• 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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• 제18권1호
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• pp.205-213
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• 1993

The purpose of the study was to evaluate the degree of the marginal leakage of esthetic restorative materials on root caries restoration. 120 cavities were prepared to $90^{\circ}$ butt joint on all margins on the crown and root portion, and divided into 4 groups. The four groups of cavity were filled with Amalgam(Dongmuyung Dental Alloy Co., Ltd, KOREA), Silux$^{(R)}$(3M Co., USA)-Scotch Bond 2$^{(R)}$(3M Co., USA), Silux$^{(R)}$-All Bond$^{(R)}$(BISCO USA), and GC Fuji II$^{(R)}$(G-C Co., JAPAN) respectively. The apical margin of the preparation was finished to leave a flash of restorative material. The coronal margin of the preparation was finished not to leave a flash of restorative material. All specimens were sectioned longitudinally with Isomet Low speed saw(Buether Ltd, USA). The degree of dye penetration was evaluated as the parameter of marginal leakage under the stereoscope. The results were as follows. 1. At the enamel and dentin/cementum margins, the margin were finished to leave a flash of material showed less marginal leakage than that were finished not to leave a flash of material (P<0.001). 2. The enamel margins showed less marginal leakage than the dentin/cementum margins(P<0.001). 3. There was no significant difference in the degree of the marginal leakage between Silux$^{(R)}$-Scotch Bond 2$^{(R)}$ group and Silux$^{(R)}$-All Bond$^{(R)}$ group.

• Restorative Dentistry and Endodontics
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• 제20권2호
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• pp.671-684
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• 1995

The purpose of this study was to compare the apical sealing ability, overfilling and obturation of lateral canals using two gutta-percha techniques: Thermafil obturators and cold lateral condensation. Eighty numbered epoxide blocks with one major and five lateral canals were divided into four experimental groups and obturated according to experimental groups. Four experimental groups were as follows: Group 1 : Filling with Thermafil plastic obturators and sealer(ThermaSeal) Group 2 : Filling with Thermafil plastic obturators only, without sealer(ThermaSeal) Group 3 : Fillng using lateral condensation with sealer(AH-26) Group 4 : Fillng using lateral condensation without sealer(AH-26) All the blocks were stored in 100% relative humidor at room temperature for 7 days. Each block was placed in centrifuge tube filled with India ink, and then centrifuged for 20 minutes at 3,000 rpm. Apical leakage was measured from the apical foramen to the most coronal level of dye penetration in millimeter under a stereoscope. The length of gutta-percha and sealer in each of the lateral canals was measured, too. The presence or absence of overfilling of gutta-percha and sealer was recorded. The data was analyzed by one-way ANOVA. The obtained results were as follows: l. Apical dye leakage was almost: not occurred in Group Willed with Thermafil and sealer) and Group 3(filled using lateral condensation with sealer), and there was no significant difference in linear leakage between two groups(p>0.01). 2. In both Thermafil and lateral condensation groups, linear leakage of Group I, 3(filled with sealer) was less than that of Group 2, 4(filled without sealer), and there was no significant difference in linear leakage between Group 1, 2, 3(p> 0.01). 3. Overfilling during obturation of Group 1, 2(filled with Thermafil) was more than Group 3, 4(filled using lateral condensation), and there was no significant difference between groups(p> 0.05). 4. Groups filled with Thermafil had significantly more gutta-percha than groups filled using lateral condensation in all lateral canals(p <0.01), the total length of gutta-percha and sealer found in all lateral canals were similar in Group 1 and Group 3.

• Restorative Dentistry and Endodontics
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• 제19권1호
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• pp.205-216
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• 1994

The purpose of this study is to evaluate of apical plug materials for the contral of extrusion and sealing ability of high-temperature thermoplasticized gutta-percha in plastic root canal blocks. Seventy seven plastic blocks with canal preformed were instrumented with # 50K file 1 mm beyond apical foramen. Blocks were randomly divided into 5 groups of 15 blocks each. Group 1 was filled by high-temperature thermoplasticized gutta-percha only. The another 4 groups were placed with apical plug materials each other and then remaining space was back filled with high temperature thermoplasticized gutta-percha Apical plug materials were used as follows; Group 2: Thermoplasticized gutta-percha (Thermoplasticized gutta-percha group) Group 3 :. Calcium hydroxide powder (Calcium hydroxide group) Group 4 : Silver point (Silver point group) Group 5 : Gutta-percha cone softened by chloroform (Gutta-percha cone group) All the blocks were stored in 100 % relative humidor at room temperature for 14 days. Filling material extruded was removed carefully and then weighed in analytic balance. Each block was placed in centrifuge tube filled with India ink, and then centrifuged for 20 minutes at 3,000 rpm. Apical leakage was measured from the apical foramen to the most coronal level of dye leakage in millimeter by two examiners under a stereoscope. The data were analysed statistically by Student's t-test The obtained results were as follows; 1. The amounts of material extruded through the foramen decreased in all of groups used apical plug materials (P<0.01). 2. Silver point group and gutta-percha cone group were similar linear leakage to high-temperature thermoplasticised gutta-percha technique only (P>0..5). 3. Calcium hydroxide group and thermoplasticized gutta-percha group showed more liner leakage than high-temperature thermoplasticized gutta-percha only (P<0.01, P<0.05). 4. High-temperature thermoplasticized gutta-percha technique with silver point and gutta-percha cone as apical plugs showed less linear leakage and less extrusion of filling material.

• Restorative Dentistry and Endodontics
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• 제26권1호
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• pp.77-85
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• 2001

The purpose of this in vitro study was to compare the apical leakage in extracted teeth filled with gutta-percha subsequent to dressing with one of three different calcium hydroxide preparations. Thirty six extracted teeth with single canal were used in this study. After working length determination, canals were prepared with K flexo files to a #40 at the working length. Step-back flaring was produced by using #45, #50 K flexo files and #2, #3, #4 Gates Glidden burs. The teeth were randomly divided into 3 groups of 10 each : the remaining six teeth were used for negative and positive leakage control: Group 1, dressed with pure calcium hydroxide powder (Sigma, USA) mixed with distilled water; Group 2, dressed with Metapaste (Metadent, Korea) ; Group 3, dressed with Vitapex (Neo Dental, Japan). Teeth were sealed with Caviton (GC, Japan) and incubated in 100% humidity, at 37$^{\circ}C$ for 1 wk. All kinds of calcium hydroxide were removed from the canal with a MAF and 5% NaOCl. The canals were filled with AH-26$^{\circledR}$ sealer and gutta-percha using lateral condensation technique, incubated in 100% humidity, at 37$^{\circ}C$ for 2 days for the sealer to be set. The teeth were coated twice with nail varnish except for an area of approximately 2mm surrounding the apical foramen. All specimens were placed in 2% methylene blue solution for 2 days. The root were sectioned longitudinally, the amount of apical leakage was measured to the most coronal part of the root canal to which the dye had penetrated. The independent measurements were made for each root using a stereomicroscope ($\times$40 magnification) and the average was recorded for statistical analysis. The results were as follows ; 1. The mean of apical leakage in group of pure calcium hydroxide ranged 0.102$\pm$0.156mm, in Metapaste$^{\circledR}$ ranged 0.062$\pm$0.069mm, and in Vitapex$^{\circledR}$ ranged 0.067$\pm$0.072mm. 2. Group of pure calcium hydroxide exhibited more leakage than those of 2 manufactured calcium hydroxide preparations, but it was not statistically significant. 3. Group of water-based Metapaste$^{\circledR}$ showed lesser leakage than that of oil-based Vitapex$^{\circledR}$, but it was not statistically significant.

• Restorative Dentistry and Endodontics
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• 제34권6호
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• pp.484-490
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• 2009

본 연구의 목적은 glucose leakage test를 이용하여 soft chelating irrigation이 근관 충전의 sealing ability에 미치는 영향을 평가하는 것이다. 발치된 45개의 단근치를 수집하여 치관부를 잘라내 치근이 총 13mm가 되게 하였다. 근관은 K3 NiTi 구동 기구를 사용하여 성형하고 #45/.06 taper까지 확대하였다. 3개의 실험군(n=13)과 2개의 대조군(n=3)으로 나누었다. 실험군은 다음의 세척 방법으로 처리하였다. 1군, 2.5% NaOCl로 세척; 2군, 2.5% NaOCl로 세척 후 17% EDTA로 최종 세척; 3군, 2.5% NaOCl과 15% HEBP 혼합 용액으로 세척, 근관은 gutta-percha와 AH Plus를 사용하여 측방가압으로 충전하였다. $37^{\circ}C$, 습도 100%에서 7일 동안 보관하고 glucose leakage model을 이용하여 치관부로부터 치근부 방향의 미세누출을 정량화하였다. 1, 4, 7, 14, 21, 28일 째 누출된 glucose의 농도를 spectrophotometry로 측정하였다. 분석 결과 모든 실험군에서 실험 기간 동안 누출이 증가하는 경향이 있었다. HEBP처리군은 실험 기간 동안 EDTA처리군과 유의한 차이를 보이지 않았다. HEBP처리군은 21일 이후부터 도말층으로 덮인 NaOCl처리군에 비해 유의하게 낮은 누출을 보였다. HEBP로 처리된 상아질은 EDTA로 처리된 상아질과 비슷한 양상의 폐쇄를 보였으나 도말층이 남아있는 상아질보다는 우수한 sealing ability를 나타냈다. 그러므로 약한 킬레이트제인 HEBP는 EDTA의 대안이 될 수 있을 것이다.

• Restorative Dentistry and Endodontics
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• 제26권5호
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• pp.379-386
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• 2001

This study was performed to evaluate the sealing ability of various retrograde filling materials by using bacterial penetration and dye penetration test. One hundred and forty extracted human teeth with single, straight canals and mature apiece were collected and used for this study. All canals were instrumented using an engine driven Ni-Ti file (ProFile). After removing 3mm from the apex of tooth, a standardized 3mm root end cavity was prepared using an ultrasonic instrument. The 70 teeth were randomly divided into 7 groups : 6 groups for retrograde filling using Super-EBA, ZOE, Chelon-Silver, IRM, ZPC and amalgam. The 7th group was used as a negative control. Nail varnish was applied to all external root surfaces to the level of the reseated root ends to prevent lateral microleakages. The specimens were then sterilized in an ethylene oxide sterilizer for 24 hours. 2 mm of the reseated root was immersed in a culture chamber containing a Tripticase Soy Broth with a phenol red indicator. The coronal access of each specimen was inoculated every 72 hours with suspension of Proteus vulgaris. The culture media were observed every 24hours for color change indicating bacterial contamination. The specimens were observed for 4weeks. The remaining 70 teeth were submitted to a dye penetration test. The canals of all teeth were first sealed with AH26 and obturated using an Obtura II system. Root resection, root end preparation and retrograde filling was performed as above. All specimens were suspended in 2% methylene blue dye for 72 hours before being ion gitudinally split. The degree of dye penetration was then measured using a stereomicroscope at 10 magnification and evaluated. The results were as floows : 1. In the bacterial penetration, the degree of leakage was the lowest in the Super-EBA, followed by, in ascending order, ZOE, Chelon-Silver IRM and ZPC. The amalgam showed highest bacterial leakage of all(p<0.01). 2. In the dye penetration, the degree of microleakage was the lowest in the Chelon-Silver and Super-EBA, followed by, in ascending order, IRM, ZPC. The ZOE and amalgam showed the highest microleakage of all (p<0.05). These results suggested that the eugenol based cement, Super-EBA, have excellent sealing ability as a retrograde filling material.

• Restorative Dentistry and Endodontics
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• 제46권3호
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• pp.35.1-35.11
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• 2021

Objectives: Endosequence Bioceramic Root Repair Material (BC-RRM) is used in endodontic microsurgery. It is available as a paste and a putty. However, no studies to date have examined the sealing ability of these forms alone or in combination as root-end filling materials. Hence, this study aimed to compare the sealing properties of these 2 forms of BC-RRM. Materials and Methods: Forty-two extracted upper anterior teeth were divided into 3 experimental groups, a positive and negative control. After the root canal treatment, the root ends were resected, retroprepared and retrofilled with either putty, paste + putty or mineral trioxide aggregate (MTA). The teeth were mounted in tubes so the apical 3 mm was submerged in Brain Heart Infusion (BHI) broth. The coronal portions of the canals were inoculated with Enterococcus faecalis and BHI broth and incubated for 30 days. The broth in the tubes was analyzed for colony forming units to check for leakage of bacteria from the canal. The teeth from the groups were sectioned and analyzed using scanning electron microscopy (SEM). The Kruskal-Wallis test and analysis of variance were used to analyze the data with a significance level p < 0.05. Results: The BC-RRM and MTA groups showed similar sealing ability. The positive control showed leakage in all samples. The SEM imaging showed the presence of bacteria in all experimental groups at the material-tooth interface. Conclusions: No significant differences were noted in the experimental groups, providing sufficient evidence that any combination could be effectively used during endodontic microsurgery.

• Restorative Dentistry and Endodontics
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• 제23권2호
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• pp.537-549
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• 1998

본 연구의 목적은 미세치근단 수술법에서 사용되는 치근단 절제방법 및 역충전와동 술식을 종래의 치근단 수술법에서 사용해 온 술식 및 방법과 치근단 미세누출의 측면에서 비교, 연구하고자 함이다. 치근단 절제방법 및 역충전와동 형성 방법에 따른 치근단 누출을 평가하기 위해서는 최근에 발거된 상악 중절치, 측절치 및 견치 71개를 절제 각도 및 와동 형성방법에 따라 5개의 군으로 분류하여 실험하였으며, 근관협부 처리에 따른 치근단 누출을 평가하기 위해서는 최근 발거된 상악 제 1대구치의 근심협측 치근 44개를 근관협부의 처리 유무에 따라 2개군으로 분류하여 실험하였다. 각 시편치아에서 근관을 형성하고 측방가압법으로 충전한 후 각 군에 따라 저속 다이아몬드 절단기를 이용하여 치근단 3 mm를 절제하였으며 저속 round bur와 초음파 스테인레스 스틸 기구를 이용하여 역충전와동을 형성하고 IRM으로 역충전하였다. 시편을 2% methylene blue 용액에 7일간 침잠시킨 후 35% 질산 용액에서 용해시킨 다음, 원심분리한 상층액을 비색계를 이용하여 누출 색소의 홉광도를 측정하였다. 결과치는 이원변량분석법과 Duncan's Multiple Range Test를 이용하여 분석하였으며, 다음과 같은 결과를 얻었다. ${\cdot}$ 사면을 부여하지 않고 치아 장축에 대해 직각이 되게 치근단을 절제하고 치아 장축에 평행하게 역충전와동을 형성한 경우, 초음파기구를 이용한 군과 저속 round bur를 이용한 군사이에는 미세누출에 있어서 유의한 차이가 나타나지 않았다(p>0.05). ${\cdot}$ 사면을 부여하면서 치근단을 절제하고 치아 장축에 평행하게 역충전와동을 형성한 경우, 초음파기구를 이용한 군은 저속 round bur를 이용한 군에 비해 유의하게 적은 치근단 누출을 보였다(p<0.0001). ${\cdot}$ 초음파기구를 이용하여 역충전와동을 형성한 경우에는, 치근단 절제시 사면의 부여에 관계없이 치근단 누출에 유의한 차이가 나타나지 않았으나(p>0.05), 저속 round bur를 이용한 경우에는, 사변을 형성하지 않은 군이 사면을 형성한 군에 비해 유의하게 적은 미세누출을 나타내었다(p<0.0001). ${\cdot}$ 치근단 절제시 사변을 부여한 경우에는, 저속 round bur로 치아 장축에 평행하게 역충전와동을 형성한 군은 치아 장축에 직각으로 역충전와동을 형성한 군에 비해 미세누출이 적게 나타났지만, 유의한 차이는 나타나지 않았다(p>0.05). ${\cdot}$ 초음파 기구를 이용하여 근관협부를 따라 역충전 와동을 형성한 군은 저속 round bur를 이용하여 근관협부를 따라 역충전 와동을 형성하지 못한 군에 비해 유의하게 적은 치근단 누출을 나타내었다(p<0.0001).

• Restorative Dentistry and Endodontics
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• 제35권5호
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• pp.335-343
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• 2010

연구목적: 본 연구의 목적은 수종의 sealer를 이용하여 각기 다른 양의 잔여수분이 존재하는 근관을 충전 시, 근관충전의 sealing ability를 glucose leakage model로 평가하는 것이다. 연구 재료 및 방법: 발치된 90개의 단근치를 치관부를 잘라내고 #45 / 0.06 taper까지 확대한 후, 12개의 실험군 (n = 7)과 2개의 대조군 (n = 3)으로 나누었다. 실험군을 3가지 습윤 상태에서 (a, DRY; b, PAPER POINT DRY; c, WET) 4종류의 sealer로 (Group 1-3: Sealapex; Group 4-6: AH plus; Group 7-9: Tubuli-seal; Group 10-12: EndoRez), warm vertical compaction method를 이용해 충전하였다. $37^{\circ}C$, 습도 100%에서 7일 동안 보관하고 glucose leakage model을 이용하여 치관부로부터 치근부 방향의 미세누출을 정량화하였다. 1, 3, 7, 14, 21, 30일 째 누출된 glucose의 농도를 spectrophotometer로 측정하였다. 결과: 관찰기간 동안 AH plus/DRY군 (Group 4)이 12개 그룹 중 가장 적은 양의 leakage를 보였다 (20.78 mmol/L). 반면에 Tubuli-seal/WET군 (Group 9)이 12개 그룹 중 가장 높은 양의 leakage를 보였다 (178.75 mmol/L). 결론: 본 연구의 결과는 충전 시 근관 내의 습윤 상태와 sealer 종류가 microleakage에 유의한 영향을 미친다는 것을 입증하였다. 그러므로 sealer 종류에 따라 각기 다른 근관 건조 방법을 사용하는 것이 근관치료에서 더 좋은 결과를 얻을 수 있는 방법일 것이다.