a bacteriological and his to logical evaluation of 58 periapical lesions

8/4/2019 A Bacteriological and His to Logical Evaluation of 58 Periapical Lesions

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0099-2399/92/1804-0152/$03.00/0JOURNAL OF ENDODONTICSCopyright 1992 by Th e American Association of Endodontists Printed in U.S.A.VOL. 18, NO, 4, APRIL1992

A Bacte r io log ica l and H is to log ica l Eva lua t ion o f 58P e r i a p i c a l L e s i o n sB l a k e E . W a y m a n , D D S , M S , S t e v e n M . M u r a t a , D D S , M S , R o y J . A l m e i d a , M S , D P H , a n d C r a i g B . F o w l e r , D D S

P e r ia p ic a l t i s s u e f r o m 5 8 c a s e s r e q u i r in g p e r ia p ic a ls u r g e r y w a s e x a m in e d h is to lo g ic a l l y a n d c u l tu r e df o r t h e p r e s e n c e o f m i c r o b e s . T w e n t y - n i n e h a d ap o s s i b l e o r a l c a v i ty c o m m u n i c a t io n a n d 2 9 d i d n o t .A p p r o x i m a t e l y o n e - h a l f o f e a c h b i o p s y w a s s u b m i t -t e d f o r c u l tu r e w h i l e t h e o t h e r p o r ti o n w a s e x a m i n e dh is to lo g ic a l l y . C u l tu r e s w e r e p o s i t i v e fo r th e p r e s -e n c e o f b a c t e r i a i n 5 1 o f 5 8 c a s e s w h i l e b a c t e r i aw e r e s e e n h is to lo g ic a l l y in o n ly 8 o f 5 8 c a s e s . Ato ta l o f 5 0 d i f f e r e n t s p e c ie s o f b a c te r ia w e r e i s o la te df r o m th e 5 8 c u l tu r e s o f p e r ia p ic a l t i s s u e . O f 1 3 3i s o la t e s , 8 7 w e r e s t ri c t a n a e r o b e s , 3 7 w e r e f a c u l t a -t i v e a n a e r o b e s , a n d g w e r e a e r o b e s . B a c t e r o i d e ss p e c i e s w e r e f o u n d i n 1 7 c u l t u r e s , a l w a y s w i t h a d -d i t io n a l b a c te r ia . S e v e n te e n o f 5 8 b io p s ie s c o n -ta in e d fo r e ig n p a r t i c u la te m a t te r th o u g h t to b e r o o tc a n a l s e a le r . B a c te r ia w e r e fo u n d in p e r ia p ic a l g r a n -u lo m a s , r a d ic u la r c y s ts , a n d a p e r ia p ic a l a b s c e s s .A c c o r d in g to o u r d a ta , b a c te r ia , fo r e ig n m a te r ia l,m is s e d c a n a ls , v e r t ic a l r o o t f r a c tu r e s , a n d p e r io d o n -ta l d is e a s e m a y a l l c o n t r ib u te to th e c h r o n ic , n o n -h e a l in g p e r i r a d ic u la r le s io n .

Th ro u g h t h e y ear s t h e re h as ex i s t ed a d i f f e r en ce o f o p in io nreg ard in g th e p resen ce o f mic ro o rg an i sm s i n p e r i ap i ca l ti s su e .S tewar t (1) , in 1947, and later He dm an (2), in 195 l , sup por tedth e co n cep t t h a t b ac t e r i a were p resen t i n p e r i ap i ca l ti ssue . I nHe d m an ' s s t u d y (2 ), wh ich was acco mp l i sh ed p r i o r t o p resen tt ech n iq u es fo r cu l t u r i n g an aero b i c b ac t e r i a , b ac t e r i a wererepor ted in 68% of 82 per iap ical les ions . In a s tudy s imi lar toHe d m an ' s (2 ), S h in d e ll ( 3 ) fo u n d t h a t o n ly 5 % o f 6 2 p e ri ap i ca lles ions con tained bhcter ia . However , Winkler et a l . (4 ) , us inga mo d i f i ed Gram s t a in fo r p e r i ap i ca l t i s su e , were ab l e t od em o n s t r a t e t h e p resen ce o f b ac t e r i a i n 8 7 % o r 1 3 o f 1 5 casese x a m i n e d u n d e r a l i g ht m i c r o s c o p e .

Sab is ton et a l . (5 ) and Brook et a l . (6 ) i so lated numerousfacu l t a t i v e an d an aero b i c mic ro o rg an i sms f ro m p er i ap i ca lab scesses . Wi th a d v an ces i n mic ro b io lo g i ca l t echn iq u es , an -ae ro b i c mic ro o rg a n i sms can n o w b e cu l t u red . Ear l i e r i n v es ti -g a to r s co u ld cu l t u re o n ly ae ro b i c mic ro o rg an i sms wh ich d idn o t t h r i v e o n t i ssu es wi th r ed u ced o x y g en su ch as p e r i ap i ca lt issue. L ange land et a l. (7 ) cou ld n o t consis ten t ly demo nst ra te

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t h e p resen ce o f mic ro o rg an i sm s i n p e r i ap i ca l g r an u lo ma s . Inth e i r 1 9 7 7 st u d y , 3 5 sp e c imen s were ex a min e d h i s t o log i ca ll yfo r t h e p resen ce o f b ac t e r ia l co lo n i es . F iv e o f t h e 3 5 caseswere o b se rv ed t o co n t a in b ac t e r i a , b u t o n ly o n e co n t a in edb ac t e r i a in t h e "d i s i n t eg ra t i n g p a r t o f t h e ro o t can a l an dper iap ical t i ssue."

Qu o t in g Kro n fe ld (8 ) , Gro ssman s t a t ed t h a t "a t o o th wi tha g ran u lo ma may h av e an i n f ec t ed ro o t can a l , b u t s t e r i l ep er i ap i ca l t i s su e . I n g ram-s t a in ed sec t i o n s t h ro u g h i n fec t edp u lp les s t ee th i n s i tu , b ac t e r i a were a lway s fo u n d i n a b u n -d an ce wi th in t h e ro o t can a l , b u t g r an u l a t i o n t i s su e an d cy s t sa t t ach ed t o t h e ap i ces o f th ese t ee th were o f t en f r ee f ro mm i c r o o r g a n is m s , " a n d t h a t " a g r a n u l o m a i s n o t a n a r e a inwh ich b ac t e r i a l iv e , b u t i n wh ich t h ey a r e d es t ro y ed . "

Recent ly , Tronstad et a l . (9 ) invest igated the p resence ofp er i ap i ca l mic ro b i a l f l o r a o f e i g ht cases wh ich h ad n o t h ea l edwi th n o n su rg i ca l en d o d o n t i c t r ea tmen t . I n a l l e i g h t casesb ac t e r ia l g ro wth w as ev id en t o n cu l t u re . Th ree sam p les f ro meach case were cu l t u red an d T ro n s t ad e t a l . ( 9) s t a te t h a t "o u rs tu d y c lea r l y sh o wed t h a t an ae ro b i c b ac t e r i a a r e ab l e t o su r -v iv e an d ma in t a in an i n f ec ti o u s d isease p ro cess i n p e r i ap i ca lt i ssu e . " F iv e o f t h e e ig h t cases co n t a in ed m ix ed f l o r a b u t wered o min a t ed b y an aero b es wh i l e two cases were fo u n d t o co n -t a in an aero b es ex c lu s ive ly . Haap asa lo e t a l . ( 1 0 ) t r ea t ed a casein which nonsurg ical endodont ics , calcium hydroxide, sys-t emic e ry th ro m y cin , an d , f i na l ly , a r eg imen o f sy s t emic met -ron idazo le fai led to reso lve the d ra in ing f i s tu la associated wi tha maxi l lary lateral incisor . Fo l lowing per iap ical surgery , thel es io n r esolv ed . A m ix ed i n fec t i o n o f an aero b i c an d f acu l t a ti v ean aero b i c mic ro o rg an i sms was cu l t u red f ro m th e ro o t can a land the per iap ical les ion .

Iwu et a l . (1 l ) s tud ied the bacter ial con ten t o f 16 per iap icalg ran u lo m as o b t a in ed u n d er as asep t i c a t ech n iq u e as p o ss ib l e .Th ese sp ec imen s were h o mo g en i zed an d c u l t u red . F o u r t eenof the 16 cu l tu res (88% ) y ielded posi tive g rowth . T here w ere4 7 i so l at es o f wh ich 2 6 (5 5 % ) were f acu l t a t iv e an aero b es an d2 1 (4 5 % ) were s t r i c t an aero b es . Us in g an i n d i r ec t immu n o -f luoresence techniqu e, B arnet t e t a l . (12) also dem ons t ratedth e p resen ce o f Bacteroides intermedius in the t i ssue of ap er i ap ica l g r an u lo ma .

Wi th cu r r en t t ech n iq u es t o cu l t u re b o th f acu l t a ti v e an aer -o b es an d o b l i g a te an aero b es , i t ap p ear s t h a t so m e p er i ap i ca lg ran u lo mas , cy s t s , an d ab scesses d o i n d eed c o n t a in mic ro o r -g an i sms . Th e p er i r ad i cu l a r t i s su es f ro m 5 8 cases wh ich h adn o t r eso lv ed fo l l o win g co n v en t i o n a l en d o d o n t i c t r ea tmen twere ex amin ed i n o rd er t o i d en t i fy t h e b ac t e r i a , t o co mp are


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V o l . 1 8 , N o . 4 , A p r i l 1 9 9 2the h is to log ical and microb io log ical f ind ings, and to correlateth e p e r i ap i ca l mic ro b io lo g y wi th c l i n ica l s i gn s an d sy m p to m sin these cases.

M A T E R I A L S A N D M E T H O D SPeri rad icu lar t i ssue f rom 58 consecu t ive surg ical cases was

su b m i t t ed fo r h i s t o lo gi ca l d i ag n o s is a n d mic ro b io lo g i ca l cu l-t u r in g . Th e su rg ica l p ro ced u res were p e r fo rm ed b y en d o d o n t i co r g en era l d en t i s t ry r es id en t s an d t h e e n d o d o n t i c s t a f f m em -b er s . A ll t ee th h a d p rev io u s ly b een t r ea t ed en d o d o n t i ca l l y , y e tt h e p e r i r ad i cu l a r a r eas co n t i n u ed t o sh o w ev id en ce o f p a -thoses .

Da t a , su ch as sy m p to m s , p r esen ce o f f is t u lo u s t r ac t s, p e r i -o d o n t a l p o ck e t s g r ea t e r t h an 3 mm , an d s i ze o f t h e l e s i onrad iographical ly , were recorded .

Each pat ien t was ins t ructed to r inse twice dai ly w i th 1/2 ozo f P er id ex 0 .1 2 % Ora l R in se (P ro c t e r & Gam b le , C in c in n a t i ,OH) b eg in n in g 2 d ay s b e fo re su rg ery . F o l l o win g l o ca l an es -thesia o f the surg ical s i te , the area w as i so lated wi th s ter i lesp o n g es an d t h en l av ag ed wi th Be t ad in e (Go ld l in e L ab o ra to -r ies , F t . Laude rdale, FL) . Th is was fo l lowed by a s ter i le saliner i n se im med ia t e ly b e fo re su rg ery. Th e f l ap was r e f lec t ed an dcu l t u res an d b io p s i es were o b t a in ed as q u i ck ly as p o ss ib l e .Ap p ro x imate ly o n e-h a l f o f t h e b io p sy was p l aced i n a Vacu -ru in er (Bec to n Dick so n a n d Co . , Ru th er fo rd , N J ) , an an aer -o b i c sp ec imen ca r r i e r . Th e r emain in g p o r t i o n was immed i -a t e ly p l aced i n 1 0 % b u f fe r ed fo rmal in an d su b mi t t ed t o t h eDe p ar tm en t o f Ora l P a th o lo g y fo r h i s to lo g ica l d i ag n o si s .

T i s su e sec t io n s fo r h i st o log i ca l ex amin a t i o n w ere o b t a in edf r o m p a r a f f i n - e m b e d d e d t i s s u e . T h e s e c o n d s p e c i m e n w a ssu b m i t t ed t o t h e m ic ro b io lo g y lab o ra to ry fo r cu l tu re t o d e t e r -min e t h e p resen ce o r ab sen ce o f an aero b i c an d ae ro b i c mi -c ro b es . A ll mic ro b io lo g y sp ec imen s were p l aced i n a V acu t a i -n e r An aero b i c S p ec imen Co l l ec to r a s so o n as t h ey wereco l lec t ed . Th e sp ec im en s were d e l i v e red t o t h e m ic ro b io lo g yl ab wi th in 4 h o f t h e t ime o f co l lec t i on . On ce t h e sp ec im enar r i v ed a t t h e An a ero b i c S ec t i o n , i n it i a l i n o cu l a t i o n was p e r -f o r m e d i n a n a n a e r o b i c c h a m b e r ( A n a e r o b e S y s t e m s , S a nJo se , CA) co n t a in in g a g as mix tu re o f 5 % carb o n d io x id e ,1 0 % h y d ro g en , an d 8 5 % n i t ro g en . Th e an aero b i c med iain c lu d ed t h e fo l l o win g ag ar p l a t es (1 3 ) : CDC b lo o d ag ar ,pheny lethy l alcohol , b lood agar , Ba ctero ides b i le escu l in agar ,a n d K a n a m y c i n - v a n c o m y c i n l a k ed b l o o d a g a r. T h e a e r o b icmed ia i n c lu d ed t h e fo l l o win g ag ar p l a t es (1 3 ) : CDC b lo o dag ar , p h en y l e th y l a l co h o l b lo o d ag ar , ch o co l a t e ag ar , M ac-Co n k ey ag ar , an d t ry p t i case so y ag ar wi th 5 % sh eep b lo o d . Ach o p p ed m ea t b ro th (1 3 ) tu b e w as a l so i n cu b a t ed as a b ack u pcu l tu re . Bo th g ro u p s w ere i n cu b a t ed a t 3 7 C in t h e i r r e sp ec t iv ea tmo sp h er i c en v i ro n m en t s an d r ead a f t e r 4 8 h . Co lo n i es wereth en r es t r eak ed fo r i so la t i o n . P re l im in ary i d en t i f ica t i o n wasd e r iv e d f r o m p u r e c u l t u r e b a s e d o n a e r o to l e r an c e , G r a m s t ai n ,and spo t tes ts (catalase, indo le, ox idase) . Aerobic speciat ionw a s p e r f o r m e d o n t h e M i c r o S c a n W a l k a w a y (B a x t e r H e a l th -ca re Co rp . , Wes t S acramen to , CA) o r t h e Au to M icro b i c S y s -t em (Vi t ek S y s tems In c . , Haze lwo o d , M O) . B o th o f t h esein s t ru men t s a r e au to mated b ac t e r i a l i d en t i f i ca t i o n sy s t ems .A n a e r o b i c sp e c i at io n w a s p e r f o r m e d u si n g t h e R a p i d A N AII sy s t em ( In n o v a t i v e Diag n o s t i c S y s tems , In c . , Deca tu r , G A) .Th i s i s a m an u a l an a ero b i c b ac t e r i a l i d en t if i ca t io n sy s t em th a tu t il i zes co n v en t i o n a l an d ch ro m o g en i c su b s t r a tes .

B a c t e r i o l o g y o f P e r i a p i c a l L e s i o n s 1 5 3R E S U L T S

There were 58 per iap ical les ions invest igated in th is s tudy ,su b m i t t ed b y sev en p rac t i ti o n er s . O f t h e 5 8 l es io n s , 2 9 h adn o d e t ec t ab l e co mmu n ica t i o n wi th t h e o ra l cav i t y . Th e r e -ma in in g 2 9 co mm u n ica t ed wi th t h e o ra l cav i t y t h ro u g h e i t h e ra ver t ical roo t f racture o r f i s tu la , o r had per iodontal pocketso f 4 mm o r g rea t e r. S ev en o f t h e 5 8 l es i on s d emo n s t r a t ed "n og ro wth " o n cu l t u re . I n o n e o f th ese cases, t h e p a t i en t h adrece iv ed an ti b io t ic t h e rap y fo r 1 wk b efo re t h e su rg ery .

M icrobiological Find ingsIn t h e 2 9 l es i o n s wi th n o d e t ec t ab l e co mmu n ica t i o n wi th

th e o ra l cav i t y , 2 4 (8 3 % ) d emo n s t r a t ed g ro wth o f mic ro o rg a-n i sms o n cu l t u re . Of t h ese 2 4 p o s i t i v e cu l tu res , 9 co n t a in edo b l i g a te an aero b es , 6 h ad o n ly f acu l t a t i v e an aero b i c b ac t e r i a ,7 co n t a in ed b o th an aero b i c an d f acu l t a ti v e an aero b i c b ac te r i a ,an d 2 co n t a in ed o n ly ae ro b i c b ac te r i a . F iv e p ro d u ced n ogrowth . A s ing le microorgan ism was grown in 13 cu l tu res ,t h e o th e r 11 were p o ly micro b i a l w i th two t o s i x mic ro o rg a-n i sms i so l a ted . Th e av erag e n u m b er o f iso l a tes p e r case was1 .7 2. Th e f i v e mo s t co m m o n ly i so l a t ed mic ro b es , in d escen d -ing order , were Staphylococcus ep idermid is , Fusobacter iumnucleatum, Propionibacteriurn acnes, Peptostreptococcus mi-cros, a n d Bacteroides gracil is (Table 1 ) .

In t h e r emain in g 2 9 l es i o n s wh ere t h e re was a p o ss ib l eco m mu n ica t i o n b e tw een t h e o ra l cav i t y an d t h e p e r i r ad i cu l a rl es io n , t h e re were 2 7 (9 3 % ) p o s i t i v e cu l tu res co n t a in in g o n eo r mo re b ac t e r i a . Two h ad n o g ro wth . E l ev en o f 2 7 co n t a in edo n ly an aero b i c b ac t e r i a wi th 1 o r m o re i so l a tes , 5 h ad o n lyfacu l t a ti v e an aero b es , 1 0 g rew b o th an aero b i c an d f acu l t a ti v ean aero b i c b ac t e r i a , an d 1 co n t a in ed ae ro b i c mic ro b es . E ig h tco n t a in ed o n e m ic ro o rg an i sm an d t h e r emain in g 1 9 werep o ly micro b i a l w i th two t o e ig ht i sol a tes . Th e av erag e n u m b erof iso lates per case in th is g roup wa s 2 .86 . F our o f the f ivemo s t co mmo n ly i so l a t ed b ac t e r i a were an aero b es (Tab l e 1 ) .Bac t e ro id es sp p . was cu l t u red f ro m 1 7 o f t h e 5 8 cases , i t wasn ev er a s i n g le i so la t e b u t a lway s p resen t ed wi th o n e o r m o readdi t ional bacter ia .

Histological FindingsHisto log ical ly , o f the 58 b iopsies subm it ted , 41 we re d iag-

n o sed as p e r i ap i ca l g r an u lo mas , 1 6 were p e r i ap i ca l cy s ts , an d1 was a pe r iap ical abscess . O f the 58 cases which we re t reatedsurg ical ly , the et io logy of the n onhe al ing les ion was n o t de-t e rmin e d a t t h e t im e o f su rg ery in 3 5 tee th . Th ere were 2 3cases i n w h ich t r ea tmen t i r r eg u la r i ti e s o r t h e l o ca t i o n o f t h el es io n s ma y h av e co n t r i b u t ed t o t h e n o n reso lu t i o n fo l l owin gco n v en t i o n a l en d o d o n t i c ca re : s ev en t ee th h ad v er t i ca l r o o tf r ac tu res , s ix t ee th h ad mi ssed can a l s , f o u r t ee th w ere p e r fo -r a t ed , two h ad t h e ro o t ap ex an d l es i o n p e r fo ra ti n g i n to t h emax i l l a ry s in u s , tw o co n t a in ed f a i li n g s il v e r p o in t s wh ich weren o t r e t r ea t ab l e , an d tw o h ad sev ere p e r io d o n t a l d i sease .

In t h e 5 8 cases fo r wh ich b o th t h e mic ro b io lo g i ca l sp ec im enan d t h e b io p sy were su b mi t t ed , b ac t e r i a were d e t ec t ed mic ro -b io log ical ly and h is to log ically in on ly 8 cases o r 14%, wherea s5 1 cases h ad p o s i t i v e cu l tu res fo r 8 8 % . Th ere were sev en cases(1 2 % ) i n wh ich n o b ac t e r i a were d e t ec t ed b y e i t h e r meth o d .

P ar t i cu l a t e fo reig n mate r i a l t h o u g h t t o b e ro o t can a l sea l e rwas detected in 17 of the 58 b iopsies .


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1 5 4 W a y m a n e t a l.T A BL E 1 . B a c t e r i a l s p e c i e s r e c o v e r e d f r o m p e r i a p i c a l l e s i o n s

w i t h p o s s i b l e o r a l c a v it y c o m m u n i c a t i o n ( C ) a n d w i t h n o o b v i o u sc o m m u n i c a t i o n ( N )

SpeciesFacultativeAnaerobes Anaerobes Aerobes

C N C N C NGram-positive cocciStreptococcus salivariusS. mitisS. mutansS. constellatusS. M G intermediusS. intermedius 3S. anginosus constellatusS. milledS. sanguis IIGroup F/~-streptococcusStaphylococcus hominisS. au ricularisS. epidermidisS. aureus

S. capitisS. warneriPeptostreptococcu s micros 10 4P. anaerobius 1P. magnus 1Gem ella morbillorumGram-negat ive cocciViellonella parvula 1 3Moraxella osloensisGram-positive rodsEubacter ium lentum 3Actinomyc es odontolyticus 2 1A. meye ri 1A. israeli 2Propionibecterium acnes 4 4Corynebacterium speciesC. pyogenesLactobacillus ecidophilus 1L. casei 1Bacillus pumilusB. speciesBifidobacterium 1Gram-negat ive rodsFusobacterium nucleatum 8 5F. necrophorum 2F. varium 1F. species 1Becteroides intermedius 6B. gracilis 4 3B. melaninoge nicus 2 1B. buccae 4B. oris 1B. distasonis 1B. porphom onas gingivalis 1B. fragilis 1B. Ioesche# 1CDC Group M-S 1Pseudomonas aeruginosaTota l 56 30

11111 31 112 1

15 711 21

1 1

1 8 1 8

4 11

1 19 2

T h e e s t i m a t e d a r e a o f th e p e r i r a d i c u l a r r a r e f a c ti o n s s e e no n t h e p e r i a p ic a l r a d i o g r a p h s r a n g e d f r o m 4 t o 1 0 0 m m ~ f o ra ll b u t o n e c a s e i n w h i c h t h e e s t i m a t e d a r e a w a s 3 0 0 m m 3.T h i s p a r t i c u l a r l e s i o n c o n t a i n e d t h r e e a n a e r o b e s , r o o t c a n a l

J o u m a l o f E n d o d o n t i c ss ea le r, a n d h a d n o o b v i o u s c o m m u n i c a t i o n w i t h t h e o r a lcav i t y .

D I S C U S S I O NM a n y p a r a m e t e r s w e r e i n v e s t i g at e d i n t h is s t u d y o f 58

p e r i a pi c a l l e s io n s w h i c h w e r e r e f r a c t o r y t o n o n s u r g i c a l e n d o -d o n t i c t r e a t m e n t . C a r e w a s t a k e n t o p r e v e n t c o n t a m i n a t i o no f t h e p e r ia p i c a l s p e c i m e n s a s d e s c ri b e d i n " M a t e r i a l s a n dM e t h o d s . "

O u r r e s u lt s c o r r o b o r a t e t h e r e s u l ts o f T r o n s t a d e t a l . (1 0 ),Iw u e t a l . ( 11 ), and B a rn e t t e t a l . ( 12 ). I n t he pe r i ap i ca l t i s sueo f th e 2 9 c a s es in w h i c h t h e r e w a s n o o b v i o u s c o m m u n i c a t i o nw i t h t h e o r a l c a v i t y , 2 4 , o r 8 3 % , c o n t a i n e d m i c r o o r g a n i s m s .T h e r e w a s a t o ta l o f 5 0 m i c r o b i a l i s o la t e s c u l t u r e d f r o m t h e s epe r i ap i ca l l es i ons , o f w h ich 30 w ere anae rob es , 18 w ere f acu l -t a t i ve anae robe s , and 2 w ere ae robes (Tab l e 1 ). O f t he 29c a s es w i t h a p o s s i b le c o m m u n i c a t i o n w i t h t h e o r a l c a v i ty , 2 7 ,o r 9 3 % c o n t a i n e d m i c r o o r g a n i s m s . T h e r e w a s a to t a l o f 83m ic ro b i a l i so la t e s . F i f t y - s i x w ere anae robes , 18 w ere f acu l t a -t i ve anae robes , and 9 w ere ae robes (Tab l e 1 ) . The pos s ib i l i t yo f c o n t a m i n a t i o n i s a p l a u s ib l e e x p l a n a t i o n f o r th e p r e s e n c eo f a e ro b e s . H o w e v e r , t h e f a c t t h a t t h e r e w e r e 7 s a m p l e s o f t h e5 8 i n w h i c h n o g r o w t h o c c u r r e d w o u l d s e e m t o v e r i f y t h a tt h e t e c h n i q u e u s e d w a s r e l i a b l e a n d a v o i d e d c o n t a m i n a t i o n .T h e p r e s e n c e o f b a c t e r ia i n t h e s e p e r i ap i c a l l e s i o n s w o u l dp r o v i d e a n e x p l a n a t i o n f o r n o n r e s o l u t i o n o f s o m e n o n s u r g i c a lt r e a t m e n t c as es . T h e r e w a s n e i t h e r a p r e p o n d e r a n c e o f c o c c in o r r o d s w i t h b o t h b e i n g p r e s e n t . N e i t h e r w e r e t h e r e m a n ym o r e G r a m - p o s i t i v e m i c r o b e s th a n G r a m n e g a ti v e o n es .

O f t he bac t e r i a i so l a t ed f ro m these l e s ions , m os t , i f no t a ll ,h a v e a l s o b e e n i s o l a t e d f r o m t h e r o o t c a n a l s p a c e . T h e s em i c r o o r g a n i s m s p r o d u c e m a n y p r o d u c t s w h i c h a r e p a t h o -g e n i c . T h e s e m i c r o b i a l v i r u l e n c e f a c t o r s d e s t o r y m a n y h o s tr e s is t an c e m e c h a n i s m s , t h u s p e r m i t t i n g t h e s u r v i v a l o f th e s em ic robes i n t he pe r i ap i ca l a r ea (14 ) .

O f in t e r es t i s t h e f r e q u e n c y o f th e g e n u s B a c t e r o id e s . G r i f f e ee t a l . 05 ) s t a t e t ha t Bacteroides melaninogenicus a c t u a l l yr e fe r s t o a g r o u p o f s p e c i es w h i c h i n c l u d e Bacteroides gingi-valis a n d B. intermedius. In add i t i on , Sundqv i s t e t a l . ( 16 )have l i s ted Bacteroides loescheii as a spec i e s fo rm er ly c l a s s i -f ied B. melaninogenicus. In a l l i n s t ances , i n ou r s t udy i nw h i c h a B a c t e r o i d e s s p e c i e s w a s i s o l a t e d , o t h e r m i c r o o r g a -n i sm s w ere a l so cu l t u r ed . Th i s suppor t s t he i r ( 16 ) t he s i s t ha to t h e r b a c t e r i a m u s t b e p r e s e n t i n o r d e r f o r B a c t e r o i d e s s p p .t o a c h i e v e t h e i r p a t h o g e n i c i t y . P r o t e i n a s e s f r o m t h e s e b l a c k -p i g m e n t e d b a c t e r i a h a v e a l so b e e n s h o w n t o i n a c t i v a t e m a n yfac to r s i n t he bo dy ' s de f ense sys t em ( t 4 ) . I n ou r r e su lt s , w ef o u n d B a c t e r o id e s i n o n l y 1 7 o f t h es e 5 8 l e s i o n s, w h i c he m p h a s i z e s t h a t o t h e r b a c t e r i a m a y b e a s i m p o r t a n t a s B a c -t e r o id e s i n r e f r a c t o r y p e r ia p i c a l l e si o ns . A l t h o u g h t h e n u m b e ro f case s i n ou r s t udy w as sm a l l , no t a l l l e s i ons w i th t heB a c t e r o id e s s pp . w e r e s y m p t o m a t i c a n d a c o r r e l a t i o n b e t w e e ns y m p t o m s a n d t h e p r e s e n c e o f th i s m i c r o b i a l s p e c ie s c o u l dn o t b e m a d e .

T h e r e w a s s o m e c o n c e r n t h a t t h e f a c u l t a t i v e a n a e r o b e ss u c h a s Staphylococcus epidermidis w e r e c o n t a m i n a n t s i n t h en o n c o m m u n i c a t i n g g r o u p . H o w e v e r , t h es e m i c r o b e s h a veb e e n i s o l a t e d f r o m t h e r o o t c a n a l s p a c e ( 1 4 ) . I n t h e i r s t u d y ,T r o n s t a d e t a l . (9 ) a ls o i s o l a te d m a n y o f th e s e s a m e m i c r o b e sf rom non hea l i ng pe r i ap i ca l l e s i ons . Sab i s t on e t a l. ( 5 ) s im i l a r l y


4/4

Vo l . 18 , No . 4 , A p r i l 1 9 9 2i so la t ed f acu l t a ti v e an aero b e s f ro m p y o g en i c d en t a l i n f ec t i o n sin wh ich asp i r a t es were t ak en a n d cu l t u red .

Th e m ain d i f f e r en ce b e tween t h e 2 9 les i o ns co mm u n ica t i n gwi th t h e o ra l cav i t y an d t h e 2 9 l es i o n s wi th n o o b v io u sc o m m u n i c a t i o n w a s th e a v e r a g e n u m b e r o f m i c r o b e s . T h ea v e r ag e n u m b e r o f m i c r o b ia l s p e c ie s i so l at e d f r o m t h e c o m -mu n ica t i n g g ro u p was 2 .8 6 co mp ared wi th 1 .7 2 sp ec i es i nth o se cases wi th n o co mm u n ica t i o n . P o ss ib l e me an s o f co m-mu n ica t i o n w i th t h e p e r i ap ex i n t h ese cases were p e r i o d o n t a lp o ck e t s g rea t e r th an 4 m m , a f i s tu lo u s t r ac t, o r a v e r t ica l r o o tf r ac tu re . S a l i v a ry co n t amin a t i o n wo u ld acco u n t fo r t h eg rea t e r n u mb er o f mic ro o rg an i sms i n t h ese cases as we l l a sthei r pers is tence in these per i rad icu lar les ions . Of these 29" c o m m u n i c a t i o n c a s e s ," n o m i c r o b e s w e r e c u l tu r e d f r o m t w oc o m p a r e d w i th f i v e i n t h o s e w i th " n o c o m m u n i c a t i o n . "

N o g r o w t h c o ul d b e d u e t o s m a l l n u m b e r s o f b ac t e r iap resen t i n t h ese l e s io n s , an i n ad eq u a t e sp ec im en , d ea th o f t h ean aero b i c mic ro o rg an i sms , sy s t emic an t i b io t i c s , o r t y p e o fc u l tu r e m e d i u m . A s m a l l n u m b e r o f b a c t e r ia w o u l d a l s o b ed i f fi cu l t t o d e t ec t h i s t o lo g i ca ll y . P r i o r t o t h e a d v en t o f cu r r en tan aero b i c cu l t u r i n g t ech n iq u es , Lan g e l an d e t a l . ( 7 ) were ab l eto d emo n s t r a t e b ac t e r i a l co lo n i es i n o n ly 5 o f 3 5 cases i nwh ich p e r i ap i ca l t i s su e was ex amin ed u n d er a l i g h t mic ro -sco p e . In o u r s t u d y , t h e re w ere 5 8 cases i n wh ich sp e c imen sfo r cu l t u re an d h i s t o lo g i ca l ex amin a t i o n were su b mi t t ed . Ofth ese 5 8 b io p s i es ex amin ed u n d er a l i g h t mic ro sco p e an ds t a in ed wi th h em ato x y l i n an d eo s in , b ac t e r i a were seen in 8 ,o r 14%, whi le bacter ia we re g rown in 51 (88%). I t i s app are n tt h a t t h e b e s t w a y t o d e t e r m i n e t h e p r e s e n c e o f m i c r o o r g a n is m sin per iap ica l t i ssues is th rough cu l tu r ing o f these les ions .

Th e p resen ce o f b ac t e r i a i n 5 1 o f 5 8 p e r i ap i ca l l e s io n sco r r esp o n d s wi th t h e f i n d in g s o f T ro n s t ad e t a l. ( 9 ) an d Iwue t a l. ( l 1 ), b o th i n t h e p resen ce an d t y p es o f mic ro o rg an i sm sin t h ese l e s io n s . Ou r s t u d y a l so su p p o r t s t h e ea r l ie r s t u d i es o fS t ewar t (1 ) an d Hed man (2 ) , i n wh ich t h ey r ep o r t ed f i n d in gbacter ia in a s ign i f ican t perce n tage o f per iap ica l les ions .

Th e p resen ce o f p a r t i cu l a t e fo re ig n mate r i a l, b e l i ev ed t o b eroo t cana l sealer , in 17 of the 58 b iopsies i s o f in teres t . Th issea l e r m ay ac t a s a fo re ig n b o d y an d co n t r i b u t e t o t h e p e r s i s t -en t n a tu re o f m an y o f t h ese l e s io n s . Th ese sea l e r r em n an t sa re k n o wn to b e r eso rb ed i n so me cases (1 7 ) an d t h i s o ccu r sth ro u g h t h e p h ag o cy to s i s o f t h ese p a rt i c les b y ma cro p h ag eswh ich a r e d e r i v ed f ro m t i s su e h i s t i o cy t es an d b lo o d -b o rnmo n o cy t es (18 ).

T h i s i m m u n e r e s p o n se t o t h e s e a l e r m a y c o n t r ib u t e t o t h ep er s i s ten ce o f t h ese l e s i on s as w e l l a s t h e m ic ro b es w h ich a r eth e re. Ad d i t i on a l l y , t h e cy to to x i c i t y o f f r esh ly p rep ared ro o tcan a l seal e r s h as b een d em o n s t r a t e d an d m ay ad d t o t h ep ro b l em o f n o n h ea l i n g (19 ).Al th o u g h t h e n u m b er o f l e si o n s i n t h i s s t u d y is smal l i nco mp ar i so n t o t h e s t u d y b y Bh ask ar (2 0 ) , g r an u lo mas werea l so t h e m o s t co m m o n p er i r ad i cu l a r le s i o n id en t if i ed . Bh ask ar(20 ) r ep o r t ed t h a t 4 8 % o f h i s 23 0 8 cases were g ran u lo m asan d 4 2 % w ere cy s ts . Ou r r esu l t s in d i ca t e t h a t o f t h e 5 8 b io p s i essu b mi t t ed , 4 1 (7 1 % ) were g ran u lo mas an d 1 6 (2 7 % ) werecysts.

In cases o f n o n h ea l i n g p e r i r ad i cu la r l e s i on s , b o th ae ro b i can d an aero b i c b ac t e r i a an d ex t ru d e d sea l e r ma y co n t r i b u t e t oth e p e r s i s t en t p a th o si s . H o wev er , t h e r esu lt s o f t h i s s t u d yd em o n s t r a t e t h a t t h e p resen ce o f b ac t e r i a an d sea l e r in t h ese

B a c t e r i o l o g y o f P e d a p i c a l L e s i o n s 1 5 5l e s io n s i s n o t t h e o n ly cau se fo r f a i l u r e t o h ea l . Twen ty - th reeo f 5 8 cases h ad i r reg u l a ri t ie s i n t r ea tme n t o r l o ca t i o n wh ichmay h av e co n t r i b u t ed t o t h e n o n h ea l i n g a f t e r ro o t can a lt r ea tmen t : s ev en h ad v er t i ca l r o o t f r ac tu res , s i x co n t a in edmissed can a l s , f o u r h ad b een p er fo ra t ed , two h ad l es i o n sp en e t r a t i n g i n to t h e max i l l a ry s i n u s , an d two h ad sev erep er io d o n t a l d i sease . S ev en t een o f t h e l e s i o n s co n t a in ed ex -t rude d sealer.

The authors wish to thank M rs. Maria Garcia, anaerobic microbiologist, orher valua ble technica l assistanc e and Dr. W illiam A. Walke r 111,Dr. William G.Schindier, Dr. Q. Micha el Fuhs, Dr. R ichard E. Rutledge , Dr. Daniel M. Kier, Dr.Gerry Myers, and Dr. R ichard Morgan for their clinical contributions.The views expressed in this art icle are those of the authors and do no treflect the off icial policy of the Department of Defense or other d epartments ofthe U .S. government.Dr. Wayman s chief, EndodonticsSection, Departmentof G eneral Dentistry,Wilford Hall USAF Medical Center, Lackland AFB, T exas, Dr. M urata s formerchief, Endodontic Section, Department of General Dentistry, Wilford H all USAFMedical Center, Dr. Almelda s chief, Microbiology Branch, Wilford Hall U SAFMedical Center. Dr. Fowler is assistant chairman, Department of Oral Pathol-ogy, Wilford Hall USAF Medical Center. Address requests for reprints to CO L

Blake E. Waym an, Department of General Dentistry, Endodontics Section,Wilford Hall USAF M edical Center/SGDG, Lackland AFB, TX 78236-5300.

Ref eren ces1. Stewart GG. A study of bacteria found in root can als of anterior teethand the probable ngress. J Endod 1947;2:8.2. Hedm an WJ. A n investigation nto residual periapical nfection after pulpcanal herapy. Oral Surg 1951 4:1173-9.3. Shindail E. A study of some periap ica l r o e n tg e n o l~ and the irsignificance. Oral Surg 1961 14:1 057-65 .4. W inkler TF III , Mitchell DF, H ealey HJ. A bacterial study of humanperiapical pathosis employing, a mod if ied gram tissu e stain. Oral Surg1972;34:109-16.5. Sabiston CB Jr, G rigsby BA, Segerstrom MT. Bacterialstudy of pyogenicinfections of dental odgin. Oral Surg 1976;41:430-5.6. Brook I, Grimm S, Kielich RB. Bacteriology of acute periapical abscessin children. J Endodon 1981 7:378-80.7. Langeland K, Block R M, Grossm an LI. A histopathologic and histobac-tedologic study o f 35 periapical endod ontic ~,urgical specime ns. J Endo don1977;3:8-23.8. Kronfeld R. Histopatho logyof the teeth and their surrounding structures.2nd ed. Philadelphia: Lea & Febiger, 1939:209.9. Tronstad L, Barnett F, Riso K, S lotz J. Extraradicular endodontic nfec-t ions. Endod Dent Traumatol 1987;3:86-90.10. Haapasalo M, Ranta K, Ranta H. Mixed anaerobic periapical nfectionwith sinus tract. Endod D ent Traumato11987;3:83-5.11. Iwu C, MacFadanaTW, Mackenzie D, Stanhouse D. The m icrobiologyof periapical granulomas. Oral Surg 1990;69:502-5.12. Barnett F, Stevens R., Tronstad L. Demonstration of Bacteroidesintermedius in periapicai issue using ndirect immunofluorescencemicroscopy.Ended Dent Traumato11990;6:153-6.13. Phillips E, Nas h P. Culture media. In: Lenne tte EH, Balow s A, Haus lerWJ, Shadomy HJ, eds. M anual of clinical microbiology. 4th e d. W ashington,DC: Am erican Society for Microbiology, 1985:1051-92.14. Co hen S, Bum s RC. Pathways of the pu lp. 4th ed. St. Louis: CVMosby, 1987:364-72.15. Griffee M, Patterson S, Miller C, Karl'awa yA, deObarrio J. Bacteroidesmelaninogenicus and dental infections: som e questions and so me answers.Oral Surg 1982;54:486-9.16. Sundqvist G, Johansson E, Sjogren U. Prevalenceof black-pigmentedBacteroides species n root canal nfections. J Endodon 1989;15:13-9.17. Augsberger RA, P eters DD. Radiographic evaluation of extruded ob-turation m aterials. J Endedon 1990;16:492-7.18. Cotran RS, Kumar V, Robbins SL Robbins' pathologic basis of disease.4th ed. Philadelphia:WB Saunders, 1989:61-3.19. Pascon EA, Spangherg LS, Langeland K. Cytotoxicity of endodonticsealers. General Session IADR [Abstract 474]. J Den t Res 1987;66(specialissue):200.20. Bhas kar SN. Periapieai esions--typ es, incidence, and clinical eatures.Oral Surg 1966;21:657-71.

a bacteriological and his to logical evaluation of 58 periapical lesions

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