Skip Navigation
Skip to contents

Restor Dent Endod : Restorative Dentistry & Endodontics

OPEN ACCESS

Articles

Page Path
HOME > Restor Dent Endod > Volume 31(1); 2006 > Article
Original Article Cytotoxicity and genotoxicity of newly developed calcium phosphate-based root canal sealers
Hee-Jung Kim, Seung-Ho Baek, Kwang-Shik Bae
2006;31(1):-49.
DOI: https://doi.org/10.5395/JKACD.2006.31.1.036
Published online: January 31, 2006

Department of Conservative Dentistry, College of Dentistry, Seoul National University, Korea.JFIFddDuckydqhttp://ns.adobe.com/xap/1.0/ Adobed     ! 1AQa"q 2#w8B36v7XRr$9bCt%u&Ws'(xy4T5fH  !1AQaq"2B Rbr#u67Ѳ3sTt5v8Sc$4ĂCÔ%UӅFV ?_Aנj- H>>,m*>fzp"TrKkr^r.|_&]|*vPuܶvoQ1mwVJUhu-I"=LniAƕ8"۲ k*ҿ[yu:.vUQ+)%F DHyVBk>Hy8jݹ q~9D4KRmzQ)^ʔ.J%k_tVi5NTjg!'ky|5asOȻ)R۸ߩFMԿ3L4j6dڜ#NIwUF]JqB/(FafJRzq3\G՛ ?~\ 6)6W4m[O^L0E&rRMض*C .]Unl-1 1r#Rj/&QɈ׉˩s6Rj=5Tg.y.·Pӡ:JJS:C8-2u]d&vUz;7p9 5VnL֢"y)">iי(IDDd| Yj0; LRfS:ktYK%*N2^m|&dğth":ey)uPQZW)gcC3Pv&MMWd&Ŵ۲mvTRoժM03*F3Yd6\8,\hݻ kߔi<k NTwSԪmljj[>->ptU%'LR>&EBH$MQAUx[$Z6vi&_a.KIQ{hyƒ j"JOC9eFҝfj;˚Ω<[3_m% lQ@4g=5$(J]Yc-OMq<Ǎ wSzڗ)k$7VIP붾ͯnV+卵*t]iЎD31~SA1éC2u)ʼnQn-Uoi3:grI8ؓWm*G zܕ)ZקJ}Y YlGeJ6cB2I NS3Q>k=KTBT]W6+SOXQgGR? telˊ%-Re\hѯ2TF"C/OJΩ6r[N.0{SpljjX1“jOsӥ;ҭhe}xu`Ք&.)yO̒ Fߑ.$Qw;9Iw2o+RVJMSOj[SoҌZ%;`d$blQ{Ro{Imڌ>3egf\O֝Uzx"䢸g+mv%Gʆ:|V[N'&ס-ޝ'kfE|K,G&˳98Juin/\\Qݿ̋v~Ǩ!rtWU d|E߫R4d}.qPw*Ӭv5YEcn~f5c%MTMkb-F>5JT,})QHg%{("ӔȸWMsYyWNRrkkJr0XドnͫT}r-jj,Ŕʍ\Q2Ri>v$5!]"JB2WɅ)]VԜUc8i|.jeRO6^V.¸ Q&#|ܶ-*uOG%JAtRZRr]FFG\۩w+?'zչSѧt jz>KW&ot{7P&2D;&\\>Q2JzܗAKSfeNn[jRrԕf6,q,F1tRfԗ>vֶևj-&R'Zi2=xv~Elbsvm8=ӛ"ū񕜈BȩlWau[]ٷBߨF~J!|Ipr3R̴#Yp)={7:G{+:\W}n|Q#%)7^-h"Ƒq:M*%J&$T軨I333׎g_- ucBwwjp[6i25$̏bU’ٱRv?G\~#Iͪb7<<}Ezt" q_Inw,7-d,G÷%T* Wg1"䥱kq/A.,_KhqŒxwvo u2ۥۧ.bQ}XκA$֣ +K״ZUNmڸII{.v{5z5ѮRme[moyƾd~cRݾK'j.\i&/S6f|b=5: p!6i_ 4j6=.si˧eƾtS^c.Y^RJVS-Vi3,esi08?H$GvZgg?gi䤟2adw릿:"۪lkSN>q-4kI܋ێe̊qۅgDoѨ9; #T.Q;7#~_Ufstb_'w~Xw1Xk,vcOt._}v}8"(4Z\ۘgk?J?bm_c!g{HZV]Fkk%~gEt)b秴vΰB|꽸}mp~E6ݹv;7P٤v+ri*3Ԣ|'O14_~7nP{7ZU\Vű[ +7󖱅o#:ǥŬ\|3r%TJX]V7ez¨Y]lc|O3V! R zbJ'PnGqVJ"19WVeOF埜EaEJωqCN5Z g-9[S<$sUK5b|7sn\7x qmv##FF\ w[=-43$^ooVSiXօv7iB۴yg>]Vf"r$J3""32!Zh[K%7GvNLs+4nB/B{vlsobJaҺJR:0g%&zR\ S3T[&ִor*ⷳc3ʊO[iozW٨%$gn:ܶWwFBԹjHP&z u&F2\f;ipW73 [; '_̽b;vib!oec dC-tS__$Xs]l9&z$2/N>%'[}b{h/{`{Ji׉׏ YJB/X%}.|+{(S:qz]4_Kѵo`^tY_4S#* ^zvݾMr+TrkQ g.8Ͽ^i>ӈǙvix>$o( ^qt*&t1oJVu-ql5U6jCЉmĻ*"?JT=K'O/|=Vo}l0b}}f?X[?/\JSBe,kP8ETJ==?.p5ފgbU9}ǶdNKk—_$8̸͓ۍ8Di\BԿ-1v{FF]|.^ۅ{vl12׏z7-R7wE?\nh\jN/Kձr_oBw"N QMBZqe-m:ӨSn6j4%!hQ;sv'm4kcM=!8\m[M4{SMliۇ%eֽR&N:{2A8)THLK3Zj[jPBx#BگMf:G1\`edcʮ?|w(-̮vXt,bW2;.ιNHRR#YwTM"<;mk\.foIDjmlJ;vxy7o7i\,KQŊ9d^Mmgc L*.T6tLeIuOH3SJQ3=F/ʿ<9\JM6mN6=<{xkP!F1QR[I$6ُimXu2An2yԒMU q f[IB-'䤯jYm52&JG\zд\~vdg QtHGXw&1Lw+nDEdC1w|YJmvP)HZ>i0BPβә?R:QO["]I_Jʏۍ>QKyu^bycBq4lXF~l [\*N>-J6,Gq(Zr5h]CwYӤU~ʶߑ u*SIv%ZfJ7)! FS*s_\|IŸZ)J ]ܜi4"z[+Z,MOZ))}|Ʀ(RUNIII.S'ˍO~˨rn}M)xxӕ0 eyҵ7YMAB]ӣU:/ѭ*6bcwP͵ "+qēVjŹO|GtY4V j[mLV M -m>",B$ GD1~j6O4|LxnNmqATNR3ε|DŽa[fmn-ڭ+FiK7Pcm;r5 l8r{#-]'nrFh2ruycb;pW=njRqRJ(d mnpckNnʹ+6]tz~E=ʕ l ZZ5jSi3#47.Lcfe`9؏v囜.F\-UZ:*0_<Νu9Lӵm&)_3\^ҹ3"1n1v_|uRʞͫr'iȧN_kH׺8xXrj=\МH)V\ˬ.Xʸ oVRC}ySU9/OBY먌5 ٿwޞ)rw8Ӫi5*5ZΗcGƱ !ZۄlmpjJ -l <R̵/JAպZuq\IdUS 48wXJJtcg4cI~aqߓwŷrm-v)G7yS^7H^-\mŌAq|"m9IBnF㏉9[N+mmy/!KKۉ%n +BdddfFF6FQRN-U5;Sv'm4kcM=Mn)\qιqUd9F%",6MGdT%-+~ f%+y֛^3SrF>6lc(֪vۊN;g._0Sѧ]ETWرkQKzGe9ʨsKA"yC y2\[5 rԭ7Gk5Mzw_4sM3hxЊ'oÍ5jsub )ͪ~tR2H]R͍>̋m6=%(˿(Wrr-܅y5(ܔJ޺YunW̹븹NsqK ]/QR#"ZMDfD|43Qw|._ԡSqTZBg??O Ϥ)/E_U|i}2 9Z?¹0:x'3,whǣ?C y-A~=daJј&M?D1_PS+Oi&;a @;Dž7[ zZC"bv:jjMQk$M RԸ3uA\=wI.AwC"^.{?-\NSiˏ"b}T/}q/ o.1M}R%:-ZniʒL$SgrBW*,Mw'N\ɇ{s\j]VryG'8f`}'N<*/`U숻z CwHq18J+vԕKss4R53/&XTt1bZƟo\=%nO)h$rBi-nKĪ^ ջڜlwkYm[̑+/QrZo%TQ;TLs($2C:s.%+eoNttq۰kK7O0m_t_pZ1SsSM7"mevFZ[w -FJ*T*jФQRg BSu|]g:ɵzjqwmltL.e3sRMچkSmjkmWœިm++¦'tILk*բQ D,PB\lI[9{%Gb R6öۍmX-MaʉA931cs..G4CujQտ[9 }G-xwl)IQz j Ó"rqe&=]꾧֎c)<kӳ+0JrRR3'TnXi^xMF Bު*tIL.[h"2"nKzZe'ZV/RrNYz]8죝n]Ķܩ>^Ժ]u-7^\mZjܣ9+Rmn ߑv?oꋘ?&ƪy^N4o=3-ؔ̿*`}V݁ ƒPu8%$ ݗ]wt;\y\>='OjPIp/nJU8{϶FNMsf"ίNqƹ(+ ݮF2Km |jܴZs%zf*eȫ?]4)I۵nR&FX + [jDh(#哑9q9Eծj8noǕZf\J-l&Z˫}`ӎhyrΉn\űn]9pʌӣ"׮Wt?N4_I_~54#/my1Xr*척aS#DT >q ssΛW;3oUaJSRMDgQnt:Ql,/ ܷfRqiM Ȼ>Cob;A>ڦWقM9X~/!'MW.}Vrߔꔵ!5|iB(0-zF=}okڢE$^wW~nokY߮\6՜̌{i-AF*9)\t9IV6۸5ZUF6R$ŨQIq砳YUZ]eyv >hI櫥N )&l JulwE1GDOuFN2| }馥uC1rޫV+^gdb&W[4<^e4YW,d|htͮsUM)۸8:{3d{AѢ)~ \#J=NdƮꮓ90 |1K$v*?мS ]i$J,C,SG?/_՜pMSƯM|mG1V1$~K>CSvkuj=&) -,yLjuFHK{c駗.SOua;BrSqj-ۍZ#'Jys7[g2z/.u4+XV2VQ.ޕ)$"(%)#Z7suZ%j }BǬݕe)Jvz8zJf:hIN|svO1O#IEcۍjݽ:SdὮvu^@:o^5cs>i/VqmVm]ؔܢn6'vޑ̗J4Wn@OlKbX ;n:hgJ9ŻyǑz8f܌q&Y fN0N;[69 rbׅC2/#kE l&2~èMR.*%g=Ft.%؝e8<.e=Uv{~㻏"EˑnvDѭ͜Lu3u0:U֝$[M5<:oi+V4V9 6nXvx&_ q Qqw3W:uϔ2yb/(ɳ|5zQiJ#r|Hw#.W?4aDŲ\ugWG;Cw鐢K|xg)##=O.dF˟jMUvWĻsr.z]kPc9"]R)mkfOd*uYf١RsB Aîh=k]ʳUrrZsq`d#r$/Ը3o^&lRWȍyuW̦Y4QDUMJ65ƒ[+ygk XK_±k#y:8(TJOSQhJt2.DR}"5[) r)6V6u5k:eXZmv𭤔!푊Q[qQ}ҹLE- 8qIZG|UM4j}Mܕ[Vwm{} Naqµ"ԈM zOpKѰ?IAD3Ir0'/q1itoB5{%wkOBn-ۜduqIzYK60{+DʕܞqIt";r1mG/\/ym[6JƫR \L=S=OT@Ix[TMm{>ݾտ֒ݸӉLYIx>+"JVNzx||5rI?C{oz8۹e\R-^\A2F R+N9 vlT]"ۭ d)t֞i #E2jB@׵=#/N+!ĕhx}I!cM`ąZ*ŻɄҒ߮Y.Z}='/oۙ3IpW̮hT7cTSuz9>B}΄&h!>lӵn~j˅IvU.'v'CSZw8QK3G> ,J59ٷ+HSg䧎hJdzvwv-cvxS5[̊n~ؿ%ַX?O0\6ne 6kn9.ϯ} *h 8_QhLݣ7q +=XBҲ5?[[)+F`=4 }B,sNg==u*Nj9k_GJ)+R~GSPBȒZ:(K]heL=vKPӢwq(NrG^ثϣ?#tC?.ͼ[ۅo؞y#%ǛjVyLSw%T*s92JTM%"YkQО.q)gCͲn8cgi6j1MѾ[{9h^vƘǚםidfi.^RHmg&rׇz:}݃}xT$ضk'5s-狶,\vpbPD،=Okf.c#cdz2FK5T!&)|ntD<+OŹU i-G[EE*FDfeaf2QƤM\UG_{ǹm%\yrGy:.\4wjPGUJޕUV7Do\7Vy_13w;[?c]H\$IJ,*L]3b%L{y.JRKG2sq,B6T}(#nW|km+q5] r㪍bJ@y{byz,b踊3ϻJ,'^xd،)JVw#.Vټc''ÝպWtbRؒJz۠8!o9IۄS95E9ؔ-e9JR{dmnッ<[~n${~Њ$W?&ՐY_? #a.ߑv?oꋘ?&ơ|y^N4o=3t=~7!/M3>n8W홎2M`Qx+ z qy8%]7_~540ۦ彷]Wq CѡwkďyF5Dum_}~P(5.(X,K9vᯐ?leB9;Jhm#3{CxGE-S{;@Fz˙]=O'!ɿ]' r`:7'2bЖ>Iy,/eTy/V<.H?UYY{\^#ѣr9^7?xoRȆ7EoS_&??zϾM?(~Q-K&>"~aߨ t7Emsϛ+?;fCr)fY+>z$tIkjn_>vnrֳki-˹l= t;'EyC¥|/BLwBJdgjۛ$s S1|ɍV%JI6KvəhzIlBYɒ|0"Sy0F>eo5W)O+X˻u';v)2vVq۳kۮws?UʑBǴYO漪e2MIjPAک\b1)DDؚKm6ZWΨgȕ۶yjڳ 2ضN[C[|r@9Jfo<_eI7q.|cÊV߷:i.:$ȋ)1%%)ADZCEBxJ0MJۥy(bNsKM9k43IwNt.\%N簤I'.j|ƃ2$grBEٌ\}9:v*!n7M(ɽ]7c@XxƱԨ37īf62cTTfFK]9wntQHͮvٱI/f|j=7}\_V5U^+:uljSȃY(XI.ȱmo1甅jڎIZ2>#\*:gY|4k\8ZwSqtyA!+];бޞKծË¥e)#5ap.QK^8VdU{*ѽL\=qmjnB5>{ Ӟ`v±5 ^k&O~Oshɷ,;6nOW>u6{RqS`)S%jp\ipdEBLfTWy$GIYw~䲭J.1vSY5z.V>^+Ǎvc.I[R{QsNR3ӎfhd>y?UJ*}~[e\i5U^͛E]G_FS(Iɿ]i8:4zj~շsW,ˆsy:%O}iur]iF5~3M:Ӟ#N06)4ߧgdawIotiz:1r5YDZLHBSi;NQc44la=Y kQIT*ըl:tq2(է9VO4뒳܂~2rq'nrVZŦ[t7\oլfb/mlpc.I8콚q^1iE~䰳mi[dۧw֤ICfdFeCsg:i| 6擣׋* 96lust^{%99UNRvaMܽo ammi$em4D6DD\nA%$$#}۷/ݕr99JMն[oT޲E"KTaP+HGkŴj5TM5xƱOS-k`ۛkٝWz;{kS}F;~q|~^_|euwnE'pSupUP)V]vE+t =ZRaVdG6= *.ϼnj9:UɷbېmF_tޫgHjVS'śǕًdkkѻ_]Kv?nT>)^e=Ar1'3ԔILyD?:-^in):{7.؂\.:V }#뺾.3r̸*xbFM aȵz 6SQ:ײj[ 8nn iFMw rR"5M5I旘35f^j='j:nNW.ʭocZvZKV^ɚJ.cM1ZI7E'6rg탸5oZ=[m Z`\hbMUR١Ȗĉ):Jin!_7Dй+f̷eKҷvͨBPR(V`y6tw*MRΝcB.ڭTnc;P$8nFvm4(D(R#R-L -2:FP lxZKQc6I("Km%$E, 78uXIFA$RQI$JbInG]c[ֹ:ZM+n^')JmJMJRu{e)7jQDw~%yQl}BZujSSf۩QZ+Dzhd5o%BIc'GZ?}΍:>Ɵivז-%݌J5MqGWTVʦh݇ܟ~Օ_6 n'{3~mϬj'J11OȻn߃r Qr\3y٘+WӍ'WxEs^O3 o~[|7>]]H9݇ZomT@]?5B:Z߂'`V_+/MSKX߆ޠk3?o7y:4R/7þ] iG߬aBRU&?r&/} cQߥGj2?C5Yśe7hU=?+ x龳f-܈czW^7p%-(\D4h{UK&ӡn^m]Fݢ:`δvj俜F+) y[{{ 7 tu>gvrěOj'5 iRg[ͶFjGe n~qT$ci ۚ0oԹc*jL[sVWqj\ݻ&6"WoK:cnWmrv)o>66(F>=W^bf#c zzʞtپy%mՉPël e}J.\Zk4ttt>oEM=q)hJjI=ͥ(%]脼_88ф;͛gWG;Cw~˘$4=uWdĜTثNDkiQL9U*O"4XP`02,Ge-k5$h>ܼ]3vr6!9RQPIVSnM(ۓ{>;/Qͱv{3&-[rc)ܚI$n{Sv3[j00)-D3z}MRzVQпj,T[uVs0\}Sid;r(ݝJ>æʺL&c[jPK0~d(FKÝW\m]GTcF|Iׁ)I3~#oX%vҦEݑؼ5Żv2qAZTE^..M{ʐfȏ2##.R}*KʛZz^ӞN*lPťLf\G6[WVQquV]XAi)5J!,$iJ6o$tPZc;Kjx_n3`qIelV~vLy{fn匋Ѿn%;zV.n'-ұdd2߽1bZksPe3TI9)$ԩIN9Vơ\=2885N\ p)/a柛w9g_lױo8ݷ iixJV& ғRi{N^_oAŮE6Y7I$Nk$|Q)-*4Z)^¸%4Qm [I%.c-OV+C֧R#%ѨCe3i;w$G+_dy| Fzj$DI(=OA gj%v/]8qԯNIS*֩',Q%\44ZZ%D|Ǧʴ6&vֵI$%8(ԬƾS&#Z. }6z?b/|Jl{ץv&mpx4Z$”ڝ4-H%dGKfM:sKSRWeJAn]>s6应-W9'H]'uȫYvgK^\czp|My\鏩w/ËQ.)]\QiS`8uL뚛̸=J"ܻi\å'-)54Ue]:K\퓡vK xwBqrH\*֕TnzC.mT=t-H]SČ~Nu╏NÅ3f|͡G~B+Xm[Q7U{9"~jgK Zoʰ7"qJ,ekSeNGgϳ] ^.6:s}_,%eRg<5⿨z{ZPun#jRІ.6g T.!]xa c#jN$Zpl̋H WZu8WmMRýsĮ?Mco~sx TU҆Q :KDG4n42.<3/'^?6/ܠڒ^yrrÿr2\D}}B]^E~^T cɛ7϶Y[<֞[7d}2%QPqOLEQR\CIsj1?\}%tJ0e~ *sk"*)&ۓEi#{1J8Hrt|'ܝRr8)=ƔN'RVz:cf]F7bZyZUȘ4x8,#JG̒?.W9XnO]KO]%]ƻ O5Γ/3qÓj؍/r̺rƵ 5\&m6h.xoeX[=<3%< lZ"2h\Z[&jW3ejm?k&[]ųj+{N{66leu_+lj]q* 7g*knأYv= q ەdxЬZ|%GUrQ3jLŒqET]1% qkXYūYc[7Ś]QY\jko\</Lc7+'hMSUc6qXyؙ~6#ѯv.0$BQi5YyIhɍiy=KD!n3Vm[V%W-B%swa97ajۗ m+9~]fKq|Ddaˑ0A]_v޺mM5* F-BYHJ5}q>ʉ.6hyDmpD׬'-_v5;5[8K[viJ.3dR:oYHHh9I7:۽fi+wm^ [)odPѱ52CZUJicSw\&_s0uBȍh32džzQflcd^m|7GѹE!fO5]]H9݇ZomT@]?5B:Z߂'`V_+/MSKX߆ޠk3?o7y:4R/7þ] iG߬aBRU&?r&/} cQߥGj2?C5Yśe7hU=?+ x龳f-܈czW^7p%5|Y:SJE\U-(a_cƣUǽXXKiȞNlmۊڭڄR!**ܤMeȽ$|X5(Ź\rJ~ܮ]>'HB0cp XFr_c?f?7<ukSgov¥iG>>䙗i.+t+bOjIܶ . i^:nm}s}(3>NZ$2Qg([".>i.ƾ)B̋M8+"- >eE6DݥJnJˣt׻ 5.˅nJGwZD~!i۶a,Db3ZQ3O#KO5/֍ozuK'GbRi᝘NV_ҝcvם ZoX}F6z 7e5_e:ۓj=AB+iܔERadMBq*ԯ DwI/Gy*mĥiRKg6skY/#SN4e$-yXM YL?^ĸNNӪ{$r1JJRSLO]Aqm>V/s[~i/j+m>z}eI"Qvp]{ZԼ:{vPAG2=T͡@ڐ#u"E*>C;o$~C#_d/HBq^YRٽzIKbOm\~żjFFGdiQ(*/i*#.FF]©m=BmpQQQSP&Ҫ!T&^>:y)$ˑÐFčI Bӡ-t!bM WҦŶ'UZ=}zvn~oT/\ǒ'nr8 AJIӆz<^uߖ4eFC1i+v!3qNyߕni?4JZlmYFXFۼO0B\m[ tʄU3s"Sr(NJ;SKW72L4̏BVdf^Ҹj\]ȱ۪(ӷm?J-KEmWڽ^4<8qu%9pŹW~877ܾeVгS(յe^C]yX͹! םm4FGȋ\y'Z FX7e)|Gjt߹#gb\ŧq_([R8[qU$Z (ʻezV2V!iQ,i$JE˂٩ a(GK'O{vnBvryRd-RK4=qxZJMl_CuuIz @Rt㮽޳!|68\-l[џ84-2Pu" RJ_^OL>G1~XnBŬw6J0*Uvlږ1N G1q9IUm*'oWu][&UyYZbBZRZNfEJf"+2nF~Eû7n1xv.RUM$6 lAxSQJ&n5ܞwlEói"#>4׿Q.nEq7Oko[1wg8ZQwZYiqtm&~">Bo?w͡ni2峋NCEy Ҕ+%ZJ ʩq*fpˤl,~^Mχk1+:ݕ z&Y`KLӪУDr3[*Z :(SL&ݻ۬Vqsyԭs x|iI߽zZrg.:mp%6ԜvgmpIUt;QbS.Է) ǨKSV,*lڌ|5Jt3#NP.=+OZ~/G سIgbꥹJnl_DUM\iM!֔wVZuԺ,yV.Q>f v:݇WiaŸN5Ҕ[M7SsrvǣrMW= \8ZW-jsnڕ.ZnF2qt ً[ٻޘY۷Zm"Jxr&NAfA-݌to9s359݆mZ+N1-qS$D=17 x׵+%_ ve4ir6Z$FDڗnFtOr'7'{9C˨ꤡaYoace{Refnft RR"4%ʌm:Sj3)OdInTO>X'vxV#jܮw9Fog;5.~Y5\~18YQܹvj4+~t7S ﬕs %^۵ڴDZV69R^Y+rj$ԇoJKR5wB9C>Y:l+EǎS{ʲ{T6Wi* ^^9k/y/Cs\g*qڵgn4T8mERr|Ti+iPe;;.i\EBEJ 丬i9ɧM-ԼsGDrZ>r#R>~X9y4b棇9JwV۔%m(b[Tjvl}۩~nDԺ{Zo-YuK1vx.nWuO+jN [ٮ0%"΢CdTJK-RަH"$I(*ve &҉FzB,_Vpqp9m8werv')E;o&QE׵^d9˦j\_,ڵugZȻ̧8k+jK{wmr@3ӭ2 wFkzFVqs1؛.v'I%$[iT]D5Dl2 nk7qUxԫLS+sا3/ΖeZYK<["%-g/kRs:f3;*E ت wJ%)5&+&rw*霣i|sMҴ|;R+fm䡩.!**dӶ-6s6,]zAXMWjmnz%SJߴm2UXw7MQ%<!tKys#P,W>s;3IYwx<+i_\\\U6 u7P|xbn_k&ӓVOe䦒 VUr,-㘘"-LZeOSҠթrEvq8Kf%5%&K"#%vD/.ZYYŏ+p$nZkvއuW9㓱Z G wYIFyf)?ƎUm5ԉ/'k84{KO:rQI}XRuԪ|*lu)3qZ[mSm5R3".Xcَ5c®ࢫI*۳~wRϿQWޝ(EJrri&ۥ^ʶ齲Im|[yb;mnm֩uiܘq>E+Ikx߄3r33-5𹻖09ϖ9[Tz~mr5NsWl$oPusޛ^{Z;);sڹf\3oٹZmԉ/'k84{NO:rQIBø8Bݱ3n֤DiK4u& ofSȒܩx<˘|N0Fչ]qsp"}! QWw@t4ӭ+cO5%]'*{eM߲DRO1y*q8w++e!c߶ܪlZWّM欼 CQ̼빶lX{vib/V/ ai;x6~]+z]MWB>re-:lgk}պ!#9?%܋V-c[z!W?c7YNm/jRr[HOzԻefճ0q15Zp#rkQQ0tU-AmڵP/cȕ?0cZYj;:0ZM=D6g ?'UN+ձ[K ܖB2'xq9{|۫N0ku 7xaj;n\ 2[VznMlWiKbSk))f..)Km)&bGZ=>OR܍W:j'rM'wYz&/鶧{Sʵb"vջq[I-ՌZH._x*BagC'T(Q:$ͳQcMCKy?3g'ߝqnT);qs #ؤZ}OOI:cfnc8W~qy.;^pVl]Hԓ>^H^@7-AA܃nmL(uWܻS߿ Td95Bdh4t6*dDh!EhI[iŨ\L.&Nc ܮf^;$R)\rip9I|ٺ?#R.ZDZ;/]nݻqs\QE9M&Bd ]N mN*D>tgbK>+ˏ.!23]BȔR1ɝ^j'k2ƮqBQq[$di]icV/e`޵B.FIIJqbi>Ӥ|p; 6${)RU>_e}^dzdfzi %ekRVUS?6'hׂ)5.\+qUgzE2C˷ecŏ^֔ibk shesFWJ#~> Wk~ݨ}ڶ>ơǚ)׽ZƉo~B-ڼrvoE:Ʃ3ۣK7+Y`WirS):{>ڛ}:wԨ(J_";6R%[u&ƫdZ_\'np| RJwNeTW,=rrbnkڄ[M3ܴz)3- R.?:okۼ0TU'w{6&w7j1z3ON'fGoO?)S_bQ_¿R(^ԴԴG.EtMڇ&RUiW uQjU> Kiu1d<ѥIQ'RQ1:O/lŗᏩiʂv&Jc{D5 Tt)1.n[n۶X}RjqnOʽ(~[Ns{ސ⛌uO,kgo֢dRNQȄ .'6W!׌P朼tdZjFGE"]K@'i۪N;sI[{SOzk>`rRR+!σj8&TjlvA̷Q?HyjyLHNտJMjܶT۽lG?SnKN%<‘ nq[N0Sq[Ta(&t(|HGO~gvkݻTR4&Z$#ViOY1r$6YF?e4U/Mvxų:zbU^gQQ+NW_'4jfz^c'#`rvrڡ(IJ/J ݦ6 ]-CW |_{v*_q3^DZ}Ic6Uڌ8p7{crZq5ki`)mU6|-Z5^iEz3P=:Cu7DF'k%}<C-޹ֲ̱#\,(f88%X-N(ck0VLR~} G"-8ӏ/ϰKq?(#nrVTmZ;zióM4 m |UT'C^_1X.gXM{%ʤd 4\ovN":"y-,T)fLQgۢr=/CƹǨJVr[a+!rT|%Y\ٱzsS>jͱ.oOc6f$q% ǒGo;n[];ߎjrk{~\VۓNIGn:iqxo |~t5)Rxעri{Vi&NUOl_ѮMfsޕkЄay.0P{7N((BaIP$ K"U6Gl ݙqJRu+qN$ m#*p<|{:>-Ev=86N*MM긭U*uѾ?/^o7;'u,h4݌xښRM:5.(/ \իU.{F^rmF-Jɷ.>Q"[4xT^OZ~mK}T0ݛ^SAo9u?lX(' qj%=X}"^e4wˠ|rܫ 6I\Ķ;Ӻw!'ڍWg{ i U_9Avhۣƾ+:vs/MK[ɭīe{`Zgb}r[i'GE2J7Nez579wRq+Un ]J.cJ4M:h箽Wxxm^ pc\wcN%'My $$| :$Fqɏ¾^қP9J6Wxvu}ݵP>Z'FFdg"-; [¢cmWkÎT8nG%ݣ7*\խCLRYZͤiD&J#'ehbSyXK|y*ӞpS̍R`[pTr/Eg)K+92{_ n3zwz'oŸۤ+sOj J:`T>Cf*lwd\fYOP"R E֢̔L4ɥ :;.b(B02rJ蠟9>V'9M%)IqnhP<%,r'P/vNSwr#w"ݨaqc(|{kd=^0jTMR2ULNz|.<|^PfY22##!,K~E BEJۜ&jRNsHަޛg\r,v؜.jK3)[EJ2ii{KEiHP^&]Gn8x=K}Wx/KI9-ϵwQ%spܾ[^R}S3$qvq8M[ ozKxcqmJ/ӿ{_}7&ݨ\f6ZSyQz& 7ۉ[8~UNn|nkiTB+4RI8'Nc%tn{!]Ȋo.nEmʱn𵵥J A+wy#+ikǒڂ;՛s85'KmE:Ђu""Iģ5p=БbTY-ͽڔ詻ngL2Q}$de# fs^o{DUUsfwӶ;s1T,ǤtޒQ\෼J=.tKU,7čJ5 N$y3kdSMQU~mO[03 $zAڟsF5^뜞"Կ QHmrR"ӳηer+ҔZ]hE-6Jmt'ޒ=O[sQj)6K}?e4v_KfZheޓ=BV[bY}lݒTTЬ{ȫvO_qpRApVŗ 6ju=*BR)g "O1yhb=tqJ gtm\b3RY+JQ^Ō֍\յ\>+uSi{=x ^w;uӘ#ĸzLn*$anok߷CBӷ}5Yqvdž<( "_OWit5:EZj2 B ρ1̊fi[n!HQF82q1牙nqnEpT(2RMoM4ϳOu ':֧_Xjsg jP^(ڙ{2%E͖j^}ZU[Q$'U) <܂%!s"m R'G5M0<+zM6qYm$ڕ$3ǧH]?o2N<8F1̻r_my[Rf59NjpzBnl7*{.QP 3N&^BLJPjAHCK2Q}$#~YMq8 k(MFMU)8MEqTy+Tʞ-ar5yܕOXw!e;q-Jqܶ䓊Y:LC UE{/t>r"lI9)3KJjϤA 6SEE$d߇3KG*En|P\ԭTn6I-ƍKTj<1H_zwGr19wF N8ݝ+a9ɫM6mhePi%mmD! """"""*1bRKrD"vnrM۫mmĽm]ӡiG~e"˩ lhRTMk^MX["Jݱk7_ޕ*DqĒ&flՒ}`W}~SմZ{ĕ~wm*/{{ѹ_-0ط#P]xlڱ~Tn5wi*lڪ (JxioϏbqKYR|!|KN53 OS222$jzww%i}>N)E+rۥ7c$Ofl/LNث\6H9: FY󡈾I)fB֔JI_ ֣^: 9mY{66㒢7Uj]:.-os[R&gMF3˸#໹kmjq^8W"PΦURjʄWa˧T!͋ lW48JB2ko+ /Nw QwQzQ ے%$ޓ7^YL|r7!v%Trܥ &|M8~ybrn[RV gSn{{*#2#ԽᢏӴHak" ӌcwҜw&RJ07ױ>Ļ =^ BɆ)v32.M1=#6%̠tҤnzqMwԣ~s*%-j|_m*.Yx9Sz=)qE4 3pk+,`=kNRڥ=B=nŔNAx)Q$ԩȧ4z3t#Z2lҮYn$S%y- JzGpu|LBV7ZW#;Wwipܷ%(6jFG5#{$D"uۭ~]֫SrD܃fҎӾ+Tu>-ZTQ& N|$沸ii>eRWݳu'[O̻j8JۻEѩ[]vni= ڒ,[_%kC7I3Nv$4ɎЈeٸoUu:[}Do5|zNq=Tre%ɧ6&~DȍF]ƞG5q m]/w/ \ʲr8=oʔe9U(W"|S]uZd#?Se[W"ֿh][-7Nu:T=)R}.;ml*5Dlf $fF(̏T hiIUU4Szɕ t(%_|2 ~6eM;TƗK[f&]LK^CE2[ȏBOd;Mi|cx,^6;sیGpQ\NuJIFTJ~đArh* B"$H쉩eXPRj?sl"ԥ)su]xpԴY%VESH"ЋJǰ K&5^Ukzׄ8kEgS2h&Se\ Yl]WҶp-ZUvi7QS:4byqOo+[̺腋[6-_Fo.6[7$p&^ _GZԸߍkc.qqoI[9m߸YxOZЦ1uoiSH)P9Uʄjcq= S>֙NeR><;+ڌk%_qT].srNO?s[=vH[]RZHRMtᩗVؾ:/~u)ԍdg%=edVrISb{6vSu=(ܥ)mTv/J}̇8 S3ad:^hBSf؉OɔLhI_1d8,L><_A0y3rXq"'(۱;mFNII.v5_(^q~X>y{3צ I*Vܛv/jW' T'NR'j%ꔩ:mJ3SB}΋!-H-RJBТQoedi9tjENenPpke.%4]#{:>mkEɱdYWl\\\'nRM4&U>?Ќˉk÷!𴪛]]5}UqG~ݏI"O~s6(Ļ)qO~h}uԕd}Q~G,oE!&G&/]_H-O=o{k\̭bkv.Ô܈+;arZx)m?M\3lU$mk-CFXjTv6u' g:Vn_*qk:VC A%'4JV%EY)#BғO4<e׿jQQ]yUr4=wm[K1r׵%Iũ-O}|kC;/VcݩWZ)EHdžTru]8hgĵ-;=>U_ InvTm_jBM+QiF"9*{DI/iuo(=TzϖmPQl_v4z>T*ȴ>YF;ε\t]EH4ꌇ[VrLzef 2T^V>g2~kg5~Nק;{~Z~W}&ŒBӿS2$J?~(Yœ"˲ߩ\O]: J׉ښT{mmIѩn3˧)4LdFZ/zUG>U> n 5& ϴ-KJi2o]uKljvK3$bԔҚV旧iY5.ίfi96v7!v))FJM4{jG~Jt/lUE%pTAFe4qQk\ve۽/u/Im+W')v{\-E|Pms7߮DZRr۞/mu*1ՙaB܆ -xg3#6ۥtRogʌU)׎]ZҞNnŞr}F1Nnޞ;cZ{N}ۿMiuxʉ*3qi'9KHQ$WJxXyرŔe~[v5~/jN9Q4o6rJv FrdxM*iRjMzUinHdн7ᾞS=S'7 } ̽zt7K|_g J=Lq+/Bw_\ۧx\HJUPzQ<hqF[V0x==CsU7q|^ {)Iq38$_A(VgcKu06Ƅ"%i~_ˉk QCܣB8Ku/񋇵u([w}$F|8TՠI.E !;RJ^}MɒD_q2];Ɖ{5}*n7nEInO{Mwv}&q+v [V}Ĝ@%>#dXQ$f;iep.GquixVt x6bj͵mlKقQ[T]zs/&yەnM'W}!Fp_d^Tu N{ɻ'l{խ2.sTu{W^H&;1s)Pӛ6>$mě;Łnj= fLT)>׸+qReɴ[UR\L*P/!$Ӊ3Q 'K=m~6XqW3^W+ųO_[F$rR*u"T%@O +%# ]˽!aܽz{ͷvQh쩎]hGތ5ɇ*DzJDRNLi 4:{~2FmXY-zzĽ^f=]uū{/+&c:Ma{ĝDp2m܍kHș/(--m_vݮK(V{R}.k&yƴ7i^4@3f sK3^Ř˸B=]?gt5KbZB<e;kQLpxuWC}n 5ҴepB##~q= `x]KWF {GfŲ}?G.I9pjWkU]>={7q{kO/^I3==f1ɏ%nnʫ/Zu_yXN<57ۍ'vy/"8넭M2eԷ&Y,в33%IkjMr7xf nmQkX4踼>a-GcIeތw&U=-:qnW)z¥j :WqSZvԒ#j"KrIU)%qrmRoDGQ~SYRsu*V)  ,/x)MFD6O#]z 96[Ui(JRfw'y$GeUީkdMF-ݻ98F2d[o{Rn0n-xsV6Dh|Eb2E:KCOӪv4SJCr"J!!m,hRLD| ZYFm/X~ΧfrN&4Ƒ=Z9Mh.Mܵw/BdrܥniŪ8ɧ|y%œ[M=_tj?F!z5\evM:\ ~F-sg钬OWq“iiȍ<Gi%%n2rqͻllƑ)okw7}\Uk-:&fj솘XerV9yZuʼşdFC=rmo%~ZN78X(N)_7.Εn1MpJ}62jjJdI";R5&iLԸc:jmqiQj$ujp\{;v5B񥍪Xn Ą4qOERjzN(Ga٠䌡)p*v(J7#ZۻZ8O W uONb+^Qipv9GvֽƼϯrYƖKGJQDNPhRJjᡧC"21"9ѓS1;R_O7/WGz)8fE%F2ukmvSov/iZ&/]~KmI[:^~ͤ\kMi稜\ywJt3W7 8Ʒ~ݥeFgѼw"8VVSج\뻆}ݭ/J6Q)d|)zU3>k\L=;ow֯gN3pKѫ|wmkZ$z^2R:E)f>ς нd|#׆?\ǔpV{;\$ƵE%-ͪm0S6[n< kE[}mvE4DDZ^$OZ0*$~XUv҅B@^?]so#%ojw;Y#SxxueBگy v^i-)s)zV jC{7Gt.w3v,ygg8s]aE_,*E tY5k٨h=o"m泏:\6w噓aiL׎n^c\75AGkЯ0Lf46َ`egZ˓p/k;̛]kq!ݸzpԭG"}R9Ve>ˏHUjJ-&7nrnwG*Xv\˱/vN}O)ʼn&CV͍f̵]r\PMB-6Du-#RͰtRN^)mT _}nSȕC*_xBuTkJW[`ɩ`ejvsngP ڻ.-WUtܑqԹQj)t;vN&RNũT+8%IXӃ5fK՛-d9 ]CƑm|nZ-6=Hz,*aEm W3VzRšdY~Xf׀Xx"]s;)5u*ُHB BRGS6bݶؿ 9j[1*jױga7oX CUI%0v#~\-O-Ꙛuɷ쏪&5mY٦M`LJ2qK~HZbr =N'YobI. (^ ׾{_ ?OJ`S`3BN[}5w6:ǵ/iSlt=4F*d&T4y/#. ɵim5Uֲf 眕6Y7 fơ=3dϕq뚩$qTM-%r!$@A? ޾V0c~{[{;򥧅a~ڵ»&ڄv1ek=wb MLkNAԬw-x>~/r=e73VeVN)K%Sښe"+3uXuچrn ֺVzscJ峻m}vb㶓n\YbIUBT%*,0nov=;z꣓S/nSXSpl##k9mXGrZv^Gde!ŷRԠzQyjC]`gToPov{j~KRBMY}i[߶9KL2ԉO0K#m>wB[ٍ+n[[b٦DX ݲpo] [\m5qdT()mo4Oy9Ie b][wղmM~vmi۱~t \}$яimRk(L c Cvk7r9_r1 ;zv|F@KyZ[&jEji/"6$69ml#e]9s\{ScL}Ȣؿ0q/nZ*t,CLoD߉Njǚy=Pgmu6^]l-["çUʖMlʍp-"qmU>۷uFOJ%Ǔkx 'g=睋k[3u,{³WɘݪF]ՍeFX"Oy\,cچ=w/gn Ļ]#2? vqy-gXnR.^}ݺFs{ŝG]}e|#0mjx"ƬWكm?rgU^xVB":Dt>@LRbun~ݭ,w+v⪕;\U(RYa61>#Jm˞Μ9g9XKaG='u8gf}'qy#ɉw J]We.ʲ-<+&q%s?2dњztҼn`cΤmmqMdz O[-ߩӲ&;[tmܝVnr">{x<8U+p:Ig]zjGkt,uzf}dؠoJaکqEq -(:d<պ=eKy[˗^%ZXkX[C2߱\ITTLGzANM￵i]K>UsOGDDD.ZF6* ҃V Zhz{'xp^`wo8r0h ZmJ5"jb[l=yUu7-;7IT%:jFjߖm0tzU'K)څNۧYJ)4IQ}^KWm7kSP>q;ނ#)'n7&׊r?óM{IwR\j2Qn[v pe#/tAF\ϵ225q֒om6z})6҅*oqDsMf CNIN=T S2t,_ѧ}kveMF0J\Rnnݙܹy[rUc-j{yGtkQ%s]5qB.Nw.JN1LvR Ui5J ZESQԙr):MJ+g}χ!2;q([jAud][ljVK3$ײSJI=/|&tl'*n۽f.frܥ jQO8>&Z];.|7T/C}$ڋUmP2Reҭ8hFF\L 3~e v\۫]ݝNmrnB%*]Z«hKc=BTLG :V74$=Ǘy+EX'4tn(I:Ѝ;Df8c,k1%dJ6.j6ź{N~l6&*fœI7 WAlGOu-ҢH,,(ǔe뿋쩨kM܍ZſgRvQ' 9)?n|er˭|I|-fGK.rΛp8XV1%K6mvG+tc+qE&ǸC_Nm:l=_/m5^[dߌڇ.c<%:)tQ$Ow~-aY;UJ>=F)2[nk؆?훐M=l6[4(O.]2#-H^n#->&mp5~Fӛ+|| S,xag%qkEUzUgæBhߕP(7]kFnq?֖CpruZ6*rEڊtS|*tI*E}7R<,nUU֫^I7Q*mSly%rdȓd8hE<9oHhMfNSRj[i7D[Rj݊+kდq{"$$H?p\̅S?㭻;t~R߁)^/>Qj`yt[w ԛ;²~+ߔ_ YW~|o]?x^ᯛ `ʼn;g)T@vWn]>&4lp+$D̢1l|ȨF%-}.9[}w~ ԠLM9hСablfe&QoW!s?wjLK?s7yO>(=C~_nyǜu?v3vyo oI@qV-jeES^[9WoSܝh"l2C1a͔CiJ@3:Pճw=/7ovuk+\V;lDgն<[A+rX~d;m!_s8ݖ׷;;.0llUC+?i#_crʙ1~C.\–q ul8Hܶ2m`ܻM3Tov|Bs rɵ"oLS- DКw=Tv@f'6|YlD͓Y%׵-#Ѯo%:&!3o%\J<02;K87>^vgƓ# ;ݝmz^Y6=PS39U%~ &f# }o!muH;ʲŇ˷yvP+&.7e[3'vR4Yj̗IZ`e˽3o[WU{ m[sUbۋZǾۆl6~9'V*.\S2<Sd*zY[aŶ`]C$n.v^Ʌ dng>ەZ,Mmϑ :n6nϦezWqUJ4! ۇ4R! =>>Fn|Q[{pRO17ƕ~._I''00k=b՛o}Osðc2'o\3}ݭQ^2 . R1yKȣtAݿ-uܾw!`?1Whn|gzUo[ECWwjUIן)^h#1ɭ!/Z np;o;ΗŻkXs."6E`Z1 עӐ9Kl8qd q} 2Stt;#j>;խabONŗ=fwP1j)l6J̶|gV2`y/0E˛6+ԫ1? 6}KW c\KoKͨ2ۅFw–s*TԞLיuDx .kCzWXhy۶gLu|%TnupǺl-S* PRaLnT+c+*xl.v!.U=|; !_L̎뱚U=4hm:ٯ"y)$:>%(n}X'p[ȴ ^˒4kƓmzDx \ 'NqamP7nyN݅=j7%McSڵj%STy qXymvCg{w/w=wSW5r̹u erծˊsOm=DhEҚRb#n)QOxtվQwe]I}wCa'"[ۂ-z}2UuKP$㜉ԧ:mc<Ý>RoL?wu|%ҷ&K y_!y9 ??:tq3(UU-lkS'ɸ@jdzQˬR] EVPW1DJq2n:,c|ǻ̑;y{X,ۂ.u.b˕u.tKBjQ"[S園S`ٮdNبeJ&9Ơ ~0a(Vm٘L+Jr*vڑE( x0+tp˕ n';wm-ޜMOxX>{#2%jgb2M[`K*\5@8l'e=0u+w ֘鳾{y܀:R*Ya]"Ӧ%ktynlۣ65,3gU}{GYrb;ge'TKwǘ.,rpܚV]Tr,!dp /ԺU,xՉ>s׽~W5oTh yx?xrrx?)?ilbT׬,z$Ԏ.UH٠\U1pU:]JwSrGZq8àd驐,N67QYBӢD㏙W!Q25ϸo9ms-7-%3CihO.J鯽-;MZM8ku-7k9S$8]q2E(}bۏI[DKOK}3KUB^u %Y,u.-&f#]'܆o$x`Yu,dzwM;#oKxn;\[d7}Rb+*Y䛂ZuBӱl{j0O̓}LhK;[aֶaGL{Cb#S.T[>߃F]NK"u^LUʐ_ykW?!GRj29͖qa'0[npcDvV)qz9R)PۨM^aJx W] r>];eN3vxdmĘ(5W2K1䪖weF{mE/QP6\u54x5[hۮ-Nk”i[lUgL]J}5 S:EhiUrgHl!ŒJ$pe=q^b͵Q' ?6|R\,JA ڵ"TDꈭ:ymg`B5t%M] <N_zv2_Ortٵ/i/ReӮ*7[qүqEG* m"[I:6e^p"I$jԴęh!m)]GZkcjS!{e^z}+Cѥ9;R|/ֱeiUԏCNu2Zhcٗg$ݭwvr P8*7/Lk~I'Km1+MW%Bk|oOm>-#qj*|Dbѱkn|n{v#jĮqNpMIUm(7Liz;{ҜݞڝVƚVϬ+sO!OstGvxӉ']uӎ4g_ 1^-8ۦ k!)Ύ5O;YSB#2Zzχ;<.ֵOtge~.(RC#wFZeGZٸ6FFJ4e2ˇpJT$[wgV)q6muDGJ56q\I!̗ y/I~RtJ9kJ]Iy*'FN0s.[l!fw'y(7$œ WƫgyΙdMEU JQJv̋vmrۖ.jWR_M֨djYgSj0^\y'EoECjm$ IƩK>Z28J2TiJ2N#}.s cArl嫶nB.FIJ.)۔\ZiM>/hLĸ=C1s[?YMqp|94- 鮝𦔽/k^#NT(Y LS$6˩}{;5 )B۷W$qpN)qqoot}ZDVә;7TiK|6f3h$dԄ}fqݡ>Nb򗉉+ͶO]>ߡ_VtYf79ڰիF sq~prս|QM)g%l0ocJȨHz V;Bb/kLAcfPJ,ԭ{ƍgpjNR6VSI*$!yV足jᇑ.](EܣqM\qJ2eZT).<9UB/(B0j)mtKEj#׿fDI-=rZړj|'Nڤ]k*i$5qt"ݙPM6E4ke^Z8ۏhz$Q(R Ay2zfRñnpnkbkI:=j &ΝșW?׵d{+ύM'??XqeeĽ.[o=UxFS=ӷdZwenՄ]_X=ĭVa* pKs0ބۍfJ3 gz̚i|wnxtjc¼5${(1fXQ65ȼb̶Zkn>%FQMJXӡ{TZEVNᖣimT/37cNJUPnP҂ZOE~"-Rc4^b- FEͧtf5[)S!OZIښݲ͑;tvܡ+N)AR=hCNn;wL16-:特7M$=Tҕ-.R[HٷnXk sn[ҞD-0WS9p9:-Ϸ-jѬNu{ҹfv)[Ľvwfg(ٷfe+0mYj8Q1\ݧg]Eǎvڿc!4#j5̋C2"}BRriFp7=ô\TZ:\BLfj#I22װ<;صZl j 6:l"6]۸ K'6RTѯ^ئOԓV\?$x7s#r:Oh{ց=MmuHԷd{pN /܅:UE#Yy+(SgQ(Щ)RHzw>^Ѿݻ>mK&^ '$Jۻ&w%F|xfz%˳ L~3N?Cy9 v w/{ƿ kz3x> sXv}vP"@WyC z`'톽Dw%-tt yVY\wmuPYQA0iG-2JP,6/gˢ]u.-n!Zw.N7Q]Df}Q0({a\@=i_X7gFǘ8^⻲}G MZ1)WEfO12G+=-B@z\`||w6ċj߬m}UwRox֢I &c~XGP6Qndpvܻul'V7^FJt^{b^B(L~sѣ6@߿^xqU!ڙ5|Vpvef-uӥ^3  FSDɯKD%0r}FF穛r7 +o"V8tv̖NQU!5uFd"bCr^bJ=֤fM#ʳԷP0O-9xRBm\=`r-:;~3Tl(nXtXi%2Vٛ#vwqƴ`L@"H‹qW.j,JM5B[)WܺUeZFqc'V˷1W7V̾-MHФwn8N;HPSdݷC7&2j.W\τGŎ'Vb]c.x+Rx1%C2T{myg[qU|+m:M:շ8҉yWd)ՋWS%%:iqlʹmGwݹ WnNŤѩ5(9hTٵDdGUi-)vSs2 2{OnT$Xck n:¶(lASLeȔBjμPpTb2~N2~%^k[ܗ[Jzs0ӓHBKq[}JَA-$dFQgjxxFv4r/x*Rm% `4J(&iv7SkԲmSH1YWmx 8n.k']:Z˭_W >ڃXЩ. jTq%Aā[E}amc]D:rmHRiu:uӚӢ\p(5-q%e)(۬ҖȽIf<߽pr&ݫVfY91q2ĭEQgYbTGQ&,yL+N$[q*RVۉQ=FuTܻ>f>f㋳8N6$܌n)9&»iˤsX,݅܍ȩv+sRTpO}d?Wn/Inpȸ%O]StQO|v5\}7Zwb.AIVK^:wb{[uݯcytO߶S<{8KSRׁH̏N7ۚ[xkwYy_'ZӵF+>쌛ZUĦreE9F[24De{}@:ExWs-\ǻ7K-\JNvEk%:s˙#κ].oͳ;լ7wB6nwu:$L; DkI#Wz.:Xp(˅v$Sq,wn\qIN-e<5Oe+vuYTpcojUI_ާP8 O 7&VL8z$_B-H-[uh]T{|8=qVRN-:Ij:7PUtXϷmy鉿:RIM~33ӸS2#׳GdŲ5+/Bx{(WzȨ5Y㞎#|˖+ ط.|e<o/rߔX>7s}VE.OVti׽ .5nNJO"95{#q}Ay9do]R"M6z\tnNS-D!@3N_jicWsy*5uٮRcWv/.,j}=S)j5C^> Ie =gu9ӛqjtz]۪TMoߧI!Ǧ¶m:,"[L!{qAv-o 3{"KʼnrIkfٶj2ƙ؄S`7` k6jzޞ?e5G&6uʷ2%ԒRKE*G\Npom F/V |C0.q_eenƣ<5Oh'67ɪn[SĽ{ڔjǘzs;~׌(ۂ`ܢ1ƣ` _l9Va6%UQWh~P~\F^ZHR@:ۧCJ{ôGeBh;~ۧnU J\O+n2 RҠ)ng}Kh{5+S×ܛ.1ZjG)iRȤIN 4%{oΜ/eO[Nffd ĹK?nnԼMqX'܌nZvq<ķbFnͪaQ`5 s,M_լ?-@_{w{ӺձJ}GF[%v\5[ŒGkOw/ΜM9rjË%2+rd~+󲕛C9U۳r[aJǭm|˒LAʨSCq[XMۺoubfp:t+ΤĻo ][ zt-*67kvS7D·MMCQXm;)܎n_h%]4ܙnRk!]ڵsDUF"`R, &#R_*[z*ZqFXɻ]7|۵w+'pFDەs=r./ᐚm3Hשy yD"jHCr':sA65نѮ^o1V/ f;nFr3VM)e*- s D'H݅fӧ\*޷[k<7u<-]֍Q8R h|p=WlW3s%Q %3l}@U-K6f-NϿu|ڴmWN׮[׸F*mW\%r! C78:޳vBG7ŵ.JթԚ2x)ST!řn~9 W:Wpܢ件{xf8ٳwKE ҰWxVB\qBZ 2wMb[lGSnyԚ~z9ZmያvoN2Afnݽjf>)j3 !;gOYʹK" Wftڎ+׭b*2ϻK>ۢӱeyԪXISUm[z+ugX%0lϏnvg!;t{BqPj>PyvR7Cj]O%+ݲ :qiMj6W}3vC/R=4Som]ŗ=ю, TF6U_-\6MyskwMr&Q\wjKܩyMϣUj0*}RZܷSdY3>Zjqj6TgzpA/M`/Cmл,޻feE[/+uk^Vs1W$G(JsW2ٰu*߻q*Y޵.Wi:ur5T),=0uRmho.twܖiYwrWHntvEj8qhf`Ͻpf(R&>Ki%I7$QӖm-2 ~yߗQ-앑/ x[k8nw.c㩵k}]FkbJl:{.(˩n0Hqvαp7 귎.Gupx[N`Yq'+ruU7[ү+>!xrȫoSo]OC# d^Q]\>!ƛGw^Mx"-+%vdX-:M2UR%d>%l ioSu6lsj7D P>XxHz Ukà(n^Q V>5cVtWj SEiJdznyej[lE' 3kuٌNn4JW)gB {4 j6&]' m-(ZMEz8cz>WZ6#7+[,MR-Z!4ܓtCyE|umj1ƽvƷV\;%>Q :#Le(iVz5 4ũۤUWxX ^(ҔsլB2w-V ^R+; ˂M\z+Uwr+RWY⺧~ Q*JcYSNSλUd8in=v K낫k\IRרSUaCFmϿ5̗P|u ZTԕ}>oYѲ1sfP+sQkX8Gb~6r,s>^\,mGL+7[n-E\.Fqḕcl*Jmjb5 ,m]c}NXfeVlǸJ5eˡ$4%g~N p4Y*WwW٧<8v#;qԩTut,m"#Y D\5V`\\Lȋ];LȇiS6ϝZ l>LruR\v=ǘϔDg=ԈdFZ+M{=|,[;0>RiSi4,S5}yxw&(E7&fݙ4UՕ! ~'Id)]ǽu2K-fޭ \08Vڅ쓬=Vy^^ IhyKR-B#Ըr=]mܻӾ'*Umkoy rTqT_i,/8Q^<ݤ|4ԻO(܄"'5N~#m.(Ҿ2i6Uev&I*<}҄$eNtÛzyWJubW^iBW.܅Wڮg]irO6Ve90sgv.+sV޿aޔ[p?3q*FutUo*eL\KM'EG*ZcAFfG5J 5jj=MJ3OK:k˝'NMB7m3uFҕ\-Ywg%PRqMIyZGY9|μvn߻5cWݷa^+X֥vnݘ\v7m>Fgzv"-;Ew֝}1|RjN𿊀7g#֟*GQQ|#/bo]p$>_Un9гUbn9׃ErQBU-^vDmVh'<R[fdHT]*~}3j;nvjc7s-rӳ Y8[n[1pJx kX[Jk9Mn!_Nю6x:iZ˦U |߉^Ԛ݃hYxk &U^bwKk.[jE+P(˞=9j@snCv7%c_7=xǁ<l {t'酚+1F‹l׭:ݻILruǶkL-L(K0L1&>wXB(pm;1fpnlp֓%Skidkt(U +xulo'/ڕeN r=^pZZ:Pnj8Hf"48ijY[ N[yZٻ+=  ø:3 ?^ܷ^Sr#YK[UF?CuhC b]GM')mڏsNrܗI]ljq6VB. W,UK"YX5{c >Iqā> T:n!,5l2VzCl|+I[*SrjnS6٨y+x,@>П.g+!rn9>N|W>OZT_ut Y""v7|sfި;Pclm EùN,{'fNT%U&LfH8~1v>Il}统u6P˗c(WV~H^bMU.o*oOF0N:_:6Smr_.b+|ݶYY غF,mwjv>f*>QM뭱Sd:`N{l/⎱;n-z~"Gze퇎J5S KG9!Gn;N1 ݎ h6m|S?ɂ5'WOÞ 7|7^ao @mxGmi^jϽ>01Mf0լD3-2T. VXR"ɥV Kl J O7|u?bvа;6.eߓ|[1bmRr,eRz`z 6܎-ͨku͹Fː dPhYgZUj}nvX;z=gVեTv_J }\1n7w2J?ޘγc\E 1Aޑzq;\r]]\Y&[nsNei\uURje*Qk2CSl*xJz-xٶlm+|UjUؓ`Ladqiĩ!Gd\W~fz;Tn*PdRM&T4`չSWq5k훶(N"Ӎ% V]֦wb.nUO!u*J&Oӕ2e|Z=eV쫚΅g#+/RW:طnbi*Wyo)p{:ETKؚR(RY+r웓r(IF) VmȵNB:h Q1ғ|u8E]{,'$-TR[j49l*3"I鯴zhd>Q+\BkNF=.$ZR4Nwհ(IpNi.(Gi33#33e$FXK*NdWrud[r{xnk$v2ıh+J1TQ[#JQl[tRO]LHKٮ NӍnF񨔤֞Em'MILB"ԋ%dBŋ+p̿_17jzT~4pc Vo\ƹb9Rq-'1j;8ܗ)hE%DZKS<璸Bu*%*Yw5ڻ9ۣ^z4U; Ñk\U(o~G?VUĎ:?P?_F_Kߤ~ᓾI |pr.Ok\SklRhҪz{­P .}SktZ7UQ4ڌIM8̈eaӊJZ%FFZu,KZvln廐SNFIVtuNi?CM5]+Ph,{jN JSR$IS^tSUVrORYu.9WyP6 [Kiu m!X|]Y79ӄ)\ģ)pbڳr%*&ꑶ_-H*dzk)1 V3')UAϹٶWRxe'պn۫h7AR9 EAJeGLms!%D| A 5]/Q3eb̄vnVn%za\m kZnv([emqrIҕij|""><hjJשvvǕ|Pޟs}V~2&Z?+2N&Z4w@)4iSڪ_>/JN9Hiۏuf8'It[ȲR.hZ$ȋ_Y ~U<UUO*6b)Ovzڜj\R̋.$FsQuҊj^נ䈈y<zZIuP[}Qm=C?zN(Exqu/kn S-FzKZzOסӽjJ\)F3b!r5ٝ|;6 o=-3*λ]αb\abqRi-w޵⦪~b8Kpo)Z=>)ғ"5/GTZLE-輵f7ݘ۹~+&+w/7GFI:l33fg.N~۲\2|*cnermnnM+Fq"ѪIz%j =YW8@~gc/~?N'?)«qȸs➟n=k" X“m֮VreMh2[uݖ] *FܖN)MȐ`f0 g,C9̑o;ddudJ=In13:ݒvvdMUEJLp^,6t-@͐9'{7m{-3,>hnF;ѰM)->>+Ěz!R* :`e--m7nB\u{b U>[8֪]6^ߤLʦ\DFNo$$dͶlgno8OrsQ\l̯hRo8tuNo+ CTxu!2[>ctFpeޓƻֶR"3QrQuOѳgwQr;S~)6HhZw/GgVTmUf_yt7%$];zLWF̰xy2Ʉu!MCmš_0[W6jf#a-KLi+3Q7c^qg%s<1aYIQeZf+}>;S6L0]Yu_h9߻<ƅpmiM$AVvŚ,*#t2.8Y)-Zhshü97/#Oro"u^/uFgWɺ,p:6a,^x%$Yve^3PƗMnTP&yS}OJ '덫MH^:rXԴJۋ/rI;S*,+yz1hv)Qw^ڍJ2oL׊q(\fDj:^T%vOadɂnS}ZO)N*λdaȜkG_PIEO}нa(^iQX᯦-7^)%g'SJx(.S9zVɴZ{E ))ۅi/s7 VIV-|sj0*UBTHIqRf>FP$KqN0 R̻8j\GcC}IUz\i 6F)Q{Gҧ3qSzKj-Az VЛS-zy:8*mNk|D鿓ND2u+0Yŝ7kqm·?8Ib]u>˗^_>(]vӋzv+ݩ){vZrJ2RQ몋C$z [,pp,8mڊbR]Il .f~d/ݓs㓓mͶ{mgjQwn=Oic9ܚm4Q/6ݨ[TƧ?nԶoytf{@AzT{e{[O'ZRZt~AGD?s3􌿂ՉIw'|~U\ w~di:Kޱ)U/sU%njѩ&GSP^ǝd)..!^U` 1wX[aԇSxoFV6_扐)T 2Mfd=ۖͭiZ7KK Bi9%7@<3<ճԻU,},a}FRqɛr i@ONJvK KLN M, ʖv0n-]DwlI-X6ܶ$Jʴh5O+mOI+Ra瞠\ MG7BفjYo1#͖0V`Ѱ2M?c8>-Crt*JkIGS:e#hPKx[鱼>{5m;wcն&>j-M֥^َ) 6yȜl_w{-ō̱r> U=]iw3)r*]:K]6BdCTZ|>gf}LW}[$'Y5 &c -j.z6R 67MԷFMnÌwI7w5E}o޽+K ֵy4܌ȥW"COyR[q5Ӱ͙f[v"_#q{MV6܍3"u9BK(41ӯqˇc${ߝCi6I(OmθzҜ5k^:>Jzw.>qV8{vU[ڶEm|DžBz].KHjI]x;Mɗ{m,qZXr忇2u^RO2Z}ZێS[2Jen!*NDcrBUً4<ǼMҲs1Zw57c3&ĖڻzmP*FuJG1-dN:|OU}ҵgi2t~F^^Z.VxjvŧnNNh<:]^~NN+ge^g.SԔGFe߯'[vn'(ScJ]kܗ7eJOlRrfziݮq̋S"\*U<*W]k$FջV}? 7g#֟*GQQ|#/bo]p$>_Un9;l S VvQU%OLU{οmU6bZ1MTx%!֙Q7, J=!3 ;Q,ڌ;6ͱ݅q^&ߔ·n #WbwӖX.HtG)N&d̵zpI,n cu ޖUj+VXUp[w]N o.J6Z8Ts&utxln;~HPHS/xw`G\ʡ¿rj Z^vt"[L:SD\h0sUwR,}[x^X,R2Vn< ]2YDr[SRKs8tXb̷G?Ps Tv 3be,zVz D[/I.KOEQrm'$7|[J>r S`5յwT#\w1FTz\Ԛ &"ׅhSHrD\'r]~/>p;:Piuu:"9ő=tTaS7V2rӷk7mb[^WmPp*[y.Þ6f]cizJCgRR@UVl큝.WJP1N{/\whZ ػϧӱE7|E֫Sί.x-Y&pi%v''-x6r'Ws*6=DwwUu]=C?MK [yrtܒG$!WGqJ*%SAz ED[^)/tė/g=#Omd.|^n/sl׉g DZqemqowݮRzUܜ=ڽ-o/Iۖ;qVʘgPp|mm;6zGl9.8pwWgsJ2qPbe}}UpNjٯ}7TMQKrؽtEx%v w߾8%|j;~|}pK]ơ/ w߾8%|j;~|}pK]ơ/ w&~e_H 8PL7:%ʭ5Kw&U2vwR_+rm'}C7#rWoO&HoG?M$UR7{FU]u ;# !Wk`|W>׹潇9Vn)6)*ҹ{%qV4q>W1vi#T"Qk&GwxcJBJ- Ϸ^ˁxkU}ԣ/3.;]J=<*)cS)ROK9H=,r zX @)cS)Da^ԽQ gxJI=w֣gf*TRj

Corresponding author: Kwang-Shik Bae. Department of Conservative Dentistry, College of Dentistry, Seoul National University, 28 Yeongun-dong, Chongro-gu, Seoul, 110-749, Korea. Tel: 82-2-2072-2650, Fax: 82-2-2072-3859, baeks@plaza.snu.ac.kr
• Received: May 7, 2005   • Revised: November 17, 2005   • Accepted: December 8, 2005

Copyright © 2006 Korean Academy of Conservative Dentistry

  • 2,238 Views
  • 8 Download
  • 3 Crossref
prev next
  • The purpose of this study was to compare the cytotoxicity by MTT test and genotoxicity by Ames test of new calcium phosphate-based root canal sealers (CAPSEAL I, CAPSEAL II) with commercially available resin-based sealers (AH 26, AH Plus), zinc oxide eugenol-based sealers (Tubliseal EWT, Pulp Canal Sealer EWT), calcium hydroxide-based sealer (Sealapex), and tricalcium phosphate based sealers (Sankin Apatite Root Canal Sealer I, II, III).
    According to this study, the results were as follows:
    1. The extracts of freshly mixed group showed higher toxicity than those of 24 h set group in MTT assay (p < 0.001).

    2. CAPSEAL I and CAPSEAL II were less cytotoxic than AH 26, AH Plus, Tubliseal EWT, Pulp Canal Sealer EWT, Sealapex and SARCS II in freshly mixed group (p < 0.01).

    3. AH 26 in freshly mixed group showed mutagenicity to TA98 and TA100 with and without S9 mix and AH Plus extracts also were mutagenic to TA100 with and without S9 mix.

    4. Tubliseal EWT, Pulp Canal Sealer EWT and Sealapex in freshly mixed group were mutagenic to TA100 with S9 mix.

    5. Among those of 24 h set groups, the extracts of SARCS II were mutagenic to TA98 with and without S9 mix and AH 26 showed mutagenic effects to TA98 with S9 mix.

    6. No mutagenic effect of CAPSEAL I and CAPSEAL II was detected.

    7. There is no statistically significant difference between CAPSEAL I and CAPSEAL II at MTT assay and Ames test in both freshly mixed group and 24 h set group.

The biocompatibility of root canal sealers is important for the clinical success of endodontic therapy because they may come into direct contact, especially when extruded, with surrounding soft and hard tissues for a prolonged period of time.
Various studies have revealed that eluatable substances or degradation or corrosion products from root canal filling materials may gain access to surrounding tissues (periodontal ligament, alveolar bone) through numerous connections, e.g., dentinal tubules, accessory and lateral canals, and apical foramen1,2). Araki et al.3) investigated the diffusion of 14C-formaldehyde through radicular dentin 72 h after the application of formocresol into the root canal of cat canines. It was found that formaldehyde was distributed from the pulp space into the body.
There are many brands and types of root canal sealers in use today. They may be divided according to their ingredients: zinc oxide-eugenol (ZOE)-based, resin-based, calcium hydroxide-based, glass ionomer-based, and calcium phosphate-based.
For many decades the root canal sealers most frequently used were those based on ZOE, which, despite their satisfactory physico-chemical properties, do not present a favorable biological behavior. The presence of a chronic inflammatory process is observed in apical and periapical tissues after their use leading to tissue injury attributed to the presence of free eugenol, which may act as a cell depressor4,5).
Results from these studies showed that endodontic materials possessed both beneficial and undesirable properties. Thus biocompatibility of root canal sealers is as important as physical and chemical features.
The beginnings of the application of calcium phosphate materials as bone substitute or bone graft may be traced to Albee, who reported in 1920 that a triple calcium phosphate compound used in a bony defect promoted osteogenesis or new bone formation6). Levin et al.7) reported in 1974 the first dental application of a tricalcium phosphate ceramic in periodontal defects in dogs.
Brown and Chow8) reported on a self-hardening calcium phosphate cement (CPC) that contained equimolar mixture of finely ground tetracalcium phosphate (TTCP) and dicalcium phosphate anhydrous (DCPA) or dicalcium phosphate dehydrate (DCPD) as the solid phase. When mixed with water, the cement forms hydroxyapatite (HA) as the only end product, which is the major mineral component of tooth and bone. Formation of HA in such mixture does not release acidic or basic by-products. The setting reaction of calcium phosphate cement is Eq. 1:
(Eq. 1)
Because the HA is formed in an aqueous environment, it is more similar to biological apatite than is the HA formed in high temperature processes. Since CPC has a neutral pH and contains only calcium phosphates, it was found to be highly biocompatible and osteoconductive9).
Gruninger et al.10) reported that testing cement (containing TTCP, DCPD, HA, and sodium fluoride) was neither toxic nor mutagenic, and performed implants were well tolerated by the animals and no adverse tissue reaction was reported. Hong et al.11) evaluated the histologic reactions to a calcium phosphate cement composed of TTCP, DCPA or DCPD in the periapical and periodontal tissues. They reported that only a limited inflammatory response to CPC was found after 6 weeks of implantation in the periodontal area, and the bone formation activity and biocompatibility in general were found to be even better in the periapical region in 16 week specimens.
As a result of its ease of use, together with excellent biocompatibility and bone replacing properties, CPC has been investigated for use in a number of medical and dental procedures, including use in reconstruction of frontal sinus and augmentation of craniofacial skeletal defects12), pulp capping and cavity lining13,14), repair of periodontal bone defects15), and endodontics16).
In vitro studies and animal models have indicated that it is also useful in endodontics as a sealer in root canal treatment14,16,17). Krell and Wefel17) reported that CPC as a root canal sealer appeared similar to Grossman's cement sealer in apical and dentinal tubule occlusions. Sugawara et al.14) showed that CPC had a better sealing ability than Grossman's sealer. In addition to being used as a sealer, in vitro studies have shown that CPC can also seal a furcation perforation and could be used as an apical barrier for apexification18). These results suggest that CPC has potential to promote the healing of bone in endodontic treatment.
Recently, we have developed the new calcium phosphate-based root canal sealers (CAPSEAL I, CAPSEAL II) composed of a mixture of TTCP, DCPD and zirconium oxide as solid phase and sodium phosphate buffer as liquid phase, complied with the standard of ISO-6876 (the International Organization for Standardization) applicable to the dental root canal sealing materials. Kim et al. showed the new sealers revealed a lower tissue response in the subcutaneous implantation test19).
Root canal filling materials are usually in close contact with living tissue. Thus, the biological properties of those materials are important as cytotoxic materials can damage periapical tissues, and material with mutagenic potential can induce DNA mutations, possibly causing malignant transformation of the cells. In vitro test model to determine the cellular responses is one of the methods for evaluating the biological compatibility of root canal sealers. This has the advantages that many factors and variables can be controlled and the cytotoxicity can be determined with reliability and reproducibility20).
The short-term Ames test has been recommended as the mutagenesis-screening test for chemicals and environmental samples because of its extensive database and good correlation with carcinogenicity. Also its low cost, simplicity, and speed make the Ames test an important and widespread part of biological examinations of dental materials and of standardization protocols.
The purpose of this study was to compare the cytotoxicity and genotoxicity of newly developed calcium phosphate-based root canal sealers (CAPSEAL I, CAPSEAL II) with another type of commercially available calcium phosphate-based sealers, resin-based sealers, ZOE-based sealers and calcium hydroxide-based sealer using MTT assay and Ames test.
The root canal sealers used in this study were: new calcium phosphate-based sealers (CAPSEAL I, CAPSEAL II), another commercially available calcium phosphate-based sealers (Sankin Apatite Root Canal Sealer (SARCS) I, SARCS II, SARCS III, Sankin kogyo, Tokyo, Japan), resin-based sealers (AH 26, AH Plus, Dentsply DeTrey, Konstanz, Germany), ZOE-based sealers (Pulp Canal Sealer EWT, Tubliseal EWT, Kerr, Detroit, MI, USA) and calcium hydroxide-based sealer (Sealapex, Kerr, Detroit, MI, USA). Components of CAPSEAL I and CAPSEAL II are listed Table 1.
A. Cytotoxicity test

1. Cell Culture

L929 mouse fibroblasts were grown in minimum essential medium (Gibco, Grand Island, NY, USA) supplemented with 10% fetal bovine serum (Gibco, Grand Island, NY, USA) and antibiotics (Gibco, Grand Island, NY, USA). Cells were cultivated in plastic culture flasks with vented cap at 37℃ in a humidified 5% CO2 containing incubator. Subcultivation was performed on sufficient cultures.

2. Preparation of Test Materials

The commercially available root canal sealers were prepared according to the manufacturer's instructions. Both CAPSEAL I and CAPSEAL II were mixed in 1.5 P/L ratio (g/g). The mixed materials were extracted in cell culture medium (1 g/2 ml) immediately after mixing (fresh mixed group), or after 24 h from mixing (24 h set group), for 24 h at 37℃ in a humidified 5% CO2 containing incubator. Each extracted medium was filter-sterilized through a 0.2 µm filter (Corning Incorporated, Corning, NY, USA).

3. MTT assay

This assay represents the capacity of mitochondrial dehydrogenase in viable cells to convert a yellow water-soluble tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT; Sigma, St. Louis, MO, USA) into dark blue formazan crystals. 2 × 104 cells in 50 µl culture medium were seeded in flat-bottomed 96-well microplates (Costar, Corning Incorporated, Corning, NY, USA). After overnight attachment, cells were treated with various eluates of sealers (50 µl/well) for 24 h. Then 20 µl MTT solution (5 mg/ml) was added to each well and incubated for 4 h at 37℃. 50 µl dimethyl sulfoxide (DMSO; Sigma, St. Louis, MO, USA) was added to each well to dissolve the formazan precipitate, and the plates incubated for 2 h. Subsequently, the absorbance at 570 nm was measured using a microplate spectrophotometer (PowerWave, Bio-Tek Instruments, Inc., Winooski, VT, USA). Intact cells in 50 µl of culture medium served as a control for cell viability.
B. Genotoxicity test

1. Preparation of Test Materials

The commercially available root canal sealers were prepared according to the manufacturer's instructions. Both CAPSEAL I and CAPSEAL II were mixed in 1.5 P/L ratio (g/g).
The mixed materials were extracted in DMSO (0.1 g/2 ml), immediately after mixing (fresh mixed group), or after 24 h from mixing (24 h set group), for 24 h at 37℃ in a humidified 5% CO2 containing incubator. The quantities assayed for each material were 5, 2.5, 1.25 and 0.62 mg/plate. In case of AH 26 and AH Plus, lower concentrations were tested, down to 0.15 mg/plate.
Negative control was solvent control, DMSO. Chemicals used as positive are listed in Table 2.

2. Ames test

The Ames test was performed as the standard plate incorporation assay on minimal glucose agar (MGA) plates according to Maron and Ames21).
Two tester strains of Salmonella typhimurium TA98 and TA100 were used to detect frame-shift and base-pair mutations respectively. The overnight culture of the bacteria was performed in nutrient broth Oxoid No. 2 (Oxoid LTD., Hampshire, England) following the standard plate incorporation assay procedure.
The extracts of test sealers and bacterial broth (0.1 ml) were added to 2 ml of molten top agar in sequence with vortexing. Then the contents of the test tubes were poured onto the surface of MGA plates. The bacteria were then incubated at 37℃ for 2 days and revertant colonies were counted. The plates were hand-counted but when the plates had above 100 colonies/plate, these were counted automatically (Chemi-Doc, BioRad, Hercules, CA, USA).
The experiments were carried out in the presence and in the absence of a metabolically active microsomal fraction (S9, Moltox, Annapolis, MD, USA) from rat liver. Tests were run in triplicate for each material's dosage.
C. Statistical analysis
The results from the MTT test and Ames test were analyzed using the Kruskal-Wallis test and Mann-Whitney U test.
A. Cytotoxicity test
CAPSEAL I and CAPSEAL II were less cytotoxic than AH 26, AH Plus, Tubliseal EWT, Pulp Canal Sealer EWT, Sealapex and SARCS II in case of freshly mixed group (p < 0.01). The extracts of freshly mixed groups were more toxic than those of 24 h set groups (p < 0.001). SARCS II of freshly mixed group showed more cytotoxic effect than other calcium phosphate-based sealers.
AH 26, Tubliseal EWT, Pulp Canal Sealer EWT, and Sealapex of 24 h set groups showed cytotoxic effect (p < 0.05). There is no significant difference between CAPSEAL I and CAPSEAL II in both freshly mixed group and 24 h set group. Figure 1 shows the cytotoxic effects of test root canal sealers on L929 fibroblasts.
B. Genotoxicity test
The results of the experiments are presented in Table 3 to 6. Colonies appearing in the absence of a background lawn were survivors of the killing effect of the test chemical and were not counted as revertants. This happened when most of the bacteria on the plate were killed because of the toxic effect of the test chemical, which allowed the survivors to grow into small colonies by using up the available histidine in the top agar.
AH 26 in freshly mixed group was mutagenic to TA98 and TA100 with and without S9 mix. AH Plus extracts also were mutagenic to TA100 with and without S9 mix (Table 3). The extracts of Tubliseal EWT, Pulp Canal Sealer EWT and Sealapex were mutagenic to strain TA100 with S9 mix in case of freshly mixed group. The other sealers in freshly mixed group showed no mutagenic response. Pulp Canal Sealer EWT, Sealapex and SARCS II were toxic to TA98 and TA100 at higher doses (Table 3 and 4). Among the test sealers of 24 h set group, the extracts of SARCS II were mutagenic to TA98 with and without S9 mix and AH 26 showed mutagenic effects to TA98 with S9 mix (Table 5 and 6). There was no statistically significant difference between CAPSEAL I and CAPSEAL II in both freshly mixed group and 24 h set group.
The MTT assay is a colorimetric method for quantifying viable cell numbers. The methyltetrazolium ring is cleaved by mitochondrial dehydrogenase in viable cells to formazan, which has a blue color and can be measured with a spectrophotometer17). The amount of formazan produced is directly proportional to the total viable cell number over wide range of cell numbers. The MTT assay reflects cell numbers at any stage in their growth cycle. Since dead cells are unable to produce the colored formazan product, this assay can be distinguished from dead cells22). The advantages of this method are its simplicity, rapidity, and precision, in addition, it does not require radioisotopes.
In this study, the in vitro test of newly developed calcium phosphate-based root canal sealers (CAPSEAL I, CAPSEAL II) and other commercially available root canal sealers were compared. Clinically, root canal sealers are inserted into the mouth in a freshly mixed and/or incompletely polymerized stage, but even after the setting period, it is still possible that potentially toxic constituents may be released from the materials by leaching into tissue fluids. For these reasons, in current study, cytotoxicity experiments were performed to estimate the cytotoxic potential of diffusible components of the set sealers. Because of different amounts of reactive substances in the fresh and set states, differences can be seen between the toxicity of fresh and set sealers. In a study in which cytotoxicity of eight root canal sealers were evaluated, Matsumoto et al.23) reported that moderate and strong cytotoxicity was observed in the fresh sealers and definite toxicity was also noted in the set sealers.
Many investigators showed AH 26 had a severe cytotoxic effect24-27). These toxic effects of AH 26 could be caused mainly by formaldehyde, which is released primarily during the initial setting reaction25). And the toxicity of AH 26 may be related to amines that accelerate epoxy polymerization4).
Cohen et al.28) reported that AH 26 and AH Plus exhibited severe reactivity by agar diffusion test using L929 cells. Tai et al.29) also showed that AH Plus was found to be a cytotoxic agent on three different cell lines by MTT test.
On the other hand, Koulaouzidou et al24) showed that AH Plus indeed exhibited a lower cytotoxic potential compared to AH 26.
Beltes et al.30) tested the cytotoxicity of two glass-ionomer root canal sealers. Ketac-Endo exhibited a very low cytotoxicity in all experimental periods. It proved to be a very biocompatible material. In contrast to this study, Willershausen et al.31) reported strong inflammatory reaction for Ketac-Endo, whereas Endion was found to evoke a low increased PGE2 release in all of the cell lines. Kolokuris et al.32) showed mild inflammatory reaction was observed with Ketac-Endo.
Briseno and Willershausen33) tested the four calcium hydroxide-based sealers using human gingival fibroblast. Sealapex demonstrated a relatively low cytotoxicity after 3 days of culturing. Recently several researchers investigated the biocompatibility of calcium phosphate-based sealers34). They concluded that these materials showed mild to moderate inflammatory responses and did not exert any cytotoxic effects.
Leyhausen et al.35) reported that no genotoxic or mutagenic effects were found with AH Plus. In other in vitro study, Koulazodou et al.24) reported that AH Plus exhibited a low cytotoxic potential compared with AH 26. However the results of the current study do not correlate with those obtained by Cohen et al.28) who evaluated the toxicity of AH Plus and found severe toxicity. In this study, AH 26 and AH plus were severe cytotoxic especially in state of fresh mixed. The Tubliseal EWT and The Pulp Canal Sealer EWT, ZOE-based sealers, were also toxic. Eugenol could inhibit macrophage function and may influence inflammatory reactions in the periapical tissues36). Eugenol liberation from eugenol-containing compounds is initially high just after mixing. Even after the sealer has set, free eugenol is still available for release over an extended period37,38).
The SARCS II especially revealed the most cytotoxic among the calcium phosphate-based sealers in this MTT assay. This reason may be due to the polyacrylic acid and iodoform, which it contains. Polyacrylic acid has a low pH and may leak out gradually to the surrounding tissue during the setting process39). The CPC containing polyacrylic acid showed an imflammatory response caused by the toxicity of unreacted polyacrylic acid40). In addition to polyacrylic acid, the poor cellular response of the SARCS II may be attributed to iodoform because the only difference between the SARCS I and the SARCS II is that the SARCS II contains iodoform. Iodoform-based tooth filling paste reportedly cause considerable tissue necrosis and have higher cytotoxicity than ZOE41).
New calcium phosphate-based sealers (CAPSEAL I, CAPSEAL II) showed acceptable biocompatibility than the ZOE-based sealer, resin-based sealer and calcium hydroxide-based sealer by MTT assay and Ames test. The CAPSEAL does not have polyacrylic acid. The liquid phase of this is sodium phosphate solution instead of polyacrylic acid. Sodium phosphate is already known to show excellent tissue responses43). It has pH7.4 and enhances hydroxyapatite formation compared with polyacrylic acid. The new sealers contain the Portland cement as one component of the powder phase. The Portland cement and mineral trioxide aggregate (MTA) have similar chemical constitutions, except that MTA contains bismuth oxide44). Portland cement and white Portland cement have comparable tissue reactions to MTA and no cytotoxic and genotoxic effects45-46). CAPSEAL I and CAPSEAL II also had no cytotoxic effects in L-929 fibroblasts and no mutagenic responses in this study.
Although further investigation is needed for the more information on the tissue adaptabilities of CAPSEALs, the results from our study suggest that CAPSEALs have the potential to be used in clinical situations.
The purpose of this study was to compare the cytotoxicity and genotoxicity of new calcium phosphate-based root canal sealers (CAPSEAL I, CAPSEAL II) with commercially available resin-based sealers (AH 26, AH Plus), zinc oxide eugenol-based sealers (Tubliseal EWT, Pulp Canal Sealer EWT), calcium hydroxide-based sealer (Sealapex), and tricalcium phosphate based sealers (Sankin Apatite type I, Sankin Apatite type II, Sankin Apatite type III).
According to this study, the results were as follows:
  1. The extracts of freshly mixed group showed higher toxicity than those of 24 h set group in MTT assay (p < 0.001).

  2. CAPSEAL I and CAPSEAL II were less cytotoxic than AH 26, AH Plus, Tubliseal EWT, Pulp Canal Sealer EWT, Sealapex and SARCS II in freshly mixed group (p < 0.01).

  3. AH 26 in freshly mixed group showed mutagenicity to TA98 and TA100 with and without S9 mix and AH Plus extracts also were mutagenic to TA100 with and without S9 mix.

  4. Tubliseal EWT, Pulp Canal Sealer EWT and Sealapex in freshly mixed group were mutagenic to strain TA100 with S9 mix.

  5. Among those of 24 h set groups, the extracts of SARCS II were mutagenic to TA98 with and without S9 mix and AH 26 was shown mutagenic effects to TA98 with S9 mix.

  6. No mutagenic effect of CAPSEAL I and CAPSEAL II was detected.

  7. There is no statistically significant difference between CAPSEAL I and CAPSEAL II at MTT assay and Ames test in both fresh mixed group and 24 h set group.

  • 1. Haikel Y, Wittenmeyer W, Bateman G, Bentaleb A, Allemann C. A new method for the quantitative analysis of endodontic microleakage. J Endod. 1999;25: 172-177.ArticlePubMed
  • 2. Jacobson SM, von Fraunhofer JA. The investigation of microleakage in root canal therapy. An electrochemical technique. Oral Surg Oral Med Oral Pathol. 1976;42: 817-823.PubMed
  • 3. Araki K, Isaka H, Ishii T, Suda H. Excretin of 14C-formaldehyde distributed systemically through root canal following pulpectomy. Endod Dent Traumatol. 1993;9: 196-199.
  • 4. Mittal M, Chandra S, Chandra S. Comparative tissue toxicity evaluation of four endodontic sealers. J Endod. 1995;21: 622-624.PubMed
  • 5. Pascon EA, Leonardo MR, Safavi K, Langeland K. Tissue reaction to endodontic materials: methods, criteria, assessment, and observations. Oral Surg. 1991;72: 222-237.ArticlePubMed
  • 6. LeGeros RZ. Calcium phosphate materials in restorative dentistry: a review. Adv Dent Res. 1988;2: 164-180.ArticlePubMedPDF
  • 7. Levin MP, Getter L, Adrian J, Cutright DE. Healing of periodontal defects with ceramic implants. J Clin Periodontol. 1974;1: 197-205.ArticlePubMed
  • 8. Brown WE, Chow LC. A new calcium phosphate setting cement. J Dent Res. 1990;69: 672.PubMed
  • 9. Fukase Y, Eanes ED, Tagaki S, Chow LC, Brown WE. Setting reaction and compressive strength of calcium phosphate cements. J Dent Res. 1990;69: 1852-1856.ArticlePubMedPDF
  • 10. Gruninger SE, Siew C, Chow LC, O'Young A, Ts'AO NK, Brown WE. Evaluation of the biocompatibility of a new calcium phosphate setting cement[abstract]. J Dent Res. 1984;63: 200.
  • 11. Hong CY, Lin SK, Kok SH, Wong MY, Hong VC. Histological reaction to a newly developed calcium phosphate cement implanted in the periapical and periodontal tissues. J Formos Med Assoc. 1990;89: 297-304.PubMed
  • 12. Shindo ML, Costantino PD, Friedman CD, Chow LC. Facial skeletal augmentation using hydroxyapatite cement. Arch Otolaryngol Head Neck Surg. 1993;119: 185-190.PubMed
  • 13. Matsuya Y, Antonucci JM, Matsuya S, Takagi S, Chow LC. Polymeric calcium phosphate cements derived from poly(methyl vinyl ether-maleic acid). Dent Mater. 1996;12: 2-7.ArticlePubMed
  • 14. Sugawara A, Chow LC, Tagaki S, Chohayeb H. In vitro evaluation of the sealing ability of a calcium phosphate cement when used as a root canal sealer-filler. J Endod. 1990;16: 162-165.ArticlePubMed
  • 15. Sugawara A, Nishiyama M, Kusama K, Moro I, Nishimura S, Kudo I, Chow LC, Takagi S. Histopathological reactions of calcium phosphate cement. Dent Mater J. 1992;11: 11-16.ArticlePubMed
  • 16. Chohayeb H, Chow LC, Tsaknis PJ. Evaluation of calcium phosphate as a root canal sealer-filler material. J Endod. 1987;13: 384-387.ArticlePubMed
  • 17. Krell KF, Wefel JS. Calcium phosphate cement root canal sealer-scanning electron microscopic analysis. J Endod. 1984;10: 571-576.PubMed
  • 18. Chau JY, Hutter JW, Mork TO, Nicoll BK. An in vitro study of furcation perforation repair using calcium phosphate cement. J Endod. 1997;23: 588-592.ArticlePubMed
  • 19. Kim JS, Baek SH, Bae KS. In vivo study on the biocompatibility of newly developed calcium phosphate-based root canal sealers. J Endod. 2004;30: 708-711.ArticlePubMed
  • 20. Beltes P, Koulaouzidou E, Kotoula V, Kortsaris AH. In vitro evaluating of the cytotoxicity of calcium hydroxide-based root canal sealers. Endod Dent Traumatol. 1995;11: 245-249.PubMed
  • 21. Maron DM, Ames B. Revised methods for the Salmonella mutagenicity test. Mutat Res. 1983;113: 173-215.ArticlePubMed
  • 22. Mosmann T. Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assays. J Immunol Methods. 1983;65: 55-63.ArticlePubMed
  • 23. Matsumoto K, Inoue K, Matsumoto A. The effect of newly developed root canal sealers on rat pulp cells in primary culture. J Endod. 1989;15: 60-67.PubMed
  • 24. Koulaouzidou EA, Papazisis KT, Beltes P, Geromichalos GD, Kortsaris AH. Cytotoxicity of three resin-based root canal sealers: an in vitro evaluation. Endod Dent Traumatol. 1998;14: 182-185.ArticlePubMed
  • 25. Spangberg L, Langeland K. Biologic effects of dental materials. I. Toxicity of root canal filling materials on HeLa cells in vitro. Oral Surg. 1973;35: 402-414.PubMed
  • 26. Spangberg LS, Barosa SV, Lavigne GD. AH 26 releases formaldehyde. J Endod. 1993;19: 596-598.ArticlePubMed
  • 27. Huang FM, Tai KW, Chou MY, Chang YC. Cytotoxicity of resin-, zinc oxide eugenol-, and calcium hydroxide-based root canal sealers on human periodontal ligament cells and permanent V79 cells. Int Endod J. 2002;35: 153-158.ArticlePubMed
  • 28. Cohen BI, Pagnillo MK, Musikant BL, Deutsch AS. An in vitro study of the cytotoxicity of two root canal sealers. J Endod. 2000;26: 228-229.ArticlePubMed
  • 29. Tai K, Huang F, Chang Y. Cytotoxic evaluation of root canal filling materials on primary human oral fibroblast cultures and a permanent hamster cell line. J Endod. 2001;27: 571-573.ArticlePubMed
  • 30. Beltes P, Koulaouzidou E, Kolokuris I, Kortsaris AH. In vitro evaluation of the cytotoxicity of two glassionomer root canal sealers. J Endod. 1997;23: 572-574.ArticlePubMed
  • 31. Willershausen B, Briseno B, Schafer D, Schulze R. Cytotoxicity of root canal filling materials to three different human cell line. J Endod. 2000;26: 703-707.PubMed
  • 32. Kolokuris I, Beltes P, Economides N, Vlemmas I. Experimental study of the biocompatibility of a new glass ionomer root canal sealer (Ketac Endo). J Endod. 1996;22: 395-398.ArticlePubMed
  • 33. Briseno BM, Willershausen B. Root canal sealer cytotoxicity with human gingival fibroblast III. Calcium hydroxide-based sealers. J Endod. 1992;18: 110-111.PubMed
  • 34. Bilginer S, Esener T, Soylemezoglu F, Tiftik AM. The investigation of biocompatibility and apical microleakage of tricalcium phosphate based root canal sealers. J Endod. 1997;23: 105-109.ArticlePubMed
  • 35. Leyhausen G, Heil J, Reifferscheid G, Waldmann P, Gerutsen W. Genotoxicity and cytotoxicity of the epoxy resin based sealer AH Plus. J Endod. 1999;25: 109-113.PubMed
  • 36. Segura JJ, Jmenez-Rubio A. Effect of eugenol on macropage adhesion in vivo to plastic surfaces. Endod Dent Traumatol. 1998;14: 72-74.PubMed
  • 37. Economides N, Ioannis K. Experimental study of the biocompatibility of four root canal sealers and their influence on the zinc and calcium content of several tissues. J Endod. 1995;21: 122-127.ArticlePubMed
  • 38. Kolokouris I, Nikolaos E. In vivo comparison of the biocompatibility of two root canal sealers implanted into the subcutaneous connective tissue of rats. J Endod. 1998;24: 82-85.ArticlePubMed
  • 39. Yoshikawa M, Hayami S, Tsuji I, Toda T. Histopathological study of a newly developed root canal sealer containing tetracalcium-dicalcium phosphates and 1.0% chondroitin sulfate. J Endod. 1997;23: 162-166.ArticlePubMed
  • 40. Takechi M, Miyamoto Y, Ishikawa K, Toh T, Yuasa T, Nagayama M, Suzuki K. Initial histological evaluation of anti-washout type fast-setting calcium phosphate cement following subcutaneous implantation. Biomaterials. 1998;19: 2057-2063.ArticlePubMed
  • 41. Wright KJ, Barbosa SV, Araki K, Spangberg LS. In vitro antimicrobial and cytotoxic effects of Kri 1 paste and zinc oxide-eugenol used in primary tooth pulpectomies. Pediatr Dent. 1994;16: 102-106.PubMed
  • 42. Yuan H, Li Y, de Bruijn JD, de Groot K, Zhang X. Tissue responses of calcium phosphate cement: a study in dogs. Biomaterials. 2000;21: 1283-1290.ArticlePubMed
  • 43. Miyamoto Y, Ishikawa K, Takechi M, Yuasa M, Kon M, Nagayama M, Asaoka K. Non-decay type fast-setting calcium phosphate cement: setting behaviour in calf serum and its tissue response. Biomaterials. 1996;17: 1429-1435.ArticlePubMed
  • 44. Camilleri J, Montesin FE, Di Silvio L, Pitt Ford TR. The chemical constitution and biocompatibility of accelerated Portland cement for endodontic use. Int Endod J. 2005;38: 834-842.ArticlePubMed
  • 45. 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.ArticlePubMed
  • 46. Saidon J, He J, Zhu Q, Safavi K, Spangberg LS. Cell and tissue reactions to mineral trioxide aggregate and Portland cement. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2003;95: 483-489.ArticlePubMed
Figure 1
Effect of tested root canal sealers by MTT assay. Percentage of absorbance at each concentration compared with that of control was calculated. Each bar represents a mean ± SD.
jkacd-31-36-g001.jpg
Table 1
Composition of CAPSEAL I and CAPSEAL II
jkacd-31-36-i001.jpg
Table 2
Positive control chemicals
jkacd-31-36-i002.jpg
Table 3
Mutagenicity of resin-based, ZOE-based and calcium hydroxide-based sealers in freshly mixd group. The number of colonies are the mean values ± SD of triplicates.

Rever. = revertants; Resp.= response; Tox = toxic; Neg = nonmutagenic and nontoxic; Mut = mutagenic

jkacd-31-36-i003.jpg
Table 4
Mutagenicity of calcium phosphatebased sealers in freshly mixd group. The number of colonies are the mean values ± SD of triplicates.

Rever. = revertants; Resp.= response; Tox = toxic; Neg = nonmutagenic and nontoxic; Mut = mutagenic

jkacd-31-36-i004.jpg
Table 5
Mutagenicity of resin-based, ZOE-based and calcium hydroxide-based sealers in 24 h set group. The number of colonies are the mean values ± SD of triplicates.

Rever. = revertants; Resp.= response; Tox = toxic; Neg = nonmutagenic and nontoxic; Mut = mutagenic

jkacd-31-36-i005.jpg
Table 6
Mutagenicity of calcium phosphate-based sealers in 24 h set group. The number of colonies are the mean values ± SD of triplicates.

Rever. = revertants; Resp.= response; Tox = toxic; Neg = nonmutagenic and nontoxic; Mut = mutagenic

jkacd-31-36-i006.jpg

Tables & Figures

REFERENCES

    Citations

    Citations to this article as recorded by  
    • In vitrocytotoxicity of four calcium silicate-based endodontic cements on human monocytes, a colorimetric MTT assay
      Sedigheh Khedmat, Somayyeh Dehghan, Jamshid Hadjati, Farimah Masoumi, Mohammad Hossein Nekoofar, Paul Michael Howell Dummer
      Restorative Dentistry & Endodontics.2014; 39(3): 149.     CrossRef
    • A comparative evaluation of cytotoxicity of root canal sealers: anin vitrostudy
      Gautam Pyarelal Badole, Manjusha Madhukar Warhadpande, Ganesh Kothiramji Meshram, Rakesh Namdeoraoji Bahadure, Shubha Gopal Tawani, Gopal Tawani, Shital Gautam Badole
      Restorative Dentistry & Endodontics.2013; 38(4): 204.     CrossRef
    • Comparison of biocompatibility of four root perforation repair materials
      Min-Kyung Kang, In-Ho Bae, Jeong-Tae Koh, Yun-Chan Hwang, In-Nam Hwang, Won-Mann Oh
      Journal of Korean Academy of Conservative Dentistry.2009; 34(3): 192.     CrossRef

    • ePub LinkePub Link
    • Cite
      CITE
      export Copy Download
      Close
      Download Citation
      Download a citation file in RIS format that can be imported by all major citation management software, including EndNote, ProCite, RefWorks, and Reference Manager.

      Format:
      • RIS — For EndNote, ProCite, RefWorks, and most other reference management software
      • BibTeX — For JabRef, BibDesk, and other BibTeX-specific software
      Include:
      • Citation for the content below
      Cytotoxicity and genotoxicity of newly developed calcium phosphate-based root canal sealers
      J Korean Acad Conserv Dent. 2006;31(1):36-49.   Published online January 31, 2006
      Close
    • XML DownloadXML Download
    Figure
    • 0
    Cytotoxicity and genotoxicity of newly developed calcium phosphate-based root canal sealers
    Image
    Figure 1 Effect of tested root canal sealers by MTT assay. Percentage of absorbance at each concentration compared with that of control was calculated. Each bar represents a mean ± SD.
    Cytotoxicity and genotoxicity of newly developed calcium phosphate-based root canal sealers

    Composition of CAPSEAL I and CAPSEAL II

    Positive control chemicals

    Mutagenicity of resin-based, ZOE-based and calcium hydroxide-based sealers in freshly mixd group. The number of colonies are the mean values ± SD of triplicates.

    Rever. = revertants; Resp.= response; Tox = toxic; Neg = nonmutagenic and nontoxic; Mut = mutagenic

    Mutagenicity of calcium phosphatebased sealers in freshly mixd group. The number of colonies are the mean values ± SD of triplicates.

    Rever. = revertants; Resp.= response; Tox = toxic; Neg = nonmutagenic and nontoxic; Mut = mutagenic

    Mutagenicity of resin-based, ZOE-based and calcium hydroxide-based sealers in 24 h set group. The number of colonies are the mean values ± SD of triplicates.

    Rever. = revertants; Resp.= response; Tox = toxic; Neg = nonmutagenic and nontoxic; Mut = mutagenic

    Mutagenicity of calcium phosphate-based sealers in 24 h set group. The number of colonies are the mean values ± SD of triplicates.

    Rever. = revertants; Resp.= response; Tox = toxic; Neg = nonmutagenic and nontoxic; Mut = mutagenic

    Table 1 Composition of CAPSEAL I and CAPSEAL II

    Table 2 Positive control chemicals

    Table 3 Mutagenicity of resin-based, ZOE-based and calcium hydroxide-based sealers in freshly mixd group. The number of colonies are the mean values ± SD of triplicates.

    Rever. = revertants; Resp.= response; Tox = toxic; Neg = nonmutagenic and nontoxic; Mut = mutagenic

    Table 4 Mutagenicity of calcium phosphatebased sealers in freshly mixd group. The number of colonies are the mean values ± SD of triplicates.

    Rever. = revertants; Resp.= response; Tox = toxic; Neg = nonmutagenic and nontoxic; Mut = mutagenic

    Table 5 Mutagenicity of resin-based, ZOE-based and calcium hydroxide-based sealers in 24 h set group. The number of colonies are the mean values ± SD of triplicates.

    Rever. = revertants; Resp.= response; Tox = toxic; Neg = nonmutagenic and nontoxic; Mut = mutagenic

    Table 6 Mutagenicity of calcium phosphate-based sealers in 24 h set group. The number of colonies are the mean values ± SD of triplicates.

    Rever. = revertants; Resp.= response; Tox = toxic; Neg = nonmutagenic and nontoxic; Mut = mutagenic


    Restor Dent Endod : Restorative Dentistry & Endodontics
    Close layer
    TOP