이은혜 1 최항문 2 박세희 1 김진우 1 조경모 1 * 강릉원주대학교치과대학 1 치과보존학교실, 2 구강악안면방사선학교실 ABSTRACT EVALUATION OF RADIOPACITY AND DISCRIMINABILITY OF VARIOUS FIBER REINFORCED COMPOSITE POSTS Eun-Hye Lee 1, Hang-Moon Choi 2, Se-Hee Park 1, Jin-Woo Kim 1, Kyung-Mo Cho 1 * 1 Department of Conservative Dentistry, 2 Department of Oral and maxillofacial radiology, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea The purpose of this study was to compare radiopacity and radiographic discriminability of various FRC-Posts. Six FRC-Posts were investigated ; 1) FRC Postec Plus (Ivoclar Vivadent AG, Schaan, Liechtenstein), 2) Snowlight (Carbotech, Lewis center, OH, USA), 3) Dentin Post (Komet Brasseler, Lamgo, Germany), 4) Rely-X Fiber Post (3M ESPE, St.paul, MN, USA), 5) D.T.-Light Post (BISCO, Schaumburg, IL,USA), 6) Luxapost (DMG, Hamburg, Germany) The radiographs of each post with a reference 1 mm / 2 mm aluminum step-wedge was taken using digital sensor. The optical density were calculated by gray value of 10 10 pixel and compared in mm Al equivalent at five points. Six maxillary incisors of similar radiopacity were used. Radiographs of posts in Mx. incisors of lingual side of dry mandible were taken. We showed radiographs and asked the questionnaire to 3 radiologists, 3 endodontists, 3 general practitioners. The questionnaire was comprised of choices of the highest, lowest radiopaque individual post and the choices of best discriminable post at apical, coronal area. The following results were obtained. 1. Each post system showed various radiopacity. 2. There was change of discriminability between each post and simulated specimens regardless of examiner. Although each post showed various radiopacity, the difference of radiopacity did not affect on discriminability. [J Kor Acad Cons Dent 35(3):188-197, 2010] Key words: Radiopacity, FRC-post, Discriminability, Digital sensor, Aluminum step-wedge, mm Al equivalent -Received 2010.4.19., revised 2010.4.23., accepted 2010.4.27.- Ⅰ. 서론 *Corresponding Author: Kyung-Mo Cho Department of Conservative Dentistry College of Dentistry, Gangneung-Wonju National University 123 Chibyon-dong Gangwon-do, 210-702, Korea Tel: 82-33-640-2467 Fax: 82-33-642-6410 E-mail: drbozon@gwnu.ac.kr * 이논문은 2009 년도강릉원주대학교치과병원학술연구조성비지원에의하여수행되었음. 188 방사선불투과도 (radiopacity) 는구강내치과재료에요구되는중요한특성중의하나이다. 치과진료의진단은방사선사진에크게의존하고있고주위해부학적구조물들과의경계를명확히하고수복물의적합도, 이차우식증, 장기안정성의지속적검사를위해치과수복재료의방사선불투과도는중요하다. 1-3)
포스트는과도하게상실된치아의치관부의코어를유지하기위해사용되는근관내구조물로방사선학적분석이가장유용한평가방법이므로근관치료후코어수복재료는내부의기포와변연부이상을검사할수있을정도의방사선불투과도가요구되고포스트는현재포스트의위치와추후의재치료시의적합한판단을위해충분한방사선불투과도가요구된다. 4,5) 섬유강화레진포스트 (fiber reinforced composite post, FRC-Post) 는기존의금속포스트의비심미적이고높은강도로인한치근파절을유발하는등의단점을보완하고자 1990년 Duret 등에의해레진기질과카본섬유의구성으로소개되었다. 6-9) 그후레진기질에석영, 글래스, 지르코늄등의섬유를함유하는다양한 FRC-Post가개발되어이전의금속포스트와달리상아질과비슷한탄성계수를가지고응력을분산시켜포스트의끝으로응력이집중되는것을막아치근파절가능성을줄이는장점을보이는등높은성공률에따라현재임상에서널리사용되고있다. 10-13) 국제표준기구 (International Standards Organization, ISO) 는폴리머충전재, 수복재, 접착제의방사선불투과도기준에대해정한바있다. 이들재료는상아질과비슷한방사선불투과도를갖는것으로알려져있어참고기준으로사용된알루미늄과비교되었으며같은두께의알루미늄과같거나더높은방사선불투과도를가져야한다고명시되었다. 14-17) 그러나포스트의방사선불투과도기준에대해서는명시하지않고있다. FRC-Post는금속포스트에비해낮은방사선불투과도를가지므로방사선불투과도가충분하지못한제품은천공이나근관내의틈새등을간과할수있는단점을가지게되기에이들의방사선불투과도에대한연구가필요하다. 6,7) 본연구에서는디지털방사선법을이용하여 6가지 FRC- Post 의방사선불투과도를비교하고, 각각 3 명의구강악안면방사선과전공자와 3 명의치과보존과전공자, 3 명의일반치과의사로구성된세시험자군에서의식별능력을평가하고자하였다. 1. 연구재료 Ⅱ. 연구재료및방법 1) FRC-Post system Table 1 과같이시중에서판매되는 6 개의 FRC-Post 를연구에사용하였다. 2) 디지털센서와방사선촬영기디지털센서로 Schick CDR (Schick technologies Inc., LIC NY, USA) 를사용하였다. 방사선촬영기로 Heliodent DS (Sirona dental systems, Bensheim, Germany) 를사용하였다. 3) 실험치아최근에발거된사람의상악전치중에서치근만곡도가적고하나의근관을가지며유사한방사선불투과도를갖는치아 6 개를사용하였다. 2.5% 차아염소산나트륨에 24 시간동안보관후치근표면의치주조직잔사와치석을초음파스케일링과치근활택술로제거하고, 실험전까지생리식염수에보관하였다. 4) 알루미늄 step-wedge 1 mm 씩의두께차이를갖는 1-10 mm 알루미늄 stepwedge 와 2 mm 씩의두께차이를갖는 2-20 mm 알루미 Table 1. Composition of FRC-Post FRC-post Composition Size FRC-Postec Plus Glass fiber in Resin matrix, (Ivoclar Vivadent AG, Schaan, Liechtenstein) Yitterbium trifluoride 1 Snowlight Zirconia AR-glass in Epoxy matrix (Carbotech, Lewis center, OH, USA) #14 Dentin Post Glass fiber in Resin matrix (Komet Brasseler, Lamgo, Germany) 070 Rely-X Fiber Post Glass fiber in Resin matrix (3M ESPE, St.paul, MN, USA) 2 D.T.-Light Post Quartz fiber in Epoxy matrix (BISCO, Schaumburg, IL, USA) #1 Luxapost Glass fiber in bis-gma based quartz matrix (DMG, Hamburg, Germany) green 189
a b Figure 1. Aluminum step-wedge. a. 1 mm step, b. 2 mm step. Figure 2. Radiographic image of post with aluminum stepwedge. Figure 3. Measuring point of post. 1. Apex of post 2. 4 mm to apex of post 3. 7 mm to apex of post 4. Point of inclination change 5. 10 mm to apex of post 늄 step-wedge 를제작하였다. 2. 연구방법 1) FRC-Post 의방사선불투과도평가각 6 가지포스트를알루미늄 step-wedge 와함께 7 ma, 60 kv 의설정하에디지털센서와방사선촬영기의관구가 40 cm 떨어진거리에서 0.25 초동안노출하여방사선사진을촬영하였다 (Figure 2). Adobe Photoshop CS2 (Adobe system, San Jose, CA, USA) 을이용하여포스트만을촬영한디지털영상에 서포스트의다섯지점에서각부위의 10 10 화소 (pixel) 를지정한후평균회색조값 (average gray scale value) 를측정하였다 (Figure 3). 회색조단계 (gray scale value) 는 0 ( 검정색 ) - 255 ( 흰색 ) 의 256 단계로나타낸다. 이값은재료의방사선감쇠를따르는데다음의공식을이용하여흡광도 (absorbance) 로전환할수있다. 18,19) A = -log10 (T) = -log10 (1-G/255) A: absorbance T: transmittance G: gray scale value 190
디지털켈리퍼 (CD-15CP, Mitutoyo Corp., Kawasaki, Japan) 를사용하여방사선불투과도를측정하는다섯지점에서의포스트두께를측정하여각지점에서포스트 1 mm 두께의흡광도로환산하였다. 알루미늄 step-wedge 의각두께에따른흡광도를계산하여그래프를만든후각측정지점의흡광도를역으로대입하는방법을사용하였다. 각측정지점에서포스트두께 1 mm 에해당하는방사선불투과도를동일두께의알루미늄당량 (equivalent mm/al) 으로비교하였다. 하악골의순측에 7 mm 두께의 base plate wax 로연조직을재현하였다. 여섯개의각포스트영상을모아한장의사진을만들고 (Figure 4), 6 개의치아시편부위만을모은뒤배열순서를임의로변경하여재조합한치아시편사진을 5 장만들었다 (Figure 5). 2) 식별능력평가 (1) 치아시편준비실험치아는 #330 carbide bur (Komet Brasseler, Lamgo, Germany) 와 Endo Z bur (Dentsply Maillefer, Ballalgues, Switzerland) 를사용하여근관와동을형성하였다. Size 0 barbed broach (MANI, Inc., Tochigi, Japan) 를이용하여치수를제거하고 #10 stainless steel K-file (MANI, Inc., Tochigi, Japan) 로치근단공개방을확인한뒤근관이하나임을확인하였다. 입체현미경 (S5, Carl Zeiss Surgical Inc., Jena, Germany) 을이용하여 #15 SS K-file tip 이치근단공을통해서육안으로확인되는파일길이에서 1 mm 짧은위치를근관의작업장으로설정하였다. 근관의치경부 1/3 부위는 gates glidden drill (MANI, Inc., Tochigi, Japan) 을사용하여확대하였으며통법에따라.06 taper profile (Dentsply Maillefer, Ballalgues, Switzerland) 을이용하여 ISO #40 까지확대하였다. 근관형성단계마다 #10 K-file 을이용하여치근단공개방을확인하였고, 2.5% 차아염소산나트륨을 #27 gauge needle 과 luer lock syringe (ShiFeng, Schuan, China) 를사용하여세정하였다. 근관충전재로 AH-26 실러 (Dentsply, Konstanz, Germany) 와.06 taper #40 gutta percha cone (Diadent, Cheongju, Korea) 를이용하였다. System B heat source (Sybronendo, Glendora, CA) 를이용하여치근단 4 mm 를충전한후 Obtura (Obtura Spartan, Fenton, MO, USA) 를이용하여 back filling 을하였다. 근관충전된 6 개의치아를치근단에서 11 mm 의길이로일정하게치관부를제거한후각제조사의포스트드릴을이용하여포스트공간을형성한후별도의접착제없이포스트를식립하였다. Figure 4. Radiographic image of posts. (2) 방사선사진촬영및판독각포스트가식립된치아시편을사람의건조하악골의설측에위치시켜개별포스트촬영시와같은조건하에서방사선촬영하였다. Finger 등 7) 의연구방법을응용하여건조 Figure 5. Radiographic images of simulated specimens. 191
판독자성명 : 화면에순차적으로 6개의 FRC-Post가나열된 1장의사진과아래의그림과유사한 6개의치근에각기다른 FRC-Post가식립되어있는사진 5장이보여집니다. 치과의사 3 명의세군을시험자로선정하여같은조건의암실에서사진 1 장당 5 분의시간을설정하여 Figure 4, 5 의사진을보여주었다. 포스트의사진에서는 Figure 6 의설문지내용중 1, 2 번두항목을, 치아시편사진들에서는 1 번부터 4 번의문항에응답하도록하였다. Ⅲ. 연구결과 1. 방사선불투과도평가 각사진에서다음과같은질문을공통으로하게됩니다. 1. 포스트길이전반에걸쳐가장방사선불투과도가높은포스트는어떤것입니까? 2. 포스트길이전반에걸쳐가장방사선불투과도가낮은포스트는어떤것입니까? 3. 포스트의치근단에서상아질과가장구분이잘되는포스트는어떤것입니까? 4. 포스트의치관쪽끝에서상아질과가장구분이잘되는포스트는어떤것입니까? 매사진마다판독과기록을하는시간은 5분입니다. 참고기준으로사용된 1 mm 와 2 mm 알루미늄 stepwedge 의두께에따른흡광도를그래프로나타냈다 (Figure 7). 다섯지점에서의방사선불투과도를평균으로비교하였을때각 FRC-Post 는다른값을보여 FRC Postec Plus, Snowlight, Dentin Post, Rely-X Fiber Post, D.T.- Light Post, Luxapost 의순서로방사선불투과도가높았다 (Table 2, 3). 실험에사용된모든포스트가포스트의치근단부위보다치근단에서 10 mm 떨어진지점이동일두께대비높은알루미늄당량을보였다. Figure 6. Questionnaire. 1.2 포스트와상아질사이의식별능력을평가하기위해치아시편사진에서치관부끝과치근단에서상아질과포스트부위의 10 10 화소의평균회색조값 (average gray scale value) 을측정하였다. 두값의차이를구하여포스트의치관부끝과치근단에서포스트사이에식별도의높고낮은순위를정하였다. 임상경력 5 년이상의구강악안면방사선과전공자 3 명, 치과보존과전공자 3 명, 전문과정수련을하지않은일반 Absorbance 1 0.8 0.6 0.4 0.2 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 mm Al Figure 7. Absorbance of aluminum thickness. Table 2. The value of radiopacity at each measuring point of post (absorbance/mm post) Point FRC Postec Plus Snowlight Dentin Post Rely-X Fiber Post D.T.-Light Post Luxapost 1 0.1683 0.1180 0.1234 0.1106 0.1100 0.0823 2 0.1646 0.1300 0.1263 0.1244 0.1196 0.0929 3 0.1753 0.1323 0.1249 0.1296 0.1191 0.0935 4 0.1750 0.1343 0.1194 0.1307 0.1269 0.0942 5 0.1836 0.1343 0.1435 0.1307 0.1202 0.1008 mean 0.1734 0.1296 0.1275 0.1252 0.1192 0.0927 192
Table 3. The value of radiopacity at each measuring point of post (mm Al/mm post) Point FRC Postec Plus Snowlight Dentin Post Rely-X Fiber Post D.T.-Light Post Luxapost 1 2.40 1.54 1.60 1.44 1.48 1.02 2 2.47 1.90 1.79 1.78 1.68 1.28 3 2.69 1.96 1.81 1.90 1.70 1.33 4 2.68 1.99 1.77 1.97 1.89 1.34 5 2.82 1.98 2.16 1.97 1.76 1.45 mean 2.61 1.87 1.83 1.81 1.70 1.28 Table 4. The value of radiographic images of simulated specimens (absorbance) Point FRC Postec Plus Rely-X Fiber Post D.T.-Light Post Luxapost Dentin Post Snowlight coronal 0.6004 0.5553 0.5677 0.5614 0.5314 0.4874 middle 0.6072 0.6284 0.5870 0.5870 0.5144 0.5257 apical 0.6004 0.6212 0.6004 0.5870 0.5257 0.5492 mean 0.6026 0.6016 0.5850 0.5785 0.5239 0.5208 Table 5. Difference of radiopacity between dentin and post at apical area (absorbance) FRC Postec Plus Rely-X Fiber Post Luxapost D.T.-Light Post Dentin Post Snowlight 0.0660 0.0629 0.0555 0.0542 0.0486 0.0403 Table 6. Difference of radiopacity between dentin and post at coronal area (absorbance) Rely-X Fiber Post FRC Postec Plus Luxapost Snowlight Dentin Post D.T.-Light Post 0.1333 0.1283 0.0969 0.0677 0.0544 0.0215 2) 식별능력평가포스트를치아시편내에삽입한후사람의건조하악골에위치시킨사진에서상아질, 치조골과중첩된포스트의방사선불투과도를측정한결과를 Table 4 에나타내었다. 포스트만의방사선불투과도를측정했을때와다른방사선불투과도순위를보이나가장높은방사선불투과도와가장낮은방사선불투과도의차이는유사하게나타났다. 치아시편사진에서포스트의치근단부위와치관부에서의상아질부위와포스트사이의방사선불투과도차이를 Table 5, 6 에나타냈다. 치관부와치근단부위에서각포스트마다다른방사선불투과도차이를보였다. 세시험자군사이의식별결과를 Table 7 과 8 에각문항별정답률로나타냈다. 포스트만을촬영한사진에서방사선불투과도가가장높은것과낮은것을선택하는문항은세시험자군모두 100% 정답률을나타냈다. 그러나치아시편을촬영한사진들에서는구강악안면방사선과전공자가높은정답률을, 일반치과의사가낮은정답률을보였으나같은치아시편을순서만바꾸어나열한 5 장의 Table 7. The percentage of correct answers in radiographic image of post (%) Examiner Radiographic image of post Q 1 Q 2 mean Radiologist 100 100 100 Endodontist 100 100 100 General practitioner 100 100 100 사진들에서정답률이사진마다일관되게나타나지않았다. 치아시편을촬영한사진들에서방사선불투과도가가장낮은것을선택하는문항은일반치과의사가낮은정답률을보였다. 치근단부위와치관부에서의포스트부위와상아질부위의구분에대한문항에서치근단에서는구강악안면방사선과전공자가일반치과의사보다높은정답률을보이나치관부에서는그렇지못한결과를보였고치아시편의순서를바꾼여러사진에서정답률의일관된경향을보이지않았다. 193
Table 8. The percentage of correct answers in radiographic image of simulated specimens (%) Examiner Q 1: Highest radiopaque post Picture 1 Picture 2 Picture 3 Picture 4 Picture 5 mean Radiologist 100 33 67 0 100 60 Endodontist 67 33 67 0 67 47 General practitioner 33 0 33 33 67 33 Examiner Q 2: Lowest radiopaque post Picture 1 Picture 2 Picture 3 Picture 4 Picture 5 mean Radiologist 33 33 33 33 33 33 Endodontist 100 33 33 33 33 46 General practitioner 67 0 33 0 33 27 Examiner Q 3: Best discriminable post at apical area Picture 1 Picture 2 Picture 3 Picture 4 Picture 5 mean Radiologist 67 33 67 33 67 53 Endodontist 67 0 33 0 67 33 General practitioner 33 0 0 33 67 27 Examiner Q 4: Best discriminable post at coronal area Picture 1 Picture 2 Picture 3 Picture 4 Picture 5 mean Radiologist 0 67 33 67 0 33 Endodontist 0 33 0 100 0 27 General practitioner 67 33 33 67 0 40 Ⅳ. 총괄및고안 Tagger 와 Katz 20) 는근관충전용실러의방사선불투과도를평가한연구에서광학송신기의사용없이디지털화된방사선사진필름과특화된컴퓨터소프트웨어와장비를이용하여디지털영상을컴퓨터에서보다상세하게분석하였다. 이와유사한다른연구에서는소프트웨어를이용하여디지털영상에서완전히검은색상을 0 으로정하고완전히흰색상을 255 로수적화하여각기다른정도의색상을 256 단계의수적인값으로나타내는화소의회색조값 (gray-pixel value) 으로평가했다. 21,22) 이후 Sabbagh 23) 등은화소의회색조값을 mm 단위의동량의알루미늄두께로환산하여각재료의방사선불투과도를비교하였다. 또한 Brian 5) 등은화소의회색조값을이용하여각재료의흡광도를계산하여영상분석을하였다. 디지털방사선사진법은촬영후분석과정에서광학송신기의사용과정이사라지고필름의현상과정에서의오류를배제할수있다는점에서기존의방사선사진법에서보다더일관된결과를나타낼수있다는장점을가진다. 24-26) 여러치과용수복재의방사선불투과도에대한연구중 Marouf 15) 등에따르면국제표준기구에서 1994 년에레진 강화형글래스아이오노머시멘트 (resin modified glass ionomer cement) 는같은두께의알루미늄보다최소두배의방사선불투과도를가져야한다고하였다. Akerboom 16) 등은국제표준기구에서 1995 년에구치부복합레진 (posterior composite resin) 에대해서는같은두께의알루미늄보다높은방사선불투과도를가져야한다고하였다. 근관충전재에대해서는최소한 3 mm 두께의알루미늄의방사선불투과도를가져야한다고국제표준기구에서 2000 년에명시하고있다고이전의연구들에서발표된바있다. 27-30) 그러나포스트의방사선불투과도에대한기준은명시한바없었기에본연구를구상하게되었다. Finger 7) 등은지르코니아섬유를함유한 FRC-Post 제품들은금속포스트에비해낮은방사선불투과도를보이지만방사선사진상에서명확하게구별할수있을정도의적합한방사선불투과도를가지는데비해퀄츠또는유리섬유포스트들은방사선사진상에서간신히구별하거나구별되지않을정도였다고보고한바있으며 Soares 4) 등도지르코니아섬유성분의포스트가더높은방사선불투과도를보였다고보고하였으나본연구에서는이전의연구들과다른결과를보였다. 본실험의결과에서는유리섬유성분인 FRC Postec 194
Plus 가다른유리섬유나지르코니아섬유가첨가된포스트들보다높은방사선불투과도를보였다. 이는강화섬유만이방사선불투과도에관여하는것이아닌섬유를둘러싸는기질도방사선불투과도에관여하기때문인것으로사료되며, FRC Postec Plus 의레진기질에첨가된 Yitterbium trifluoride 이방사선불투과도에크게영향을미쳤기때문이라고생각할수있다. Yitterbium trifluoride 는방사선원으로사용되는물질로방사선불투과도를높이는역할을한다고알려져있으며치근단수술시치근단폐쇄물질의구성성분으로도사용되고있다. 31,32) 포스트만을촬영한사진에서가장높은방사선불투과도값과가장낮은값의차이와치아시편내식립시가장높은방사선불투과도값과가장낮은방사선불투과도값의차이가비슷함에도불구하고, 포스트만을촬영한사진에서는가장방사선불투과도가높은것과가장낮은것을선택하는문항에대해구강악안면방사선과전공자, 치과보존과전공자, 일반치과의사모두 100% 의정답률을보였다. 그러나치아시편내에삽입하고하악골에위치한후에는시험자군별 67-33% 정도의정답률을보여인접구조물이있는경우시험자의특성에상관없이식별능력이떨어짐을보여임상상황에서는포스트제품사이에방사선불투과도의차이가매우커야만식별능력의차이를보일것이라유추할수있다. 치근단부, 치관부끝에서의포스트와상아질사이의방사선불투과도차이를평가하는문항에서, 시험자군사이에평균정답률의차이를보이기는하나세시험군모두같은치아시편의순서만변경하여나열한 5 장의사진임에도 5 장의사진에걸쳐일관되지못한정답률을보였기에연구에사용한포스트들의방사선불투과도차이는식별능력에크게영향을미치는정도가아니라고생각한다. 방사선식별능력이우수하다고여길수있는구강악안면방사선과전공자, 임상에서의진료술식에있어포스트에보다친숙할수있는치과보존과전공자, 전반적진료에경험이풍부한일반치과의사의특성을가정한세군의식별능력을전반적으로비교해볼때 4 가지문항의시험자군별정답률에서구강악안면방사선과전공자군이일반치과의사군보다높은정답률을내는경향은있으나구강악안면방사선과전공자군도 100% 의정답률을내지못하였고같은시편이나열된사진들임에도불구하고사진전체에걸쳐일관된경향을보이지못하므로본연구의결과만으로구강악안면방사선과전공자의식별능력이일반치과의사보다우수하다고단정짓기는어려우며군별시험자군의수가작다는점이본연구의한계이므로보다많은수의관찰자군을설정으로하는연구가필요할것으로사료된다. 치관부에서의포스트와상아질부위의방사선불투과도차이를비교할때대부분의시험자들이포스트공간과상 아질사이의틈새때문에식별의혼돈이온다는지적을하였는데이는임상에서포스트드릴을사용할때흔들림으로인해포스트의규격과정확히일치하지않는포스트공간이생길가능성이시편제작과정중에반영된결과로시편제작시에깊게고려해야할부분이라고할수있다. 본실험에서는별도의접착제사용없이치아내에식립하였으나포스트와함께사용하는시멘트의영향에관하여 Ibrahim 6) 등이방사선불투과성시멘트는방사선불투과도가낮은포스트의경계를명확하게할수있다고발표한바있어향후이루어질연구에서는접착제의방사선불투과도를고려한실험군을설계하여접착제가포스트의식별능력에미치는영향도고려해야할것이다. 추후 FRC-Post 의적절한방사선불투과도에대하여표준화된포스트시편을이용한연구가필요할것으로사료되며반드시치조골, 치은, 인접치, 수복물등이있는임상의상황에서포스트주변상아질과명확한구분이되는가에대한식별능력에대한평가도필요하리라생각한다. Ⅴ. 결론 본연구는디지털방사선법을이용하여 6 가지 FRC-Post 의방사선불투과도를비교하고, 구강악안면방사선과전공자, 치과보존과전공자, 일반치과의사등세시험자군의방사선학적식별능력을평가하여다음과같은결과를얻었다. 1. 각 FRC-Post 는다양한방사선불투과도를보였다. 2. 가장높은방사선불투과도와가장낮은방사선불투과도를가지는포스트를고르는질문에서포스트만나열한경우실험군모두 100% 의정답률을보였으나포스트를치아에넣고치조골을중첩시킨경우정답률의변화를보였다. 3. 포스트주변상아질과구분되는정도를묻는질문에대해시편의조합순서를바꾸자일관된식별결과를보이지않았다. 위의결과로볼때본연구에사용한 FRC-Post 들은임상에서사용시임상가의특성에상관없이식별능력에영향을미칠정도의상아질과의방사선불투과도차이를갖지않으므로방사선불투과도가 FRC-Post 의선택의단일기준이되기는어려우며추후적절한방사선불투과도차이에대한연구가필요할것으로사료된다. 참고문헌 1. Eliasson & Haasken. Radiopacity of impression materials. Oral Surg Oral Med Oral Pathol 47(5):485-491, 1979. 2. International Standards Organization. ISO 4049. 195
Dentistry-polymer-based filling, restorative and luting materials, 3rd Ed. 2000. 3. O Rourke B, Walls AWG, Wassell RW. Radiographic detection overhangs formed by resin composite luting agents. J Dent 23(6):353-357, 1995. 4. Soares CJ, Mistsui FHO, Neto FH, Marchi GMM, Martins LRM. Radiodensity evaluation of seven root post systems. Am J Dent 18(1):57-60, 2005. 5. Brian J, Rasimick BS, Steven G, Allan SD, Barry LM. Measuring the radiopacity of luting cements, dowels, and core build-up materials with a digital radiography system using a CCD sensor. J Prosthodont 16(5):357-364, 2007. 6. Ibrahim H, El-Mowafy O, Brown JW. Radiopacity of nonmetallic root canal posts. Int J Prosthodont 19(1):101-102, 2006. 7. Finger WJ, Ahlstrand WM, Fritz UB. Radiopacity of fiber-reinforced resin posts. Am J Dent 15(2):81-84, 2002. 8. Bouschlicher MR, Cobb DS, Boyer DB. Radiopacity of compomers, flowable and conventional resin composites for posterior restorations. Oper Dent 24(1):20-25, 1999. 9. Schwartz RS, Robbins JW. Post placement and restoration of endodontically treated teeth: A literature review. J Endod 30(5):289-301, 2004. 10. Goracci C, Gorciolani G, Vichi A, Ferrari M. Lighttransmitting ability of marketed fiber posts. J Dent Res 87(12):1122-1126, 2008. 11. Al-Hazaimah N, Gutteridge DL. An in vitro study into the effect of the ferrule preparation on the fracture resistance of crowned teeth incorporating prefabricated post and composite core restorations. Int Endod J 34(1);40-46, 2001. 12. Akkayan B. An in vitro study evaluating the effect of ferrule length on fracture resistance of endodontically treated teeth restored with fiber-reinforced and zirconia dowel systems. J Prosthet Dent 92(2):155-162, 2004. 13. Naumann M, Preuss A, Frankenberger R. Reinforcement effect of adhesively luted fiber reinforced composite versus titanium posts. Dent Mater 23(2):138-144, 2007. 14. Shah PMM, Sidhu SK, Chong BS, Pitt Ford TR. Radiopacity of resin-modified glass ionomer liners and bases. J Prosthet Dent 77(3):239-242, 1997. 15. Marouf N, Sidhu SK. A study on the radiopacity of different shades of resin-modified glass-ionomer restorative materials. Oper Dent 23(1):10-14, 1998. 16. Akerboom HBM, Kreulen CM, Amerongen WE, Mol A. Radiopacity of posterior composite resins, composite resin luting cements, and glass ionomer lining cements. J Prosthet Dent 70(4):351-355, 1993. 17. Turgut MD, Attar N, Onen A. Radiopacity of direct esthetic restorative materials. Oper Dent 28(5):508-514, 2003. 18. Steven Gu, Brian JR, Allam S, Lee B. Radiopacity of dental materials using a digital X-ray system. Dent Mater 22(8):765-770, 2006. 19. Brian J, Rasimick BS, Rinal PS, Barry LM, Allan SD. Radiopacity of endodontic materials on film and a digital sensor. J Endod J 33(9):1098-1101, 2007. 20. Tagger M, Katz A. Radiopacity of endodontic sealers: development of a new method for direct measurement. J Endod 29(11):751-755, 2003. 21. Yoshiura K, Kawazu T, Chikui T. Assessment of image quality in dental radiographypart 1. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 87(1):115-122, 1999. 22. Carvalho JR, Sobrinho LC, Correr AB, Shinhoreti MAC, Consani SDN. Radiopacity of root filling materials using digital radiography. Int Endod J 40(7):514-520, 2007. 23. Sabbagh J, Vreven J, Leloup G. Radiopacity of resin based materials measured in film radiographs and storage phosphor plate. Oper Dent 29(6):677-684, 2004. 24. Hyo-Jung Kim, Sung-Kyo Kim. Radiopacity comparison of tooth colored restorative materials with digital radigraphy. J Kor Acad Cons Dent 25(4):499-508, 2000. 25. Kleier DJ, Shibilski K, Averbach RE. Radiographic appearance of titanium posts in endodontically treated teeth. J Endod 25(2):128-131, 1999. 26. Tagger M, Katz A. Radiopacity of endodontic sealers development of a new method for direct measurement. J Endod 29(11):751-755, 2003. 27. Tasdemir T, Yesilyurt C, Yildirim T, Er K. Evaluation of the radiopacity of new root canal paste/sealers by digital radiography. J Endod 34(11):1388-1390, 2008. 28. Baksi BG, Sen BH, Eyuboglu TF. Differences in aluminum equivalent values of endodontic sealers: conventional versus digital radiography. J Endod 34(9):1101-1104, 2008. 29. Chang-Kyu Kim, Hyun-Wook Ryu, Hoon-Sang Chang, Byung-Do Lee, Kyung-San Min, Chan-Ui Hong. Evaluation of the radiopacity and cytotoxicity of resinous root canal sealers. J Kor Acad Cons Dent 32(5):419-425, 2007. 30. Tae-Min Kim, Seo-Kyoung Kim, In-Nam Hwang, You- Chan hwang, Byung-Cheol Kang, Suk-Ja Yoon, Jae- Seo Lee, Won-Mann Oh. A comparative study on radipacity of root canal sealers. J Kor Acad Cons Dent 34(1):61-68, 2009. 31. Rud J, Rud V, Munksgaard EC. Retrograde root fillingt fillientin-bonded modifigaard in compo ite. J Endod 19(9):477-480, 1996. 32. Niederman R, Theodosopoulou JN. A systematic review of in vivo retrograde obturation materials. Int Endod J 36(9):577-585, 2003. 196
국문초록 이은혜 1 최항문 2 박세희 1 김진우 1 조경모 1 * 강릉원주대학교치과대학 1 치과보존학교실, 2 구강악안면방사선학교실 본연구의목적은수종의섬유강화레진포스트의방사선불투과도와식별도를비교하고자하는것이다. 이번실험을위해 1) FRC Postec Plus (Ivoclar Vivadent AG, Schaan, Liechtenstein) 2) Snowlight (Carbotech, Lewis center, OH, USA) 3) Dentin Post (Komet Brasseler, Lamgo, Germany) 4) Rely-X Fiber Post (3M ESPE, St.paul, MN, USA) 5) D.T.-Light Post (BISCO, Schaumburg, IL,USA ) 6) Luxapost (DMG, Hamburg, Germany) 등 6 종의섬유강화레진포스트를사용하였다. 각포스트를참고기준으로사용한 1 mm, 2 mm 간격의알루미늄 step-wedge 와함께디지털센서를사용하여방사선촬영하였다. 방사선불투과도는각포스트의다섯지점에서 10 10 화소의평균회색조값으로계산하였고동일두께의알루미늄당량으로비교하였다. 치아시편으로비슷한방사선불투과도를보이는상악전치 6 개에포스트를식립후건조하악골의설측에위치시켜방사선사진을촬영하였다. 포스트만을촬영한사진과치아시편의방사선사진들을구강악안면방사선과전공자 3 명, 치과보존과전공자 3 명, 일반치과의사 3 명에게보여주고설문지를작성하도록요청하였다. 설문지는포스트와포스트가식립된치아시편사진에서방사선불투과도가가장높은포스트와낮은포스트를고르는문항, 치근단과치관부끝에서인접상아질과가장식별이잘되는포스트를고르는문항을포함하였다. 실험의결과는다음과같았다. 1. 각 FRC-Post 는다양한방사선불투과도를보였다. 2. 가장높은방사선불투과도와가장낮은방사선불투과도를가지는포스트를고르는질문에서포스트만나열한경우실험군모두 100% 의정답률을보였으나포스트를치아에넣고치조골을중첩시킨경우정답률의변화를보였다. 3. 포스트주변상아질과구분되는정도를묻는질문에대해시편의조합순서를바꾸자일관된식별결과를보이지않았다. 이에본연구에사용한포스트는다양한방사선불투과도를보이나식별능력에영향을미칠정도의방사선불투과도차이를보이지않는것으로사료된다. 주요단어 : 방사선불투과도, 섬유강화레진포스트, 식별도, 디지털센서, 알루미늄 step-wedge, 알루미늄당량 197