operative Dentistry

Preventive resin restorations: indications, technique, and successLouis W. Ripa* / Mark S. Wolff* *

Although preventive resin restorations have been reported since 1977, there is littleuniformity concerning the indications for this procedtire, nor is there a standardtechnique. This article proposes diagnostic criteria for pit and fissure occtusal cariesand diagnosis-related considerations for treatment planning for preventive resin re.stora-tions. A step-by-step "laminate" technique, which includes, successively, a glass-ionomer cement liner, a posterior composite resin, and a sealant, is described. Thesuccess rates reported for several clinical studies of preventive resin restorations arepresented, although the criteria for this restoration, treatment methodology, and thedeterminates of success vary from sttidy to study.(Quititessence Int 1992,-23.307-315.)

Introduction

Preventive resin restorations represent an evolution inthe use of dental resins on posterior teeth that beganwith the studies of pit and fisstire sealants in the 196ÜS.Sealants are indicated for teeth with caries-free pitsand fissures, whereas preventive resin restorations areused for pits and fissures with diagnosed earies.

A preventive resin restoration is a conservativetreatment that involves limited exeavation to removecarious tissue, restoration of the excavated area with acomposite resin, and application of a sealant over thesurface of the restoration and remaining, sound, con-tiguous pits and fissures (Fig la). This treatment is analternative to the customary approach in which, in ad-dition to carious tissue, sound pits and fissures are pre-pared and an amalgam restoration is placed (Fig lb).

* Professor and Chairman. Department of Children's Dentistry.State University of New York at Stony Brook. School of DenialMedicine, Stony Brook, New York 11794.

"* Clinical Assoeiate Professor, Direetor, Division of OperativeDentistry, Department of Restorative Dentistry, State Univer-sily ot New York at Stony Brook.

The purposes of this article are to: (I) examine theindications for preventive resin restorations, (2) de-scribe the technique, (3) review the success of clinicalstudies, and (4) discuss the advantages and disadvan-tages of this new technique.

Indications for preventive resin restorations

Preventive resin restorations are used on the oeclusalsurfaces of premolars, permanent molars, and primarymolars. Despite several clinical studies of the proce-dure, no uniform indications have been estabhshed.A broad, but nonetheless encompassing, statement is:A preventive resin restoration K indicated when tlie cariouslesion in a pit or fissure is small and discrete. Thus, theclinician must make diagnostic decisions concerningthe existence, size, and location of a lesion, and atreatment planning decision that a preventive resinrestoration is the most appropriate treatment.

Diagnosis

Diagnosis involves radiographie, visual, and taetileassessment. King and Shaw demonstrated that radio-graphs are insufficient for the detection of occlusallesions, presumably because many lesions are too smallto create a radiographie image.' For placement of apreventive resin restoration, the radiograph must showno evidence of proximal caries that would mandate a

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reventive Resin Resto

Fig 1 a Occlusal sutiace treated with preventive resin res-torations. Excavation is limited to caries removai. Posteriorcomposite resin restorations are placed. The restorationsand all occlusai pits and fissures are covered with sealant.

Fig lb Occlusai surface treated with conventionai amalgamrestorations. Extension for prevention requires the elimina-tion of sound, as well as carious, pits and fissures in theoutline form.

Table 1 Diagnostic and treatment planning consideration? for pits and fissures

Clinical signExplorer catchDiscoloration*Enamel softness

Diagnosis

Treatment options

NoNoNo

Sound

No treatmentSealant

YesNoNo

Sound

Seaiant

YesYesNo

Questionable

Sealant

YesYesYes

Carious

Preventive resin restoraiionConventional restoration

White, undermining de mineraliza! ion.

more extensive restoration. It should be remembered,however, that clinical radiographs underestimate thetrue extent of carious lesions,"'' and the actual size isusually larger than its radiographie image imphes.Although, for research purposes, teeth with radio-graphic evidence of dentinai caries have received pre-ventive resin restorations,'' if occiusal caries extendsinto the dentin so that it can be detected radiographic-aily, the lesion is too large for a preventive resin res-toration. Occlusai iesions that can be identified clinic-ally, but are not radiographieally dctectabie, presentno radiographie contraindication to a preventive resinrestoration.

Lesions exhibiting frank cavitation are easy to detectchnically. Borderline cases that fali between a soundtooth surface and obvious caries are the most difficult.It is tiiese less-obvious cases that demand ail tlieoperators diagnostic skili and usually require a pre-

ventive resin restoration. Visual and tactile inspectionis made with the teeth thoroughly air dried and prop-erly illuminated. The pits and fissures of the occlusalsurface are carefully probed with a sharp explorer todetermine if the explorer tip "catches'" or resists re-moval after insertion into a pit or fissure with moderateor firm pressure,' A catch alone is insufficient evi-dence of caries, because the explorer may be wedgedbetween the cusps or in a pit or fissure, but it is anindication to more closely examine the area.

Drying the tootii will drive out fluids present in themieropores of demineraiized enamel, and the affectedarea will appear a matte white in contrast to the glossof normal enamel. While a dark stain usually shouldhe ignored during diagnosis, a ioss of normal trans-lucency of the ename! surrounding a pit m(.licates thepresence of demineraiization and suggests a develonine

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Normal enamel is hard, and softness represents thesine qua non of caries diagnosis. Softness is determinedby the taetile feel of the explorer. If the explorer pene-trates at the base of a pii or fissure, or if chalky whiteenamel ean be scraped oft' the walls, the area is carious.

Table 1 presents the possible permutations of the re-sults of visual and tactile examinations of teeth thaiare radiographically sound, together with appropriatediagnoses and treatments. While other visual and tac-tile combinations are possible, such as discolorationwithout an explorer catch and softness, they are eitherchnically illogical or highly unlikely.

Treattnent plan

When all the results of the examination for clinicalsigns of caries are negative, the surface is diagnosed assonnd and requires either no treatment or a sealant.The treatment options for sealants are discussed eise-where.*"̂ When the only sign is an explorer catch, thesurface is still considered to be sound.'' However, pitsand fissures that catch the explorer are difficult for diepatient to clean and can serve as niduses for cariesdevelopment (Fig 2); therefore, a sealant is recom-mended. Questionable surfaces are those with positivevisual and tactile findings, eg, explorer catch and dis-coloration, but that lack the definitive finding of soft-ness at the base or sides of the pits or fissure. Sealantsare also recotnmended for those teeth.

In their review of the management of questionablecarious fissures, Meiers and Jensen^ cited four clinicalstudies that evaluated "borderline" carious fissuresover a period of 24 to 41 months. It was reported that47% to 73% of the borderhne cases progressed to astage of definite caries. These figures indicate that pre-ventive treatment, such as the use of sealants as dis-cussed above, is preferable to a philosophy of watchfulwaiting. Too often, dentists "watch" as caries progresses.Should a lesion inadvertently be sealed there is nodanger, because there is sufficient clinical evidencedemonstrating that properly sealed lesions do not ad-vance and that the bacteria, which are isolated fromtheir principal nutrient source, decrease in viabilityand number.*'''"'' As stated by the American DenialAssociation,'^ "It appears that as long as the sealantprovides a physical barrier between the caries and theoral environment the lesion does not progress and itsbacterial population decreases dramatically over time."

The combination of an explorer catch and definitesoftness at the base or along the walls of a pit or fissureis evidence of caries. Usually, a white halo of under-mining demineralization also surrounds the affected

Fig 2 Cross section of an occlusal fisstjre. Pits and fissuresare difficult to clean and encotjrage the dietobacterial factorsresponsible tor caries.

area. When caries is diagnosed, either a preventiveresin or conventional restoration is indicated. The indi-cation for a preventive resin restoration is that the le-sion in the pit or fissure be small and diserete. Smallrefers to the width of the lesion, rather than the depth,and discrete means that the lesion does not extendalong a fissure. Although more than one discrete lesionmay be present, they should not be conftuent, whichwould require a wider cavity preparation.

While the decision to use a preventive resin restora-tion is made during the treatment planning session,the final confirmation of this decision may await theactual treatment visit. Careful opening into the affectedarea enables the operator to confirm the presence ofcaries and determine its extent. Excavation should beperformed with a small round, pear-shaped, or round-ended bur with a width not exceeding 1.0 mm to restrictthe size of the preparation (Table 2). If the width of thepreparation exceeds more than one third the distancebetween the buccal and lingual cusp tips, a conven-tional restoration should be considered, becausecavosurface margins are likely to be placed in areas ofmasticatory stress."*" Simonsen,•" however, has reporteduse of preventive resin preparations slightly largerthan a No. 2 round bur, which would have a diametergreater than l.tl mm.

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Table 2 Standard bur sizes aud shapes

Shape

RoundPearRound-ended

0.5

1/4

0.6

1/2329

Diameter (mm)

0.8 1.0

1 2330 331245

i.2

3332

1.4

4

Technique

Several methods for preparing preventive resin resto-rations are descrihcd in the literature. The differ-ences between the methods are minor, and all are ac-complished using the following treatment sequence;(I) anesthesia and isolation, (2) preparation, (3) resto-ration, and 14) sealant application. The following de-scription of the preventive resin restoration techniqueis consistent with other published descriptions. Figures3 to 10 show the principal steps of the clinical sequence.

1. Administer local anesthesia.Rationale. Although optional, infiltration or blockanesthesia should be considered for the patient's com-fort. Excavation with high-speed burs may be painfuldespite the minimal instrumentation associated withthe procedure. Application of the rubber dam retainersmay be painful.

2. Isolate with rubber dam. Only the tooth or teethbeing treated need be isolated (Fig 3).Rationale. A procedure involving conditionmg withacid, application of composite resin and sealant, andpossible use of a glass-ionomer lining cement is tech-tiique sensitive and time-consuming. Each of these stepsis sensitive to moisture contamination, A rubber damprevents salivary contamitiation of the treatment area.

3. Remove caries. A small round, pear-shaped, orround-ended bur is used (Fig 4 and Table 2). The cavo-surface margin is not beveled.

Rationale. There are no rules of cavity design becausethis is a bonded restoration. The goal is to remove allcaries and as little tooth structure as possible. Penetra-tion beyond the dentoenamcl ¡unction is not necessary,if all caries has been removed. Small burs arc used toconserve tooth structure and help ensure a narrow cav-ity preparation. Cavosurface margins are not beveled,because Eisenberg and Leinfelder'^ found, in a 2-yearstudy, that beveling the cavosurface margin has no sig-nificant effect on the clinical performance oC posteriorcomposite resins.

4. Provide pulpui protection if necessary. Calcium hy-

droxide is placed only on the floor of the preparation.Glass-ionomer lining cement should cover all of thedentin and not extend onto the enamel (Fig 5),Rationale. If caries removal extends deeply into thedentin, calcium hydroxide and glass-ionomer linersare indicated.^*-" Calcium hydroxide stimulates re-parative dentin when the preparation approaches thepulp. Glass-ionomer lining cement bonds to dentin,-'^is an insoluble barrier to the acid etchant,^'' provides asurface to which the composite resin micro mechanicallybonds,''""" and releases fluoride to the cavity walls,"^Shallow preparations in dentin should be lined onlywith glass'ionomer cement. Preparations that are h-mited to enamel do not require a liner.

5. Clean the occlusal stirface. An aqueous slurry offine pumice in a rotating rubber cup is used to cleanthe occlusal surface, including the cavosurface margin(Fig (>). The tooth is washed and dried.

Rationale. Maximal bond strengths are obtained whena prophylaxis is given prior to acid conditioning.*^While there is no evidence to confirm the value of usingpumice instead of other cleaning agents, it is behevedthat flavored, oil-based, or fluoride-containing prophy-laxis pastes may adversely influence the conditioningof the enamel.

6. Condition the entire occlusal suiface. The surface,including the cavosurface margin and enamel cavitywalls, is etched with phosphorie acid gel or liquid,then thoroughly washed and dried (Fig 7).Rationale. Conditioning creates pores in the enamel andenables the microseopie infiltration of dental resin intothe tooth surface, where it polymerizes and bonds."'''The usual etching time is 60 seconds, although 20-secondetching periods have been studied."''' ""̂ Etching of theglass-ionomer cement surface is also re comme nded,"**unless a light-curing product is used. Within the narrowconfines of the cavity preparation, it sometimes isdifficult to avoid etehing the glass-ionomer liningcement: however, with careful application of a geletchant, it can be avoided. Etching for more than 30seconds eauses a precipitate film to form over the glass-ionomer cement surface.''^ If acid is applied to theglass-ionomer cement, formation of this film becomesthe time-determining cotisideration for the conditioningstep."*" Washing removes the calcium-phosphate reactionproducts of the phosphoric acid conditioning agentand enamel. The tooth is washed for 10 to 20 seeondsto achieve maximal bond strength.^"

7. Place hotiding agent. The eavity walK ,-irid surfaceof the glass-ionomer cement liner are euvcred with abonding agent (Fig 8).

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Fig 3 Tooth to be treated with a preventive resin restorationis isolated with a rubber dam.

Fig 4 Caries removal. The No, 245 bur in this picture hasa rounded end and a diameter of 0.80 mm. Three discretecarious areas are to be removed.

Fig 5 Placement of glass-ionomer lining cement. Fig 6 Occlusal surface is cleaned with an aqueouspumice slurry to remove contaminants that might interferevüith bonding.

Fig 7 Ail surfaces to be bonded are etched with phosphoricadd.

Fig 8 Bonding agent is placed on the oavity walls andsurface ot the glass-ionomer cement liner.

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Fig 9 Posterior eomposite resin restorative materialplaced into the minimal cavity preparations.

Fig 10 Sealant has been applied to the tooth and the res-toration surface.

Rationale. Use of a bonding agent improves the bondstrength between a glass-ionomer cement and compositeresin.^' Because some glass-ionomer cements includeresin, an intermediate bonding agent should facilitatebonding between the glass-ionomer cement and thecomposite resin. If the cavity preparation is limited toenamel, and glass-ionomer cement is not used, abonding agent is still employed.

8. Place a posterior composite resin into the preparation(Fig 9). If a light-curing composite resin is used, it isplaced in increments of 2 mm or less.Rationale. The composite resin mieromeehanicallybonds to the conditioned enamei and provides an effec-tive marginai seal.̂ "* Bonding occurs between the com-posite resin and prepared glass-ionomer cement anddentinal walls.'"'"" An incremental buildup should beused for light-curing composite resin, to ensure com-plete polymerization."^" Care should be taken not tooverfill the eavity preparation. Placing the properamount of composite resin is easier to accomplishwhen a light-curing product is used, because the appli-cation is in small increments, and the initiation ofpolymerization is controlled completely by the operator.

9. Apply sealant. The previously acid-conditionedocclusal surface and the restoration surface are cov-ered with sealant, which is allowed to harden or lightpolymerize (Fig 10). Retention and coverage of thesealant are checked. If sealant can be pried from thepits or fissures with an explorer, the tooth and restora-tion are re-etched for 10 seconds, washed, and dried,and new sealant is applied. '

Ratiotmle. Sealant prevents caries of the pits and fissuresthat were not included in the eavity preparation. Thelaminate technique of sealant, composite resin, and

glass-ionomer cement minimizes microleakage.^''10. Equilibrate occlusion. Ii a scmifilled sealant wasused, the occlusion must be equilibrated after removalof the rubber dam.

Rationale. Unfilled sealants wear quickly to accommo-date a patient's occlusion, but semifilled sealants aremore abrasion resistant and require removal of highspots. ̂ '

Clinical success

Simonsen and Stallard,^'' in 1977, were the first to de-scribe preventive resin restorations and to report theresults of a chnical trial. Since then, a number of clinicaireports have appeared: however, studies have differedin the seleetion of teeth to be treated, in whethercaries should be removed, and in the clinical techniqueused. These differences make comparison difficult.

The results of several representative studies arelisted in Table ^.^^-^^-^"-''^ Only studies in which therewas eomplete caries removal are included. Three ofthe studies compared preventive resin restorations toother treatments. Azhdari et aP'' treated a controlgroup of teeth with occlusal amalgam restorations andnoted that the preventive resin technique was 25%less time-consuming than placing an amalgam restora-tion. Raadal^'' compared a sealant and composite resincombination to sealants alone and found a slightlyhigher retention rate for the preventive re^in restora-tion, indicating that placing sealant over ihc compos-ite resin did not affect the longevity oí rhe enamel-sealant bond. Walls et ai""'' calculated that [eeth in theirstudy treated with amalgam restorations ],¡^^\ 250^ Q̂the occlusal surface involved in the restoration while

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teeth restored with preventive resin restorations had5% of the occlusal surface involved.

Although the cited studies employed different criteriato judge the success of preventive resin restorations,the evaluations principally were of the longevity of thesealant portion, the amount of wear, and the presenceof a new carious lesion or restoration on the treatedsurface. The results, judged by the gênerai term per-cent sticc ess. were highiy favorable (Table 3}, The mostcommon cause of failure was wear of the resin, whichcould be compensated for by the addition of morematerial at a recall visit, Houpt and coworkers''" re-ported that of 205 teeth treated with preventive resinrestorations, only 13 (6%) developed new lesions duringa 4-year period. After 6.5 years, of 104 teeth still inthe study, 11 (11%) had developed caries, and 65% ofrestorations were considered completely successful."^

Discussion

The principal advantage of preventive resin restorationsover conventional ones is that they are less invasive.Hence, sound tooth tissue is not removed unnecessarily.

The most important and difficult decisions, namelythe caries status of the looth and the treatment plan,are made before the aetual invasive step is begun. Nomatter how scientificaliy founded, caries diagnosis is asubjective determination that relies on the clinical skilland experience of the operator. Dentists' diagnosisand treatment planning decisions vary greatly.**McKnight-Hanes and coworkcrs** reported consider-able variation in the treatment decisions of 20 dentistswho evaluated the occlusal surfaces of extracted per-manent molars. The greatest differences occurredamong teeth with questionabie or carious occlusalsurfaces. Treatment recommendations ranged fromsealants and preventive resin restorations to amalgamrestorations, Brownbill and Sctcos'"' conducted a similarstudy in which 20 operators evaluated the caries statusof occlusai surfaces of extracted moiars. For someocclusal sites, treatment recommendations ran thegamut from no treatment to a sealant, preventive resinrestoration, or conventional restoration.

The problem in clinical specificity is rooted in thesubjectiveness of the diagnostic method as well as theiack of specific criteria for the indications for preventiveresin restorations. This article attempts to amelioratethe situation by recommending criteria for makingdiagnostic and treatment planning decisions involvingocclusal pits and fissures. Through a modification of

V̂ criteria for the visual and tactile diagnosis of

Table 3 Success of preventive resin restorations

StudyDuration

(yr)

Success"

Simonsen and StallardAzhdarietal-''"Waliieretal'""'Houpt etal**'Walls et al''̂Simonsen and Jensen''^RaadaP"*Simonsen''Houpt et al'''Houpt et al *̂Houpt et a l"Simonsen and Landy^''

1.01,01,25'''1.52.02,52.53,03,04,06.57.0

1008682919796849911646590

' Complete retention and caries Iree.^ Average,

pit and fissure caries, the clinical signs of sound, ques-tionable, and carious pits and fissures were listed andthe diagnosis was related to the appropriate treatment(see Table 1 ). Whether use of these criteria by dentistswill reduce the variability reported in diagnosis andtreatment selection remains to be determined. Never-theless, the caries criteria have been used in clinicalcaries trials for nearly a quarter of a century, wherediagnostic reproducibility is paramount, and havestood the test of time.

One reason for the slow adoption of sealants hasbeen dentists" concern that caries will be inadvertentlysealed.*^*^This same concern may extend to prevent-ive resin restorations, A dentist could diagnose andremove caries in one pit, only to leave an untreatedlesion in another pit. There is considerable clinical evi-dence that, once sealed, lesions will not progress andwill become inactive,''''""^ so this concern should notconstitute a barrier to the use of preventive resin resto-rations. In fact, cognizant of these results, some chnicalresearchers recommend deliberately ieaving caries be-neath a seaiant or preventive resin restoration, '•'-''•'̂ •2"™

The method described in this article has been referredto as the laminate technique because of the successiveuse of different materials. Other versions of the pre-ventive resin restoration technique have been pubiished.One involves the use of a glass-ionomer cement, in-stead of a composite resin, restoration beneath thesealant,""" The philosophy expressed by Croir"* thatresins bond to enamel, whiie glass-ionomer cements

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bond to dentin, influenced the choice of materialsdescribed in the present article.

The laminate technique takes advantage of the de-sirable properties of each of the materials employed.The glass-ionomer cements pose no significant threatto pulpal vitality and are used to protect the pulp aswell as for their bonding properties to the dentin. Therelease of ftuoride by glass-ionomer cements to adja-cent tooih structure is an additional benefit, althoughit may be superfluous, considering the low failure ratereported for preventive resin restorations. Posteriorcomposite resins bond to conditioned enamel and tothe glass-ionomer cement surfaee. The interlockingbetween the tooth and dental materials reduces gapsbetween the cavity walls and cavosurface margin andthe restoration, thus making marginal leakage unlikely.The sealant provides further micromechanical inter-locking uver the entire occlusal surface and protectsfrom caries the sound pits and fissures not included inthe cavity preparation.

Because of the degree of reported success and itsminimal invasiveness, the preventive resin restorationis the treatment of choice for small, discrete lesions ofthe pits and fissures.

References

1. King NM. Shaw L: Value of bitewitig radiographs in detectionof occlusal caries. Communilv Dent Orai Epidemiol [919:7:218-221.

2. Flaitz CM. Hicks MJ. Silvitswne LM: Radiographie, his-tologie, and electronic cotnparison of oeetusal caries: an invitro sttidy. Pediatr Denl 1986;8:24-.28.

3. Gwinnett AJ: A eomparison of proximal carious lesions asseen by clinical radiography, contact mieroradiography andlight microscopy, i / Im DentAssoe 1971;83:1078-108t).

4. Me rtz-Fair hurst El, Ca!t-Smith KM, Schuster GS, et al: Clin-ical perfortnance of sealed composite restorations plaeed overcaries compared with sealed and unsealed amalgam restora-t i ons . / ^m DentAssoe 1987; 115:689-694.

5. Radike AW: Criteria for diagnosis of dental caries, in I'ro-ceeding.s of the Conferenee on ¡he Ciinieal Testing of CarioslaticAgents. Chicago, Atnerican Dental Association, 1972, pp 87-88.

6. Simonsen RJ: Pit and fissure sealant in individual patientcare programs. / Denl Educ 1984 ;48(suppl): 42-44.

7. Bohannan HM, Disney JA. Graves RC, et al: Indications Forsealant use in a community-based preventive dentistry pro-gram. J Dent Educ 1984;48(suppi):45-55.

8. Meiers JC, Jensen ME: Management of the questionable ear-iüus fissure: invasive versus noninvasive techniques. .' AmDentA.sMc 1984; 108:64-68.

9. Handelman SL, Buonocore MG, Heseck DJ: A preliminaryreport on the effect of fissure seatant on bacteria in denlatcaries. J Prostiie! Dent 1972;27:390-392.

in. Handelman SL, Buonocore MG, Sctioute PC: Progress reporton the effect of a fissure sealant or bacteria in dental caries.JAm Dem A.mn- t973; 87:ltH9-tt91.

11. hlandelman SL: Microbiologie aspeéis of sealiny carious le-sions. J Prev Dent 1976:32(2):29-32.

12. Handelman SL, Washburn F, Wopperer P: Two-year report ofsealant effect on bacteria in dental earies. ¡Am DentAssoe1976;93:967-970.

13. Handelman SL, Leverett DH. Solomon ES. et ai: Use ofadhesive sealants over oeelusal carious lesions: radiographieevaluation. Commtmiiy Dent Orai Epidemioi 1981;9:256-259.

14. Handelman SL: Effecl of sealant placement on occlusalcaries progression. Clin Prev Dent t982:4(5): 11-16.

15. Leverett DH, Handelman SL, Brenner CM, et al: Use of seal-ants in ttie prevention and early treatment of carious lesions:cost analysis.//Im DentAssoe 1983; 11)6:39-42.

16. Handelman SL, Leverett DH, Iker HP: Longitudinal radio-graphic evaluation of the progress of caries under sealants. JPedod I985;9:119-126.

17. Handelman SL, Leverett DH, Espeland M, et al: Retentionof sealants over carious and sound tooth stirfaces. CommunityDem Orat Epidemiol 1987;l5:l-,5.

t8. Mertz-Fairhurst EJ, Schuster GS, Williams JE, et al: Clinicalprogress of sealed and unsealed caries. Part L Depth changesand bacterial eounts. / Proslhel Dem t979;42:521-526.

19. Mertz-Fairhurst EJ, Schuster GS, Wiliiams JE, et al: Clinieaiprogress of sealed and unsealed caries. Part IL Standardizedradiographs and elinieal observations. J Prosthet Dem 1979;42:633-637.

20. Mertz-Fairhurst EJ, Schuster GS, Fairhurst CW. Arrestingcaries by sealants: results of a elinical study. J Am Dent A.tsoc1986;112:194-197.

21. Going RE: Sealant effeet on incipient earies, enamet malura-tion, and future caries suseeptibility. J Dem Edue 1984;4R(biippl): 35-41.

22. Going RE, Loesehe WJ, Grainger DA, et al: Tbe viability ofmierourganisms in carious lesions five years after coveringwith a fissure sealant. J / lm Dem Assoc 1978;97:455-462.

23. Jensen OE, Handelman SL: Effect of an autopolymerizingsealant on viability of niicroflora in ocelusal dental cariesScand J Dent Res 1980;88:382-388.

24. Jeronimus DJ, Till MJ. Svenn OB: Reduced viability ofmicroorganisms under dental sealants. ASDC J Dent ChiidI975;42:275-28O.

25. Mieik RE: Fate of in vilro earies-like lesions sealed withintooth strueture J Dem Re': 1972;5t(speeial issue):225(abstrNo. 710),

26. Ripa LW: Studies ot pits and fissures, in Buonocore MG (ed):The Use Of Adhesives in Dentistry. Springfield, til, Charles CThomas, Publ, t976, pp 120-152.

27. Swift EJ Jr: The effect of sealants on dental caries: a review.JAm Dem Assoc 1988;I16:700-7Ü4.

28. Thelaide E, Fejerskov O, Migasena K, et al: Effect of fissuresealing on '"ern, ero flora in ocelusal fissures of human teeth.Areh Oral Bwi t977;22:251-259.

29. Anieriean Dental Assoeiation Council on Dental Materials,

:r~ ' '?T^"^ "'' '"' '̂̂ ^̂ -^lt 74

31. Simonsen RJ: Preventive resin restorations I A>„ r^1980; 100:535-539. avions, j ^ , „ Dem Assoc

32. Simonsen RJ: Potential uses of pit-and-fissure seal • •novative ways. A review. J Public Health Den, \l^l '^'3051II " '" ly»2;42:

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33. Houpt M. Shey Z: Occiuvii resmrulion using fissure sealantinstead of "extension for prevention." Qumtessence bu 1985;t6489^y2

Raadal M: Foiiow-vip study ot seating and fiiling with compos-ite resins in ihc prevenlion of occlusai caries. ComtnuniiyDent Oiat Epidemiol 1978;û: 176-lSO.

Eisenberg 13P, Leinfetder KF: Efficacy of beveling posteriorcomposite resin preparations. J Esthet Dent iyyO;2:7ü-73.Slanley HR, Going RE, Chauncey HH: Human pulp responseto acid pretreatment of dentin and in L-oniposite restoration.J Am Dent Assoc t975;9t:St7-825,

Tobias RS, Browne RM. Ptant CG, et al: Pulpai response toa gtass ionomer cement. Br Dent J t97S;t44:345-35ll,

Moutit GJ: Clinieal requiretnents for a successful "sandwieb"-dentine to glass ionomer cement lo eomposite resin. AustDentJ 1989:34:259-265.

Wails AWG: Glass polyatkenoate (giass-ionomer] cements: areview. J Dem 1985:14:231-246.

MeLean JW, Powis DR, Prosser HJ, et al: The use of giass io-nomer cements in bonding composite resins to dentine. Br

4t. Causton B. Sefton J. Williams A: Bonding class II compositeto etehed glass ionomer cement, fir DentJ 1987;163;321-324.

42. Swartz ML, Phillips RW. Ciark HE: Long-term F releasefrom giass ionomer cements. 3 Dent Res t9S4;63:158-l60.

43. Miura F, Nakagawa K, Ishizaki A. Scanning eiectron micro-scopic studies on the direct bonding system. ButI Tokyo MedDent Unix- 1973;20;245-260.

44. Gwinnett AJ. Matsui A: A study of enamel adhesives. Thephysical relationship between enamel and adhesive. ArchOral Bio! t967;12:t615-t620.

45. Stephen KW, Kirkwood M, Main C, et al: Retention of a fii-ied fissure sealant using reduced eteh time. A two-year studyin 6 to 8 year old children. Br Dent J 1982;153;232-233.

46. Eideiman E, Shapira J, Houpt M: The retention of Fissuresealants using twenty-second etch time. ASDC J Dent Child1984;51:422-424,

47. Fuks AB, Grajower R, Shapira J: In vitro assessment of mar-ginal leakage of sealants placed in permanent molars withdifferent etching times, ASDC J Dent Chitd 1984;51:425^27.

48. McLean JW: Giass-ionomer cements. Br Dent 3 1988;164:293-300.

49. Smith GE: Surfaee deterioration of glass-ionomer cementduring acid etching: an SEM evaluation. Oper Dem19S8;13:3-7.

50. Williams B, von Fraunhofer JA: The influence of lhe time ofetching and washing on the bond strength of fissure sealantsapplied to enamei. 3 Oral Rehahil 1977;4:139-I43.

51. Subrata G. Davidson CL: The effect of various surface treat-ments on the shear strength between composite resin andglass-ionomer cement. 3 Dent 1989; 17:28-32.

52. Wilson EG, Mandradjieff M, Brindock T: Controversies inposterior composite resin restorations. Dent Ctin North Am

53. Hormati AA. Futler JL. Denehy GE: Effeets of contamina-tion and mechanical disturbance on the quality of acid-etchedenamel. 3 Am Dem Assoc 1980:100:34-38.

54. Saunders WP, Strang R, Ahmiul t: In vitro assessment of Ihemicroieakage around preventive resin (iaminate) restora-tions, ASDCJ Dent Child 1990;57:433-43fi.

55. Raatlal M: Ahrasive wear of fiiled and unfiiied resins in vitro.SaindJ Dent Re.s 1978;86:399-403.

.56, Simonsen RJ, Slallard RE: Scaiant-rcstoration!, utilising adiluted fiiied composite resin one year results. QuintessenceInt lil77;8:77-84.

57. Simonsen RJ, Jensen ME: Preventive resin restorations utiiiz-ing diluted fiiled eomposite resins: 30 month resuits. J DenlRes 1979;58(speciai issue A):26I (abstr No. 676),

58. Simonsen RJ, Landy NA: Preventive resin restorations: frac-ture resistance and 7-year ciinical results. J Denl Res 1984;63(special issue): 175(abstr No. 175).

59. Azhdari S, Sveen OB, Buonoeorc MG: Evaluation ot a lusto-rative preventive technique for iocaliïed occiusul caries, JDent Res 1979;58(special issue A):330(abstr No. 952).

60. Houpt M, Eideiman E, Shey Z, et al: OcciusaJ restorationusing fissure sealant instead of "extension for prevention,"eighteen month results. J Dent Res 1982;61:214(abstr No. 324).

61. Houpt M, Eideiman E, Sbcy Z, et al: Occlusal restorationinstead of "extension for prevention." ASDC J Dem Child1984;.'it:270-273.

62. Houpt M, Eideiman E. Shey Z, et al: Occiusai compositerestorations: 4-ycar results. y,4ni Denr Assoc l985;tIl);35t-353.

63. Houpt M. Fuks A, Eideiman E, et al: Com posite/sea i antrestoration; 6W-year results. Pediair Dent 1988; 10:304-306.

64. Walker JD, Jensen ME, Pinkham JR: A eiinieal review of pre-ventive resin restorations. ASDC J Dent Child I99O;57;257-259,

65. Wails AWG, Murray JJ, McCabe JF: The management of oe-elusal caries in permanent molars. A clinical trial comparing aminimai composite restoration with an occlusal amalgam res-toration. Br DentJ t988;t64:288-292.

66. MeKnight-Hanes C, Myers DR, Salama FS, ct ai: Comparingtreatment options for occlusai surfaces uliliîing an invasiveindex. Pediatr Dem 1990:12:241-245,

67. Brownbill JW, Setcos JC: Treatment selections for fissuredgrooves of permanent molar teeth. ASDC J Denl Child 1990;57:274-278.

68. Gift HC, Frew R, Hefferren JJ: Attitudes toward and use ofpit and fissure sealants. ASDC J Dent Ciitld 1975;42:460^66,

69. Frazier PJ: Use of sealants: societal and professional factors./ Dent Educ 1984:48(suppl):80-95.

70. Mertz-Fairhurst EJ, Williams JE, Pierce KL, et ai: Seaiedrestorations: 4-year results. Am J Dent 1991:4:43-49.

71. Gareia-Godoy F: Tiie preventive giass ionomer restoration.Quintessenee ¡nt 1986;17;617-ftl9.

72. Giircia-Godoy F; Preventive giass ionomer restorations. Am JDem l988;t:97-99.

73. Henry RJ, Jerrell RG:The glass ionomer rest-a-seal./lSDCiDenl Ctnid 1989:56:283-287.

74. Croil TP: Glass ionomers for infants, children, and adoles-cents. 7/Im DentAs.íoc 1990-,120:fi5-6S. D

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