• Restorative Dentistry and Endodontics
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• 제33권3호
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• pp.198-203
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• 2008

본 연구의 목적은 동적하중 하에서 네 종류의 근관치료용 임시충전재의 밀폐효과를 비교하는 것이다. 44개의 건전한 인간 대구치에 표준화된 근관와동을 형성한 후 Caviton, MD-Temp, IRM 및 ZOE를 이용하여 충전하였다. 이 후, 1% 메틸렌블루 용액에 담근 상태에서 반복하중기를 이용하여 1 Hz의 속도로 98 N의 하중을 기능교두에 1,000번 가한 다음 시편을 양분해 미세누출을 평가하고 one-way ANOVA (p = 0.05)와 사후 검정으로 Duncan's multiple range tests로 통계분석 하였다. Caviton 군과 MD-Temp군이 IRM군과 ZOE군보다 통계적으로 적은 미세누출을 보였으며 (p < 0.05), 본 실험결과로 볼 때 Caviton과 MD-Temp가 IRM과 ZOE보다 동적하중 하에서 근관와동 밀폐효과가 우수하다고 사료된다.

• 한국가축번식학회지
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• 제20권1호
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• pp.35-42
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• 1996

본 실험은 체외수정에 의해 생산된 생쥐 배반포기배를 초자화 동결하였을 때 straw 제작방법 및 융해조건이 배반포기배의 생존성에 미치는 효과를 검토하고자 실시하였다. 융해시 각 straw내 동결보존액이 초자화 상태로 유지되는지를 확인하기 위하여 동결보존액 충전과 봉인방법이 다른 세 종류의 straw I, II, III가 제작되었는데, 이러한 모든 straw는 실온에 1~10초까지 노출된 후 $25^{\circ}C$ 수조에 침지되었다. 수정란은 20% ethylene glycol에 5분, EFS 40 용액에 1분간 노출된 후, straw내로 옮긴 다음 straw I과 II의 경우는 straw powder로, straw III는 straw powder와 열처리로 봉인하여 액체질소에 침지하여 다음과 같은 결과를 얻었다; 1) Straw I embryo column은 융해시 3~6초의 실온 노출을 제외한 대부분의 노출시간에서 불투명한 반초자화 상태로 변화되었다. 그러나 Straw II embryo column을 사용하였을 때 다소 개선되었으나 완전히 초자화 상태를 유지하지는 못하였다. 반면, Straw III embryo column의 경우는 융해시 완전한 초자화 상태를 유지할 수 있었다. 2) Straw III loading 방법을 사용하여 초자화 동결, 융해된 난자의 생존율은 Straw I loading 방법을 사용하였을 때에 비해 유의하게 높았으며(P<0.05), 표준오차 범위는 낮게 나타났다. 3) 초자화 동결보존된 난자를 실온에 3, 5, 10초간 노출한 후 $25^{\circ}C$ 수조내에 침지하여 융해하였을 때, 배양 24시간째 생존율은 72.7~87.1%이었고, 배양 48시간째 탈출배반포기배까지의 발달율은 34.0~48.4%이었으며, 융해시 각 처리간 유의차는 인정되지 않았다. 본 연구 결과, 초자화 동결 융해 후 높은 생존율 및 낮은 오차범위는 Straw III loading 방법과 double 봉인방법 및 적절한 2단계 융해법을 사용함으로서 얻을 수 있었다.

• Restorative Dentistry and Endodontics
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• 제29권1호
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• pp.51-57
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• 2004

본 연구는 에폭시레진계 봉함제 (AH26)과 두 가지의 상아질 접착제와 함께 근관충전을 시 행하였을 때와 에폭시레진계 봉함제 단독으로 사용하였을 때의 미세누출을 혐기성 세균모델을 이용하여 평가하였다. 52개의 단근치를 이용하여 .04, .06 taper Profile (Dentsply-Maillefer, Ballaigues, Swiss)을 사용하여 변형된 crown-down pressureless법으로 근관형성 하였다. 형성된 치근을 12개씩 무작위로 나누어 4개의 실험군으로 하였으며, 나머지 치아 중 2개를 양성대조군에, 2개는 음성대조군으로 사용하였다. 제1군은 All Bond 2(Bisco, Itasca, IL, USA)를 적용하고 거타퍼쳐와 AH26 (Dentsply, Konstanz, Germany)을 이용하여 continuous wave of condensation technique으로 근관충전 하였으며, 제 2군은Prime ＆ Bond NT (Dentsply, Konstanz, Germany)를 적용 후 거타퍼쳐와 AH26을 이용하여 충전하였으며, 제3군은 17％ EDTA를 적용하여 도말층을 제거한 후 거터퍼쳐 와 AH26을 사용하여 충전하였다. 제4군은 17％ EDTA를 적용하지 않고 거터퍼쳐와 AH26을 사용하여 충전하였다. Fusobacterium nucleatum (VPI 10197)을 추적자로 이용한 혐기성세균모델을 사용하여 혐기성배양기에서 배양시키면서 60일 동안 각군에 대한 미세누출 여부를 관찰하였다. 매일 배양액의 혼탁도와 색상변화를 관찰하여 기록하였다. 제4군에서 통계학적으로 유의할만한 미세누출을 가장 많이 보였으며(p<0.0005) 나머지 3개의 실험군에서는 서로간의 통계학적으로 유의할 만한 차이를 보이지 않았다. 주사전자현미경 관찰 시 제 1군과 제2군의 상아질 접착제가 상아세관으로 침투한 소견을 관찰 할 수 있었다.

• 대한소아치과학회지
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• 제36권2호
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• pp.310-317
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• 2009

치외치는 치아의 교합면에 부가적인 교두나 돌기(tubercle)를 가진 치아의 형태 이상이다. 치외치는 1-4%의 유병율을 보이며 하악 소구치에서 발생 빈도가 높다 치외치의 돌기는 쉽게 마모되거나 파절되어 치수 노출, 치수 생활력 상실, 안면부 감염, 골수염 등을 일으킬 수 있다. 또한, 돌기가 파절될 때 치외치의 치근단이 미성숙 상태인 경우가 많아 근관 치료가 쉽지 않다. 미성숙 영구치의 근관치료 시 수산화칼슘이 널리 사용되어 왔으나 내원 빈도 단축을 위해 여러 대체 재료들이 제안되어 왔다. 그 중 하나인 Mineral Trioxide Aggregate는 우수한 생체적합성과 변연 폐쇄성을 특징으로 하며, 미성숙 영구치의 근관치료 시 치료 기간을 단축시킬 수 있다. 본 증례보고에서는 치외치로 인한 치수 괴사로 봉와직염이 발생한 환자를 Mineral Trioxide Aggregate로 치료하였다. 미성숙 치근단을 가진 하악 소구치에 Mineral Trioxide Aggregate를 이용한 치근단형성술(apexification)을 시행하여 임상적 및 방사선학적으로 양호한 결과를 얻었으며, 한 증례에서는 치근단유도술(apexogenesis)의 결과와 같이 계속적인 치근 성장이 관찰되었다.

• 구강회복응용과학지
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• 제23권1호
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• pp.95-104
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• 2007

I. Objective The primary requirement of an endodontic root canal sealer is the biologic compatibility, because they remain in close contact with living periapical tissues over a long period of time. The aim of this study was the evaluation of cytotoxicity and genotoxicity of resin-based root canal sealers, AH 26 and ADSEAL. II. Material & Methods In this study, human periodontal ligament cells, human oral cancer cells (KB) and mouse osteoblasts (MC-3T3-E1) were used. Specimens of AH26, ADSEAL were eluted with culture medium for 1, 3, 5 and 7 days. Cytotoxicity was evaluated by using tetrazolium bromide reduction assay (MTT assay) for mitochondrial enzyme activity and cell viability. Genotoxicity was evaluated by using alkaline single cell gel electrophoresis assay (Comet assay). Also cell apoptosis induced by AH 26 was detected by Hoechst33258 staining. III. Results AH 26 and ADSEAL exhibited cytotoxic effects in all investigated cell groups. Genotoxicity was also noted for both sealers in mouse osteoblasts (MC-3T3-E1). But, ADSEAL presented significantly low cytotoxicity and genotoxicity compared with AH 26. Cytotoxicity and genotoxicity induced by AH 26 resulted in apopotosis. IV. Conclusion Our results clearly indicate that the recently invented ADSEAL has better biocompatibility than another resin based root canal sealer, AH 26. However ideal root canal sealer should have not only biocompatibility but also satisfactory physico-chemical properties such as sealing ability and stability. Thus continuous studies and developments should follow.

• 대한두개안면성형외과학회지
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• 제21권1호
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• pp.49-52
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• 2020

The specialized structure of the upper eyelid ensures complete closure of the eye and eyeball sealing. An upper eyelid injury can cause various symptoms associated with eyeball trauma, not just scar formation or eyelid deformity. In this report, we describe a case of lagophthalmos observed after wound repair in a patient with a crushing injury caused by a grinder. Several surgical techniques are used to treat lagophthalmos or scar contracture. In most cases, a releasing procedure is performed after 6 months of initial repair. However, if the patient has severe symptoms that are not relieved by conservative care, early revision is inevitable. We describe a case of early lagophthalmos successfully resolved with pentagonal wedge resection, fat redistribution, and full-thickness skin grafting. After the revisional surgery, we observed that the patient regained the ability to completely close the injured eyelid, with restoration of function and favorable cosmetic outcomes. Pentagonal wedge resection to release a retracted structure, fat redistribution to prevent readhesion, and full-thickness skin grafting for enough amount of skin to regain upper eyelid function is useful for scar release and lagophthalmos following crushing injuries of the upper eyelid.

• Restorative Dentistry and Endodontics
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• 제19권2호
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• pp.461-472
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• 1994

The purpose of this study was to evaluate the sealing ability according to types of spreader and compatibility of accessory cone used in lateral condensation method. 120 plastic blocks with canal preformed were instrumented with K-,H-files and Gates-Gllidden bur. Shaped plastic blocks were divided into six experimental groups according to spreader and accessory cone used in lateral condensation. Then they were obturated by lateral condensation method without -sealer. Six experimental groups were as follows: Group 1 : Filling with #30 spreader & #25 gutta-percha cone Group 2 : Filling with #30 spreader & Fine accessory cone Group 3 : Filling with #3 spreader & #25 gutta-percha cone Group 4 : Filling with #3 spreader & Fine accessory cone Group 5 : Filling with #20,#30 spreader & #25 gutta-percha cone Group 6 : Filling with #2, #3 spreader & Fine accessory cone All the blocks were stored in 100% humidor at room temperature for 2 days. Each block was placed in centrifuged for 20 minutes at 3,000 rpm. Apical leakage was mesured from the apical foramen to the most coronal level of- dye leakage in millimeter under a stereoscope. The data were analysed by ANOVA. The obtained results were as follows; 1. In groups using two spreaders(Group 5,6), the linear leakage was less than one spreader using groups(Group 1-4). 2. Tn groups using two spreaders(Group 5,6), there was no significant difference in linear leakage between standardized -spreader group and non standardized group (p>0.01). 3. When one spreader was used(Group 1-4), standardized-spreader groups showed less linear leakage than nonstandardized spreader groups(P<0.01). 4. In case of using same spreader(Groupl,2 & Group 3,4), there was no significant difference in linear leakage according to accessory cone type. 5. It needs to use one more spreaders to increase apical sealability.

• Restorative Dentistry and Endodontics
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• 제19권2호
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• pp.409-428
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• 1994

Endodontic surgery is performed when conventional endodontic therapy fails or is contraindicated. In such cases, retrograde filling materials including amalgam, composite resin, and various cements have been used. Biocompatibilty and margin sealing ability of retrograde filling materials are important for the long term success of endodontic surgery. In vitro cell culture is frequently used as the method of measuring the biocompatibilty of dental materials. The purpose of this study was to evaluate the cytotoxicity of six kinds of retrograde filling materials including newly developed light curing glass ionomer cements. Each material was mixed according to. the manufacture's instruction and evaluated as : freshly mixed, 24-hour after mixing, and 168-hour after mixing respectively. The elution solution was extracted after 24-hour contact with materials using media. Cytotoxicity was evaluated by direct contact, or elution contact. Test results of radiochromium($^{51}Cr$) release, cell viability using tetrazolium dye (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl dimethyltetrazolium bromide(MTT) test and lactate dehydrogenase(LD) of damaged L929 cells were analyzed. In the $^{51}Cr$ release of direct contact, all experimental retrograde filling materials except amalgam and glass ionomer cement showed increased cytotoxicity compared to control. In the $^{51}Cr$ release of elution solution, the released $^{51}Cr$ was so minimal that it was impossible. to evlauate the cytotoxicity exactly. The elution solutions of glass ionomer cement and IRM showed marked cytotoxicity in MTT test. LD enzyme activity was highest in tests of direct contact with composite, light curing composite, and light curing glass ionomer cement and IRM. Amalgam revealed least cytotoxicity while IRM showed cytotoxicity using all three methods. Composite, light curing composite and light curing glass iomomer cement were cytotoxic in the tests of $^{51}Cr$ release and LD activity. Glass ionomer cement showed cytotoxic effect only in the MTT method. From these results it is suggested that the standardization and optimization of cytotoxicity testing, especially using elution solutions, should be strongly advised.

• Restorative Dentistry and Endodontics
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• 제15권2호
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• pp.104-114
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• 1990

The purpose of this study was to evaluate the adaptation of root canal filling material to the dentinal wall of root canal and to compare the sealing ability of the root canal filling materials using ultrasonic endodontic instrument with injection-molded thermoplasticized gutta-percha filling method and lateral condensation method. Fifty fresh human single root exlracted for orthodontic treatment, were randomly selected, and instrumented by step-back technique. And then, the teeth were divided into 5 groups according to each root canal filling methods. In the experimental group 1 and group 2, the root canals were filled with gutta perdia cases using ultrasonic instrument with and without sealer. In the experimental group 3 and 4, using jection-moldeed thermoplasticized gutta-percha method by obtul$^{(R)}$ canals were filled with and without sealer. In the control group, the canals were filled with sealer by lateral candensation. And then, 5 teeth of each group were immersed in black Indian ink, decalcified and cleared. The depth of dye penetration into the root canal were evaluated with stereoscope (Reichert Ltd., USA). Among the 5 teeth remaining in each group, the single longituding grooves were made on the labial and lingual root surfaces and then immersed in the liquid nitrogen to fracture the teeth spontaneously without any distortions of gutta-percha. Each specimens were examined with X-650 Scanning Electron Microscope(Hitachi ltd, Japan) to show the adaptation to the canal wall, void, homogenicity of filling material and location of gutta-percha or sealer in the dentinal tubules of the root canal. The observations were as follows : 1. The experimental group 1 showed smaller mean dye penetration than control group, and showed the penetraton of sealer in the dentinal tubules of apical third of the root canal. 2. The experimental group 2 and group 4 showed the penetration of gutta-percha in the dentinal tubules of root canals. 3. The experimental group 1 and group 3 showed less mean dye penetration than the experimental group 2 and group 4. 4. The experimental group 1 and group 2 showed better adaptation of filling materials than control group.

• Journal of Chest Surgery
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• 제26권1호
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• pp.44-46
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• 1993

There are several methods for managing pneumothorax through thoracoscope. Among them, electric cautery of bleb or bulla is very simple to do and can be done through the conventional thoracoscope. It is cosmetically excellent because it needs only incision. It is economically cheap comparing other methods because it does not need staplers or clips and other disposables. However, this method has been controversial for its success rate because of the ability of sealing off the air-leaking from the lung tissue. To evaluate the success rate, 29 cases of pneumothorax treated by electric cautery and instillation of oxytetracyline solution through the thoracoscope were analyzed. Among 29 patients, 18 were male and 11 female ranging 17 to 43 years old. The indications for thoracoscopy were recurrence in 20 cases and persistence in 9 cases. The underlying casuses of pneumothorax were bleb in 10 cases and bulla with bleb or not in 19 cases. Twenty one cases were successful [4%] and 8 cases were failed. The failed 8 cases were explored from 14 to 28 days after thoracoscopy.Six cases were explored through transaxillary minithoracotomy and 2 were done through limited posterolateral thoracotomy. The causes of failure were the necrotic lung tissue occured by excessive electric cautery in 6 cases and the necrotic lung tissue and residual bulla in two cases. In 10 bleb cases, 9 were successful [90.0%]. But in 19 cases of bulla, 12 were successful [63.2%]. In conclusion, the success rate of electric cautery through thoracoscope was 72. 4% and the causes of failure were lung necrosis and residual bulla. The success rate of the bleb cases was higher than that of the bulla cases.