DOI: 10.5395/JKACD.2010.35.6.445 치근단역충전용포틀랜드시멘트신복합재료의물리적성질고찰 이상진 조옥인 염지완 박정길 허복 김현철 * 부산대학교치의학전문대학원치과보존학교실 ABSTRACT Physical properties of novel composite using Portland cement for retro-filling material Sang-Jin Lee, Ok-In Cho, Jiwan Yum, Jeong-Kil Park, Bock Hur, Hyeon-Cheol Kim* Department of Conservative Dentistry, Pusan National University School of Dentistry, Yangsan, Korea Objectives: The aim of this study was to compare apical sealing ability and physical properties of MTA, MTA - AH-plus mixture (AMTA) and experimental Portland cement - Epoxy resin mixture (EPPC) for a development of a novel retro-filling material. Materials and Methods: Forty-nine extracted roots were instrumented and filled with gutta-percha. Apical root was resected at 3 mm and the retro-filling cavity was prepared for 3 mm depth. Roots were randomly divided into 3 groups of 15 roots each. The retro-filling was done using MTA, AMTA, and EPPC as the groups divided. Four roots were used as control groups. After setting in humid condition for 24 hours, the roots were immersed in 1% methylene blue dye solution for 72 hours to test the apical leakage. After immersion, the roots were vertically sectioned and photos were taken to evaluate microleakage. Setting times were measured with Vicat apparatus and digital radiographs were taken to evaluate aluminum equivalent thickness using aluminum step wedge. The results of microleakage and setting time were compared between groups using one-way ANOVA and Scheffe s post-hoc comparison at the significance level of 95%. Results: AMTA and EPPC showed less microleakage than MTA group (p < 0.05). AMTA showed the highest radio-opacity than other groups and the novel EPPC showed 5 mm aluminum thickness radio-opacity. EPPC showed the shortest initial and final setting times than other groups while the MTA showed the longest (p < 0.05). Conclusions: Under the condition of this study, the novel composite using Portland cement-epoxy resin mixture may useful for retro-filling with the properties of favorable leakage resistance, radio-opacity and short setting time. [J Kor Acad Cons Dent 2010;35(6):445-452.] Key words: Epoxy resin; MTA; Portland cement; Radio-opacity; Retro-filling; Setting time -Received 4 June 2010; revised 24 August 2010; accepted 30 August 2010- Lee SJ, DDS, MS, PhD student; Cho OI, DDS, MS, PhD student; Yum J, DDS, MS, PhD student, Clinical lecturer; Park JK, DDS, PhD, Associate Professor; Hur B, DDS, PhD, Professor; Kim HC, DDS, PhD, Associate Professor, Department of Conservative Dentistry, Pusan National University School of Dentistry, Yangsan, Korea *Correspondence to Hyeon-Cheol Kim, DDS, PhD. Associate Professor, Department of Conservative Dentistry, Pusan National University School of Dentistry, 3-3 Beomeo-ri, Mulgeum, Yangsan, Korea 626-810 TEL, +82-55-360-5222; FAX, +82-55-360-5214; E-mail, golddent@pusan.ac.kr * 본연구는 2010 년도부산대학교병원임상연구비지원으로이루어졌음. JKACD Volume 35, Number 6, 2010 Novel retro-filling composite using Portland cement 445
서 1993 년에치근단치근단역충전및근관천공부충전재료로소개된 mineral trioxide aggregate (MTA) 는그목적에적합한성질을가진유용한치과재료로임상의여러분야에확대적용되고있다. 1 MTA 의밀폐능력과생체친화성은여러연구 2-4 에서입증되었고이러한장점으로인해 MTA 는치근단역충전, 천공부충전뿐만아니라치수복조, 치수절단술, 근첨폐쇄술 (apexification; artificial apical barrier placement), 근첨유도술 (apexogenesis) 및재혈관화 (revascularization) 등의술식에사용되는대표적인치과재료로자리잡고있다. 3-8 하지만 MTA 는임상적용에있어서너무긴경화시간과불리한조작성이여전히문제가되고있다 9,10. 제조사에따른 ProRoot MTA (Dentsply Tulsa Dental, Johnson City, TN, USA) 의경화시간은 4-6 시간이며, 다른연구보고에따르면 75 분 11 에서 4 시간 12 에이르며심지어 72 시간 13 에이른다는보고도있을정도로다양하다. 이렇게긴경화시간은근첨폐쇄술, 치수복조술등의임상술식을시행하는경우환자의추가내원을필요로할수있으며, 특히치근단수술의경우처럼조직액이나혈액에노출될수있는상황에서는경화되지않은 MTA 는씻김 (wash-out) 현상이생겨미세누출에의한실패를초래할수있다. 또한제조사의권고사항인 3 : 1 ( 분말 : 액 ) 의분액비로혼합한 MTA 를역충전와동에적용하기가어렵다는것에많은임상가들이동의한다. 이러한 MTA 의단점을극복하고자다양한첨가물에의한경화시간의촉진, 적용기구의개발, 새로운대체물의개발등이연구발표되고있다. 14-16 본연구는치근단역충전재료로서 MTA 의이러한단점을극복할수있는재료로 MTA 와 AH-plus root canal sealer 의혼합물과개발재료인신개발재료인 Portland cement-epoxy resin 복합물의여러물성을 MTA 와비교분석하여임상에보다쉽게적용할수있는새로운역충전재료의개발을목적으로시행되었다. 론 재료및방법 완성된치근을가진 49 개의발거된인간단근치를사용하 였다. 모든치아는초음파를이용하여세척후 5.25% 차아염소산나트륨 (NaOCl) 용액에 20 분간담근후생리식염수로다시세척하였다. 저속다이아몬드디스크 (Horico diamond disk 350; Pfingst & Company, Inc., South Plainfield, NJ, USA) 를사용하여모든치아의임상치관을잘라내었다. #10 K-file 을사용하여치근단공을통과시킨후근첨공을지나는길이에서 0.5 mm 뺀길이를작업장으로결정한후 ProTaper Universal NiTi file (Dentsply Maillefer, Ballaigues, Switzerland) 을사용하여 F2 크기까지근관을성형하였다. 근관형성을하는동안세척액은 5.25% 차아염소산나트륨용액을사용하였고최종세척은 15% EDTA 용액을 2 분간적용하였다. 치근단형성은모두 #30 K-file 을사용하여완성한후 AH-plus selaer 를근관내에 paper point 를이용하여도포하고 continuous wave of condensation technique 으로충전하였다. 근관접근와동은자가중합 Glass Ionomer cement (Ketac-Fil; 3M ESPE, St. Paul, MN, USA) 로충전하였다. 미세누출 근관충전이끝난모든치근은저속디스크를사용하여치아장축에수직으로근단공에서 3 mm 떨어진곳을절단하였다. 모든치근은표면에 nail varnish 를 2 회도포하여완벽한밀폐를도모하였다. 음성대조군으로사용할 2 개의치근을제외한모든치근은길이 3 mm, 폭 1 mm 인실린더형다이아몬드버를이용하여 3 mm 깊이의근단역충전와동을형성하였다. 치근은무작위로 15 개씩 3 개의실험군으로분류하였다 (Table 1). 첫번째 MTA 군은제조사의지시 (powder : liquid = 3 : 1) 에따라혼합한 MTA 를 hand plugger (S-Kondensor; Obtura Corporation, Fenton, MO, USA) 로치근단와동을역충전하였다. 충전이끝난모든치근단와동은멸균증류수에적신면구를사용하여다듬어마무리하였다. 두번째 AMTA 군은 MTA 와 AH-plus sealer 의혼합물 (1 : 1 중량비 ) 을충전용 Centrix syringe (C-REZ syringe & tip; Centrix dental Coporation, Shelton, CT, USA) 를사용하여주입충전하고알코올솜을사용하여잉여충전물 Table 1. Experimental groups Group No. Material preparations MTA 15 MTA mixed with sterile water as manufacturer s instruction AMTA 15 MTA mixed with AH plus sealer EPPC 15 Portland cement mixed with epoxy resin, barium sulfate Positive control 2 Apical preparation and no apical filling Negative control 2 No apical preparation and nail varnish coating on entire root surface MTA, mineral trioxide aggregate; AMTA, AH-plus mixture; EPPC, epoxy resin mixture. 446 Lee SJ et al. JKACD Volume 35, Number 6, 2010
을제거하고다듬었다. 세번째 EPPC 군은 Portland cement 와 Epoxy resin 을혼합 (1 : 1 wt. Ratio) 하고방사선불투과성을위하여 Barium Sulfate 를 35% 중량비로추가혼합한후 AMTA 군과같은방법으로주입충전하였다. 2 개의치근은양성대조군으로사용하기위하여역충전을시행하지않았다. 역충전이완료된모든실험군은상온에서젖은거즈로덮고밀폐용기에서 24 시간동안경화되도록하였다. 이후, 1% Methylene blue 용액에 72 시간동안담가미세누출착색이일어나도록하였다. 치근을세척및건조시킨후, 저속다이아몬드디스크를사용하여근단부역충전재료를종단하도록치아장축방향으로 5 mm 이상치근단을분리하고다시절단된부위의치관측을치아장축에수직으로절단한후파절시켜시편을제작하였다. 근단부미세누출을평가하기위해디지털카메라 (Canon 350D; Canon Co., Tokyo, Japan) 를이용하여각시편의절단면을사진촬영하였다. 미세누출의평가는역충전와동의수직벽을따르는누출을평가하였으며, 수직적인누출이없는경우는 0 점, 1 mm 이내는 1 점, 1-2 mm 는 2 점, 2-3 mm 는 3 점, 와동축벽을지나쳐근단부역충전와동의치관측상연까지착색이일어난경우는 4 점으로점수를부여하였다. 경화시간 각재료의경화시간은주문제작한 Vicat apparatus 를사용하여측정하였다. 직경 1 mm 의 Vicat needle 을사용하였으며 300 g 무게로시편에압입하중을가하였다. 역충전에적용한동일한방법으로각실험군을 5 개씩혼합하여혼화가완료된시점부터 5 분간격으로경화정도를평가하였다. Vicat needle 의팁이 5 mm 이내의깊이로침하가일어나기시작하는시간을초기경화시간 (Initial setting time) 으로결정하였고, 혼화물의표면에 Vicat needle 에의한흔적이나타나지않는시점을최종경화시간 (Final setting time) 으로기록하였다. 17 대기습도 ( 건조도 ) 에의한경화시간차이가나타나지않도록측정시간을제외하고는밀폐공간에시편을유지하였다. 방사선불투과도 각재료들을실험비율에따라혼합하여두께 1 mm, 내경 8 mm 로주문제작한금속링 (washer) 에채워넣어방사선불투과도측정용시편을만들었다. 완전히경화된시편을각 3 개씩만들어순수 (99% 이상 ) aluminum 으로제작한 step wedge (1-10 mm 두께 ) 와함께방사선사진을촬영하였다 (Figure 1). 디지털 X-ray sensor (Schick Figure 1. Aluminum step-wedge used in this study and representative digital radiograph image. technology Inc., Long Island City, NY, USA) 를사용하여 60 Kv, 2 ma, 0.08 초노출시간의촬영조건으로시편에서 10 cm 떨어진곳에서촬영하였다. 디지털 X-ray 이미지를 Photoshop (Adobe photoshop 7.0; Adobe systems Incorporated, San Jose, CA, USA) 을사용하여 aluminum wedge equivalent thickness (mmal) 를평가하였다. 통계분석 미세누출점수와경화시간에대해각군간의차이를 SPSS ver. 12.0 (SPSS, Chicago, IL, USA) 을사용하여통계처리하였다. 일원배치분산분석및 Scheffe 사후검증으로유의수준 95% 에서시행하였다. 미세누출 결 과 미세누출점수를부여한예를 Figure 2 에나타냈다. JKACD Volume 35, Number 6, 2010 Novel retro-filling composite using Portland cement 447
Figure 2. Representative samples from each group with dye leakage score. MTA specimen shows leakage with score 2 and AMTA and EPPC specimens show no leakage. MTA, mineral trioxide aggregate; AMTA, AH-plus mixture; EPPC, epoxy resin mixture. Figure 3. Representative samples of radiograph from each group with aluminum step wedge (Left; MTA with 6 mmal, Mid; AMTA with 10 mmal, and Right; EPPC with 5 mmal). MTA, mineral trioxide aggregate; AMTA, AH-plus mixture; EPPC, epoxy resin mixture. Table 2. Leakage score, setting time (min) and aluminum equivalent radio-opacity (mmal) Leakage Setting time (min) Radio-opacity Initial Final (mmal) MTA 2.8 ± 0.8 a 164 ± 9 b 594 ± 36 a 5.7 AMTA 0.8 ± 0.9 b 183 ± 4 a 404 ± 92 b 9.7 EPPC 1.0 ± 1.1 b 62 ± 4 c 83 ± 3 c 5 MTA, mineral trioxide aggregate; AMTA, AH-plus mixture; EPPC, epoxy resin mixture. a,b,c ; Different superscripts means significant differences between groups in vertical row (p < 0.05). AMTA 와 EPPC 가 MTA 보다낮은미세누출을보였다 (p < 0.05, Table 2). 경화시간 EPPC 군이다른군에비해가장빠른경화시간을보였다 (p < 0.05, Table 2). 최종경화시간은 MTA 가약 10 시간이걸렸지만 EPPC 군은평균 83 분으로나타났다. 방사선불투과도 각군의 aluminum equivalent radiopacity 를측정한방사선사진의예를 Figure 3 에나타냈다. AMTA 가가장높은평균불투과도인 9.7 mmal 로측정되었고 EPPC 는 5 mmal, MTA 는 5.7 mmal 의평균불투과도를보였다. 고 MTA는뛰어난밀폐능력, 생체친화성, 항균성, 방사선불투과성등치근단역충전재료로서의많은장점을가지고있음이많은연구들에서입증되었다. 1,2,11,12 하지만이런많은장점과함께 MTA는긴경화시간, 조작의어려움, 고비용이라는문제점도동시에가지고있다. 먼저긴경화시간 찰 은조직액과혈액등에장시간노출되어야하는치근단역충전재료의특성상충전된재료의 wash-out 이문제점으로제기되고있고, 10 이를극복하고자많은연구와시도가이루어지고있다. 일반적으로시도되는방법은 MTA 에경화촉진제를첨가하는방법이다. Wiltbank 등 14 은 MTA 에 Portland cement accelerator 로 Calcium chloride, Calcium nitrite/calcium nitrate, Calcium formate 등을첨가했을때유의할만한경화시간단축을보고하였고, 또다른최근연구에서는 15% Disodium hydrogen orthophosphate(na2hpo4) 액을 MTA 와혼합함으로써물성의변화가없는성공적인경화시간의단축을나타냈다고보고하였다. 18,19 치근단수술과정은특성상시야가좁고기구의접근성이제한될수밖에없으며이러한영역에사용되는재료의조작성은임상사용에있어서매우중요한요소이다. MTA 는 granular consistency 를가지고있음으로해서조작시간 (working time) 이불과 4 분여정도로짧고조작성이떨어지며, 이를극복하고자특별히고안된이송기구도개발되었지만여전히임상사용에는어려움이없지않다. Ber 등은 MTA 에 1% 의 Methycellulose-anti-washout ingredient 를첨가했을때 zinc oxide eugenol cement 과유사한정도의조작성을얻을수있었다고보고하고있고, 20 Kogan 등의연구에서는 NaOCl gel, K-Y Jelly 와 5% 448 Lee SJ et al. JKACD Volume 35, Number 6, 2010
CaCl2 을 MTA 와혼합했을때경화시간의단축과더불어조작성의향상이있었다고보고했다. 21 또다른최근연구 22 에서는 23.1wt% 의 calcium lactate gluconate 용액을물대신에 MTA 와혼합해사용함으로서경화시간의단축뿐아니라뛰어난조작성을얻을수있다고발표했다. 근관치료에사용되는 epoxy resin 계열의 sealer 인 AHplus 는근관충전시미세누출의차단에매우효과적인재료로보고되고널리사용되고있다. 23 또한 AH-plus 의생체친화성이나독성에대한여러가지연구에서도양호한결과를보고하고있다. Leyhausen 등의연구에서는 AH-plus 의경우유전독성 (genotoxicity) 이나세포독성 (cytotoxicity) 이거의없다고보고했고, 24 Scarparo 등이발표한다른종류의 sealer 와의비교연구에서도제한적인초기의염증반응만이나타났다고보고하고있다. 25 최근개발된 Methacrylatebased resin sealer 인 EndoRez, Epiphany, Metaseal 등과의비교연구에서도 AH-plus 가생체적합성및세포독성비교에서모두더양호한결과를보였다. 26 따라서본실험에서는미세누출차단과생체적합성에서모두뛰어난결과를보이는 AH-plus 와 MTA 를섞어사용함으로써조작성의확보와폐쇄능력향상, 생체적합성을얻을수있을것으로기대하고실험군에포함하였으며, 이러한가능성을바탕으로 AH-plus 의주성분인 epoxy resin 과 MTA 와성분이유사한 Portland cement 의복합물을새로운치근단역충전재료로개발및제안하고자본연구를시행하였다. 이번연구에서사용한 AH-plus-MTA mixture, Portland cement-epoxy resin mixture 는모두 Centrix syringe 를사용한주입충전이용이하였으며알코올솜을사용한마무리에도적절한점도및조작성을가지고있었다. 이렇게주입방법에의한조작이가능한것은 Epoxy resin 을전달및기저제로사용하였기때문이다. 하지만, EPPC group 의경우몇몇시편에서역충전상태혹은미세누출의평가과정에충전물내부에기포가혼입된것이발견되기도하였다. 이는방사선불투과성확보를위해수작업으로진행한 Barium Sulfate 의혼화과정중에나타났거나주입충전을위한 syringe 내로넣는과정에서유입된공기에의한영향도있을것으로사료된다. 그렇지만이러한기포혼입에도불구하고미세누출실험결과또한 MTA 를단독으로사용한경우보다 Epoxy resin 과혼합한 AMTA, 개발중인 EPPC group 에서유의하게적은미세누출을보였다. 이는조작성향상에의해주입충전후충분한가압이가능했던점과 Epoxy resin 이가지는접착밀폐효과에의한것으로사료된다. 27,28 이러한미세누출감소결과는 methacrylate 계열의 resin 을 MTA 와혼합하여실험한이전의 Kim 등의연구결과와도일치된다. 29 MTA 의또다른단점중하나는너무고가의재료라는문 제이며, 이런이유로 MTA 와 chemical composition 이유사한 Portland cement 가 MTA 의대체재료로서많이연구되고있고, 9,30-32 특히생체독성문제에있어서도 Portland cement 가 MTA 와유사하다는결과가보고되고있다. 33 따라서이번연구에서사용한 Portland cement-epoxy resin mixture 는저가의대체제로서도가능성있는재료로서선택되었다. Portland cement 등의 hydraulic cement 의경화시간측정에는 Vicat needle, 17 Gilmore needle 34,35 등을사용하는데이번연구에서는 1 mm 직경의 Vicat needle 을이용하여 300 g 의하중으로조사하였다. 본실험에서는 Vicat method 에따라초기경화시간과최종경화시간을구분하여측정하였는데, 이번연구에서측정한 MTA 의최종경화시간은 10 시간이나되어일반적으로발표된평균 MTA 경화시간인 164 분 11,12 에비해훨씬늦은경화시간을보였다. 아마도기존연구에서발표된경화시간은초기경화시간일수도있을것으로판단된다. 그러나최종경화이전까지는습도나수분에의한 wash-out 현상이일어날수도있으므로최종경화시간을비교하는것이적절할것으로사료된다. 또한 MTA 의특성에의해분액비, 혼화방법이나시간, 응축시의압력, 습도등주위여건에의해경화시간이다양하게나타난것으로추정된다. 13,21,36-37 본실험에서는 EPPC 가최종경화시간이가장짧고 MTA 가가장길게측정되었다. MTA 는일반적으로 Portland cement 에비해긴경화시간을가지는것으로발표되는데, 이는 MTA 가 sulfur 와 tricalcium aluminate 가상대적으로적게함유되었기때문이다. 38 본실험에서 AMTA 의긴경화시간은 AH-plus sealer 의긴경화시간 ( 제조사발표자료 ; 8 시간 ) 때문인것으로사료된다. AH-plus 자체의경화시간보다약 1 시간짧은정도의최종경화시간을보였는데이는 MTA powder 의추가에의한것으로판단된다. 실험적재료인 EPPC 는상대적으로아주짧은경화시간을나타냈는데이는 epoxy resin 의경화에주로의존했기때문인듯하며이는임상적용시장점이될수있을것이라고추정된다. 방사선불투과성검사결과는 AMTA 군에서가장높게나타났는데이는제조사가발표한 13.6 mmal 에이르는 AH-plus sealer 가가지는본래의높은방사선불투과성에기인한것으로보인다. 실험적복합물인 EPPC 군은 MTA 와유사한정도로나타났으며임상사용에적절할것으로생각된다. EPPC 군에서는방사선불투과성을위해중량비 35% 의 barium sulfate 를첨가하였는데 Bismuth oxide 를첨가한다른연구보고 30,39 에비추어볼때, barium sulfate 에의한물성변화혹은혼합비율에따른차이에대해서추가연구도필요할것으로생각된다. 아울러이번연구에서복합물의일부로사용한 MTA 혹은 Portland cement 는수분을사용하지않고혼화하였으 JKACD Volume 35, Number 6, 2010 Novel retro-filling composite using Portland cement 449
므로, 수분과접촉함으로서생기는수화과정 40 이제한되었을것이다. 이는수화과정에의해형성되는부산물의생성또한제한됨을의미하며, MTA 가가지는생체친화적인장점즉강알칼리성성분에의한항염작용등이발현되지않을수도있을것으로추정된다. 이상의연구결과에비추어 Portland cement-epoxy resin mixture 는치근단역충전재료로사용하기에충분한조작성을가졌고, MTA 에비교해유의할만한미세누출의감소를보였기에치근단역충전재료로서의뛰어난물리적성질을가진것으로보인다. 그러나, 향후이혼합물의생체적합성및독성에대한추가적인연구가필요할것으로사료된다. 결 본연구의조건하에서, 신개발재료인 EPPC 는치근단역충전재료로서기존의 MTA 보다양호한밀폐능력과방사선불투과성및짧은경화시간등의역충전재료로서적절한물리적성질을가진것으로보인다. 론 References 1. Torabinejad M, Watson TF, Pitt Ford TR. Sealing ability of a mineral trioxide aggregate when used as a root end filling material. J Endod 1993;19:591-595. 2. Camilleri J, Pitt Ford TR. Mineral trioxide aggregate: a review of the constituents and biological properties of the material. Int Endod J 2006;39:747-754. 3. Pitt Ford TR, Torabinejad M, Abedi HR, Bakland LK, Kariyawasam SP. Using mineral trioxide aggregate as a pulp-capping material. J Am Dent Assoc 1996;127: 1491-1494. 4. Salako N, Joseph B, Ritwik P, Salonen J, John P, Junaid TA. Comparison of bioactive glass, mineral trioxide aggregate, ferric sulfate, and formocresol as pulpotomy agents in rat molar. Dent Traumatol 2003; 19:314-320. 5. Bakland LK. Management of traumatically injured pulps in immature teeth using MTA. J Calif Dent Assoc 2000;28:855-858. 6. Witherspoon DE, Ham K. One-visit apexification: technique for inducing root-end barrier formation in apical closures. Pract Proced Aesthet Dent 2001;13:455-460. 7. Holden DT, Schwartz SA, Kirkpatrick TC, Schindler WG. Clinical outcomes of artificial root-end barriers with mineral trioxide aggregate in teeth with immature apices. J Endod 2008;34:812-817. 8. Banchs F, Trope M. Revascularization of immature permanent teeth with apical periodontitis: new treatment protocol? J Endod 2004;30:196-200. 9. Camilleri J. The physical properties of accelerated Portland cement for endodontic use. Int Endod J 2008; 41:151-157. 10. Islam I, Chng HK, Yap AU. Comparison of the physical and mechanical properties of MTA and portland cement. J Endod 2006;32:193-197. 11. Chng HK, Islam I, Yap AU, Tong YW, Koh ET. Properties of a new root-end filling material. J Endod 2005;31:665-668. 12. Torabinejad M, Hong CU, McDonald F, Pitt Ford TR.. Physical and chemical properties of a new root-filling material. J Endod 1995;21:349-353. 13. Sluyk SR, Moon PC, Hartwell GR. Evaluation of setting properties and retention characteristics of mineral trioxide aggregate when used as a furcation perforation repair material. J Endod 1998;24:768-771. 14. Wiltbank KB, Schwartz SA, Schindler WG. Effect of Selected Accelerants on the Physical Properties of Mineral Trioxide Aggregate and Portland Cement. J Endod 2007;33:1235-1238. 15. Ber BS, Hatton JF, Stewart GP. Chemical modification of proroot mta to improve handling characteristics and decrease setting time. J Endod 2007;33:1231-1234. 16. Asgary S, Shahabi S, Jafarzadeh T, Amini S, Kheirieh S. The properties of a new endodontic material. J Endod 2008;34:990-993. 17. American Society for Testing and Materials. Standard test method for time of setting of hydraulic cement by Vicat needle. ASTM C191-04. West Conshohocken, PA: American Society for Testing and Materials; 2004. 18. Huang TH, Shie MY, Kao CT, Ding SJ. The effect of setting accelerator on properties of mineral trioxide aggregate. J Endod 2008;34:590-593. 19. Ding SJ, Kao CT, Shie MY, Hung C Jr, Huang TH. The physical and cytological properties of white MTA mixed with Na2HPO4 as an accelerant. J Endod 2008; 34:748-751. 20. Ber BS, Hatton JF, Stewart GP. Chemical modification of ProRoot MTA to improve handling characteristics and decrease setting time. J Endod 2007;33:1231-1234. 21. Kogan P, He J, Glickman GN, Watanabe I. The effects of various additives on setting properties of MTA. J Endod 2006;32:569-572. 22. Hsieh SC, Teng NC, Lin YC, Lee PY, Ji DY, Chen CC, Ke ES, Lee SY, Yang JC. A novel accelerator for improving the handling properties of dental filling materials. J Endod 2009;35:1292-1295. 23. Whitworth JM, Baco L. Coronal leakage of sealer-only backfill: an in vitro evaluation. J Endod 2005;31:280-282. 24. Leyhausen G, Heil J, Reifferscheid G, Waldmann P, Geurtsen W. Genotoxicity and cytotoxicity of the Epoxy resin based root canal sealer AH plus. J Endod 1999;25:109-113. 25. Scarparo RK, Grecca FS, Fachin EV. Analysis of tissue reactions to methacrylate resin-based, epoxy resinbased, and zinc oxide-eugenol endodontic sealers. J Endod 2009;35:229-232. 26. Al-Hiyasat AS, Tayyar M, Darmani H. Cytotoxicity evaluation of various resin based root canal sealers. Int Endod J 2010;43:148-153. 27. De Almeida WA, Leonardo MR, Tanomaru Filho M, Silva LA. Evaluation of apical sealing of three endodontic sealers. Int Endod J 2000;33:25-27. 28. Oguntebi BR, Shen C. Effect of different sealers on thermoplasticized Gutta-percha root canal obturations. J Endod 1992;18:363-366. 29. Kim JC, Kim MR, Ko HJ, Won KY. Apical microleakage of MTA with 4-META/MMA & TBB resin as a root-end filling material. J Kor Acad Cons Dent 2009; 450 Lee SJ et al. JKACD Volume 35, Number 6, 2010
34:371-376. 30. Coomaraswamy KS, Lumley PJ, Hofmann MP. Effect of bismuth oxide radioopacifier content on the material properties of an endodontic Portland cement-based (MTA-like) system. J Endod 2007;33:295-298. 31. Ribeiro DA, Duarte MA, Matsumoto MA, Marques ME, Salvadori DM. Biocompatibility in vitro tests of mineral trioxide aggregate and regular and white Portland cements. J Endod 2005;31:605-607. 32. Islam I, Chng HK, Yap AU.Comparison of the physical and mechanical properties of MTA and portland cement. J Endod 2006;32:193-197. 33. Chang SW, Yoo HM, Park DS, Oh TS, Bae KS. Ingredients and cytotoxicity of MTA and 3 kinds of Portland cements. J Kor Acad Cons Dent 2008;33: 369-376. 34. American Society for Testing and Materials. Standard test method for time of setting of hydraulic-cement paste by Gillmore needles. ASTM C266-03. West Conshohocken, PA: American Society for Testing and Materials; 2003. 35. International Organization for Standardization. Dental root canal sealing materials. ISO 6876:2001(E). Geneva, Switzerland: International Organization for Standardization; 2001. 36. Watts JD, Holt DM, Beeson TJ, Kirkpatrick TC, Rutledge RE. Effects of ph and mixing agents on the temporal setting of tooth-colored and gray mineral trioxide aggregate. J Endod 2007;33:970-973. 37. Fridland M, Rosado R. Mineral trioxide aggregate (MTA) solubility and porosity with different water-topowder ratios. J Endod 2003;29:814-817. 38. Dammaschke T, Gerth HU, Züchner H, Schäfer E. Chemical and physical surface and bulk material characterization of white ProRoot MTA and two Portland cements. Dent Mater 2005;21:731-738. 39. Saliba E, Abbassi-Ghadi S, Vowles R, Camilleri J, Hooper S, Camilleri J. Evaluation of the strength and radiopacity of Portland cement with varying additions of bismuth oxide. Int Endod J 2009;42:322-328. 40. Camilleri J. Hydration mechanism of mineral trioxide aggregate. Int Endod J 2007;40:462-470. JKACD Volume 35, Number 6, 2010 Novel retro-filling composite using Portland cement 451
국문초록 치근단역충전용포틀랜드시멘트신복합재료의물리적성질고찰 이상진 조옥인 염지완 박정길 허복 김현철 * 부산대학교치의학전문대학원치과보존학교실 연구목적 : 이연구의목적은새로운근단역충전재료를개발하기위해 MTA, MTA 와 AH-plus 혼합물 (AMTA), 그리고실험적개발재료인 Portland cement-epoxy resin composite (EPPC) 의미세누출및물리적인성질을비교하는것이다. 연구재료및방법 : 발거치아 49 개를근관성형하고 gutta-percha 와 sealer 로충전하였다. 각치아의치근을근단부 3 mm 에서절단하고 3 mm 깊이의역충전와동을형성하였다. 15 개씩무작위로분류한치근을세군으로나누어각각 MTA, AMTA, EPPC 로충전하였고네개의치근은대조군으로사용하였다. 각군의재료로역충전이완료된모든실험군을젖은거즈로덮고 24 시간동안경화시켰다. 경화후 72 시간동안 1% methylene blue 염색액에담근후, 치근단을수직절단하여사진을촬영하고미세누출을평가하였다. Vicat apparatus 를사용하여실험군별로경화시간을측정하였으며, aluminum step wedge 를사용한디지털방사선사진을촬영하여각군의방사선불투과도를평가하였다. 미세누출과경화시간에대해각군간의차이를일원배치분산분석및 Scheffe 사후검증으로유의수준 95% 에서평가하였다. 결과 : AMTA 와 EPPC 는 MTA 군에비해적은미세누출량을보였다 (p < 0.05). AMTA 는가장높은방사선불투과도를보였으며개발재료인 EPPC 군은 5 mm aluminum 두께의방사선불투과도를보였다. MTA 가가장긴경화시간을나타낸반면 EPPC 군은다른군에비해초기경화와최종경화모두가장짧은경화시간을나타냈다 (p < 0.05). 결론 : 이연구조건하에서, 신개발재료인 EPPC 는치근단역충전재료로서기존의 MTA 보다양호한밀폐능력과방사선불투과성및짧은경화시간등의역충전재료로서적절한물리적성질을가진것으로보인다. 주요단어 : 경화시간 ; 방사선불투과도 ; 에폭시레진 ; 역충전 ; 포틀랜드시멘트 ; MTA 452 Lee SJ et al. JKACD Volume 35, Number 6, 2010