근관 밀폐도에 미치는 도말층 및 상아질 접착강화제의 영향

양진석,김원재,황인남,오원만 대한치과보존학회 2000 Restorative Dentistry & Endodontics Vol.25 No.4

The purpose of this study was to evaluate effects of smear layer and dentin primers on the sealing ability of root canals. 126 extracted human teeth with single, straight canals and mature apices were used. The Samples were first classified into six groups as follows : presence of smear layer; absence of smear layer; Scotchbond Bond Multi-Purpose; All Bond 2; Mac Bond 2; Clearfil Liner Bond 2. A Positive control was also established. All teeth except the control group were then obturated with thermoplasticized gutta-per-cha and AH26. Electrochemical and dye penetration technique were later used to evaluate the degree of microleakage through the root canal. Seventy teeth were then immersed in a 1 % potassium chloride solution and An external power supply(DC 10 V) was then applied to the circuit for the electrochemical microleakage test. The degree of Microleakage was determined over period of 28 days before being evaluated. In total, 48 teeth were submitted to the dye infiltration technique. All specimen were suspended in 2 % methylene blue dye for 1 week before being longitudinally split. The degree of dye infiltration was measured under a stereomicroscope at×10 magnification and evaluated. The results were as follows: 1.Apical microleakage increased throughout the test period in all group and one group having a smear layer showed a dramatic increase under electrochemical test (p<0.05). In the group having smear layer, the degree of apical microleakage was the highest, and the microleakage was much higher than in the smear layer removed group in electrochemical test (p<0.05). Scotchbond Multi-Purpose, All Bond 2, Mac Bond 2 and Clearfil Liner Bond 2 showed lower microleakage than one group having smear layer. The All Bond 2 and Clearfil Liner Bond 2 treated groups showed the lowest microleakage in electrochemical test (p<0.05). 2.There was no significant difference between the experimental groups in dye penetration technique. These results suggested that the removal of the smear layer from root canal and concomitantly the application of dentin primer into root canal could improve the sealing ability of root canal obturation, 1

EDTA의 세정시간에 따른 근관 내 smear layer의 제거효과에 관한 연구

이자경,박상혁,최기운 大韓齒科保存學會 2006 Restorative Dentistry & Endodontics Vol.31 No.3

본 연구는 EDTA 용액의 적용 시간에 다른 도말층의 제거 효과를 비교하여 EDTA 용액의 최적 적용 시간을 알고자 시행되었다. 단근치 35개를 NaOCI 용액 하에서 근관 형성 후 대조군은 NaOCI 용액 5㎖로 2분간, 실험군은 30초군, 1분군, 2분군으로 세분하여 17% EDTA 용액 5㎖로 각각 30초, 1분, 2분간 세정하였다. 세정이 끝난 치근의 도말층 제거 정도와 상아 세관의 erosion 정도를 주사전자현미경을 이용하여 관찰한 결과는 다음과 같다. 1. 대조군: 도말층이 전혀 제거되지 않았다. 2. 실험군: 1) 중간⅓: 세 군 모두에서 도말층이 거의 완전히 제거되었고, EDTA 적용 시간이 증가할수록 erosion 발생 빈도가 증가하였다. 2) 치근단⅓: 2분군이 다른 두 군에 비해 도말층 제거 정도가 우수하였다. 따라서 erosion 발생을 최소화면서 도말층을 효과적으로 제거하기 위해서는 17% EDTA 용액을 2분간 사용하는 것이 적절한 것으로 사료된다. This study was to verify that the combined application of NaOCI and EDTA was more effective in removal of smear layer than the application of NaOCI alone. Furthermore it was aimed to find out the optimal time for the application of EDTA. Thirty five single rooted teeth were cleaned and shaped. NaOCI solution was used as an irrigant during instrumentation. After instrumentation, root canals of the control group were irrigated with 5㎖ of NaOCI for 2 minutes. 30 sec, 1 min, and 2 min group were irrigated with 5㎖ of 17% EDTA for 30 sec, 1 min, and 2 min respectively. Then the roots were examined with scanning electron microscopy for evaluating removal of smear layer and erosion of dentinal tubule. The results were as follows; 1. The control group: The smear layer was not removed at all. 2. The other groups: 1) Middle⅓: All groups showed almost no smear layer. And the erosion occurred more frequently as increasing irrigation time. 2) Apical⅓: The cleaning effect of 2 min group was better than the others. The results suggest that 2 min application of 17% EDTA should be adequate to remove smear layer on both apical⅓ and middle⅓.

Smear layer 처리에 따른 미세누출에 대한 연구

이정민,박상혁,최기운 대한치과보존학회 2006 Restorative Dentistry & Endodontics Vol.31 No.5

본 연구는 도말층 제거 여부에 따른 근관 밀폐효과를 평가하기 위해 단근관 치아를 3% NaOCI 하에서 Ni-Ti file을 이용하여 crown-down 법으로 근관 형성 후 최종세정제로 NaOCI을 사용한 군과 EDTA를 사용한 군, 6개월 보관한 NaOCI-6군과 EDTA-6군으로 분류하였다. Continuous wave법으로 근관 충전 시행 후 색소 침투를 시행한 다음 해부학적 근첨에서 1.5 mm(Level l), 3.0 mm(Level 2), 4.5 mm (Level 3)에서 수평절단 하여 누출률을 측정하였다. 1. 모든 실험군에서 평균 누출률은 치근단부에서 치경부로 갈수록 감소하였다. 2. NaOCI 군의 누출률이 EDTA 군보다 level l, 2, 3에서 높게 나타났으나 level l에서만 통계학적 유의차를 보였다 (p<0.05). 3. NaOCI-6 군의 누출률이 EDTA-6 군보다 Level l, 2, 3에서 높게 나타났으나 level l에서만 통계학적 유의차를 보였다 (p<0.05). 4. NaOCI-6 군의 누출률이 NaOCI 군에 비해 Level l, 2, 3에서 증가하였으나 level l에서만 통계학적 유의차를 보였다 (p<0.05). 5. EDTA-6 군의 누출률이 EDTA 군에 비해 Level l, 2, 3에서 증가하였으나 통계학적 유의차는 없었다. 6. 주사전자현미경 관찰 결과 NaOCI 군과 NaOCI-6 군은 도말층이 제거되지 않아 상아세관내로 sealer 및 근관충전 재가 침투하지 못한 반면, EDTA 군과 EDTA-6 군에서는 도말층이 제거되고 상아세관내로의 sealer와 근관충전 재의 침투가 관찰되었다. 이상의 연구결과 EDTA를 이용하여 도말층을 제거한 경우 근관충전 즉시와 6개월 후 치근단 1/3 부위의 근단부 미세누출을 감소시킬 수 있을 것으로 사료된다. The purpose of this study was to compare the sealing ability of root canal obturation with or without the treatment of smear layer. Eighty extracted human teeth with one canal were selected. Instrumentation was performed with crown-down technique. After instrumentation, root canals of the NaOCI group and NaOC1-6 group were irrigated with 3% NaOCI. EDTA group and EDTA-6 group were irrigated with 17% EDTA. Then all teeth were obturated using continuous wave obturation technique. NaOCI group and EDTA group were immersed in methylene blue solution for 84hours. NaOCI-6 group and EDTA-6 group were immersed in methylene blue solution for 6months. The teeth were sectioned at 1.5 mm (Level 1), 3.0 mm (Level 2) and 4.5 mm (Level 3) from the root apex. The length of dye-penetrated interface and the circumferential length of canal at each level were measured using Sigma-Scan Pro 5.0. 1. The mean leakage ratio was decreased cervically. 2. NaOCI group showed higher mean leakage ratio than EDTA group at each level. But there was significant difference at level 1 only (p<0.05). 3. NaOCI-6 group showed higher mean leakage ratio than EDTA-6 group at each level. But there was significant difference at level 1 only (p<0.05). 4. NaOCI-6 group showed higher mean leakage ratio than NaOCI group at each level. But there was significant difference at level 1 only (p<0.05). 5. EDTA-6 group showed higher mean leakage ratio than EDTA group at each level. But there was no significant difference. 6. In NaOCI group and NaOCI-6 group, scanning electron micrographs of tooth sections generally covered with smear layer. In EDTA group and EDTA-6 group, tooth sections showing the penetration of sealers to opened dentinal tubules. The results suggest that removal of smear layer was effective to reduce the apical microleakage of the root canal.

Effects of dentin surface preparations on bonding of self-etching adhesives under simulated pulpal pressure

Siriporananon Chantima,Senawongse Pisol,Sattabanasuk Vanthana,Srimaneekarn Natchalee,Sano Hidehiko,Saikaew Pipop 대한치과보존학회 2022 Restorative Dentistry & Endodontics Vol.47 No.1

Objectives This study evaluated the effects of different smear layer preparations on the dentin permeability and microtensile bond strength (µTBS) of 2 self-etching adhesives (Clearfil SE Bond [CSE] and Clearfil Tri-S Bond Universal [CTS]) under dynamic pulpal pressure. Materials and Methods Human third molars were cut into crown segments. The dentin surfaces were prepared using 4 armamentaria: 600-grit SiC paper, coarse diamond burs, superfine diamond burs, and carbide burs. The pulp chamber of each crown segment was connected to a dynamic intra-pulpal pressure simulation apparatus, and the permeability test was done under a pressure of 15 cmH2O. The relative permeability (%P) was evaluated on the smear layer-covered and bonded dentin surfaces. The teeth were bonded to either of the adhesives under pulpal pressure simulation, and cut into sticks after 24 hours water storage for the µTBS test. The resin-dentin interface and nanoleakage observations were performed using a scanning electron microscope. Statistical comparisons were done using analysis of variance and post hoc tests. Results Only the method of surface preparation had a significant effect on permeability (p < 0.05). The smear layers created by the carbide and superfine diamond burs yielded the lowest permeability. CSE demonstrated a higher µTBS, with these values in the superfine diamond and carbide bur groups being the highest. Microscopic evaluation of the resin-dentin interface revealed nanoleakage in the coarse diamond bur and SiC paper groups for both adhesives. Conclusions Superfine diamond and carbide burs can be recommended for dentin preparation with the use of 2-step CSE.

Nonlinear Analysis of Reinforced and Prestressed Concrete Shells Using Layered Elements with Drilling DOF

김태훈,최정호,김운학,신현목 한국콘크리트학회 2005 콘크리트학회논문집 Vol.17 No.4

This paper presents a nonlinear finite element procedure for the analysis of reinforced and prestressed concrete shells using the four-node quadrilateral flat shell element with drilling rotational stiffness. A layered approach is used to discretize, through the thickness, the behavior of concrete, reinforcing bars and tendons. Using the smeared-crack method, cracked concrete is treated as an orthotropic nonlinear material. The steel reinforcement and tendon are assumed to be in a uni-axial stress state and to be smeared in a layer. The constitutive models, which cover the loading, unloading, and reloading paths, and the developed finite element procedure predicts with reasonable accuracy the behavior of reinforced and prestressed concrete shells subjected to different types of loading. The proposed numerical method for nonlinear analysis of reinforced and prestressed concrete shells is verified by comparison with reliable experimental results.

Soft chelating irrigation이 GP/AH Plus로 충전된 근관의 sealing ability에 미치는 영향에 대한 평가

유이숙,김태균,이광원,유미경 대한치과보존학회 2009 Restorative Dentistry & Endodontics Vol.34 No.6

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. , 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. The purpose of this study was to evaluate the effect of soft chelating irrigant on the sealing ability of root fillings by using a glucose leakage test. A total of 45 single-rooted teeth were selected for the study. The teeth were decoronated leaving a total length of 13mm. The root canals prepared using K3 NiTi rotary instruments to an apical dimension of size 45(0.06 taper). The specimens were then randomly divided into 3 experimental groups of 13 roots each and 2 control groups of 3 roots each. Specimen in each group were prepared with different irrigation protocols : group 1, 2.5% NaOCl; group 2, 2.5% NaOCl and 17% EDTA: group 3, 2.5% NaOCl and 15% HEBP. The root canals were filled with gutta-percha and AH Plus sealer using lateral condensation. After 7 days in , 100% humidity, the coronal-to-apical microleakage was evaluated quantitatively using a glucose leakage model. The leaked glucose concentration was measured with spectrophotometry at 1, 4, 7, 14, 21 and 28 days. There was a tendency of increase in leakage in all experimental groups during experimental period. HEBP-treated dentin showed no significant difference with EDTA-treated dentin during experimental period. From the 21th day onward, HEBP-treated dentin showed significantly lower leakage than smear-covered dentin. HEBP-treated dentin displayed a similar sealing pattern to EDTA-treated dentin and a better sealing ability than smear-covered dentin. Consequently, a soft chelator(HEBP) could be considered as the possible alternative to EDTA.

Impact of different agitation methods on smear layer cleaning of mesial canals with accentuated curvature

Cordova Abel Teves,Alcalde Murilo Priori,Klymus Michel Espinosa,Bonjardim Leonardo Rigoldi,Vivan Rodrigo Ricci,Duarte Marco Antonio Hungaro 대한치과보존학회 2024 Restorative Dentistry & Endodontics Vol.49 No.2

Objectives This study evaluated the impact of different methods of irrigant agitation on smear layer removal in the apical third of curved mesial canals of 3 dimensionally (D) printed mandibular molars. Materials and Methods Sixty 3D-printed mandibular second molars were used, presenting a 70° curvature and a Vertucci type II configuration in the mesial root. A round cavity was cut 2 mm from the apex using a trephine of 2 mm in diameter, 60 bovine dentin disks were made, and a smear layer was formed. The dentin disks had the adaptation checked in the apical third of the teeth with wax. The dentin disks were evaluated in environmental scanning electron microscope before and after the following irrigant agitation methods: G1(PIK Ultrasonic Tip), G2 (Passive Ultrasonic Irrigation with Irrisonic– PUI), G3 (Easy Clean), G4 (HBW Ultrasonic Tip), G5 (Ultramint X Ultrasonic tip), and G6 (conventional irrigation-CI) (n = 10). All groups were irrigated with 2.5% sodium hypochlorite and 17% ethylenediaminetetraacetic acid. Results All dentin disks were 100% covered by the smear layer before treatment, and all groups significantly reduced the percentage of the smear layer after treatment. After the irrigation protocols, the Ultra-X group showed the lowest coverage percentage, statistically differing from the conventional, PIK, and HBW groups (p < 0.05). There was no significant difference among Ultramint X, PUI-Irrisonic, and Easy Clean (p > 0.05). None of the agitation methods could remove the smear layer altogether. Conclusions Ultramint X resulted in the most significant number of completely clean specimens. Objectives This study evaluated the impact of different methods of irrigant agitation on smear layer removal in the apical third of curved mesial canals of 3 dimensionally (D) printed mandibular molars. Materials and Methods Sixty 3D-printed mandibular second molars were used, presenting a 70° curvature and a Vertucci type II configuration in the mesial root. A round cavity was cut 2 mm from the apex using a trephine of 2 mm in diameter, 60 bovine dentin disks were made, and a smear layer was formed. The dentin disks had the adaptation checked in the apical third of the teeth with wax. The dentin disks were evaluated in environmental scanning electron microscope before and after the following irrigant agitation methods: G1(PIK Ultrasonic Tip), G2 (Passive Ultrasonic Irrigation with Irrisonic– PUI), G3 (Easy Clean), G4 (HBW Ultrasonic Tip), G5 (Ultramint X Ultrasonic tip), and G6 (conventional irrigation-CI) (n = 10). All groups were irrigated with 2.5% sodium hypochlorite and 17% ethylenediaminetetraacetic acid. Results All dentin disks were 100% covered by the smear layer before treatment, and all groups significantly reduced the percentage of the smear layer after treatment. After the irrigation protocols, the Ultra-X group showed the lowest coverage percentage, statistically differing from the conventional, PIK, and HBW groups (p < 0.05). There was no significant difference among Ultramint X, PUI-Irrisonic, and Easy Clean (p > 0.05). None of the agitation methods could remove the smear layer altogether. Conclusions Ultramint X resulted in the most significant number of completely clean specimens.

칼슘수용액으로 처리한 상아질과 합착용 글래스아이오노머의 전단결합강도에 관한 연구

백영걸,이성복,박남수 慶熙大學校 齒科大學 1995 慶熙齒大論文集 Vol.17 No.1

The objective of this paper was to evaluate the shear bond strength of luting glass ionomer cement with differ calcium based solution treatment on dentin surface. 120 extracted human teeth were classified into 12 group on presence of smear layer on dentin surface and type of treatment solution. Smear layer remove on dentin surfas was done using 6% citric acid for 60 seconds. Five different dentin surface treatment solutions(calcium acetaa calcium carbonate, calcium chloride, calcium hydroxide, and calcium phosphate) were evaluated in this study! After surface modification, metal ring(inner diameter: 3mm, depth:1mm) was placed to expose the same dentin surface area and inner space was filled with luting glass ionomer cement according to the recommended procedure for standard clinical procedure. The shear bond strength of glass ionomer cement was determined after 24 hours. SEM was used for the evaluation of the surface morphologic changes and EDAX analysis was done. for determination of the change of the calcium contents of treated dentin. Following conclusions can be drawn: 1. In the group of the dentin surface with smear layer, the calcium carbonate solution was the most effective for the increase of the calcium content and the shear bond strength of glass ionomer cement to dentin surfaces. 2. In the group of the calcium carbonate treated dentin with smear layer, the shear bond strength was increased two compared to the control group and cohesive failure mode was observed. 3. The shear bond strength of cement was increased significantly by the removal of smear layer using 6% citric acid. However, additional calcium solution treatments were not effective for further bond strength increase 4. The shear bond strength of cement was significantly improved by both of the removal of smear layer and the calcium solution treatment, and the former was more effective for bond strength improvement 5. The smear layer removed/calcium solution treated groups showed dentinal tubule obstruction and crystiattachment in SEM evaluation. However, the shear bond strengths of these groups were not increased compared to the smear layer removed/no dentin treatment group.

수종의 엔진 구동형 니켈-타이타늄 합금파일의 절삭각에 따른 근관성형 효과에 관한 전자현미경적 연구

전인수,금기연,박성호,윤태철 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.6

The purpose of this in vitro study was to compare the effects of root canal debridement following rotary Ni-Ti instruments with positive versus negative rake angle. Seventy sound, extracted human anterior teeth & premolars were randomly divided into four groups. The used rotary instruments were Ni-Ti HERO642(Micro-Mega in France, 20 specimens), Ni-Ti ProFile(Maillefer, Ballaigues, Switzerland, 20 specimen), stainless steel engine reamer(Mani, Matutani Seisakusho Co.,Japan, 20 specimen) and negative control group(10 specimens) was only extirpated with barbed broach(Mani, Matsutani Seisakusho Co., Japan) Group 1 & 2 teeth were prepared to a #40 at the apex followed by 1 mm using crown-down technique. Group 3 teeth were instrumented from a #15 to a #40 in sequential order. After preparation and final irrigation, the roots split longitudinally into a bucco-lingual direction. Root halves were cross-sectioned in apical third portion again. all root specimens were prepared for SEM investigation & photographed. Separate evaluations were undertaken for smear layer on prepared walls with a five score-index for each using reference photograph in root halves. the penetration depth of smear layer into dentinal tubules was also estimated in the other halves. the following results were obtained : 1. Smear layer was observed on all the prepared walls with three experimental groups except negative control group 2. Smear layer characteristics1) HERO 642 groups showed snowy & dusty appearance & were observed only few some dentinal tubuli open on the prepared walls, and the penetration depth of it into dential tubules may be 1-2 ㎛ thick. 2) ProFile groups showed shiny & burnished appearance & complete root canal wall covered by a homogenous smear layer with no open dentinal tubuli and penetration depth of it into dentinal tubules may be 1-2㎛ thick. 3) Engine reamer groups showed obviously file's passed tracks on the prepared walls & were observed complete root canal wall covered by a homogenous smear layer with no open dintinal tubuli. The results revealed that a completely clean root canal could not be achieved regardless of positive & negative rake angle, which is in accordance with the majority of studies on root canal cleanliness In conclusion, throughout irrigation with antibacterial solutions or chelating agents is recommended to remove the smear layer on prepared canal walls.

수동과 엔진구동형 기구를 이용한 난원형 근관의 형성에 관한 주사전자현미경적 관찰

송욱,허복,이희주 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.2

The purpose of this study was to evaluate the efficiency of the preparation of oval canals using hand and engine-driven instruments with SEM observation. Thirty single-rooted teeth with oval canal were used in this study. The teeth were divided into 3 groups. In group A, the teeth were instrumented up to a size 35 K-file using RC-prep and irrigated with 5% NaOCl between each file size. In group B, the teeth were instrumented with Profile according to the manufacture's instructions using RC-Prep and irrigated with 5% NaOCl between each file size. In group C, the teeth were instrumented with GT file according to the manufacture's instructions using RC-prep and irrigated with 5% NaOCl between each file size. Then, in all teeth, a final flush of 5ml of distilled water delivered for 30s. Canals were dried with sterile standardized paper points. After preparing the canals, the teeth were sectioned along their mesial and diatal surfaces by using low-speed diamond disc, chisel and mallet. Each root section was then dehydrated in graded concentration of alcohol (70, 80, 90, 100%), mounted on an aluminum stub, sputter-coated with gold-palladium and observed with scanning electron microscope (HITACHI S-4200) in middle and apical area. The results of this study were as follows: 1. In the middle area, group B and group C showed less smear layer than group A, and it was statistically significant (p<0.05). 2. In the middle area, group B showed greater smear layer than group C, but it was not statistically significant (p>1.05). 3. In the apical area, group C showed less smear layer than group A, and it was statistically significant (p<0.05). 4. In the apical area, group A showed greater smear layer than group B, but it was not statistically significant (p>0.05). 5. In the apical area, group B showed greater smear layer than group C, but it was not statistically significant (p>0.05). 6. In all groups, the middle area was less smear layer than the apical area, and it was statistically significant (p<0.05).