http://dx.doi.org/10.5933/jkapd.2016.43.4.391 ISSN (print) 1226-8496 ISSN (online) 2288-3819 Evaluation of Remineralization Effects on Enamel Demineralization by Anti-cariogenic Agents using Quantitative Light-induced Fluorescence-digital (QLF-D) in vitro Kkotnim Lee, Miae Kim, Inkyung Hwang, Jihyun Park, Yonjoo Mah Division of Pediatric Dentistry, Department of Dentistry, Ewha Womans University Mokdong Hospital, Seoul, Korea Abstract The purpose of this study was to evaluate the difference of remineralization effects of various anti-cariogenic toothpastes on artificial carious lesions in primary and permanent teeth using quantitative light-induced fluorescence-digital (QLF-D) system. Sound human primary (n = 48) and permanent teeth (n = 48) were randomly divided into following groups : control group (Group 1), fluoride toothpaste (Group 2), functionalized tricalcium phosphate (ftcp) + fluoride toothpaste (Group 3), and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) toothpaste (Group 4). Specimens were prepared by exposure in a demineralizing solution and then treated using the different toothpastes twice daily during 14 days. All specimens were analyzed with the QLF-D system. QLF data analysis indicated three different toothpastes showed significant remineralizing effects compared to Group 1 in both primary and permanent teeth. Also, the remineralizing effects in Group 3 and 4 were significantly higher than in Group 2. This study suggested that the toothpastes containing ftcp + fluoride and CPP-ACP have the significant anti-cariogenic effects on enamel demineralization in both primary and permanent teeth, and QLF-D is an useful device to assess the incipient carious lesion and remineralization effects of the anti-cariogenic materials quantitatively. Therefore, clinicians can consider the QLF-D system for the evaluation of demineralization and remineralization in primary and permanent teeth. Key words : Quantitative light-induced fluorescence, Tooth remineralization, Toothpastes, White spot Ⅰ. 서론법랑질탈회는치태내우식유발세균들이생산하는산에의해칼슘, 인, 수산화기결정이용해되는것으로, 교정치료중인환자나구강위생이불량한환자들에서흔히관찰된다 1). 임상적으로, 탈회에의한초기법랑질우식병소는와동이형성되기전단계인 백색반점 (white spot) 으로관찰되며, 불소도포등의예방적술식에의해재광화 (remineralization) 가가능하다고여겨진다 2). 그러나이러한백색반점은임상검사시간과되기쉬우며, 중성환경조성과상실된무기질공급을통한재광화과정이지 속되지않는다면와동을형성하는깊은우식으로발전할수있다 3). 때문에, 초기병소의조기발견및적절한예방적처치를통한재광화유도가매우중요하다. 현재초기우식증의재광화및우식증의예방을위해사용되는가장대표적인제제는불소이다 3). 그러나불소는과다섭취시오심, 구토등독성발생위험이있어보다안전하며효율적인재광화제제에대한요구가높아지고있다 4). 불소이외에도초기우식의재광화를위한제제로주목받고있는 casein phosphopeptide-amorphous calcium phosphate(cpp- ACP) 는우유단백질 casein에서추출된성분으로, CPP와 ACP의결합을통해칼슘인산이온을안정화시킨형태이다 5,6). Corresponding author : Yon-Joo Mah Division of Pediatric Dentistry, Department of Dentistry, Ewha Womans University Mokdong Hospital, 1071, Anyangcheon-ro, Yangcheon-gu, Mokdong Hospital, Seoul, 07985, Korea Tel: +82-2-2650-2660 / Fax: +82-2-2650-5764 / E-mail: magic-lily@hanmail.net Received February 1, 2016 / Revised April 11, 2016 / Accepted March 25, 2016 391
CPP-ACP는치태및치면에부착되어칼슘과인산이온의저장소로작용하며, 산성환경에서칼슘과인산이온을방출하여치아표면을무기질과포화상태로만듦으로써탈회억제및재광화촉진효과를보인다 6). 다른연구에서는 tricalcium phosphate(tcp) 와불소존재시침식된법랑질의재광화를촉진시킬수있음을보고하였다 7). 그러나 TCP는불소가존재하는환경에서쉽게불화칼슘을형성하여재광화에필요한무기질이온농도를낮출수있다는한계를지닌다 8). 이에라우릴황산나트륨 (sodium lauryl sulphate) 으로 TCP 입자를코팅하여불소와의반응성을낮추고기능적으로안정화된 ftcp(functionalized β-tcp) 를이용한재광화제제가개발되었다 9). 이와같은재광화제제적용을위해무엇보다중요한것은초기우식병소의조기발견이다. 간과하기쉬운초기우식증의조기진단을위하여최근 quantitative light-induced fluorescence(qlf) 가진단장비로널리사용되고있다 10). QLF는 405 nm 파장영역의빛을조사하였을때건전법랑질과탈회법랑질사이에나타나는빛투과성차이를이용하여비침습적으로초기우식증의진단및탈회정도의정량적분석을가능하게한다 10,11). QLF-D(QLF-digital) 는특수광원과필터가내장된디지털카메라를활용하여일반백색광원영상과 QLF 형광영상을연속으로촬영할수있도록개발된제품으로, QLF 의임상적활용을더욱용이하게하였다 12). 한편, 유치와영구치법랑질은그조성및구조에서여러차이를보인다. 즉, 유치는무기질함량이낮아영구치에비해높은수분및유기질함량을보이며, 영구치보다법랑질두께가얇고, 법랑질최외층에서법랑소주의구조가나타나지않는무소주 (prismless) 법랑질층이보다빈번하게관찰된다 13,14). 이에근거하여여러연구들에서는유치와영구치에서산부식저항성및치아부식에대한민감도등의차이를보고한바있다 13,15). 그러나유치와영구치에서불소를비롯한재광화제제의효과를비교한이전연구들에서는일관된결과가관찰되지않았으며, QLF를이용하여이를비교한연구는부족한실정이다 16,17). 이에본연구에서는 QLF-D 장비를이용하여유치와영구치에서다양한항우식제품의재광화효과를정량적으로평가하고자하였다. Ⅱ. 연구재료및방법 1. 연구재료본연구는이화여대부속목동병원기관윤리위원회로부터의승인을거쳐진행되었다 ( 승인번호 2015-04-027). 실험에사용된치아는발치를주소로내원한환자들에서환자또는환자보호자의동의를받아최근에발거된치아로서, 치아우식증이나변색, 수복물등이없는건전한유치 48개와영구치 48개를대상으로하였다. 수집된치아는주변의이물질을제거하고초음파세척한후 4 생리식염수에보관하였다. 2. 연구방법 1) 시편제작치면을세척및건조한후협설면이노출되도록하여퍼티 (ExaFlex Putty; GC Co., Alsip, IL, USA) 블록에매몰및고정하고, 유치에서 2 2 mm 2, 영구치에서 3 3 mm 2 영역을제외한모든면을투명한네일바니쉬 (Max Factor ; Procter & Gamble Ltd, Surrey, UK) 로 2회도포하여코팅되도록하였다. 2) 법랑질탈회유발법랑질탈회를위해치아시편을 37 탈회용액에 5분간담근후수세및건조하였다. 탈회용액은 3-5% hydrochloric acid 와 95-97% nonhazardous proprietary components (acid chlorides, phosphorus trichloride, phosphorus pentachloride, phosphorus oxychloride) 로구성된 Calci-Clear Rapid(National Diagnostics, Atlanta, GA, USA) 용액을증류수와 1:1로희석하여제작하였다. 법랑질탈회가형성된치아시편은 Taliva (Hanlim Pharm, Seoul, Korea) 인공타액에넣어상온에서보관하였다. 3) 항우식제제의적용유치 (n=48) 및영구치 (n=48) 치아시편을무작위로 12개씩각각 4군으로다음과같이분류하였으며, 사용된제품의특성은 Table 1과같다. Table 1. Anti-cariogenic ingredients of the experimental toothpastes used in this study Material Anti-cariogenic ingredient Manufacturer 2080 Kids toothpaste 500 ppm Fluoride Aekyung Co., Seoul, Korea 2080 Original toothpaste 1000 ppm Fluoride Aekyung Co., Seoul, Korea Clinpro TM Tooth Créme 950 ppm fluoride, ftcp GC Co., Tokyo, Japan Tooth Mousse CPP-ACP 3M ESPE, St. Paul, MN, USA ftcp = functionalized tricalcium phosphate, CPP-ACP = casein phosphopeptide-amorphous calcium phosphate 392
1군 : 대조군 ( 무처치군 ) 2군 : 불소함유치약처리군 (2080 kids 또는 original toothpaste) 3군 : ftcp + 불소함유치약을처리한군 (Clinpro TM Tooth Créme) 4군 : CPP-ACP 함유치아크림을처리한군 (Tooth Mousse ) 1군은대조군으로 1일 2회 3분간탈회치면을증류수로닦은후인공타액에보관하였다. 2군은아동용또는성인용불소함유치약을이용하여 1일 2회 3분간칫솔질후세척하여인공타액에보관하였다. 3군은 ftcp와불소함유치약 (Clinpro TM Tooth Créme, GC Co., Tokyo, Japan) 을이용하여 1일 2회 3분간칫솔질후제조사의지시에따라세척하지않고인공타액에보관하였다. 4군은 CPP-ACP 함유치아크림 (Tooth Mousse, 3M ESPE, St. Paul, MN, USA) 을면봉에묻혀 1 일 2회 3분간탈회치면에적용후제조사의지시에따라세척하지않고인공타액에보관하였다. 모든실험은동일한한명의실험자가동일한시간에시행하였으며, 인공타액은 24시간마다교환하였다. 4) QLF 측정 Digital full-sensor SLR camera(model 550D, Canon, Tokyo, Japan) 에청색광과백색광의 LED가카메라본체앞에장착된 QLF-D system(biluminator TM, Inspektor research systems BV, Amsterdam, The Netherlands) 을사용하여, 암실에서법랑질탈회병소의 ΔQ( 형광소실도 %, mm 2 ) 를측정하였다. 촬영전치아시편을증류수로수회세척및 30초간압축공기로충분히건조시킨후일정한거리에서촬영을시행하였다. 측정은숙달된 1인조사자에의해동일한환경에서시행되었으며, 측정시점은시편에탈회형성전, 탈 회형성직후 (baseline), 항우식제품적용후 3일, 7일, 14일째측정하였다. 각치아마다탈회용액에의해형성되는탈회의정도가다를수있으므로, 평균 ΔQ와심한차이를보이는시편은실험에서제외하였다. 3. 통계처리통계처리를위하여 SPSS 20.0(SPSS, Chicago, IL, USA) 통계프로그램을이용하였다. 각군에서시간에따른변화의차이를알아보기위하여 Wilcoxon-Signed Rank test를이용하였으며, 군간유의성차이를비교하기위하여 Kruskal- Wallis test와 Mann-Whitney test를이용하였다. 통계분석의유의수준은 p < 0.05로하였다. Ⅲ. 연구성적 1. 항우식제품처리기간에따른재광화효과유치와영구치의법랑질탈회병소에항우식제품처리후 QLF-D를이용하여무기질소실량 (ΔQ) 의변화를측정하였다 (Fig. 1, Table 2, 3). 서로다른 3 종류의항우식제제를처리한후각각 3일, 7일, 14일째 ΔQ를측정한결과, 유치와영구치모두에서시간에따른무기질소실량의감소를관찰할수있었다 (Fig. 1). 항우식제품적용 3일, 7일, 14일경과후 ΔQ 의변화량 (ΔΔQ) 을관찰한결과, 3일동안의 ΔΔQ 와비교할때유치와영구치모두에서항우식제품적용 7일과 14일후 Δ Q의감소가유의하게컸다 (Table 2, 3). 또한유치의 2군에서는 14일동안 ΔQ 변화량이 48% 로 7일동안의 31% 와비교할때유의하게컸으나, 3군, 4군에서는 7일이후 14일까지 ΔΔ Q의변화가적었다 (Table 2). 영구치에서는 2군에서 14일동 Fig. 1. The changes of ΔQ in primary teeth (A) and permanent teeth (B). 393
Table 2. The values of ΔΔQ in primary teeth after the application of anti-cariogenic toothpastes 0-3 days 0-7 days 0-14 days Groups (%) (%) (%) -15 ± 215 86 ± 222 32 ± 426 Group 1 (1 ± 9%) (-4 ± 9%) (-1 ± 18%) -208 ± 320 a -803 ± 334 a -1223 ± 300 a Group 2 (8 ± 13%) (31 ± 13%) (48 ± 12%) -187 ± 233 ab -1336 ± 172 a -1392 ± 297 b Group 3 (8 ± 10%) (56 ± 7%) (58 ± 12%) -266 ± 251 ab -1484 ± 222 a -1546 ± 301 b Group 4 (11 ± 10%) (62 ± 9%) (64 ± 13%) n = 12, Values are mean ± standard deviation. a, b: same letters indicate statistical differences between values in each group by Wilcoxon-Signed Rank test (p < 0.05) Table 3. The values of ΔΔQ in permanent teeth after the application of anti-cariogenic toothpastes Groups 0-3 days 0-7 days 0-14 days (%) (%) (%) Group 1-60 ± 1115-78 ± 1325 146 ± 957 (1 ± 17%) (1 ± 21%) (-2 ± 15%) Group 2-278 ± 983 a -1921 ± 888 a -2509 ± 1209 a (5 ± 16%) (31 ± 14%) (41 ± 20%) Group 3-243 ± 535 ab -4547 ± 665 a -4279 ±636 b (4 ± 8%) (69 ± 10%) (65 ± 10%) Group 4 684 ± 964 ab -3533 ± 1081 a -3423 ± 1132 b (-12 ± 17%) (64 ± 20%) (62 ± 21%) n = 12, Values are mean ± standard deviation. a, b: same letters indicate statistical differences between values in each group by Wilcoxon-Signed Rank test (p < 0.05) A B C D Fig. 2. Representative images of the experimental groups, QLF-D (quantitative light-induced fluorescence-digital) images after exposure in a demineralizing solution in primary tooth (A) and permanent tooth (C), and after application of anti-cariogenic toothpaste for 14 days in primary tooth (B) and permanent tooth (D). 안 ΔQ 변화량이 41% 로 7일동안의 31% 보다유의하게컸으나, 3군, 4군에서는 7일과 14일동안 ΔQ의변화량이유의한차이를보이지않았다 (Table 3). 세종류의항우식제품적용후 14일째에는유치와영구치모두에서처리전과비교하여무기질소실량이약 40% 이상크게감소하였다 (Fig. 2). 2. 항우식제품별재광화효과서로다른 3 종류의항우식제제를처리한후아무것도처리 하지않은 1군과비교하여 ΔQ의변화량을관찰하였다 (Table 4). 유치와영구치모두에서대조군인 1군과비교시 2군은 14 일후부터, 3군, 4군은 7일후부터무기질소실량의유의한차이를보였다. 불소함유치약을처리한 2군과비교시, 3군과 4 군에서 7일동안무기질소실량의변화가더크게관찰되었다. 영구치에서는 3군과 4군에서 7일, 14일째무기질소실량의변화가유의한차이를보인반면, 유치에서는 7일째에만유의한차이를보였다. 394
Table 4. The comparison of ΔΔQ among groups (0-3/0-7/0-14 days) Primary teeth Permanent teeth Group 1 2 3 4 1 2 3 4 1 -/-/* -/*/* -/*/* -/-/* -/*/* -/*/* 2 -/*/- -/*/* -/*/* -/*/- 3 -/*/- -/*/* 4 *: statistically significant different by Kruskal-Wallis test followed by Mann-Whitney post-hoc test (p < 0.05) -: not significantly different (p 0.05) 3. 유치와영구치에서의재광화효과유치와영구치에서각제품군별무기질감소효과를비교한결과 (Fig. 3), 2군에서는 14일째유치에서영구치보다재광화효과가유의하게컸다. 이와달리 3군에서는 7일후부터영구치에서보다큰재광화효과를보였다. 4군에서는 3일째외에유치와영구치에서재광화효과의차이를보이지않았다. 항우 식제품처리 14일후처리전과비교하여무기질소실량의총변화를살펴보면, 2군에서는유치에서무기질소실량이약 48% 감소하여영구치의 41% 보다감소량이컸으며, 3군에서는유치에서약 58%, 영구치에서약 65% 로영구치에서보다큰무기질소실량의감소를보였다. 반면 4군에서는유치와영구치에서유의한차이를보이지않았다. Fig. 3. Comparison of ΔQ% between primary and permanent teeth during 14 days in Group 2 (A), Group 3 (B), and Group 4 (C), *: statistically different by Mann-Whitney test (p < 0.05). 395
4. 항우식제품종류및처리기간에따른재광화속도항우식제품종류및처리기간에따른재광화속도를비교하기위하여 1일간평균 ΔΔQ% 를분석하였다 (Table 5, 6). 그결과, 유치와영구치의 2군, 3군, 4군모두 3-7일사이에재광화속도가가장빠르게관찰되었으며, 7-14일의재광화속도와통계적으로유의한차이를보였다. 3-7일사이유치와영구치모두에서 2군에비해 3군, 4군의재광화속도가유의하게빨랐으며, 3-7일과 7-14일비교시 2군에서는 3군, 4군에비해재광화속도의감소가비교적완만하게나타났다. Ⅳ. 총괄및고찰최근질환의조기발견및예방에대한관심이높아지면서, 백색반점이라불리는초기치아우식증의재광화치료또는최소침습치료가동반되어야한다는진료지침이일반화되고있다 18). 이에따라초기우식증의진단을위하여 laser fluorescence(lf), digital imaging fiber-optic trans-illumination(difoti), electronic caries monitor(ecm), QLF 등가시광선이나레이저를이용한탐지장비들이개발되었다 18). QLF는푸른색가시광선에의해유도되는치아의자가형광성을이용하여무기질이소실된부위에서의형광소실도를정량적으로분석하는장비로, 초기우식병소탐지및무기질감소량 (ΔQ) 의정량화를가능하게하였다 19). QLF는치질의탈회상태와의상관관계가 0.82-0.92, 특이도는 0.70으로다른시스템에비해높고안정된진단능력을보여준다 20). 또한표면미세경도측정법등과달리치아를절단하지않고도탈회및재광 화에대한정량적분석이가능하여그결과를바로임상적으로적용할수있다. 이에본연구에서는유치와영구치에서로다른세종류의항우식제제적용후 QLF-D를이용하여법랑질탈회병소의재광화효과를살펴보았다. 대표적인항우식제제로가장흔히사용되고있는불소는치질의수산화인회석 (hydroxyapatite) 과반응하여불화인회석 (fluorapatitie) 을형성하고, 타액내칼슘과인산이온을치아에침착시켜탈회억제및재광화촉진효과를나타낸다 21). 불소치약내불소함유량은 500-1,500 ppm으로다양하지만, 학령전아동의경우치약을삼키거나불소증발생의우려가있어 1,000 ppm 미만의저농도불소치약사용이권장되고있으며, 네덜란드나영국등유럽국가에서는 500-600 ppm의저불소치약사용을권유하고있다 22,23). 국내에서는어린이치약의불소함량에대한적정기준이마련되어있지않은실정이나, 국제적흐름을참고하여본연구에서역시 500 ppm의불소가함유된어린이치약을연구에이용하였다. 불소함량 1,000 ppm 미만저불소치약의항우식효과에대한이전연구들은서로다른결과들을보고하였다 24-28). 그러나많은연구에서 500-600 ppm의불소치약사용시 250 ppm 의불소치약과달리 1,000 ppm의불소치약과거의유사한항우식효과를보임을증명하였다 26-28). 본연구에서는유치에불소함유량이 500 ppm인치약을적용한결과, 처리 14일후무기질소실량이처리전에비해약 48 ± 12% 감소하였다. 이는영구치에서 1,000 ppm 불소치약적용 14일후무기질소실량이처리전에비해 41 ± 20% 감소하였던것보다높은수치였다. 그러나본연구에서는한치아군내에서불소농도에따른효과비교를목적으로하지않았기때문에, 유치에서고농 Table 5. The velocity of remineralization for 1 day in primary teeth (Difference of ΔQ%/days) Groups 0-3 days/3 3-7 days/4 7-14 days/7 Group 1-0.21 ± 3.04 1.07 ± 3.90-0.33 ± 2.58 Group 2-2.72 ± 4.18-5.84 ± 3.53 a -2.35 ± 1.58 a Group 3-2.62 ± 3.26 a -12.05 ± 2.58 ab -0.34 ± 1.18 b Group 4-3.69 ± 3.47 a -12.64 ± 3.73 ab -0.37 ± 2.45 ab n = 12, Values are mean ± standard deviation. a, b: same letters indicate statistical differences between values in each group by Wilcoxon-Signed Rank test (p < 0.05).,, : same symbol indicates statistical differences between values in each column by Kruskal-Wallis test followed by Mann-Whitney posthoc test (p < 0.05) Table 6. The velocity of remineralization for 1 day in permanent teeth (Difference of ΔQ%/days) Groups 0-3 days/3 3-7 days/4 7-14 days/7 Group 1-0.31 ± 5.80-0.07 ± 3.78 0.50 ± 2.14 Group 2-1.51 ± 5.34 a -6.69 ± 2.23 ab -1.37 ± 1.15 b Group 3-1.24 ± 2.72 a -16.42 ± 1.91 ab 0.58 ± 1.31 b Group 4 4.14 ± 5.83 a -19.12 ± 3.13 ab 0.28 ± 2.13 b n = 12, Values are mean ± standard deviation. a, b: same letters indicate statistical differences between values in each group by Wilcoxon-Signed Rank test (p < 0.05).,, : same symbol indicates statistical differences between values in each column by Kruskal-Wallis test followed by Mann-Whitney posthoc test (p < 0.05) 396
도불소치약대비저농도불소치약의효과에대해서는더많은연구가필요할것이다. 불소의우식예방및재광화효과가명백함에도불구하고, 불소제제사용시불소증및과다섭취로인한부작용발생가능성등의한계점이존재한다 29). 이와달리우유단백질의 casein 에서추출한 CPP-ACP는소아가삼켜도인체에무해하며, 우수한재광화효과를갖는것으로알려져많은연구가진행되어왔다 6,30). CPP는인산칼슘의 phosphoserine 잔기와 ACP를결합시켜인산칼슘을안정화시키고이를통해미세한 CPP- ACP 집락을형성한다 31). 이는치면에서인산칼슘이과포화된안정한환경을조성함으로써법랑질의탈회를억제하고재광화를촉진한다 6). CPP-ACP와불소의항우식효과를비교한여러연구에서는CPP-ACP의재광화효과가불소와유사하거나보다높다고보고하였다 31-33). Zhou 등 31) 과 Zhang 등 33) 의연구결과에서처럼본연구에서역시유치와영구치모두에서 CPP- ACP 함유치아크림을적용한 4군이불소치약을적용한 2군보다높은재광화효과를갖는것으로나타났다. 이는아마도불소가병소의표층만을불완전하게재광화시켜무기질의심부이동을오히려차단할수있다는것과, CPP-ACP가불소제제와달리타액내가아닌자체적으로함유한무기질이온을이용한다는것에기인한다 3). ftcp는가공및코팅을통해 β-tcp를라우릴황산나트륨또는푸마르산 (fumaric acid) 과같은유기또는무기분자와결합시켜기능적으로안정화시킨형태이다 8). TCP는불소와반응을통해조기에불화칼슘을형성함으로써재광화에필요한무기질이온을소모시켜버리지만, ftcp는 TCP를기능적으로안정화시킴으로써산화칼슘과불소의불필요한상호작용을막고, 치약이나가글액과같은형태로치아에적용가능하게하였다 9). 계면활성제의하나인라우릴황산나트륨과결합시킨 ftcp는법랑질과친화성을가져치아표면에활발하게작용하며, 칫솔질시코팅이깨지면서치아에풍부한무기질이온을전달하는역할을한다 7,8). Karlinsey과 Pfarrer 9 은 ftcp와불소를함께적용시불소단독또는 ftcp 단독으로적용한경우보다훨씬높은재광화유도효과를보임을증명하였다. 이는 ftcp + 불소함유치약을적용한 3군에서불소함유치약을적용한 2군보다유의하게높은재광화효과를보인본연구결과와도일치한다. 유치와영구치법랑질의분명한구조적차이는이미여러연구에서증명된바있다 34-38). 첫째로, 유치법랑질은영구치에비해덜광화되어있어영구치법랑질의무기물함량은 97% 로수분과유기물이거의없는반면, 유치법랑질의무기물함량은 81.3-94.2 wt% 로보다낮은값을보인다 36-38). 둘째, 유치법랑질은영구치법랑질보다공극률이높고확산계수가커탈회에보다취약할수있는성질을가진다 34,35). 그러나치아우식증에대한유치와영구치의감수성차이를조사한이전연구들에의하면, 유치법랑질이영구치보다우식증에대한감수성이더높다는연구결과도보고되었으나 15,39), 유치와영구치사이에통계적으로유의한차이를보이지않았다는연구결과 40,41) 도있어 상반된결과를보였다. 유치와영구치에서항우식제제의재광화효과를비교한여러연구들에서또한통계적인차이를보이지않았거나, 영구치또는유치에서보다큰재광화효과를보였다는서로다른결과들이존재한다 16,17,34,42,43). 본연구에서는유치와영구치에서로다른세종류의항우식제품을도포한결과, 14일후 2군에서는영구치의무기질소실량은 41 ± 20%, 유치의무기질소실량은 48 ± 12% 만큼감소하여유치에서의재광화효과가보다컸으며, 3군에서는영구치의무기질소실량은 65 ± 10%, 유치의무기질소실량은 58 ± 12% 만큼감소하여영구치에서의재광화효과가유치에서보다컸다. 4군에서는처치 3일후유치에서통계적으로높은재광화효과를보였으나, 이후 7일과 14일째에는유의한차이를보이지않았다. 이처럼유치와영구치에서의재광화효과비교에서각군별로서로다른결과가관찰된것은아마도실험에이용되었던유치및영구치시편의발치전구강내맹출기간및환경이완전히제어되지못한상태였기때문일수있다. 치아시편의실험전환경제어문제는유치와영구치의우식감수성및재광화효과에대한이전의비교연구들에서일관된결론이도출되지못하고있는원인중하나이기도한데, 구강내맹출한후치아가겪게되는지속적인환경변화가법랑질미세구조의변화를일으키며, 이것이법랑질투과성에직접적인영향을미치기때문이다 34). 법랑질의투과성및이온또는분자의흡수정도는법랑질의형태및치령등에따라달라질수있는데, 이전연구에따르면미맹출치아가맹출후보다더높은투과성을보이며, 새롭게맹출한치아는이미맹출되어어느정도시간이경과된치아보다높은불소흡수율을보였다 34,44). 본연구에서는구강내맹출기간이비교적긴탈락시기의유치를연구에이용하여유치와영구치법랑질의구조적차이가일부상쇄되었을가능성이있다. 따라서유치와영구치에서재광화효과의비교를위해서는더많은연구가필요할것이다. 그럼에도불구하고본연구에서재광화제제를포함한서로다른제품을적용한결과, 유치와영구치모두에서비교적우수한재광화효과를보였으며, 이는초기우식병소에서항우식제품의적용이유치와영구치모두에서매우유의할수있음을보여주는것이다. 본연구에서는항우식제품적용 3일혹은 7일후유의한재광화효과가관찰되었으며, 재광화속도를분석한결과 3-7일사이에가장빠르게재광화가이루어짐을알수있었다. 그러나이는인공적으로우식병소를형성한직후재광화제제를적용하여나타난효과로, 임상적으로존재하는백색병소에서의결과와차이를보일수있다. 따라서실제임상에서항우식제품적용시재광화가관찰되는시기및가속화시기에대해서는더많은연구가필요할것이다. 또한본연구에서한명의실험자에의해칫솔을이용하여치아시편에항우식치약을적용하였으나이는칫솔질의횟수및강도등에서균일성을확보하기어려운한계를지닌다. 따라서추후연구에서는칫솔질을위한왕복운동기계를이용한다면보다객관적인자료를획득할수있을것이다. 397
Ⅴ. 결론본연구에서는유치와영구치에서로다른종류의항우식제품을적용한후 QLF-D를이용하여탈회법랑질의재광화효과를알아보고자하였다. 유치와영구치에서서로다른세종류의제품을처리한결과, 세군모두에서 3일혹은 7일후부터대조군에비해무기질소실량이유의하게감소하였다. 또한유치와영구치모두에서불소함유치약을처리한경우보다 ftcp + 불소함유치약, CPP-ACP 함유치아크림을처리한경우유의하게높은재광화효과가관찰되었다. 따라서불소치약사용이제한적인영유아및소아에서안정성및재광화효과를고려하여 CPP-ACP 함유치아크림사용을권장할수있으며, 불소단독함유치약보다 ftcp와불소가함께함유된치약사용이보다효과적일수있다. 본연구를통해 QLF-D가유치와영구치모두에서탈회및재광화정도를정량적으로분석하는데매우유용한장비임을알수있으며, 임상가들은초기우식병소의진단및항우식제품의재광화효과를평가함에있어 QLF-D의임상적적용을고려할수있을것이다. References 1. Ogaard B, Rolla G, Arends J, ten Cate JM : Orthodontic appliances and enamel demineralization. Part 2. Prevention and treatment of lesions. Am J Orthod Dentofacial Orthop, 94:123-128, 1988. 2. Basdra EK, Huber H, Komposch G : Fluoride released from orthodontic bonding agents alters the enamel surface and inhibits enamel demineralization in vitro. Am J Orthod Dentofacial Orthop, 109:466-472, 1996. 3. Lata S, Varghese NO, Varughese JM : Remineralization potential of fluoride and amorphous calcium phosphate-casein phospho peptide on enamel lesions: An in vitro comparative evaluation. J Conserv Dent, 13:42-46, 2010. 4. Dhar V, Bhatnagar M : Physiology and toxicity of fluoride. Indian J Dent Res, 20:350-355, 2009. 5. Reynolds EC : Remineralization of enamel subsurface lesions by casein phosphopeptide-stabilized calcium phosphate solutions. J Dent Res, 76:1587-1595, 1997. 6. Yengopal V, Mickenautsch S : Caries preventive effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP): a meta-analysis. Acta Odontol Scand, 67:321-332, 2009. 7. Rirattanapong P, Vongsavan K, Suratit R, et al. : Effect of various forms of calcium in dental products on human enamel microhardness in vitro. Southeast Asian J Trop Med Public Health, 43:1053-1058, 2012. 8. Karlinsey RL, Mackey AC, Walker ER, Frederick KE : Preparation, characterization and in vitro efficacy of an acid-modified beta-tcp material for dental hard-tissue remineralization. Acta Biomater, 6: 969-978, 2010. 9. Karlinsey RL, Pfarrer AM : Fluoride plus functionalized beta-tcp: a promising combination for robust remineralization. Adv Dent Res, 24:48-52, 2012. 10. Kim MH, Lee SH, Lee NY : Diagnosis of Early Dental Caries with Dye-Enhancing Quantitative Light-Induced Fluorescence (QLF). J Korean Acad Pediatr Dent, 42:218-225, 2015. 11. Pretty IA, Edgar WM, Higham SM : Detection of in vitro demineralization of primary teeth using quantitative light-induced fluorescence (QLF). Int J Paediatr Dent, 12:158-167, 2002. 12. Park HJ, Kim JS, Yoo SH, Shin JS : Developing of QLF-D for early detection of dental caries. J Korean Acad Pediatr Dent, 38:317-326, 2011. 13. Wang LJ, Tang R, Bonstein T, et al. : Enamel demineralization in primary and permanent teeth. J Dent Res, 85:359-363, 2006. 14. Wilson PR, Beynon AD : Mineralization differences between human deciduous and permanent enamel measured by quantitative microradiography. Arch Oral Biol, 34:85-88, 1989. 15. Hunter ML, West NX, Hughes JA, et al. : Erosion of deciduous and permanent dental hard tissue in the oral environment. J Dent, 28:257-263, 2000. 16. Badr SBY, Ibrahim MA : Protective effect of three different fluoride pretreatments on artificially induced dental erosion in primary and permanent teeth. J Am Sci, 6:442-451, 2010. 17. Calvo AF, Tabchoury CP, Del Bel Cury AA, et al. : Effect of acidulated phosphate fluoride gel application time on enamel demineralization of deciduous and permanent teeth. Caries Res, 46:31-37, 2012. 18. Lee SH : Present situation and prospect of pediatric dentistry in Korea. J Korean Acad Pediatr Dent, 39:206-225, 2012. 19. Stookey GK : Quantitative light fluorescence: a technology for early monitoring of the caries process. Dent Clin North Am, 49:753-770, vi, 2005. 20. Gmur R, Giertsen E, van der Veen MH, et al. : In vitro quantitative light-induced fluorescence to measure changes in enamel mineralization. Clin Oral 398
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국문초록 유치및영구치에서 QLF 를이용한항우식제품의재광화효과비교 이꽃님 김미애 황인경 박지현 마연주 이화여자대학교의과대학목동병원소아치과학교실 본연구의목적은 quantitative light-induced fluorescence-digital(qlf-d) 시스템을이용하여유치와영구치에형성된탈회된법랑질에서로다른세종류의항우식제품적용후각각의재광화효과를비교하는데있다. 연구를위해각 48개의건전한유치및영구치를대상으로대조군 (1군), 불소함유치약 (2군), functionalized tricalcium phosphate(ftcp) + 불소함유치약 (3군), casein phosphopeptide-amorphous calcium phosphate(cpp-acp) 함유치아크림 (4군) 으로무작위분류하였다. 유치및영구치에법랑질탈회를유발한후, 14일동안 1일 2회항우식제품을처리하였으며, quantitative light-induced fluorescence(qlf) 를이용하여재광화효과를비교분석하였다. 연구결과, 세종류의항우식제품모두유치와영구치에서대조군인 1군에비해우식병소의무기질소실량을유의하게감소시켰으며, 치약제품간비교에서는 3군과 4군에서 2군에비해유의하게높은재광화효과를나타냈다. 이를통하여 ftcp와불소함유치약및 CPP-ACP 함유치아크림이유치와영구치모두에서우수한재광화효과를보인다는것과, QLF-D가초기우식병소와항우식제제의재광화효과를정량적으로평가함에있어유용한장비임을알수있다. 그러므로임상가들은유치와영구치에서의탈회및재광화평가시 QLF-D 시스템의임상적적용을고려할수있을것이다. 주요어 : 정량광유도형광법, 치아재광화, 치약, 백색반점 400