JABAA R T I C L E S

An investigation o f p it and fissure sealant retention in 1,871 children in the Head Start program was conducted in Tennessee in September 1985 to determine the retention of the sealant after application to the occlusal surfaces o f prim ary molars of 3- and 4-year-old children. The investigation shows p it and fissure sealants are retained on prim ary molars a t a rate com parable to that expected on permanent molars.

Retention of pit and fissure sealant on the primary molars of 3- and 4-year-old children after 1 year

James R. Hardison, D D S , M P H Durward R. Collier, D D S , M P H Larman W. Sprouse, D D S , M P H Mary Layne Van Cleave, M S Ann Dea Hogan

P it an d fissu re sealan ts have b een an effec tive caries p re v e n tio n m a te ­r ia l .3' 15 M ost s tu d ie s r e g a r d in g

sea lan ts have described th e ir ef fectiveness on th e p e rm a n e n t d e n ti tio n .315

In th e p rim ary d en titio n , c h ild re n aged5 th ro u g h 9 years a re estim a ted to average 5.3 decayed o r filled su rfaces (dfs) a n d 2.5

k, decayed o r filled tee th (dfi), w ith ch ild ren ag ed 5 hav ing a n average o f 4 .0 d ecayed o r filled surfaces an d 2.2 decayed o r filled te e th .1 T h is suggests th a t th e m ajo rity o f to o th decay occurs shortly a f te r e ru p tio n .

T h e re is scan t in fo rm a tio n o n th e sta tus o f caries p reva lence o f th e p rim ary d e n ti­tio n o f c h ild re n y o u n g e r th a n 5 years. T h u s , d a ta fo r c a rie s su scep tib ility by to o th surfaces a re n o t available fo r ch il­d re n w ith recen tly e ru p te d p rim ary m o­lars.

H ow ever, th e 1979-80 N atio n a l In s ti­tu te fo r D en ta l R esearch (N ID R ) su rv ey 1 show ed th a t 54% of caries in th e p e rm a ­n e n t d e n titio n o ccu rred on th e occlusal su rfaces a n d 29% o ccu rred on buccolin - g u a l su rfaces. T h e N atio n a l P rev en tiv e D e n t i s t r y D e m o n s t r a t i o n P r o g r a m 2 sh o w ed th a t 54% o f p e rm a n e n t to o th caries o ccu rred o n th e occlusal surfaces a n d 35% o ccu rred on bucco lingua l su r-

faces. B ased on these d a ta , 83% to 89% o f caries in th e p e rm a n e n t d e n titio n o f chil­d ren aged 5 to 17 years occurs in too th surfaces w ith pits a n d fissures.

A lthough c o rre sp o n d in g d a ta fo r the p rim ary d en titio n a re n o t available, it may be in fe rre d th a t th e p reva lence o f caries by too th su rface fo r p rim ary te e th w ith occlu­sal m orpho log ica l s tru c tu re sim ilar to th a t of th e p e rm a n e n t d e n titio n ap p ro x im a te s th a t o f p e rm a n e n t tee th . I f th is in fe ren ce is co rrec t, th en p it a n d fissu re su rfaces a re at g re a te r caries risk th a n sm oo th su rfaces fo r bo th p e rm a n e n t a n d p rim a ry tee th .

As sealants a re p rim arily u sed to p re ­vent too th decay in pits a n d fissu res, it can be assum ed th a t they a re m ost ef fective in pop u la tio n s in w hich sm oo th su rface too th

Table 1 ■ Condition of occlusal surfaces at follow-up, Head Start Sealant Program, Tennessee, January 1986.

No. %

Surfaces exam ined 781 100.0Surfaces sealed 689 88.2Sealant pariially m issing 9 1.2Sealant m issing 83 10.6

decay is u n d e r co n tro l. B ecause th e m a jo r­ity o f to o th decay o ccu rs o n th e occlusal su rfaces, sealan ts a re o n e o f th e m ost im ­p o r ta n t m easu res available in th e p re v e n ­tion o f to o th decay. W hen sea lan t ap p lica ­tion is co u p led w ith th e various m e th o d s o f f lu o rid e delivery , to o th decay can be a l­m ost e rad ica ted in a ta rg e t p o p u la tio n . A re c e n t s tu d y 17 show ed th a t early caries can be a r re s te d by th e ap p lica tio n o f sea lan t o ver a ffec ted to o th su rfaces. T h u s , th e p lacem en t o f sea lan t o v e r ex is tin g inci­p ie n t ca rious lesions is n o t a te ch n iq u e to be av o id ed , b u t m ay be c o n s id e red a n a p ­p ro p r ia te p ro c e d u re fo r tre a tin g sm all le­sions as well as a ca rie s-p rev en tiv e te c h ­n ique .

E arly s tu d ies315 in ves tiga ted th e e ffec ­tiv e n e s s o f c h e m ic a lly c u r e d a n d u l ­trav io le t lig h t-c u re d sea lan ts . M ore r e ­cently , sea lan ts th a t a re p o ly m erized by ex p o su re to in ten se visible ligh t h av e been in tro d u c e d com m ercially , a n d re p o r ts 18,19 ind ica te th a t 60% to 75% o f sea lan ts m a r­ke ted a re visible-light cu red .

A sealan t th a t is esthetically accep tab le an d easily d e tec tab le is d es irab le fo r b o th p a tie n t satisfaction an d o p e ra to r co n v en i­ence. A de tec tab le sea lan t e n h an ces th e ap p lic a tio n p ro c e d u re a n d th e ease o f

JA D A , V o l. 114, M ay 1987 ■ 613

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id en tif ica tio n a t recall exam ina tions.O p tim a l b enefits fro m sealan ts can be

ex p ec ted if th e app lica tion is co m p le ted so o n a f te r ih e e ru p tio n o f th e to o th su r ­face. Logistical p ro b lem s a re e n c o u n te re d w hen se lecting a p o p u la tio n o f ch ild ren w ith recen tly e ru p te d p rim ary tee th . O n e su ch p o p u la t io n in c lu d es c h ild re n e n ­ro lled in H ead S ta rt. E nro llees a re 3 a n d 4 y e a rs o ld ; th e i r s o c io e c o n o m ic s ta tu s p laces th e m in a h igh-caries-risk g ro u p ,16 a n d they a re read ily accessible. T h u s , ch il­d re n a tte n d in g H ead S ta r t in T en n essee w ere elig ib le to p a rtic ip a te in th e study .

T h e p u rp o se o f th is investigation was to ev a lu a te th e re te n tio n o f an easily d e te c t­ab le , visible-light p o lym erized p it a n d fis­su re sea lan t a f te r ap p lica tion to the occlu ­sal su rfaces o f p rim a ry m o lars 6 to 24 m o n th s a f te r e ru p tio n .

Materials and methods

E lig ib ility e x a m in a tio n s w e re c o m p le te d o n 5 ,2 8 9 c h ild re n by d e n tis ts e m p lo y e d by th e T e n n e s s e e D e p a r tm e n t o f H e a lth a n d E n v i­ro n m e n t. A m irro r , e x p lo re r , a n d artific ia l ligh t so u rc e w ere u se d fo r th e d e n ta l e x a m in a tio n ; no ra d io g ra p h s w ere tak en . C h ild re n w ith o b ­se rv ed d e n ta l d e fec ts w ere r e fe r r e d fo r t r e a t­m e n t. C h ild re n w ith o u t d e n ta l tr e a tm e n t n e e d s w ere c o n s id e re d elig ib le to p a rtic ip a te in th e p r o g ra m . A n in fo rm a tio n sh e e t d e sc r ib in g se a lan ts a n d a p a re n ta l c o n se n t fo rm w ere sen t h o m e to be re a d , s ig n e d , a n d r e tu rn e d to th e H e a d S ta r t c e n te r .

D u r in g th e 1984-85 a cad e m ic y ea r, 1,871 ch ild re n rece iv ed sea lan t. T h e ap p lica tio n was co m p le te d by d e n tis ts a n d d e n ta l hyg ien ists e m p lo y e d by th e T e n n e s s e e D e p a r tm e n t o f H e a lth a n d E n v iro n m e n t. B e fo re th e ap p lica ­tio n p h a se o f th e p ro jec t, each o p e ra to r was re q u e s te d to co m p le te an 8 -h o u r tra in in g p ro ­g ra m on p it a n d fissu re sea lan t ap p lica tio n .

T h e ap p lica tio n p ro c e d u re was co n d u c te d a t th e H e a d S ta rt c e n te rs u sin g p o rta b le d e n ta l e q u ip m e n t. O n e n te r in g th e d e n ta l tre a tm e n t a re a , each ch ild was se a ted in a p o r ta b le d e n ta l c h a ir to c o n f irm eligibility to p a r tic ip a te in th e p ro g ra m . A fib e ro p tic d e n ta l o p e ra tin g lig h t was u se d to illu m in a te th e a re a o f th e m o u th b e in g e x a m in e d a n d tre a te d . T h e te e th des ig ­n a te d fo r tr e a tm e n t w ere c lean ed u sin g a s lu rry o f p u m ic e a n d w a te r a n d a ro ta tin g p o in te d p ro p h y la x is b ru sh . T h e p u m ic e a n d d e b r is w ere rem o v ed by w ash in g th e to o th su rface th o ro u g h ly . T h e tee th w ere iso la ted by co tton ro lls. T h e to o th su rfaces to be sea led w ere d r ie d w ith c o m p re sse d a ir a n d e tc h e d fo r 60 seconds w ith a gel p h o sp h o ric acid e tc h a n t. T h e e tc h a n t was th o ro u g h ly w ash ed f ro m th e te e th w ith w a te r a n d a s p ira te d f ro m th e m o u th . T h e q u a d r a n ts w e re r e iso la te d w ith c o tto n ro lls e x e rc is in g c a re to p re v e n t saliva co n tam in a tio n o f th e e tc h e d su rfaces . T h e q u a d ra n t was d r ie d f o r 15 seconds. A f rosty o r ve lvet a p p e a ra n c e in d ic a te d a n a d e q u a te e tch , w h ich if n o t p re s ­

e n t , in d ic a te d a n e e d fo r th e e tc h in g p ro c e d u re to be r e p e a te d . A w h ite , l ig h t-c u re d se a la n t was a p p lie d to th e occlusal su rfaces o f se co n d p r i ­m ary m o lars a n d se lected firs t p r im a ry m o la rs (those w ith w ell-d efin ed p its a n d fissures) a n d p o ly m eriz ed fo r 20 seconds p e r su rface w ith a v isible-light c u r in g u n it. T h e se a led su rfaces w ere e x a m in e d fo r sea lan t im p e rfe c tio n s a n d in c o m p le te c o v e ra g e ; r e p a irs w e re m a d e as n e e d e d .

T h e tim e re q u ire d to tr e a t each p a tie n t was 2 0 to 3 0 m in u te s . A n a v e rag e o f 10 p a tie n ts w ere tr e a te d each day . O p e ra to r s w o rk ed w ith ­o u t d e n ta l assistan ts. T o e v a lu a te th e re te n tio n o f th e se a la n t o n th e p r im a ry te e th , a g ro u p o f c h ild re n tre a te d d u r in g th e 1984-85 acad e m ic y e a r w e re e x a m in e d d u r i n g th e ¡ 9 8 5 -8 6 acad e m ic year.

T o ca lcu la te th e r e q u ire d sa m p le size, an ex ­p ected re te n tio n ra te fo r p r im a ry te e th , b ased o n resu lts of a p r io r stu d y (J. R. H a rd iso n , p e r ­sonal co m m u n ic a tio n , T e n n e sse e D e p a r tm e n t o f H e a lth a n d E n v iro n m e n t, 1984) o f 91 .1% w as a s su m e d . T h e sam p le size w as ca lcu la ted w ith a 95% c o n fid en ce level. T h e a s su m p tio n th a t th e p e r c e n ta g e o f su r fa c e s r e m a in in g sea led in th e sam ple b e in g ± 2.5% o f th e t r u e p e rc e n ta g e o f p r im a ry te e th re m a in in g sea led in th e e n tire p o p u la tio n w as also u se d in th e c a lc u la tio n . S y stem atic s im p le r a n d o m sa m ­plin g was u sed to select th e H e a d S ta rt c e n te rs in c lu d e d in th is fo llow -up study . All c h ild re n w h o h a d p a r tic ip a te d in th e ap p lica tio n p h ase o f th is se a lan t s tu d y a n d w ho w ere still a t te n d ­in g o n e o f th e H ead S ta rt c e n te rs se lec ted fo r th e fo llow -up stu d y w ere in c lu d e d in th e sam ­p le . F o llow -up e x a m in a tio n s w ere c o m p le te d d u r in g th e acad e m ic y e a r fo llow ing th e a p p lica ­tio n p h a se o f th e p ro jec t. T w o o p e ra to rs , w ho w ere e x p e r ie n c e d in sea lan t e x a m in a tio n p ro ­c e d u re s , c o m p le te d th e fo llo w -u p e x a m in a ­tio n s . O c c lu s a l s u r f a c e s w e re r e c o r d e d as “se a led ” if th e se a la n t re m a in e d in tac t, “se a la n t partia lly m issing” if only p a r t o f th e se a lan t was in tac t, a n d “se a lan t m issing” if no se a la n t was de tec tab le .

T h e u se o f visibly d e te c ta b le s e a la n t e n ­h a n c e d th e ease o f th e fo llow -up ex a m in a tio n p ro c e d u re . Fo llow -up ex am in a tio n s w ere c o n ­d u c te d in fo u r reg io n s o f th e sta te . T h e x 2 tes t d e s ig n e d to d e te c t a s ig n ifican t d if fe re n c e in p ro p o rt io n s was u se d to c o m p a re th e p e rc e n t­a g e s o f s u r f a c e s t h a t r e m a in e d s e a le d a t fo llow -up a m o n g th e fo u r reg io n s. T h e sam e

sign ifican ce tes t was u se d to c o m p a re th e overa ll ^ resu lts o f th is s tu d y w ith th e 91 .1% re te n tio n on p r im a ry te e th re p o r te d in a p r io r study .

Results

The c o n d itio n o f th e occlusal su rfaces a t th e fo llo w -u p ex a m in a tio n is show n in T a b le 1. T h e ^ o v era ll re te n tio n ra te was 88 .2% . S ea lan t was com p le te ly m issing f ro m 10.6% o f th e su rfaces sea led a t th e ap p lica tio n p h ase o f th e p ro jec t, a n d se a la n t was p artia lly m issing f ro m f.2% o f th e tre a te d su rfaces.

M e tro p o litan co u n tie s w ere n o t in c lu d e d in th e fo llow -up stu d y b ecau se o f th e p o te n tia l fo r d if fe re n c e s in ap p lica tio n te c h n iq u e s b e tw een ^ th e s e c o u n t ie s , w h e re o p e r a to r s w e re n o t t r a in e d in se a lan t ap p lica tio n , a n d th e re m a in ­ing reg io n s. T h e o th e r re g io n s th a t w ere n o t in c lu d e d in th e fo llow -up stu d y c o n ta in e d few H e a d S ta rt c e n te rs a n d w ere n o t se lec ted in th e system atic sa m p le se lection . T e e th in c lu d e d in th e fo llow -up s tu d y w ere all sea led in th e 1984- ^85 ap p lica tio n p h ase by o p e ra to rs w ho p a rtic i­p a te d in th e se a la n t ap p lica tio n t r a in in g p r o ­g ra m w ith th e sing le ex cep tio n o f o n e o p e ra to r in reg io n 4.

S ea lan t re te n tio n by reg io n is show n in T ab le2. In reg io n s 2, 6, a n d 8 se a la n t re te n tio n ra te s ra n g in g f ro m 92.5% to 96 .3% w ere re c o rd e d . * T w en ty -six p e rc e n t of th e se a la n t w as re c o rd e d as m issing o r partia lly m issing f ro m th o se s u r ­faces tre a te d in re g io n 4. E ach reg io n was tes te d ag a in s t th e o th e r reg io n s to d e te rm in e w h e th e r th e re te n tio n o f th e sea lan t v a ried sign ifican tly . T h e se c o m p ariso n s in d ic a te d th a t th e re te n tio n of sea lan ts o n te e th in reg io n 4 was s ign ifican tly low er (P < .01) th a n th e r e te n tio n in each o f th e o th e r th re e reg io n s. T h e p ro p o rt io n s o f su r- ? faces re m a in in g sealed in reg io n s 2, 6, a n d 8 w e re n o t s ig n if ic a n tly d i f f e r e n t f r o m o n e a n o th e r . T h e o v era ll re te n tio n o f 88 .2% in this H e a d S ta rt stu d y w as n o t s ign ifican tly d if fe re n t f ro m th e 91.1% re te n tio n a t f 2 m o n th s fo u n d in an e a r lie r stu d y o f sea lan t re te n tio n o n p r im a ry su rfaces . ^

Discussion

T h e re is little d o u b t th a t sea led to o th su r­faces rem a in im perv ious to d e n ta l caries fo r as long as th e sea lan t rem a in s intact.T h e success o f sealan ts d e p e n d s on th e ir

Table 2 ■ Condition of occlusal surfaces at follow-up by region, Head Start Sealant Program, Tennessee, January 1986.

Region 2 Region 4 Region 6 Region 8

No. % No. % No. % No. %*

Surfaces exam ined 147 100.0 254 100 326 100.0 54 100.0Surfaces sealed 136 92.5 188 74 313 96.0 52 96.3Sealant partially missing 0 5 2 3 0.9 1 1.9Sealant m issing 11 7.5 61 24 10 3.1 1 1.9

•Sum of percentages does not equal 100% because of ro u n d in g of figures.

6 1 4 ■ JA D A , V ol. 114, M ay 1987

A R T I C L E S

ability to rem ain firmly attached to the to o th s u r fa c e , is o la t in g th e c a r ie s - v u ln erab le pits and fissu res from the m outh. T h e sealant serves as a physical barrier, preventing caries-producing ac­tivities from affecting the sealed surface.

Early clinical reports o f sealant applica­tion on primary teeth show ed a lower rate o f retention than on perm anent teeth. Perhaps because o f these early reports, many clinicians recom m ended that seal­ants be applied only to perm anent teeth. Since the initial publications, studies8 have show n that com parable rates o f retention can be accom p lish ed for prim ary and perm anent teeth. N o special treatm ent, such as increasing the etching tim e from 60 to 120 seconds, is necessary w hen ap­plying sealants to primary teeth.

O ne potential problem that existed in the m inds o f the H ead Start Sealant Pro­gram planners was the ability o f 3- and 4-year-old H ead Start enrollees to cooper­ate for the duration o f the application pro­cedure, which was approxim ately 20 to 30 m inutes. T h ese fears proved u n foun ded as only approxim ately 5% o f the children resisted or refused treatm ent.

T h e use o f a w hite visible-light-cured sealant provides at least five advantages o v er a clear a u top o lym erized sealan t. First, the sealant is easily detectable during application and at recall exam inations. T h e likelihood o f inadequate coverage or sealant im perfections such as surface bub­bles is reduced. Second, the operator is in control o f the polym erization tim e and n eed not be as concerned with environ­m ental factors such as am bient tem pera­ture and hum idity. B ecause the polym er­ization process begins im m ediately on ap­plication o f the curing light, the problem o f saliva contam ination, w hich may be en ­countered while waiting for polym eriza­tion to occur when using autopolym erized materials is reduced. T h e third advantage o f a visible-light-cured system is the reduc­tion o f polym erization tim e. L ight-cured sealants are polym erized by a 20-second exposure to visible light; autopolym erized sealants require at least 60 seconds, and som etim es considerably longer d epend ing on room tem perature and hum idity, for polym erization to be initiated. Fourth, the problem o f an uneven distribution o f the sealant over the tooth surface, w hen the patient is in a reclined position, is reduced by applying the curing light to the sealant im m ediately after application. T h e fifth advantage is the elim ination o f m ixing the two com ponents o f the autopolym erizing

system. T his elim ination saves tim e and reduces the need for a dental assistant, w hich is especially advantageous w hen an­cillary personnel apply the sealant.

T h e application o f the sealant in the H ead Start centers provided an advantage in that it was not necessary to transport the children from fam iliar surroundings and place them in a dental office environm ent that could be interpreted as hostile. Porta­ble dental equipm ent was placed in an area o f the center w here the children could eas­ily watch the sealant application, thus al­laying patient apprehension that m ight be expected in children o f this age group.

T h e sealant retention rates at follow -up exam ination ranged from 74.0% to 96.3% fo r th e fo u r r e g io n s in v o lv ed in the follow -up (Table 2). T h ree o f the four re­g io n s e x p e r ie n c e d re ten t io n rates o f 92.5% or greater. M ost o f the operators participated in an 8-hour training pro­gram before the project, and som e had previous sealant application experience. O ne operator did not attend the training program and had no application experi­ence, which may be responsible for the lower rate o f retention in region 4.

T h e retention rates observed in regions 2, 6, and 8 are com parable to the best reported retention rates on perm anent teeth after 12 m onths.

Summary

A study investigating pit and fissure seal­ant retention on primary teeth o f 1,871 children enrolled in the H ead Start pro­gram was instituted in T en n essee in Sep­tem ber 1985. T h e objective o f the study was to determ ine the retentivity o f sealant after application to prim ary molars with w ell-defined pits and fissures.

Children from four regions in T en n es­see were reexam ined 1 year after applica­tion to determ ine the rate o f sealant reten­tion. R egional retention rates varied from 74.0% to 96.3% with a total rate o f 88.2% for all regions com bined.

S e a la n t a p p l ie d by e x p e r ie n c e d operators to prim ary teeth may be ex ­pected to be retained for periods com pa­rable to retention tim es for perm anent teeth.

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Dr. H ard ison is regional den ta l d irector, Tennessee D epartm ent o f H ealth a n d Environm ent, B ureau o f H ea lth Services, 100 9 th Ave, N , N ashville, T N 37219-5405. D r. Collier is d irec to r, division o f dental health , T ennessee D epartm en t o f H ealth and Envi­

ronm ent. Dr. Sprouse is in private practice in Oak Ridge, T N , and serves as consultant, H ead S tart P ro­gram . Ms. Van Cleave is statistics assistant d irector, T ennessee D epartm en t o f H ealth an d Environm ent. Ms. H ogan is statistical analyst, T ennessee D epart­m en t o f H ealth and E nvironm ent. A ddress requests for rep rin ts to Dr. H ardison .

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2. Bell, R.M., and o thers. Results o f baseline dental exam s in the national preventive dentistry d em onstra­tion p rog ram , R-2862-RW J. Santa M onica, CA, Rand C orp , 1982.

3. Cueto, E .I .,a n d B uonocore, M.G. Sealing o f pits and fissures with an adhesive resin: its use in caries p revention. JA D A 75(1): 121-128, 1967.

4. Buonocore, M.G. Caries p revention in pits and fissures sealed with adhesive resin polym erized by ul­traviolet light: a two-year study o f a single adhesive application. JA D A 82(5): 1090-1093, 1971.

5. G ourley, J.M . A two-year study o f a fissure seal­an t in two Nova Scotia com m unities. J Public H ealth D ent 35(2): 132-137, 1975.

6. Going, R.E., and others. Four-year clinical evalu­ation o f a p it and fissure sealant. JA D A 95(5): 972-981, 1977.

7. Horowitz, H .S., and others. Retention and effec­tiveness o f a single application o f an adhesive sealant in p revendng occlusal caries: final re p o rt a fte r five years o f study in Kalispell, M ontana. JA D A 95(6): 1133- 1139, 1977.

8. Sim onsen, R.J. T h e clinical effectiveness o f a col­o red p it an d fissure sealan t a t 36 m onths. JADA 102(3):323-327, 1981.

9. T onn , E.M. T h ree-year evaluation o f fo u r seal­ants in Los Altos, C alifornia. IADR, abstract no. 1379, M arch 1982.

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