• 대한소아치과학회지
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• 제30권3호
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• pp.385-390
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• 2003

청소년기에는 두개악안면부위의 외상성 손상이 흔하다. 그러나 상아질, 백악질, 치수를 포함하는 치아파절로 정의되는 치근파절은 비교적 드물다. 치근파절에 대하여 취 할 수 있는 적절한 조치는 파절편의 치관부위를 재위치시키고, $2{\sim}3$달간 레진강선 고정술을 시행하는 것이다. 치수괴사나 치근흡수의 징후가 나타날때까지 근관치료를 보류해야 하는데 대부분의 증례에서 파절편의 치근부위는 그 생활력을 유지하기 때문이다. 본 증례의 10세 4개월된 남아는 상악영구중절치의 치근파절을 주소로 연세대학교 치과병원에 내원하였으며, 그후 7년동안 동일부위에 2번의 반복적인 외상이 있었으나 파절편 치관부의 재위치, 레진 강선 고정술, 근관치료 시행 후 임상적으로 방사선학적으로 비교적 양호한 치료결과를 얻었기에 보고하는 바이다.

• 대한치과보철학회지
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• 제38권5호
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• pp.675-694
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• 2000

The purpose of this study was to investigate the displacement of and the stress distribution on the prosthesis, abutment, and its supporting tissues under functional load, and the effect of alteration in root length of 2nd abutment. The 3-dimensional finite element method was used and the finite element models were prepared in which the abutments of left mandibular 5 unit axed partial denture were canine, the 1st pre-molar and the 2nd molar, and the root lengths of canines were as follows. Model I : Root length of canine was 2mm longer than the 1st premolar Model II : Root length of canine was 2mm shorter than the 1st premolar Static compressive force of 300N was applied to connector between 2nd premolar & 1st molar, and then von Mises stress, displacement and reaction force were obtained. The results were as follows : 1. In fixed partial denture, prosthesis under load on pontic was rotated around mesio-distal long axis of it from longual side to buccal, and simultaneously bended in buccal and gingival direction with mesial end deformed in gingival direction and distolingual end in occlusal. 2. Clinical crowns of abutments were bended in the same directions with those in which prosthesis deforms. Due to that, roots of anterior abutments were twisted in counterclockwise with concentration of shear stress on distal or distobuccal sides of their cervices, and that of posterior was in clockwise with concentration of shear stress on mesiobuccal side of it in the same level with anterior abutments. 3. In case that root length of the 2nd abutment was longer than that of the 1st abutment, its displacement and reaction force which means the force tooth exerts on the surrounding periodontal tissues were smaller but shear stress on itself was larger than in the case root length of 2nd abutment was shorter.

• Journal of Periodontal and Implant Science
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• 제23권1호
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• pp.159-169
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• 1993

The thirty six mandibular second molars, which were extracted because of hopeless tooth due to advanced periodontal disease, were measured the length of mesial and distal root and the distance from cementoenamel junction to root separation. The molars were cross-sectioned every 1.5 milimeter from cementoenamel junction to root apex perpendicular to long axis and each section was photographed, projected and measured with a calibrated Digital Curvi-Meter(Com Curvi-8. Japan). The root surface area (RSA), percentage of the RSA and the linear variation of the RSA were calibrated for each 1. 5 mm section. The results were as follows. 1. The mean length of the roots was 12. 98mm for mesial root, 11.84 mm for distal root. The mesial root was longer than distal root.(p<0.01) 2. The mean distance from the cementoenamel junction to the point at which the root separate from the root trunk was 3.82mm for the buccal furcation and 4.75mm for lingual furcation. The buccal root separation was coronal than the lingual root separation.(p<0.01) 3. The total root surface area was $317.78mm^2$. 4. The mean surface area of the root trunk was $150.06mm^2$ and averaged 42.54% of the total root surface area. 5. The mean root surface area was $88.79\;mm^2$ for the mesial root, $78.93mm^2$ for distal root, The mesial root surface area was wider than the distal root surface area.(p<0.05) 6. In comparision, the mean root trunk surface area of the mandibular 2nd molar was wider than that of mandibular 1st molar(p<0.01), but each root of 2nd molar was smaller than that of 1st molar(p<0.01).

• Journal of Periodontal and Implant Science
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• 제40권3호
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• pp.111-118
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• 2010

Purpose: The aim of this study was to investigate whether vitrification in the cryopreservation of periodontal ligament (PDL) cells could be useful for tooth banking. Methods: In step 1, primary cultured human PDL cells were cryopreserved in 100% conventional cryopreservation media and 100% vitrification media (ESF40 media) in different temperatures for 2 weeks. In step 2, a series of modified vitrification formulae named T1 (75% vitrification media + 25% F-media), T2 (50% vitrification media + 50% F-media) and T3 (25% vitrification media + 75% F-media) were used to store PDL cells for 2 weeks and 4 weeks in liquid nitrogen. MTT assay was performed to examine the viability of PDL cells. Results: Maximum cell viability was achieved in cells stored in 100% conventional cryopreservation media at $-196^{\circ}C$ (positive control group) in step 1. Compared to the positive control group, viability of the cells stored in 100% vitrification media was very low as 10% in all test conditions. In step 2, as the percentage of vitrification media decreased, the cell viability increased in cells stored for 2 weeks. In 4-week storage of cells in step 2, higher cell viability was observed in the T2 group than the other vitrification formulae while the positive control group had the highest viability. There was no statistically significant difference in the cell viability of 2-week and 4-week stored cells in the T2 group. Conclusions: These observations indicate 100% vitrification media is not successful in PDL cell cryopreservation. Conventional cryopreservation media is currently the most appropriate media type for this purpose while T2 media would be interesting to test for long-term storage of PDL cells.

• 구강회복응용과학지
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• 제34권2호
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• pp.127-136
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• 2018

치조골 흡수가 심한 무치악 환자에서는 지지의 부족으로 유지, 안정 등의 요인을 갖추기 어렵다. 이에 추가적인 유지와 안정의 획득을 위한 노력으로 중립대의 이용 또는 단일평면교합 형성이 있다. 단일평면교합은 수평력의 제거 등 장점이 있어 오랜기간 이용되었다. 그리고 여기에 저작 효율과 심미성을 개선시키기 위해 설측교두교합이 제시되었다. 하지만 안정성 면에서는 단일평면교합과 설측교두교합 사이에 여전히 논란이 있다. 본 증례는 하악 치조골의 과도한 흡수에 의해 편평한 치조제를 보이는 두 환자로, piezography를 이용하여 기능 인상을 채득하고 단일평면교합과 설측교두교합의 의치를 각각 제작함으로써 환자에게 의치를 비교 선택할 수 있도록 하여 환자의 만족도를 높였기에 이를 보고하는 바이다.

• Parasites, Hosts and Diseases
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• 제32권1호
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• pp.53-56
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• 1994

1991년 4월 23일에 심한 상복부통을 주소로 부산 백병원 내과를 찾아온 42세 가정주부에 대한 내시경 검사에서 위벽을 뚫고 있는 아니사키스 유충 1마리를 검출하였다. 환자는 내원 약 15시간 전에 우럭 회를 먹은 경험이 있었으며 회를 먹고 약 6시간 후부터 심한 상복부통이 나타났다고 하였다. 각종 검사상 특이 소견은 없었고 위 내시경 검사에서 위체 대만부 중간부위의 점막을 뚫고 있는 아니사키스 유충 1마리를 발견하여 제거하였다. 제거한 충페는 $29.73{\;}{\times}{\;}0.94{\;}mm$ 크기이었고 ventriculus 전방 115 이상 부위까지 올라오는 맹장을 가지고 있었으며 ventricular appendage는 관찰되지 않았다. 충체의 전단에서 윤곽이 뚜렷한 3개의 구순은 관찰되었으나 boring tooth는 존재하지 않았고 후단에서 mucron도 관찰되지 않았다. 이상의 형태학적 특징 및 계측치를 토대로 하여 Pseudntewonon decipien (= Terranova type A) 제4기 유충인 것으로 동정하였다. 이 기생충의 국명을 물개회충으로 제안한다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권3호
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• pp.310-312
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• 2000

저자 등은 구강악안면 영역에 발생한 대상 포진 환자에서 병소에 대한 보존적 처치와 통증조절, acyclovir 투여를 통해 현격한 증상 완화와 포진후 신경통(postherpetic neuralgia), 치아탈락을 동반한 치조골 괴사 등의 합병증 억제를 치험하였기에, 문헌 고찰과 함께 보고하는 바이다.

• The Journal of Advanced Prosthodontics
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• 제7권1호
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• pp.51-55
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• 2015

PURPOSE. Bone density at implant placement site is a key factor to obtain the primary stability of the fixture, which, in turn, is a prognostic factor for osseointegration and long-term success of an implant supported rehabilitation. Recently, an implant motor with a bone density measurement probe has been introduced. The aim of the present study was to test the objectiveness of the bone densities registered by the implant motor regardless of the operator performing them. MATERIALS AND METHODS. A total of 3704 bone density measurements, performed by means of the implant motor, were registered by 39 operators at different implant sites during routine activity. Bone density measurements were grouped according to their distribution across the jaws. Specifically, four different areas were distinguished: a pre-antral (between teeth from first right maxillary premolar to first left maxillary premolar) and a sub-antral (more distally) zone in the maxilla, and an interforaminal (between and including teeth from first left mandibular premolar to first right mandibular premolar) and a retroforaminal (more distally) zone in the lower one. A statistical comparison was performed to check the inter-operators variability of the collected data. RESULTS. The device produced consistent and operator-independent bone density values at each tooth position, showing a reliable bone-density measurement. CONCLUSION. The implant motor demonstrated to be a helpful tool to properly plan implant placement and loading irrespective of the operator using it.

• The Journal of Advanced Prosthodontics
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• 제5권4호
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• pp.457-463
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• 2013

PURPOSE. The purpose of this study was to compare the effect of a diode laser and traditional irrigants on the bond strength of self-adhesive cement. MATERIALS AND METHODS. Fifty-five incisors extracted due to periodontal problems were used. All teeth were instrumented using a set of rotary root canal instruments. The post spaces were enlarged for a No.14 (diameter, 1.4 mm) Snowlight (Abrasive technology, OH, USA) glass fiber reinforced composite post with matching drill. The teeth were randomly divided into 5 experimental groups of 11 teeth each. The post spaces were treated with the followings: Group 1: 5 mL 0.9% physiological saline; Group 2: 5 mL 5.25% sodium hypochlorite; Group 3: 5 mL 17% ethylene diamine tetra acetic acid (EDTA), Group 4: 37% orthophosphoric acid and Group 5: Photodynamic diode laser irradiation for 1 minute after application of light-active dye solution. Snowlight posts were luted with self-adhesive resin cement. Each root was sectioned perpendicular to its long axis to create 1 mm thick specimens. The push-out bond strength test method was used to measure bond strength. One tooth from each group was processed for scanning electron microscopic analysis. RESULTS. Bond strength values were as follow: Group 1 = 4.15 MPa; Group 2 = 3.00 MPa; Group 3 = 4.45 MPa; Group 4 = 6.96 MPa; and Group 5 = 8.93 MPa. These values were analysed using one-way ANOVA and Tukey honestly significant difference test (P<.05). Significantly higher bond strength values were obtained with the diode laser and orthophosphoric acid (P<.05). There were no differences found between the other groups (P> .05). CONCLUSION. Orthophosphoric acid and EDTA were more effective methods for removing the smear layer than the diode laser. However, the diode laser and orthophosphoric acid were more effective at the cement dentin interface than the EDTA, Therefore, modifying the smear layer may be more effective when a self-adhesive system is used.

• 대한치과교정학회지
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• 제43권5호
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• pp.218-224
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• 2013

Objective: To examine the effect of bite force on the displacement and stress distribution of orthodontic mini-implants (OMIs) in the molar region according to placement site, insertion angle, and loading direction. Methods: Five finite element models were created using micro-computed tomography (microCT) images of the maxilla and mandible. OMIs were placed at one maxillary and two mandibular positions: between the maxillary second premolar and first molar, between the mandibular second premolar and first molar, and between the mandibular first and second molars. The OMIs were inserted at angles of $45^{\circ}$ and $90^{\circ}$ to the buccal surface of the cortical bone. A bite force of 25 kg was applied to the 10 occlusal contact points of the second premolar, first molar, and second molar. The loading directions were $0^{\circ}$, $5^{\circ}$, and $10^{\circ}$ to the long axis of the tooth. Results: With regard to placement site, the displacement and stress were greatest for the OMI placed between the mandibular first molar and second molar, and smallest for the OMI placed between the maxillary second premolar and first molar. In the mandibular molar region, the angled OMI showed slightly less displacement than the OMI placed at $90^{\circ}$. The maximum Von Mises stress increased with the inclination of the loading direction. Conclusions: These results suggest that placement of OMIs between the second premolar and first molar at $45^{\circ}$ to the cortical bone reduces the effect of bite force on OMIs.