생한 경우 파절편의 변위가 적고 감염의 소견이 없으면 영구치의 경우와 같이 $2{\sim}3$개월의 선부자고정으로 치료할 수 있으나, 파절편의 동요 및 변위가 심하거나 선부자고정을 할 수 없을 때에는 치관부 파절편은 제거하고 영구치배의 안전을 위해 치근부 파절편은 잔존시킨다. 본 증례는 유전치의 치근파절이 발생하여 치관부 파절편의 변위가 심한 경우에서 발치하지 않고 정복 후 선부자 고정을 $1{\sim}3$개월 간 시행하고, 파절편의 동요, 동통, 치수괴사, 감염 등의 증상없이 치유되는 양호한 결과를 얻었기에 보고하고자 한다.

• Restorative Dentistry and Endodontics
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• 제37권3호
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• pp.180-184
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• 2012

Traumatic injuries of the face often involve root fractures especially in anterior teeth. The prognosis and the treatment of the root fracture depend on the extent of the fracture line, general health and patient compliance. This case report outlines a new conservative trial treatment modality to stabilize the maxillary central incisors with horizontal root fracture on the cervical to middle third by fabricating canine guidance to remove loading on the traumatized maxillary central incisors during eccentric movements and thus inducing spontaneous healing of the fractured line between the fragments. Radiographs after thirty months showed adequate healing with no signs of pathological changes including root resorption, ankylosis or displacement. Long term follow-up revealed that vitality, stability and aesthetics were maintained and the patient was satisfied with the outcome.

• 대한치과의사협회지
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• 제52권2호
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• pp.75-84
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• 2014

During dental treatment, if a tooth were fractured suddenly by unnoticed tooth crack or vertical root fracture, it would be very embarrassing and frustrating experiences to dentists. But if it were once diagnosed as one of these teeth fracture, dentist should know about the etiology, course of fracture development, treatment modality to avoid argument with patient. In here cases and diagnostic skills, etiology and treatement methods of tooth fracture originated by internal stress and masticatory force were discussed to help dentists.

• 대한치과보철학회지
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• 제40권3호
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• pp.287-295
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• 2002

Statement of Problem. Endodontically treated teeth frequently required posts and cores to provide retention and resistance form for crowns. In spite of excellent mechanical properties of metal post and core, its metallic color can be detected through all ceramic restorations occasionally. To solve esthetic problems of metal post and core zirconia post system has been introduced recently. Purpose. The purpose of this study was to examine the fracture strength and mode of resin root analogs restored with zirconia, gold and titanium posts with resin, ceramic and metal cores after cementation with metal crowns. Materials and methods. To avoid the morphological variations of natural teeth, 40 root analogs were fabricated with composite resin. Forty resin root analogs were randomly assigned to four groups according to post and core materials: Group A: cast gold post and core and complete cast crowns, as control. Group B: titanium posts (Parapost, Coltent/Whaledent Inc., NJ, USA) and composite resin cores. Group C: zirconia posts (Cosmopost, Ivoclar AG, Schaan/Liechtenstein) and composite resin cores Group D: zirconia posts and heat-pressed ceramic cores (IPS Empress Cosmo Ingots, Ivoclar AG) After thermocycling ($5^{\circ}C{\sim}55^{\circ}C$, 30 sec.), cyclic loading was applied at 3mm below the incisal edge on the palatal surfaces at an angle of 135 degree to the long axis (2Hz, 50N, 50000cycles). Fracture strength was measured by universal testing machine (Instron, High Wycombe, UK) and fracture pattern of restored resin root analogs was also evaluated. Results and conclusion. Within the limitations of this study following results were drawn. 1. Resin root analogs restored with zirconia posts and composite resins demonstrated lowest fracture strength among tested groups. 2. There was no significant difference in the fracture strength between zirconia posts and heat pressed glass ceramic cores and cast gold posts and cores 3. The fracture strength of resin root analogs restored with titanium posts and composite resin cores was lower than that of gold posts and cores. 4. The deep oblique fracture lines were dominantly observed in root analogs restored with cast gold post and core and zirconia post and heat-pressed ceramic core groups.