tic Treatment of Teeth With Apical Period on Tit Is Single vs. Multi Visit Treatment

8/4/2019 tic Treatment of Teeth With Apical Period on Tit Is Single vs. Multi Visit Treatment

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JouRN AL OF ENDODONTICS Pr in ted in U .S.A.Cop yr igh t 1999 by The Ame r ican Asso cia t ion o f End odon t is ts VOL. 25 , No . 5 , MAY 1999

E n d o d o n t ic T r e a t m e n t o f T e e t h w ith A p i c a lP e r i o d o n t i t i s : S i n g l e v s . M u l t i v i s i t T r e a t m e n tM a r t i n T r o p e , D M D , E . O l u t a y o D e la n o , B D S , M S , a n d D a g rs t a v ik , D D S , P h D

T h i s s t u d y w a s p e r f o r m e d t o ev a l u a t e r a d i o g r a p h i ch e a l i n g o f t e e t h w i t h a p i c a l p e r i o d o n t i t is , t r e a t e d i no n e v i s i t o r i n t w o v i s i t s (a ) w i t h o r ( b ) w i t h o u tc a l c i u m h y d r o x i d e a s a n i n t r a c a n a l d i s i n f e c t i n gm e d i c a m e n t . T h e p a t i e n t s w e r e a s s i g n e d o n e o ft h e t h re e t r e a t m e n t g r o u p s b y t h e th r o w i n g o f ad i e . T h e P e r i a p i c a l I n d e x (P A l ) S c o r i n g M e t h o d w a su s e d t o c o m p a r e d i f f e r e n c e s i n p e r i a p i c a l s t a t u sf r o m t h e b e g in n i n g o f t r e a t m e n t t o a 5 2 - w k f o l-l o w - u p e v a l u a t i o n . O v e r a l l , t h e p e r i a p i c a l s t a t u s o ft h e tr e a t e d t e e t h i m p r o v e d s i g n i f i c a n t ly a f t e r 5 2 w k( p < 0 . 0 0 0 1 ) . A P A l s c o r e o f 1 o r 2 w a s c o n s i d e r e da s r e p r e s e n t i n g a " g o o d " p e r i a p i c a l s t a t u s w h i l e 3 ,4 , o r 5 w a s a " b a d " s t a t u s . W h e n b a s e l i n e P A ls c o r e s w e r e c o n t r o l l e d f o r , t h e c a l c i u m h y d r o x i d eg r o u p s h o w e d t h e m o s t i m p r o v e m e n t i n P A l s c o r e( 3, 4 , o r 5 to 1 o r 2 ), f o l l o w e d b y t h e o n e - s t e p g r o u p( 7 4 % v s . 6 4 % ) . T h e t e e t h t h a t w e r e l e f t e m p t y b e -t w e e n v i s it s h a d c l e a r l y i n f e r i o r h e a l i n g r e s u l t s .P o w e r s t at is t ic s w e r e c o n d u c t e d t o d e t e r m i n e t h en u m b e r s r e q u i r e d f o r s i g n i f ic a n t d i ff e r e n c e s b e -t w e e n t h e g r o u p s , a n d it w a s s h o w n t h a t l a r g ee x p e r i m e n t a l g r o u p s o n t h e o rd e r o f h u n d r e d s o fp a t i e n t s w o u l d b e r e q u i r e d t o s h o w s i g n i f i c a n t d if -f e r e n c e s .

N a O C 1 p r o v i d e s d i s i n f e c t i o n i n s o m e 4 0 t o 6 0 % o f t h e t e e t h t h u st r e a t e d ( 7 ). T h e s u b s e q u e n t a p p l i c a t i o n o f a c a l c i u m h y d r o x i d ed r e s s i n g b r i n g s t h e p e r c e n t a g e o f b a c t e r i a - n e g a t i v e t e e t h to 9 0 t o1 0 0 % ( 8 ) ; t h i s t r e a t m e n t r e g i m e n i s t h u s t h e c u r r e n t s t a n d a r d f o rr o o t c a n a l d i s i n f e c t i o n .

O n e i s s u e f r e q u e n t l y d e b a t e d i n r e c e n t y e a r s i s w h e t h e r c o n s c i -e n t i o u s c l e a n i n g b y i n s t r u m e n t i o n a n d i r r i g a t i o n m a y r e d u c e t h en e e d f o r a d r e s s i n g a n d e f f e c t s a t i s fa c t o r y d i s i n f e c t i o n o f th e c a n a ls y s t e m ( 9 , 1 0 ). S u c h s i n g l e - v i s i t t r e a t m e n t w o u l d , i f s u c c e s s f u l , b et i m e - s a v i n g a n d r e d u c e t h e r i sk o f i n t e r a p p o i n t m e n t i n f e c t i o n .M a n y p r a c t i t i o n e r s e x p e r i e n c e h i g h s u c c e s s r a t e s w i t h t h i s t e c h -n i q u e , b a s e d o n p a t i e n t a c c e p t a n c e , l a c k o f s i g n i f i c a n t f l a r e - u p s ,a n d p r a c t i c e m a n a g e m e n t c o n s i d e r a t i o n s . H o w e v e r , w h e r e a s af a v o r a b l e f l a r e - u p r a t e f o r o n e - s t e p t r e a t m e n t i s d o c u m e n t e d ( 1 1 ,1 2 ) , a w e l l - d e s i g n e d , p r o s p e c t i v e f o l l o w - u p s t u d y h a s n o t b e e np e r f o r m e d o n t h e l o n g - t e r m s u c c e s s o f t h i s t e c h n i q u e , c o m p a r e dw i t h c o n t r o l l e d d i s i n f e c t i o n w i t h c a l c i u m h y d r o x i d e , f o l l o w e d b yo b t u r a t i o n .

R e c e n t l y , e f f o r t s h a v e b e e n m a d e t o i m p r o v e o n t h e d i a g n o s t i ct e c h n i q u e s u s e d t o d e t e c t d i f f e r e n c e s i n r e s p o n s e t o t r e a t m e n t a n dt r e a t m e n t v a r i a b l e s . A n u n b i a s e d i n d e x s c o r i n g s y s t e m ( 1 3 ) m a ya f f o r d i m p r o v e m e n t s i n t h e s c i e n t i fi c a s p e c t o f r a d i o g r a p h i c i n t e r -p r e t a t i o n i n a l a r g e s e r i e s o f c a s e s . T h e r e f o r e , w e f e l t t h a t ac o n t r o l le d p r o s p e c t i v e s t u d y t o e v a l u a t e t r e a t m e n t o u t c o m e s w i t ht h e s e t w o t r e a t m e n t m e t h o d s m i g h t b e p o s s i b l e .

T h e p u r p o s e o f th i s s tu d y w a s t o e v a l u a t e r a d i o g r a p h i c h e a l i n go f t e e t h w i t h a p i c a l p e r i o d o n t i t i s t r e a t e d i n ( a ) o n e v i s i t o r ( b ) t w ov i s i ts , e i th e r w i t h o u t o r w i t h t h e a d d i t i o n o f c a l c i u m h y d r o x i d e a sa n i n t r a c a n a l d i s i n f e c t i n g m e d i c a m e n t .

A p i c a l p e r i o d o n t i t i s i s c a u s e d , p r i m a r i l y , b y b a c t e r i a i n t h e r o o tc a n a l s p a c e ( 1, 2 ) . T h e r e f o r e , a l o g i c a l t r e a tm e n t a i m i s t o r e m o v ea s m a n y o f t h e s e b a c t e r i a a s p o s si b l e . I f b a c t e r i a a r e r e m o v e d t ol e v e l s t h a t a r e u n d e t e c t a b l e b y b a c t e r i o l o g i c a l m e t h o d s i n u s et o d a y , a n e x t r e m e l y h i g h s u c c e s s r a t e i n t h e r e s o l u t i o n o f a p i c a lp e r i o d o n t i t i s c a n b e e x p e c t e d ( 3 , 4 ) .

T h e s c i e n t i f i c a l l y d o c u m e n t e d p r o c e d u r e f o r t h e b e s t r e s u l t s i nc a n a l d i s i n f e c t i o n i s b a s e d o n c o m p l e t e d e b r i d e m e n t a n d i r r i g a t i o no f t h e r o o t c a n a l d u r i n g t h e f i r s t a p p o i n t m e n t , f o l l o w e d b y t h ea p p l i c a t i o n o f a c a l c i u m h y d r o x i d e d r e s s i n g f o r 1 w k o r m o r e . R o o tf i l l i n g i s t h e n p e r f o r m e d a t t h e s e c o n d o r a l a t e r a p p o i n t m e n t ( 5 ) .M e c h a n i c a l i n s t r u m e n t a t i o n a l o n e c a u s e s a 1 0 0 - t o a 1 0 0 0 - f o l dr e d u c t i o n i n n u m b e r s o f b a c t e r i a ( 6 ), b u t c o m p l e t e e l i m i n a t i o n i no n l y 2 0 t o 4 3 % o f c a se s . A d d e d a n t i b a c t e r ia l i r r i g a t i o n w i t h 0 . 5 %

M A T E R I A L S A N D M E T H O D S

P a t i e n t S e l e c t i o n

T h e p r i m a r y c r i t e r i o n fo r i n c l u s i o n o f s u b j e c t s i n th e s t u d y w a st h e p r e s e n c e o f r a d i o g r a p h i c a l l y d e m o n s t r a b l e a p i c a l p e r i o d o n t i t i so n a s i n g l e - r o o t e d t o o t h o r o n o n e r o o t w i t h a s i n g l e c a n a l i n o n er o o t o f a m u l t i r o o t e d t o o t h . P a t ie n t s w e r e e x c l u d e d f r o m t h e s t u d yi f , ( a ) th e y h a d a d i a g n o s i s o f d i a b e t e s , ( b ) t h e y h a d a d i a g n o s i s o fH I V i n f e c t i o n o r o t h e r i m m u n o c o m p r o m i s i n g d i s e a s e , ( c ) t h e yw e r e < 1 6 o r > 8 0 y e a r s o l d , o r (d ) t h e a p i c a l t w o - t h i r d s o f th e r o o tc a n a l i n q u e s t i o n h a d b e e n e n t e r e d a n d i n s t r u m e n t e d o r d r e s s e db e f o r e t h e i n c l u s i o n s t a g e .

345


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346 Trope et al .Randomization

After init ial screening and registrat ions, the patients were as-signed to a treatment group (1 of 3 treatment groups) by thethrowing of a die. This ensured that each patient stood an equa lchance of be ing t rea ted wi th any method .

ConsentThe pro jec t was approved by the Commit tee on Inves t iga t ions

Involv ing Human Subjec ts a t the Univers i ty of Nor th Caro l ina ,School of Dentistry. All patients read and signed a consent formbefore init iat ion of the treatment.

TreatmentAll patients were treated by one author (D.O.) according to a

s tandard ized reg imen, inc luding e lements of access , rubber dam,and establishment of asepsis. Instrumentation was also standard-ized with 2.5% NaOC1 used as the irr igant. All teeth were obtu-rated with lateral condensation of gutta-percha and Roth 801 sealer(Roth Drug Co. , Chicago , IL) .

Treatment GroupsG R O U P 1

Experimental Group (0): Trea tment was comple ted in oneappointment.

G R O U P 2Control Group (E): Ins t rumenta t ion was comple ted a t the f i r s t

appointmen t. Th e canal was left empty , but closed for approxi-mate ly 1 wk before the second appoin tment . On the second ap-poin tment , the t rea tment was comple ted .

G R O U P 3Conventional Group (C): Ins t rumenta t ion was com ple ted a t the

f i r st appoin tment . A dress ing of ca lc ium hydroxide was p laced toremain for a t l eas t 1 wk. Trea tment w as com ple ted a t the secondappoin tment .

Radiographic TechniqueAll patients in the study had a standardized X-ray series. Pre-op,

imme dia te pos t -op , and cont rol rad iographs were taken wi th ind i -v idua l b i te -b locks a t tached to the beam-guid ing device (XCP, RinnCorp, Elgin, IL). The bite blocks were constructed in bite regis-t ra t ion impress ion mater ia l (Polyvinyls i loxane , Ker r , Romulus ,MI) and kept between appointments (Fig. 1) . The essential radio-graphs in the series were all processed under similar condit ions inthe automatic X-ray processor.

Radiographic Evaluation

Radiographic eva lua t ion was done us ing the Per iap ica l Index(PAI) Scoring System (13). This is a 5-point scale radiographic

Journal of Endodontics

FIG 1. Impression of po sition o f the radio graph ic mount. This enablesfollow-u p radiographs to b e taken at identical angles.

FIG 2. Reference radiograp hs, corresp ondin g line drawings, andtheir associated PAl scores. (Reproduced with permission from theSwedish Denta l Journal [1967].)

interpretation designed to determine the absence, presence, ortransformation of a disease state. The reference is made up of a setof f ive rad iographs wi th cor responding l ine drawings and the i rassociated score on a photographic print (Fig. 2) . These scores arebased on a correlation with inflammatory periapical status con-firmed by histology (13).

The 9 observers that part icipated in the study were made up of4 graduate oral and maxillofacial radiology residents, 2 graduateendodon tic residents, 1 oral epidemiolo gist , 1 gener al dentist, and1 experi enced endodo ntist . All were blinded to the u 'eatmentgroups and aims of the study.

Observer CalibrationCalibration was conducted by twice scoring a set of 100 cases

on ind iv idua l rad iographs . The " t rue score" was by consensus oftwo dent i s t s involved wi th the formula t ion of the sys tem. Thefo l lowing spec i f ic wr i t ten ins t ruct ions were g iven to the observers:

1. Find the reference radiograph w here the periapical area mostclosely resembles the periapical area you are studying. As-sign the corresponding score to the observed root.

2. When in doubt, assign a higher score.3. For multiroote d teeth, use the highest of the scores given to

the individual roots.4. All teeth must be given a score.

2 magnificatio n was pr ovided for optional use.Fol lowing the f i r s t observa t ion sess ion , agreement wi th re fe r -ence "true score" was assessed with kappa stat ist ics. One of the


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V o l . 2 5 , N o . 5 , M a y 1 9 9 9T AB LE 1 . W e i g h t e d k a p p a f o r o b s e r v e r s b e f o r e ( A ) a n d a f t e r ( B )

c a l i b r a t i o n w i t h r e f e r e n c e t r u e P A l s c o r e sO b s e r v e r s A B

0-OR 0 .56 0 .641 -OR 0 .57 0 .592-OR 0 .61 0 .663-ER 0 .44 0 .504-ER 0 .59 0 .675-GD 0 .38 0 .646-OR 0 .55 0 .607-OE 0 .42 0 .538-EE 0.51 0.53

OR, oral radiology resident; ER, endodontic resident; EE, experience d endodontist; OE,oral epiderniologist; GD, gene ral dentist.

a u t h o r s ( E . O . D .) h a d a b r i e f c o n f e r e n c e w i t h e a c h o f t h e o b s e r v e r so n a l l c a s e s t h a t h a d a d i f f e r e n c e o f m o r e t h a n o n e f r o m t h e " t r u es c o r e " a n d o n o t h e r r a n d o m l y s e l e c te d m i s s e d c a s e s . A s e c o n ds e s s i o n o b s e r v a t i o n w a s d o n e a t a ti m e n o t l e s s t h a n 3 d a y s a f t e r t h ec o n f e r e n c e . A g r e e m e n t w i t h t h e r e f e r e n c e w a s a g a i n e v a l u a t e d t od e t e r m i n e t h e e f f e c t i v e n e s s o f t h e c a l i b r a t i o n e x e r c i s e . T h e o b s e r -v a t i o n s e s s i o n o f t h e s t u d y r a d i o g r a p h s t h e n f o l l o w e d .

E n d o d o n t i c T r e a t m e n t o f A p i c a l P e r i o d o n t it i s 3 4 7R a d i o g r a p h s f r o m 8 1 p a t i e n ts w i t h 1 0 2 c a s e s ( T a b l e 2 ) w e r e

s c o r e d w i t h t h e P A I . S i x t y - o n e p a t i e n t s h a d s i n g l e c a s e s , 1 8 h a d 2c a s e s , a n d 2 p a t i e n t s h a d 3 c a s e s . T h e p a t i e n t s w e r e m a d e u p o f 5 4f e m a l e s a n d 2 7 m a l e s h a v i n g a m e a n a g e o f 4 4 . 6 y e a r s , w i t h ar a n g e o f 1 9 t o 7 9 . T h e s e c a s e s w e r e p r e s e n t o n 5 1 4 r a d i o g r a p h s ,a n d a t o t a l o f 5 5 6 s c o r e s w e r e g e n e r a t e d . E i g h t p a t i e n t s h a d 2l e s i o n s e a c h o n 1 r a d i o g r a p h , a n d 1 p a t i e n t h a d 2 l e s i o n s e a c h o ns e p a r a t e r a d i o g r a p h s .

O b s e r v e r V a r i a t i o n a n d T r u e S c o r e sT h e s c o r e s f r o m o b s e r v e r s 6 a n d 8 w e r e e l i m i n a t e d b e f o r e t h e

d e t e r m i n a t i o n o f t h e " t r u e s c o r e . " T h e w e i g h t e d k a p p a ( T a b l e 3 )f o r o b s e r v e r s 2 , 4 , a n d 7 d i d n o t c h a n g e , w h e r e a s t h e o t h e r s d i ds l i g h t l y .

T o t a l a g r e e m e n t u s i n g t he t h r e s h o l d f o r m o d e l s c o r e s i m p r o v e df r o m 7 0 % f o r t h e " s i l v e r s t a n d a r d " s c o r e s t o 7 6 % f o r t h e " t r u es c o r e . "

I n t e r o b s e r v e r c o r r e l a ti o n w i t h a m i x e d m o d e l r e g r e s s i o n a n a l -y s i s s h o w s a n i m p r o v e m e n t f r o m 0 . 5 9 t o 0 . 64 ( T a b l e 4 ) w i t h th ee l i m i n a t i o n o f t w o o b s e r v e r s.

T r u e S c o r esA s i l v e r s t a n d a r d o f " t r u e s c o r e " w a s o b t a i n e d b y t a k i n g t h e

m o d e l s c o r e c o r r e s p o n d i n g to a g r e e m e n t b y f i ve o r m o r e o b s e r v e r so r u s i n g t h e m e a n w h e n f e w e r t h a n f i v e w e r e i n a g r e e m e n t . T h ea v e r a g e d s c o r e s w e r e r o u n d e d o f f t o a w h o l e u n i t.

T h e " t r u e s c o r e" w a s o b t a i n e d b y a s i m i l a r a p p r o a c h f o r a s u b s e to f s c o r e s f r o m s e v e n o b s e r v e r s a f t e r e l im i n a t i n g t h e t w o w i t h t h el o w e s t c o r r e l a t i o n to t h e s i l v e r s t a n d a r d . T h e t h r e s h o l d w a s a g r e e -m e n t b e t w e e n f o u r o b s e r v e r s .

I N T R A E X A M I N E R R E L I A B I L IT YA r e p e a t o b s e r v a t i o n w a s c o n d u c t e d a f t e r m o r e t h a n 6 w k . T h e

s a m p l e c o n s i s t e d o f e v e r y f o u r t h c a s e f r o m t h e o r i g in a l s t u d y p o o lu n t i l a t o t a l o f 1 0 0 c a s e s h a d b e e n r e a d b y e a c h o b s e r v e r .

N U M B E R S A N D S T A T I S T I C A L A N A L Y SI ST h e c o n v e n t i o n a l p ro c e d u r e s h o u l d p r o d u c e a s u c c e s s r a te o f

- 8 0 % . C o m p u t a t i o n s o f n e c e s s a r y s a m p l e s iz e s f o r c o m p a r i s o n sa m o n g t r e a t m e n t s in d i c a t e t h a t s a m p l e s i ze s o f 5 5 p e r g r o u p w o u l db e s u f f i c i e n t t o d e t e c t d i f f e r e n c e s i n r a t e s o f 5 % o r m o r e , w i t h ap o w e r o f p = 0 . 2 0 ( 1 4 ). I n t h i s s t u d y , 1 0 2 t e e t h ( C = 3 1 , E = 2 6 ,O = 4 5 ) p r e s e n te d f o r t h e 5 2 - w k f o l l o w - u p e x a m i n a t i o n . B e c a u s et h e s e n u m b e r s w e r e u n l i k e l y t o b e l a r g e e n o u g h f o r s t a t i s t i c a ld i f f e r e n c e s b e t w e e n t h e g r o u p s , a p o w e r a n a l y s i s e v a l u a t i o n ( s e eR e s u l ts ) w a s p e r f o r m e d .

R E S U L T SR a d i o g r a p h i c M e t h o d

C A L I B R A T I O N

T h e o b s e r v e r s ' c o m p e t e n c e a t u s in g t h e P A l a l l i m p r o v e d w i t hc a l i b r a t i o n ( T a b l e 1 ).

E n d o d o n t i c T r e a t m e n t R e s u l t sF i g u r e 3 s h o w s t h e m e a n P A I s c o r e s f o r a l l t r e a t e d t e e t h o v e r t h e

5 2 - w k o b s e r v a t i o n p er i o d. L o n g i t u d i n a l A N O V A o f P A l w i t hr e f e r e n c e t o b a s e l i n e w a s s i g n i f i c a n t ( p < 0 . 0 0 1 ) , w i t h e f f e c t i v ed i f f e r e n c e s t a r t i n g a t w e e k 1 2. N o s i g n i f i c a n t i n t e r a c t i o n b e t w e e nt i m e a n d t r e a t m e n t w a s d e m o n s t r a t e d .

F o r t h e P A I o u t c o m e , t h e M U L T I L O G p r o c e d u r e w a s u s e d t oc o m p a r e t h e t h r e e t r e a t m e n t s w h i l e c o n t r o l l i n g f o r t h e c o r r e la t i o ns t r u c t u r e o f t h e d a t a . A r e p l a c e m e n t d e s i g n w a s u s e d w i t h t h ep a t i e n t a s t h e p r i m a r y s a m p l i n g u n i t . T h e m o d e l s e x a m i n e d p r e -d i c t e d P A I a t w e e k 5 2 b y b a s e l i n e P A l ( a l l f i v e l e v e l s ) a n dt r e a t m e n t r e ce i v e d . W e l o o k e d a t P A l a t w e e k 5 2 a s a d i c h o t o m yo f g o o d v e r s u s b a d , w h e r e g o o d w a s P A I s c o r e o f 1 o r 2 a n d b a dw a s a P A I s c o r e o f 3 , 4 , o r 5 .

T a b l e 5 g i v e s t h e d i s t r i b u t i o n o f P A l s c o r e s a t b a s e l i n e u s i n gt h e s a m e g o o d v e r s u s b a d d i c h o t o m y . A t b a s e l i n e t r e a t m e n t O( o n e - v i s it te e t h ) b e g a n w i t h 4 2 % o f t h e t e e t h h a v i n g a g o o d P A Is c o r e , w h e r e a s t r e a t m e n t C ( 2 v i s i t s w i t h c a l c i u m h y d r o x i d e ) h a dj u s t 2 3 % o f t h e t e e t h w i t h a g o o d P A l s c o r e . T h i s d i f f e r e n c e i n" s t a r t i n g p o i n t s " h a d t o b e c o n t r o l l e d f o r w h e n i n t e r p r e t i n g t h eh e a l i n g r e s u l t s a t w e e k 5 2 .

A t w e e k 5 2 ( T a b l e 6 ) , o v e r a ll 7 3 . 5 % o f t h e t e et h ( 7 5 / 1 0 2) e n d e dt h e s t u d y w i t h a g o o d P A I s c o r e , w h e r e a s 2 6 . 5 % o f th e t e e t h( 2 7 / 1 0 2 ) d i d n o t . T a b l e 6 s h o w s h o w t h e i n d i v i d u a l t r e a t m e n t sp e r f o r m e d . ( T h e s e d o n o t a c c o u n t f o r b a s e l i n e d i f f e r e n c e s s e e n i nT a b l e 5 . )

T h e r e s u l t s o f t r e a t m e n t E ( 2 v i s it s , n o c a l c i u m h y d r o x i d e ) w e r ec l e a r l y i n f e r i o r t o t h e o t h e r t r e a t m e n t m e t h o d s . F o r t h i s re a s o n , a n db e c a u s e t h i s g r o u p w a s i n c l u d e d p r im a r i l y f o r p u r p o s e s o f b a c t e -r i o l o g y , a l l f u r t h e r a n a l y s i s w a s t o c o m p a r e g r o u p s C a n d O o n l y .T h e f a c t t h a t o v e r a l l t r e a t m e n t s C a n d O e n d e d t h e s t u d y w i t hs i m i l a r p r o p o r t i o n s o f g o o d r e s p o n s e s , b u t s t a r t e d w i t h d if f e r e n tb a s e l i n e P A l s c o r es , e m p h a s i z e s t h e i m p o r t a n c e o f c o n t r o l l i n g fo rb a s e l i n e i n t h e m o d e l i n g p r o c e s s .


4/6


5/6

V o l . 2 5 , N o . 5 , M a y 1 9 9 9 E n d o d o n t i c T r e a t m e n t o f A p i c a l P e r i o d o n t it i sT AB LE 5 . D i s t ri b u t io n o f P A l s c o r e s a t b a s e l i n e f o r t h e d i f fe r e n t t r e a t m e n t g r o u p s

3 4 9

C E O T o t a lG o o d P A l (1 o r 2 ) n = 7 ( 2 3 % ) n = 8 ( 3 1 % ) n = 1 9 ( 4 2 % ) n = 3 4 ( 3 3 % )B a d P A l ( 3, 4 , 5 ) n = 2 4 ( 7 7 % ) n = l 8 ( 6 9 % ) n = 2 6 ( 5 8 % ) n = 6 8 ( 6 7 % )

C , c a l c i um hy d r ox i de ; E , em p t y be t w een v i si t s; O , one s t ep .

T AB LE 6 . D i s t r ib u t i o n o f P A l s c o r e s a t w e e k 5 2C E O T o t a l

G o o d P A l (1 o r 2 ) n = 2 5 ( 8 1 % ) n = 1 4 ( 5 4 % ) n = 3 6 ( 8 0 % ) n = 7 5 ( 7 3. 5 % )B a d P A l ( 3, 4 , 5 ) n = 6 ( 1 9 % ) n - 1 2 ( 4 6 % ) n = 9 ( 2 0 % ) n = 2 7 ( 2 6 .5 % )

T AB LE 7 . R e s u l t s w i t h t h e w e i g h t o f o n e f o r e a c h t o o t hd f W a l d F pV a l u e

O v e r a l l m o d e l 7 3 4 0 . 2 3 0 . 0 0 0 0M o d e l m i n u s i n t e r c e p t 6 1 6 7 . 3 2 0 . 0 0 0 0B a s e l in e P A l 4 2 4 2 . 6 8 0 . 0 0 0 0T r e a t m e n t 2 2 . 21 0 . 1 1 6 6

T AB LE 8 . M o d e l p a r a m e t e r s a s o d d s r a t i o sC E O

L o w e r 9 5 % l im i t 0 . 31 0 . 1 0 1 . 0 0O d d s o f g o o d O d d s r a t io 1 . 1 5 0 . 3 3 1 . 0 0P A l v s . b a d P A l U p p e r 9 5 % l im i t 4 . 2 t 1 . 1 0 1 . 0 0

T A BL E 9 . R e s u l t s w i t h e a c h p a t i e n t c o n t r i b u t i n g o n e t o o t hd f W a l d F p V a l u e

O v e r a l l m o d e l 7 3 6 1 . 5 3 0 . 0 0 0 0M o d e l m i n u s i n t e r c e p t 6 1 5 2 .4 1 0 . 0 0 0 0B a s e l i n e P A l 4 2 1 9 . 0 4 0 . 0 0 0 0T r e a t m e n t 2 0 . 7 9 0 . 4 5 8 7

T A eL E 1 0 . M o d e l p a r a m e t e r s a s o d d s r a t i o sC E O

L o w e r 9 5 % l im i t 0 . 3 5 0 . 1 5 1 . 0 0O d d s o f g o o d O d d s r a t io 1 . 3 9 0 . 5 7 1 . 0 0P A t v s . b a d P A l U p p e r 9 5 % l im i t 5 . 5 0 2 . 1 6 1 . 0 0

T AB LE 1 1 . S a m p l e s i z e s r e q u i r e d p e r g r o u p t o a c h i e v e 8 0 % ,8 5 % , 9 0 % , a n d 9 5 % p o w e r f o r g i ve n d e lt a s

D e lt a 8 0 % 8 5 % 9 0 % 9 5 %- 0 . 6 4 4 . 8 9 8 9 5 1 . 3 6 0 2 6 0 . 1 0 6 7 7 4 . 3 3 4 8- 0 . 6 3 0 1 8 4 0 . 7 0 1 4 4 6 . 5 5 8 6 5 4 .4 8 7 4 6 7 .3 8 5 4- 0 . 7 3 2 . 9 8 7 0 3 7 . 7 3 4 0 4 4 . 1 6 0 0 5 4 . 6 1 3 3- 1 . 0 1 6 . 1 63 6 1 8 . 4 8 9 7 2 1 . 6 3 8 4 2 6 . 7 6 0 5

T a b l e 1 1 s h o w s t h a t , a t t h i s D E L T A , t h e sa m p l e s i z e o f 6 7 . 3 8 5 4p e r g r o u p w o u l d b e r e q u i r e d f o r s i g n i f i c a n c e t o b e a c h i e v e d .

A n a l y s i s Adjusted for Base Line: Improved Versus N otI m pr o v e dF i g u r e 4 s h o w s P A l s c o r e s v e r s u s t i m e f o r t h e t h r e e t r e a t m e n t

g r o u p s w h e n t h e b a s e l i n e h a s b e e n a d j u s t e d t o t h o s e t e e t h t h a ts t a r t e d t h e s t u d y w i t h a P A I s c o r e a b o v e 3 . A g a i n , b e c a u s e o f t h e

P A I > 3 a t s t a rt

4 .5

3.53 " - - - . . - " % .2 i i i i i

0 1 4 1 2 2 6 5 2F IG 4 . P A l s c o r e s v e r s u s t i m e f o r t h e t h r e e t r e a t m e n t g r o u p s w h e nt h e b a s e l i n e h a s b e e n a d j u s t e d t o t h o s e t e e t h t h a t s t a r te d t h e s t u d yw i t h a P A l s c o r e a b o v e 3 .

p o o r r e s u l t s o f g r o u p E , f u r t h e r a n a l y s i s w a s l i m i t e d t o C v e r s u s O .W e c o m p a r e d g r o u p s O a n d C w h e n b a s e l i n e a t th e s t ar t o f t h et r e a t m e n t o f P A I > 3 . L i m i t i n g t o t r e a t m e n t s C a n d O a n d t o j u s to n e r e c o r d p e r p a t i e n t , t h e r e w e r e 4 1 p a t i e n t s w h o b e g a n i n t h e" b a d c a t e g o r y " w i th P A I > 3 . O f th e 41 p a t ie n t s w h o b e g a n th es t u d y w i t h a g o o d P A I s c o r e (1 o r 2 ), n o n e m o v e d t o a h i g h e r s c o r ea t t h e e n d . O f t h e 1 9 p a t i e n t s i n t r e a t m e n t C , 1 4 ( 7 4 % ) i m p r o v e d ,w h e r e a s 1 4 o f 2 2 ( 6 4 % ) p a t i e n t s o f t r e a t m e n t O i m p r o v e d . I n ac l i n i c a l si t u a t i o n w i t h s i m i l a r t re n d s i n i m p r o v e m e n t f o r t r e a t m e n t sC a n d O , t h e n e e d e d s a m p l e s i z e p e r g r o u p f o r a s i g n i f i c a n td i f f e r e n c e b e t w e e n t h e t r e a tm e n t s a t t h e 0 . 0 5 l e v e l a r e : 3 5 4 w i t h8 0 % p o w e r , 4 0 1 w i t h 8 5 % p o w e r , 4 6 6 w i t h 9 0 % p o w e r , a n d 5 7 1w i t h 9 5 % p o w e r .

D I S C U S S I O NT r a d i t i o n a l f o l l o w - u p p r o g n o s i s s t u d i e s h a v e b e e n o f l a rg e s e -

r i e s o f p a t i e n t s t r e a t e d w i t h o n e s p e c i f i e d p r o t o c o l ( 1 5 , 1 6 ), w i t ht h e r e s u l ts m e a s u r e d a s s u c c e s s r a t e s . I t is d i f f i c u l t o r i m p o s s i b l e t ou s e t h e s e s t u d i e s t o c o m p a r e t r e a t m e n t p r o t o c o l s d u e t o t h e v a r i -a b i l i t y a n d s u b j e c t i v i t y o f t h e d a t a i n t h e d i f f e r e n t s t u d ie s ( 1 7 ) .

T h i s s t u d y w a s a p r o s p e c t i v e s t u d y o n t e e t h w i t h s i m i l a r p a -t h o l o g y ( a p i c a l p e r i o d o n t i t i s ) , m a k i n g t h e c o m p a r i s o n b e t w e e nt r e a t m e n t p r o t o c o l s v i a b l e . A n i m p o r t a n t a d d e d a d v a n t a g e , i n o u ro p i n i o n , w a s t h e u s e o f t h e P A I r a d i o g r a p h i c s c o r i n g s y s t e m . T h i sm e t h o d a l l o w e d a n i m p r o v e d r a d i o g r a p h i c i n t e r p re t a ti o n o v e r t h es u b j e c t i v e r a d i o g r a p h i c e v a l u a t i o n s u s e d i n m o s t p r e v i o u s s t u d i e s .T h e P A I d e v e l o p e d b y O r s t a v i k e t a l . ( 1 3 ) a p p e a r s t o h a v e t h ep o t e n t i a l f o r e a r l y , o b j e c t i v e d e t e c t i o n o f h e a l i n g w i t h g o o d r e p r o -


6/6

3 5 0 T r o p e e t a l. J o u r n a l o f E n d o d o n t i c sd u c i b i l i t y ( 1 8 ) . I t i s b a s e d o n a h i s t o l o g i c a l c o r r e l a t i o n ( 1 3 , 1 9 )w i t h a P A I s c o r e o f 1 - 2 d e f i n e d a s h e a l e d o r m i n i m a l l y i n f l a m e da n d s c o r e s 3 - 5 d e f i n e d a s d i s e a s e d . H o w e v e r , i t i s s t i l l a s u b j e c t i v eo u t c o m e p r o n e t o o b s e r v e r v a r i a t i o n . T o o v e r c o m e t h i s d i s a d v a n -t a g e a s m u c h a s p o s s i b l e , w e u n d e r t o o k t h e r a t h e r t e d i o u s t a s k o fc a l i b r a t i n g o b s e r v e r s a n d e x c l u d i n g t h o s e w i t h s t a t i s t i c a l l y d e t e r -m i n e d d e f i c i e n t p e r f o r m a n c e , f o l l o w e d b y a c o n s e n s u s o f t he b e t t e ra n d r e l i a b l e o n e s t o p r o v i d e a c o n s e n s u s o f " t r u e s c o r e s . "

T h i s s t u d y i l l u st r a te d tw o c o m m o n p r o b l e m s w i t h a c q u i r i n gm e a n i n g f u l r e s u l t s i n c o m p a r i n g e n d o d o n t i c t r e a t m e n t p r o t o c o ls .F i r s t l y , i f t h e b a s e l i n e a p i c a l s t a t u s i s n o t c o n t r o l l e d f o r , t h e r e s u l t sc a n g i v e a f a l s e i m p r e s s i o n o f t h e e f f i c a c y o f t h e c l i n i c a l p r o c e -d u r e s . W i t h o u t c o n t r o l l i n g f o r b a s e l i n e i n t h i s s t u d y , t h e o n e - s t e pa n d c a l c i u m h y d r o x i d e t r e a t m e n t s r e s u l t e d i n a l m o s t i d e n t i c a ln u m b e r s o f t e e th w i t h " g o o d " a p i c a l p e r i o d o n t i u m ( i. e. P A l s c o r e so f 1 o r 2 ) . H o w e v e r , t h e c a l c i u m h y d r o x i d e g r o u p s t a r t e d w i t h t e e t hw i t h m a n y m o r e t e e t h i n t h e " b a d " P A I s c o r e t h a n t h e o n e - s t e pg r o u p . W h e n b a s e l i n e w a s c o n t r o l l e d b y c o m p a r i n g t h e i m p r o v e -m e n t o f t e e t h w h i c h s t ar t e d a P A l s c o r e o f > 3 a n d e n d e d t h e 5 2 - w ko b s e r v a t i o n p e r i o d w i t h a s c o r e o f < 2 , t h e d i f fe r e n c e o f 1 0 % ( 7 4 %f o r c a l c i u m h y d r o x i d e v s . 6 4 % f o r o n e - s t e p ) i s i m p o r t a n t .H o w e v e r , e v e n t h o u g h t h e d i f f e r e n c e i n t h e n u m b e r o f t e e t h w i t hi m p r o v e m e n t w a s 1 0 % f o r t h e g r o up s b e i n g c o m p a r e d , w e r a n i n tot h e s e c o n d c o m m o n p r o b l e m w i t h e n d o d o n t i c s t u d i e s i n t h a t t h es a m p l e s i z e w a s n o t l a r g e e n o u g h f o r s t a t i s t i c a l s i g n i f i c a n c e i n t h es t u d y . B e c a u s e e v e n t h e i n f e r i o r t r e a t m e n t p r o t o c o l s r e s u l t e d i na b o u t 6 0 % s u c c e s s , i t r e q u i r e s a l a r g e s a m p l e s i z e to s h o w s t a t i s -t i c a l l y s i g n i f i c a n t d i f f e r e n c e s i n r e s u l t s f o r d i f f e r e n t t r e a t m e n tp r o t o c o l s . T h e s e n u m b e r s a r e e x t r e m e l y d i f f i c u l t t o a c h i e v e i n ap r o s p e c t i v e s t u d y s u c h a s t h i s o n e. T o c o m p e n s a t e f o r t h is p r o b -l e m , w e p e r f o r m e d p o w e r s t a t i s t i c s o n t h e d a t a t o d e t e r m i n e t h es a m p l e s i z e a t w h i c h s i g n i f i c a n c e c o u ld b e a c h i e v e d f o r t h e o b -s e r v e d d i f f e r e n c e . I n g e n e r a l , a s a m p l e s i z e o f 6 7 t e e t h p e r g r o u pw o u l d h a v e r e s u l te d i n s i g n i f i c a n t d if f e r e n c e s b e t w e e n t h e s i n g l e -v i s i t a n d c a l c i u m h y d r o x i d e g r o u p s . I n t e e t h w i t h a P A I s c o r e o f> 3 ( i .e . e a s i l y d i s c e r n i b l e a p ic a l r a d i o l u c e n c i e s ) , a s a m p l e s i z e o f5 7 1 p e r g r o u p w o u l d b e n e e d e d f o r t h e o b s e r v e d d i f f e r e n c e f o ri m p r o v e m e n t o f t h e p e r i a p ic a l s t a t u s o f t h e t o o t h t o b e s i g n if i c a n t.W h e r e a s t h i s n u m b e r i s d i f f i c u l t t o a c h i e v e i n a p r o s p e c t i v e ,c o n t r o l l e d s t u d y , t h e f i n d i n g s m a y s t i l l b e c l i n i c a l l y r e l e v a n t .

A c c o r d i n g t o t h e l i t e r a t u r e , c a l c i u m h y d r o x i d e d i s i n f e c t i o n a f t e rc h e m o m e c h a n i c a l c l e a n i n g w i ll r e s u l t in n e g a t i v e c u l tu r e s i n m o s tc a s e s ( 5 ) , a n d t h e im p r o v e m e n t r a t e o f 7 4 % f o r t h e c a l c i u mh y d r o x i d e g r o u p a p p e a r s r a t h e r l o w i n l i g h t o f s u c c e s s r a t e s r e -p o r t e d f o r t e e t h w i t h n e g a t i v e c u l t u r e s . H o w e v e r , i t m u s t b e t a k e ni n t o a c c o u n t t h a t th e P M e v a l u a t io n i s a m o r e s p e c i f ic t e s t th a treq u i re s a rea l t ran s i t i o n i n t h e p e r i ap i ca l s t a t u s fo r su ccess / fa i l u rean a l y s i s . Th e re fo re , i t i s n o t su rp r i s i n g t h a t t h e p e rcen t ag es a re l o w ert h a n t h e u s u a l s u b j e c t i v e ra d i o g r a p h i c e v a l u a t i o n m e t h o d s o f s u c c e s s.

L e a v i n g t h e c a n a l e m p t y w i t h o u t o b t u r a t i o n o r a d d i t i o n a l d i s -i n f e c t i o n w a s c l e a r l y a n d c o n s i s t e n t l y t h e w o r s t m e t h o d o f t r e a t -m e n t . T h i s g r o u p w a s i n c l u d e d p r i m a r i l y t o s e r v e a s a b a c t e r i o -l o g i c a l c o n t r o l f o r t h e s i n g l e - v i s i t c a s e s . T h e s e r e s u l t s m a y b ee x p l a i n e d b y t h e f i n d i n g s o f B y s t r 6 m e t a l. ( 2 0 ) , w h e r e r e g r o w t h o fb a c t e r i a i n t h e c a n a l s o c c u r r e d t o l e v e l s s i m i l a r t o t h o s e a t t h e s t ar to f t r e a t m e n t . T h u s , i n m o s t c a s e s w h e n t h e c a n a l i s r e - e n t e r e d , t h eb a c t e r i a a r e a t a l e v e l s i m i l f i r t o t h a t a t t h e s t a r t o f t r e a t m e n t .T h e r e f o r e , t h e i n f e r i o r r e s u l t s f o r t h i s g r o u p a r e n o t s u r p r i s i n g , a n di t a p p e a r s t o b e u n a c c e p t a b l e t o l e a v e a p r e v i o u s l y i n f e c t e d c a n a le m p t y b e t w e e n v i s i t s i n c l i n i c a l p r a c t i c e .

O n e - s t e p t r e a t m e n t h a s m a n y p o t e n t i a l a d v a n t a g e s . I t i s l e s se x p e n s i v e , v e r y w e l l a c c e p t e d b y p a t i e n t s, a n d h a s b e e n s h o w n t o

r e s u l t i n a l o w e r f l a r e - u p r a t e ( 1 l , 1 2) . I t h a s b e e n s h o w n t h a ti n s t r u m e n t a t i o n a n d i r r i g a t i o n a l o n e d e c r e a s e t h e n u m b e r o f b a c -t e r i a i n t h e c a n a l 1 0 0 0 - f o l d ( 6 ) . H o w e v e r , t h e c a n a l s c a n n o t b er e n d e r e d f r e e o f b a c t e r i a b y t h i s m e t h o d a l o n e . I t h a s b e e n t h e o -r i z e d t h a t t h e l o w n u m b e r o f b a c t e r i a l e ft in t h e c a n a l i s b e l o w t h et h r e s h o l d to s u s t a i n t h e i n f l a m m a t i o n p e r i a p ic a l l y o r a r e e n t o m b e da n d k i l l e d d u e t o l a c k o f s p a c e a n d n u t r i t i o n a f t e r e f f e c t i v e o b t u -r a t i o n o f th e s p a c e i n t h e c a n a l . T h e r e f o re , s o m e h a v e a s s u m e d t h a tt h e a d d i ti o n a l d i s in f e c t i n g a c t io n o f c a l c i u m h y d r o x i d e w o u l d n o tr e s u l t i n d i s c e r n i b l y s u p e r i o r r e s u l t s . H o w e v e r , a c c o r d i n g t o t h er e s u l t s o f th i s s t u d y , t h e a d d i t i o n a l d i s i n f e c t i n g a c t i o n o f c a l c i u mh y d r o x i d e b e f o r e o b t u r a t i o n r e s u l t e d i n a 1 0 % i n c r e a s e i n h e a l i n gr a t e s . T h i s d i f f e r e n c e s h o u l d b e c o n s i d e r e d c l i n i c a l l y i m p o r t a n t .

Dr. Trope is JB Freed land p ro fessor and cha i r, D epar tment o f En dodon-t ics, Scho ol of Dent istry, University of North Carolina at Chapel H il l, ChapelHil l , NC. Dr. Delano is lecturer, Oral Radiology and Diagnosis, University ofWe st Indies Sc hool of Dent istry, Cha mps F/uers, Trin idad. Dr. Ors tavik issenio r scient ist , Sc andin avian Ins t itute of Dental Materia ls, Haslum, Norw ay,and ad junct p ro fessor , Depar tme nt o f Endodont ics, Scho o l o f Den tis try , Un iversity of North Carolina at Chapel Hil l , Chapel Hil l , NC. Address requests forreprints to Dr. Martin Trope , Depa rtmen t of Endodont ics, Sch ool of Dent istry,University of North Carolina at Chapel Hil l , Chapel Hil l , NC 27599-2707.

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