대한치과이식(임프란트)학회 학회지 제 27권 1호

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1 33 부분무치악및단일치아즉시부하법에서시기에따른고정도변화 가브리엘치과김창욱 I. 서론임프란트의조기부하법에대한보고는일찍부터있어왔다 18,29). 최근에즉시 / 조기식립임프란트에대한연구들이활발해지면서하악전치부결손부에즉시 / 조기부하임프란트를하게되었고 2), 하악전치부 over denture에도즉시 / 조기부하식립이보고되었다 7). 또한상하악전치부에단일치아회복이나부분무치악부위에즉시 / 조기식립을시도하였고 8), 심지어는흡연자나이갈이환자를제외한상하악완전무치악에도즉시 / 조기부하식립을하게되었다 30). 그러나구치부의부분무치악이나단일치아결손부위의즉시 / 조기시술은많지않는데이는해부학적인문제, 불량한골질, 생역학적으로교합력이많이작용하며, 굽힘모멘트가크게작용하여즉시 / 조기부하를주어식립하기에는많은문제점이있기때문이다. 이처럼조기부하가성공하기위해서는식립시에안정성과그에따른골유착이중요한문제인데, 안정성은다시초기안정성과이차안정성으로나눌수있는데그중에서초기안정성은골유착에필수적이므로 4) 초기안정성을보고골유착을예측할수있다 19). 초기고정은골질, 수술기법, 임프란트디자인에크게영향을받는다고하였다 14). 그중에임프란트디자인이초기고정에큰영향을주는데 O'Sullivan 20) 들은인간사체에실험한결과 tapered 디자인이초기고정도가좋다고하였고, Glauser 12) 역시 tapered 임프란트 ( 브레네막시스템Ⅳ) 가 non-tapered( 브레네막시스템 Ⅱ&Ⅲ) 보다초기고정도가높다고하였다. 또한임프란트표면처리도임프란트고정성에중요한역할을한다. rough surface 임프란트는 machined surface보다골과임프란트의접촉이현저히높고, 치유기간동안빠른골접촉이되므로이차적인안정성이증가되는것으로알려져있다 34). 부분무치악에서즉시 / 조기부하연구는많지않은데, 그중에 Glauser 14) 들의일련의연구와 Nedir 23) 등과 Bischof 3) 들의보고가있는데, 그내용을보면임프란트조기부하시시기에따른고정도변화는 Glauser 14) 들에따르면초기수개월내에감소하게되며, 이러한감소는조기부하시임프란트실패에영향을미칠수있다고하였다고, Bischof등은조기부하와지연부하를가해임프란트를식립하였을때, 치유기간동안큰차이가없었다고하였다. 본연구의목적은부분무치악또는단일치결손증례에서즉시 / 조기부하시거친표면의 tapered designed implant를사용할때, 치유기간에따른고정도의변화에어떠한영향을미치는가를알아보는데있다. II. 재료및방법 1) 연구재료본연구는 2004년 10월부터 2005년 9월까지가톨릭대학교보철과임프란트클리닉에내원한환자중, 임프란트식립시즉시 / 조기부하가가능하다고판단된 10명을대상으로실험하였는데, 환자의선택기준은다음과같다.

34 치조골이 10mm이상존재하며, 8mm임프란트식립이가능한높이와골량이충분히존재하는전신및국소질환이없는환자를선택하였다. 실험환자 10명중에남자 3명, 여자 7명이었으며, 상악에 26개하악에 18개를심었고, 상하악전치부는 4개상하악구치부는 40개를식립하였고, 그중에단일치아식립은 8개, 나머지는부분무치악에식립하였다. Table 1.

(2) 임프란트선택 44개모두테이퍼드디자인에 rough surface를가진임프란트를사용했는데, 그중에 41개는 Replace select(nobel Biocare co.,sweden) 를사용하였고, 3 개는 Tapered screw vent(zimmer co.,usa) 를사용하였다.

2 34 치조골이 10mm이상존재하며, 8mm임프란트식립이가능한높이와골량이충분히존재하는전신및국소질환이없는환자를선택하였다. 실험환자 10명중에남자 3명, 여자 7명이었으며, 상악에 26개하악에 18개를심었고, 상하악전치부는 4개상하악구치부는 40개를식립하였고, 그중에단일치아식립은 8개, 나머지는부분무치악에식립하였다. Table 1. The classification of implant placement Male Female 3 7 2) 연구방법 Max 26 Man 18 Ant Post 4 40 Single tooth Partial edentulos 8 36 (1) 술전치료계획임상검사와치근단촬영과파노라마그리고필요한경우 CT를촬영하였다. (2) 임프란트선택 44개모두테이퍼드디자인에 rough surface를가진임프란트를사용했는데, 그중에 41개는 Replace select(nobel Biocare co.,sweden) 를사용하였고, 3 개는 Tapered screw vent(zimmer co.,usa) 를사용하였다. Implant length는 short implant(8,10mm) 12개를식립하였고, long implant(13,16mm) 는 32개를식립하였다. Implant diameter는 narrow size(4.3mm) 12개, regular size(5.0mm) 9개, wide size(6.0mm) 는 23개를식립하였다. (3) 외과적수술통법에따라절개와드릴링을한후, self-taping으로임프란트를식립하였으며, 골질이좋지않은상악구치부에서는 osteotome을사용한후 self-taping을이용하여식립하였다. 즉시 / 조기부하의가이드라인은식립후 insertion torque가 20Ncm이상이고, 공명주파수분석 (RFA) 한임프란트안정지수 (ISQ) 45이상으로정하여, 위의수치이상인경우를실험대상으로하였다. (4) 보철과정즉시 / 조기식립한후인상을채득하고, short span은당일에, long span은 2주이내에임시보철물을장착해주었고, 중심위교합에서는교합이되게하고, 편심위교합에서는교합이되지않게교합조정을하였다. (5) 공명주파수분석 (RFA) 즉시 / 조기부하를가한직후 2, 4, 6, 8, 10, 12주그리고 1년으로나누어 Ostell(Integration Diagnostic Ltd, Sweden) 을이용하여측정하였는데, 임프란트상단에작은 L자형변환기를 screw로조인후부착하여측정된주파수가액정화면에표시되는임프란트안정지수 (Implant Stability Quotient) 로나타나는수치를사용하였다. 변환기의위치는일정하게임프란트장축에수직방향으로고정했으며, 오차를줄이기위해같은방향에서 3회씩측정하였다 (Fig. 1,2). Table 2. Implant length Short Long short : 8, 10 mm long : 13, 16 mm sample size Table 3. Implant diameter Narrow Regular sample size 12 9 Wide 23 Narrow : 4.3 mm Regular : 5.0 mm Wide : 6.0 mm Fig. 1. Fig. 2. 3) 통계처리가톨릭대학교통계학교실에의뢰하였고, 분석방법은반복측정분석 (Repeated measures ANOVA) 을하였다.

3 35 III. 결과 1) 임프란트성공률총 44개의식립된임프란트중 ( 상악 26개, 하악 18개 ) 3개가실패하였고그중 2개는외과적인수술기법에문제가있었고, 나머지 1개는임시보철물장착후에과부하가걸려파절이발생해서실패해, 임프란트성공률은 93.18% 였다. Table 4. ISQ potential change -every weeks mean Mean value Min.value Max. value baseline ± week ± week ± week ± week ± week ± week ± year ± Table 5. Statistical difference of initial ISQ & final ISQ All Implant Smaple size(n) 44 ISQi 65.77± 7.84 ISQf 67.0± 8.60 Statistical significance Between time P= ) 공명주파수분석 (RFA) 각주간공명주파수측정값은다음과같다. Fig. 3. ISQ value change in Immediate/Early loading period Statistical significant between baseline 초기측정값은 65.77±7.84로비교적안정된수치를나타냈다. 2주,4주,6주까지는초기측정값보다낮은수치를나타냈지만, 통계적인유의성은없었다 (Fig. 8). 8주이후부터측정값은증가되는경향이있으나, 12 주까지통계적인유의성은없었으며, 1년후측정값은 67.0±8.60으로초기측정값과비교했을때통계적으로유의한차이를보였다.

4 36 전체적인주 (week) 에대한효과는유의하지만 base line을기준으로각주를비교했을때, 유의한차이가나지않았다. IV. 고찰최근의임프란트의치료법은치료기간을단축하고, 심미성을증진하는즉시 / 조기부하개념으로발전되고있는추세인데, 즉시 / 조기부하는 Barzilay와 Lazzarra 17) 에의해처음시도되었으며, 2002년스페인바르셀로나에서 conference가개최되어즉시 / 조기부하개념을더욱정확히하게되었는데 1) 즉시부하는임프란트를식립한날에보철물이장착되는것을말하며, 조기부하는통상적인치유기간인 3-6개월보다빨리보철물이장착되는것이고, 지연부하는식립후상악 6개월, 하악 3개월의치유기간이지난후에보철물이장착되는것이라정의하였고, 2003년에 ITI conference에서는즉시부하는 48시간이내에보철을장착하고, 조기부하는 2일-12주사이에부하를가하는것으로정의하였다. 즉시 / 조기부하가성공하기위해서는임프란트의초기고정이가장중요한요소로서골질, 수술기법, 임프란트디자인에크게영향을받는다고하였는데 14), 첫째약한골질을갖는부위는실패할확률이높다고하였고 16), 골질이좋은곳에즉시식립한임프란트의 RFA는식립직후의값이 3-4개월치유기간후와같을정도로우수한초기고정을보인다고하였으며 10), 둘째 gentle 한수술이필요한데, 100um이상의동요도는초기고정을위협하는것으로알려져있으므로 6) 수술시에과열 (47도 1분 ) 이되지않도록충분한주유와 drill의속도와힘조절이필요하며, 드릴의직경을줄이며, self-tapping implant를사용하는것이좋은방법이고, 셋째로임프란트디자인문제로 O'Sullivan들은 25) 인간사체에실험한결과 tapered 디자인이초기고정도가좋다고하였고, Glauser등은 12) tapered 임프란트 ( 브레네막시스템Ⅳ) 가 nontapered( 브레네막시스템 Ⅱ&Ⅲ) 보다 RFA값이높다고하였다. 이를근거로 straight 임프란트보다는 tapered 임프란트가훨씬좋은초기고정도를보임을알수있었다. 저자의경우도 tapered 디자인된 Replace select(nobel Biocare co.,sweden) 와 Tapered screw vent(zimmer co.,usa) 를사용하여초기고정도를측정한결과위와같은결론을얻을수있었다. 또다른영향을주는요소로임프란트표면처리가있는데, machined surface보다 rough surface가조기에골과 implant사이의유착을잘되게하여, 2차고정도를좋게한다고하였는데 31), 저자의경우도이번실험에초기골유착을촉진하고광질화를촉진시키는 33), annodizing oxidation( 양극산화법 ) 을이용한 Replace select(ti-unite) 와 Ha의골에대한생화학적접착이나결합이임프란트의골에대한유착을증가시켜주어, 초기고정력을매우좋게하는 31) 표면처리방법인 Ha-coating을이용한 Tapered screw vent를이번실험에사용한결과 ISQ값이감소하지않고계속적으로증가해즉시 / 조기부하를주는임프란트치료에적합하다고생각된다. 조기 / 즉시식립후에임프란트의안정도를정확히알수있는방법이필요한데측정방법으로방사선측정, insertion torque, reverse torque, percussion test, periotest, RFA등이있지만그중에서 RFA가가장정확도가높은방법으로서공명주파수분석법 (RFA) 은공명을이용하는것으로골의 stiffness와effective marginal length에의해영향을받는데, 이것을상용화한 Ostell(Intregration Diagnostics LTD, Sweden) 은변환기가유발하는공진주파수 (RF) 를측정하고분석결과를간략화한단위인임프란트안정성지수 (ISQ) 를얻어서임프란트의안정도와골유착을측정하는것으로 35), 골과금속간의접촉율, 골밀도, 골의노출정도에따라공명주파수가달라지는데, 공명이높을수록골밀도가좋고골과금속사이의접촉이견고함을나타내식립상태가좋은임프란트임을의미한

Bischof 3) 등은 one stage implant를사용하여식립한후, 즉시부하와지연부하를비교분석했을때, 성공한증례에서 RFA값의차이가없었다고하였는데, 이는초기고정이잘되면, 즉시부하를주어도지연부하못지않는성공률을보인다는것을알수있었다.

5 37 다고하는데, Saadoun 28) 과 Sennerby와 Meredith 20) 등은공명주파수분석법을이용해즉시부하를가할수있는수치를제시하였는데, 이를바탕으로본논문은공명주파수분석법을통해시기에따른고정도변화를관찰하였다. Glauser 14) 는 ISQ가 68일경우즉시 / 조기부하를주기에적합하다고하였고, 식립후 3달동안은 ISQ가감소하다가, 6개월이후부터 12개월까지계속적으로증가한다고하였으며, 성공한임프란트는즉시 / 조기부하를가한후 3개월까지 ISQ가감소하다가 6개월부터지속적으로증가하며, 실패한임프란트는조기부하를가한후한달이지나면이미감소하기시작하여결국실패에이른다고하였다. Bischof 3) 등은 one stage implant를사용하여식립한후, 즉시부하와지연부하를비교분석했을때, 성공한증례에서 RFA값의차이가없었다고하였는데, 이는초기고정이잘되면, 즉시부하를주어도지연부하못지않는성공률을보인다는것을알수있었다. 저자의연구에서는이와같은사실들을근거로해서, 테이퍼드디자인된거친표면을가진임프란트를이용해서상하악의부분무치악이나단일치아에즉시 / 조기부하를가한후공명주파수분석법 (RFA) 을이용해임프란트안정지수 (ISQ) 를 2,4,6,8,10,12주그리고 1 년으로나누어측정한후, 식립초기와최종보철장착후의 ISQ value차이를알아보았다. 즉시 / 조기부하가이드라인으로식립후 Insertion Torque가 20Ncm 이상이고공명주파수분석 (RFA) 한임프란트안정지수 (ISQ) 45이상으로정하였고, 10 명의환자에게 44개의임프란트를식립하였고그중 3개가실패하였는데, 2개는하악구치부에식립시 taping이부족해임프란트가덜식립이되어 periimplantitis가생겨실패하였으며, 나머지 1개는임시보철물에과부하가걸려파절이발생하여실패해 93.18% 의성공률을보였다 (Fig. 4,5). Fig. 4. Fig. 5. 시기별에따른식립초기와최종보철장착후의 ISQ value차이를보면모든임프란트의 initial stability는 ± 7.84이고, final stability는 67.0 ± 8.60 로서, 즉시 / 조기부하를가한후 initial stability보다 final stability가점점높게나왔는데시간이지나면서점차골화가진행되어주위골이 calcification되었기때문이라고생각이되며, Heo와 Meredith 22) 는식립된임프란트가시간이지나면서 ISQ value가높아지는이유는임프란트주위를둘러싸고있는뼈들이점차적으로 Osseo-intergration이되기때문이라고하였다. Glauser 14) 에의하면식립후 3달까지 ISQ value가감소하다점차적으로증가한다고하였는데, 그이유는임프란트주위의물성과 bone-implant interface 가변화하기때문으로, 첫째 tapered임프란트는식립이되면서주위골에 lateral compression을가해식립된임프란트와골사이에 stress가증가되므로 ISQ value가감소된다고하였고, 둘째는부하로인해주위골이 microfracture되어 ISQ value가감소되며, 셋째는술후 healing process로뼈가흡수되면서 stiffness 가떨어져 ISQ value가감소되기때문인데, Br anemark 5) 은괴사된골의 remodeling phase로서그후에 neoapposition phase가와서 ISQ value가점차적으로증가한다고설명하였다. 본연구에서는 Glauser 14) 와달리 ISQ value가감소하지않고안정적으로나타났는데, 그이유는첫째임프란트디자인에관한것으로, straight한임프란트를사용하지않고, tapered implant를사용해좋은초기고정도를얻을수있었고, 둘째는임프란트표면처리때문인데 machined surface를사용하지않고 rough

6 38 surface를사용했기때문에, 조기에골과임프란트사이의유착이잘일어나 2nd. stability가증대된결과라고생각이된다. 요즘은즉시 / 조기부하를가하는치료가주를이루고있는데, 주로골질이좋은상하악전치부나부분무치악에많이사용되지만, 골질이좋지않은구치부의단일이나부분무치악에는조심스러운접근이필요하다고생각된다. 그렇지만확실한기준을제공하는공명주파수분석을이용한 ISQ값을사용해골질이좋지않은구치부에거친표면을가진 tapered 임프란트를식립하면성공적인즉시 / 조기부하가가능하다는생각이든다. REFERENCES 1. Aparicio C. Rangert B, Sennerby L. Immedi ate/early Loading of Dental Implants:a report from the Sociedad Espanola de Implantes World Congress Meeting in Barcelona, Spain, Clinl Implant Dent Related Res 2003;5: Balshi, T. J. & Wolfinger, G. J Immediate loading of Br anemark implants in edentulous mandibles. A preliminary report. Implant Dentistry ; Bischof, M, Nedir, R, Szmukler-Moncler, S, Bernard, J-P & Samson, J. Implant stability measurement of delayed and immediately loaded implants during healing. A clinical RFA study with SLA ITI implants. Clinical Oral Implants Research 2004, in press 4. Br anemark, P.-I., Hansson, B.O., Adell, R., Breine, U., Lindstrom, J., Hallen, O. & Ohaman, A. Osseointegrated implants in the treatment of the edentulous jaw. Experience from a 10-year period. Scandinavian Journal of Plastic Reconstructive Surgery 1977;16: Br anemark, P.-I., Zarb, G.A. &Albrektsson, T., eds. Tissue integrated prostheses: osseointe gration in clinical dentistry, 1985;I-343. Chicago :Quintessence. 6. Brunski JB. Avoid pitfalls of overloading and micromotion of intraosseous implants. Dental implantlogy Update 1993;4: Chiapasco, M., Abati, S., Romeo, E. & Vogel, G Implant-retained mandibular overdentures with Br anemark System MKⅡ implants : A prospective comparative study between delayed and immediate loading. International Journal of Oral end Maxillofacial Implants 2001;16: Ericsson,I., Nilsson, H., Lindh, T., Nilner, K. & Randow,K. Immediate functional loading of Br anemark single tooth implants. Clinical Oral Implants Research 2002;Ⅱ: Esposito, M., Hirsch, J>M>, Lekholm, U. & Thom-sen, P. Biological factors contributing to failures of osseointegrated oral implants. (Ⅰ). Success criteria and epidemiology. european Journal of Oral Scoence 1998;106: Friberg, B., Sennerby, L., Linden, B., Grondahl, K. & Lekholm, U. Stability measurements of one-stage Br anemark implants during healing in mandibles. A clinical resonance frequency study. international of oral Maxillofacial Surgery 1996b;28: Gottlander M, Albrektsson T: Histomorphometric studies of hydroxyapatite-coated and uncoated CP titanium threaded implants in bone. Int J Oral Maxillofac Implants. 1991;6: Glauser, R., Portmann, M., Ruhstaller, P., Gottlow J. & Scharer, P. Initial implant stability using different implant designs and surgical

7 39 techniques. A comparative clinical study using insertion torque and resonance frequency analysis. Applied Osseointegration Research 2001a;2: Glauser, R., Ree, A., Lundgren, A.K. Gottlow, J., Hammerle, C.H.F. & Scharer, P. Immediate occlusal loading of Br anemark implants applied in various jawbone regions: prospective, 1-year clinical study. Clinical Implant Dentistry and Related Research 2001b;3: Glauser R, Sennerby L, Meredith N, Ree A, Lundgren AK, gottlow J, Hammerle CHF. Resonance fregnancy analysis of implants subjected to immediate functional occlusal loading. Succesful versus failing implants. Clinical Oral Implants Research IS, 2004; Heo, S.J., Sennerby, L., Odersjo, M., Granstrom, G., Tjdllstrom, A. & Mestic deredith, N. Stability measurements of craniofacial implants by the means of resonance frequency analysis. A clinical polot study. The Journal of Laryngology and Otology 1998;112: Jaffin, R.A. & Berman, C.L.1991 The excessive loss of Br anemark fixtures in type Ⅳ bone: a 5-year analysis. Journal of Periodontology 2000;62:2-4. Jaffin, R.A., Kumar, A. & Berman, C.L. 17. Lazzara, R.,Siddiqui, A.A., Binon, P., Feldman, S.A., Weiner, R., Philipps, R. & Gonshor, A. Retrospective multicenter analysis of 3i endosseous dental implants placed over a 5 year period. Clinical Oral implants research 1996;7: Ledermann, P.D. Das TPS-Schrauben implantat nach siebenjahriger Anwendung. Quintessenze 1984;30: Meredith, N. Assessment of implant stability as a prognostic determinant. International Journal of Prosthodontics 1998;11: Meredith, N., Book, K., friberg, B., jemt, T. & sennerby, L. Resonance frequency measurements of implant stability n vivo. A cross sectional and longitudinal study of resonance frequency measurements on implants on the edentulous and partially dentate maxilla. Clinical Oral Implants Research 1997a;8: Meredith N,Allenye D,Cawley P, Quantitative determina tion of the stability of the implant-tissue interface using resonance frequency analysis. Clinical Oral Implant Res 1996;7: Meredith, N., Shagaldi, F., Alleyne, D., Sennerby, L. & Cawley, P. The application or resonance frequency measurements to study the stability of titanium implants during healing in the rabbit tibia. Clinical Oral Implants Research 1997b;8: Nedir, R, Bischof, M, Bischof, J.M, Beyer, S., Szmukler-Moncler, S, Bernard, J-P.2003 A 7- year life table analysis from a prospective study on ITI implants with special emphasis on the use of short implants. Results from a private practice. Clinical Oral Implants Research I4: in press 24. Nkenke E.Hahn M,Weinzierl K,Radespiel- Troger M,Neukam FW,Engelke K. Implant stabiloty and histomorphometry : a corr elation study in human cadavers using stepped cylinder implants. Clinical Oral Implant Res. 2003;14(5): O'sullivan, D., Sennerby, L. & Meredith, N. Measurements comparing the initial stability of five designs of dental implants: a human cadaver study. Clinical Implant Dentistry and Related Research 2000;2: O'Sullivan, Sennerby L, Meredith N. Influence

8 40 of implant taper on the primary and secondery stability of osseointergrated titatium implants. Clinical Oral Implant Res. 2004;15: Roberts, E.W. Bone physiology and meta bolism. In:Misch, C.E., ed. Contemporary implant dentistry, 1993; st. Louis: Mosby. 28. Saadoun, A.P. & LeGall, M.L. Clinical results and guidelines on Steri-Oss endosseous implants. International Journal of Periodontology and Restorative Dentistry 1992;I2: Schnitman, P.A., Wohrle, P.S. & Rubenstein, J.E. Immediate fixed interim prostheses supported by 2-stag threaded implants. Methodology and results. Journal of Oral Implantology 1990;16: Tarnow, D.P., Emtiaz, S. & Classi, A. Immediate loading of threaded implants at stage 1 surgery in edentulous arches. Ten consecutive case reports with 1-to 5-year data. International Journal of Oral end maxillofacial Implants 1997;12: Weinlaender M, Kenny EB et al:histomorphometry of bone apposition around three types of endosseous dental implant. Int J Oral Maxillofac Implants. 1992;7: Zechner W Tangl S et al:osseous healing characteristics of three different implant types. A histologic and histmorphometric study in mini-pigs. Clinical Oral Implant Res. 2003;14: 김영균, 황정원등 : 치과임프란트와관련된다양한논쟁. 군자출판사, 김수관 : 즉시식립및즉시부하임프란트. 대한나래출판사, 정재철, 이철원등 : 피질골이임프란트식립시초기안정성에미치는영향. 대한구강악안면임프란트학회지 vol.10 no

9 41 Abstract Periodic implant stability change in immediate or early loading method of single or partial edentulous cases Chang-Uk Kim GRADUATE SCHOOL OF CLINICAL DENTAL SCIENCE THE CATHOLIC UNIVERSITY OF KOREA SEOUL, KOREA Purpose : The purpose of this study is to evaluate the immediate or early loading on partial or single implant cases with RFA measurements. Materials & Methods : forty-four tapered designed implants(41 replace select, 3 Tapered screw vent implants) were placed in 10 patients of partial or single cases for immediate or early loading in all jaw lesions. The guidelines for early or immediate loading were the peak insertion torque more 20Nm during implant insertion and RFA ISQ values than 45 immediate after implant insertion. Apart from clinical and radiographic examinations, the patients were followed with RFA at placement, measured again every 2weeks until 12weeks and measured at 12 months. Statistical analyses were carried out to study the possible differences between the time of implant placement. Results : Three implants failed. Two of them seemed to be failed because of surgical technique mistake and one was a prosthesis of overloading due to provisional prosthesis fracture. RFA values were pretty stable during all periods. But there seemed to be significant between initial v.s. final RFA values. Conclusion : Within the limitations of this study, tapered implants with high initial stability can be used as immediate and early loading on various jaw regions. Keywords : RFA, ISQ, Immediate/Early loading, initial stability, tapered implant

00)13-3목차1~3

00)13-3목차1~3 An evaluation of marginal bone level change in single short implant : an 1-year follow up Tae-Hoon Lee, Joo-Hyun Kwon, Sunjai Kim, Chong-Hyun Han Department of Prosthodontics, Kangnam Severance hospital,