4801184 a

and properly illuminated. The use of mag-nification may also aid diagnosis. The use ofa probe should be restricted to the removalof plaque or food debris. Lesions should notbe probed as has been advocated as this maycause cavitation.1 Drying the tooth signifi-cantly improves diagnosis by driving fluidout of the micropores of demineralizedenamel, the affected area appearing a mattwhite in contrast to the gloss of normalenamel.

Dark staining is not a criteria for diagno-sis of caries alone, but loss of normal enameltransparency surrounding a pit indicatesthe presence of demineralization and mayindicate a developing lesion.

Bitewing radiographs are a pre-requisitewhen considering a sealant restoration.These should show no evidence of inter-proximal caries which may indicate that amore extensive restoration is required. Itshould be considered that the actual size ofthe lesion is usually larger than the radi-ographic image implies.2 Lesions suitablefor sealant restoration placement may be

those just into dentine. Bitewings are ofgreat importance in the diagnosis ofocclusal caries particularly with the adventof ‘hidden caries’ or the ‘fluoride syndrome’.This was first described by Millman in theearly 1980s and is the term used to describeocclusal dentine caries that is missed onvisual examination but detected radi-ographically or when a fissure biopsy isundertaken.3 It is thought to be associatedwith the use of fluoride toothpaste, com-munity fluoridation and topical fluoridetherapies. There is still controversy regard-ing the existence of ‘hidden caries’ but thegeneral consensus in the literature is that itdoes exist as an entity.4

Fibre-optic transillumination may also beof benefit in diagnosing occlusal and inter-proximal caries. Continuing developmentsare being made in the concept of electricalimpedance5 and laser fluoresence (Diagn-odent, KaVo) appears to have potential indetecting and monitoring occlusal caries.

Success rates for sealantrestorationsOne of the major problems when consider-ing the success rates of sealant restoratons isthe variation in techniques and materialsused. There are also few studies directlycomparing sealant restorations with con-ventional amalgam restorations.

Short term studies indicate a high degreeof success for sealant restorations.6–15 How-ever, longer term studies appear to indicatethat success is less predictable (Table1).16–21

For direct comparison of sealant restora-tion studies it is necessary to define successas 100% retention and no caries present inthe tooth.

However, presenting the studies in thismanner can give a misleading picture and itis necessary to consider a number of thestudies in more detail.

Mertz-Fairhust et al.21 reported 9-yearresults comparing three types of restoration:unsealed amalgams, amalgams with sealantand composite with sealant. Twenty-eightper cent of the sealants were fully retained inthe composite and sealant type, a further

358 BRITISH DENTAL JOURNAL, VOLUME 191, NO. 7, OCTOBER 13 2001

PRACTICErestorative dentistry

The sealant restoration is indicated pri-marily on the occlusal surfaces of perma-

nent molars and premolars and may also beindicated for primary molars. They are mostappropriate when the prepared cavity in a pitor fissure is small and discrete. Larger cavitieswould be more appropriately restored withamalgam or a posterior composite whilstsmaller cavities may be restored with sealantalone.

It is difficult to quantify what constitutes asmall and discrete cavity but it will be influ-enced by the occlusal area of the cavity,whether functional cusps are involved andthe morphology of the opposing occlusion.

Diagnosis of occlusal cariesThe early diagnosis of occlusal caries repre-sents one of the major challenges for thepractising dentist. While cavitated lesionsare easily detected clinically, it is lesions thatfall between a sound tooth surface and cavi-tation that are the most difficult to diagnose.Diagnosis may involve the use of visual, tactile and radiographic examination.

Visual examination should be under-taken with the teeth thoroughly air dried

The sealant restoration: indications,success and clinical techniqueD. C. Hassall,1 and A. C. Mellor,2

In this paper we have considered the available literature whichdemonstrates that sealant restorations perform at least as well asamalgam restorations and are more conservative. Success dependson retention of the overlying sealant and if this is fully retained it isunlikely that any residual caries will progress. The diagnosis ofocclusal caries and indications for sealant restorations are discussedand the clinical technique is described. We have concluded thatsealant restorations are the optimum restoration in small anddiscrete occlusal cavities.

1*Private Restorative, Prosthodontic, Periodontal andEndodontic Specialist; 2Senior Lecturer in PrimaryDental Care, University Dental Hospital ofManchester*Correspondence to: Dominic Hassall, 28 CloisterCrofts, Leamington Spa, Warwickshire CV32 6QQemail: [email protected] PAPER

Received 20.12.00; Accepted 23.03.01© British Dental Journal 2001; 191: 358–362

In briefThis article discusses:• Indications for sealant restorations• The diagnosis of occlusal caries• Clinical procedures for sealant

restorations• Success rates for sealant restorations

BRITISH DENTAL JOURNAL, VOLUME 191, NO. 7, OCTOBER 13 2001 359


41% were partially retained and only 16% ofthe sealant restorations failed because ofcaries. What is particularily interesting isthat restorations were placed over cariouslesions after minimal preparation and thatthe carious lesions did not progress beneathintact sealed restorations. The clinical per-formance of the composite and sealant typewas superior to the other restoration typesand the authors concluded that ‘sealedrestorations are superior to traditionalamalgam restorations’.

In a noteworthy study Welbury et al.21

compared minimal composite restorationswith amalgam restorations over 5 years.While only 26% of the sealant restorationswere fully retained and caries free, only 2%of the restorations failed because of cariesassociated with the restoration. There wasno significant difference in median survivaltime between the amalgam and sealantrestorations, and it was found that on aver-age amalgam restorations occupied 25% ofthe occlusal surface of the tooth, while mini-mal composite restorations occupied 5%.

Houpt et al.20 in a 9-year study demon-strated that 54% of sealant restorations hadcompletely retained sealants with 25% sus-taining partial loss. Occlusal caries wasrecorded in 25% of restorations in whichthere was sealant loss but there was noocclusal caries when the sealant was fullyretained.

The consensus from the studies is thatsealant restorations perfom at least as well asconventional amalgams and are far moreconservative of tooth tissue. It is also appar-ent that the longevity of the sealant restora-tion is dependent on the complete retentionof the overlying sealant.

If the overlying sealant is fully retainedthen recurrent caries or progression of cariesbeneath the restoration is negligible. This isconsistent with studies of caries progressionbeneath fissure sealants which indicate thatit does not progress beneath intactsealants.22– 27

Consequently if a sealant restoration isplaced, the dentist has a duty of care toensure that the retention of the sealant isregularly reviewed and repaired or replacedas necessary. In addition bitewing radi-ographs should be taken at appropriate

intervals to check there is no further cariesprogression.

Clinical procedureIt is useful to mark occlusal contacts prior topreparation. This will assist in the final deci-sion as to whether a sealant restoration isappropriate.

If it is anticipated that the cavity may be ofmoderate size then local anaesthesia will benecessary. Ideally the tooth is isolated withrubber dam (Fig. 1) This not only assists inmoisture control but also aids visualisationand cross-infection control.

What has been termed the fissure orenamel biopsy is then undertaken with asmall diameter bur such as a tungsten car-bide long pear (Jet 330, Beavers Dental).This involves cutting a minimal opening tothe depth of the enamel-dentine junctionsufficient to determine whether the caries ismore widespread (Fig. 2). All suspect areasof the fissure system should be explored.28

In this case there is dark staining and associ-ated opacity in the central pit of the tooth.

If the carious lesion extends beyond theenamel-dentine junction (Fig. 2) cariesremoval should be continued, limitingremoval to carious tissue only (Fig. 3).Probably the most reliable method of cariesassessment remains surface colour, struc-ture and hardness, and the cavity is accord-ingly assessed.29

Where there is restricted access it isimportant to thoroughly inspect the cavityto ensure that caries removal is complete(Fig. 4). The cavity is then assessed to deter-mine whether a sealant restoration is indi-cated. More extensive caries may necessitatean amalgam restoration or posterior com-posite.

Once the restorative has been placed therestoration and remaining fissures can befissure sealed. This may involve etching ofthe enamel if this has not already beenundertaken as part of the composite bond-ing procedure.

Finally the rubber dam is removed,occlusal contacts checked and any interfer-ences removed (Fig. 5).

Study Duration Success* (years) (%)

Simonsen and Stallard6 1.0 100Azhadri et al.7 1.0 86Walker et al.8 1.25 82Houpt et al.9 1.5 91Gray10 2 67–97Walls et al.11 2.0 97Simonsen and Jensen12 2.5 96Raadal13 2.5 84Simonsen14 3.0 99Houpt et al.15 3.0 77Houpt et al.16 4.0 64Welbury et al.17 5.0 26Houpt et al.18 6.5 65Simonsen and Landy19 7.0 90Houpt et al.20 9.0 54Merzt-Fairhurst21 9.0 28

* Complete sealant retention and tooth caries free

Table 1 Success of sealant restorations



A number of restorative techniques andmaterials are available for the restoration ofthe cavity. At present four types of sealantrestoration are available under the NHSGDS fee scale:

1. GDS Item 14e1: Fissure sealant alone2. GDS Item 14e2: Fissure sealant with

composite resin3. GDS Item 14e3: Fissure sealant with

glass ionomer4. GDS Item 14e4: Fissure sealant with

both composite resin and glass ionomer.

If the caries does not extend beyond thelevel of the enamel dentine junction fissuresealant only may be required. If howeverthe cavity is of a larger size a number ofoptions exist, involving the use of compos-ite resin, glass ionomer or both materials incombination.

The indications for the use of the four

Fig. 5 Checking occlusion ofcompleted sealantrestoration

Fig. 1 Toothisolated withrubber dam

Fig. 2 Cariesextendingbeyond theenamel dentinejunction

Fig. 3 Cariesremovallimited tocarious toothtissue

Fig. 4 Completedminimal cavitypreparation

BRITISH DENTAL JOURNAL, VOLUME 191, NO. 7, OCTOBER 13 2001 361


type of sealant restorations has been sum-marised by Paterson et al. (Table 2).30

It is apparent from Table 2 that there are avariety of restoratives available for use in thesealant restoration technique. The exactchoice of material may often be a matter ofoperator preference.

The use of glass ionomer may conferadvantages with regard to chemical bond-ing with enamel and dentine, fluoriderelease and possible reduction inmicroleakage.31–33

A number of recently introduced materi-als such as the ‘packable’ composites(Prodigy, Kerr; Solitaire 2, Heraeus Kulzer;Filtek P60, 3M) are available which mayoffer easier handling than conventionalcomposites. The authors have also foundthe use of coated ‘non-stick’ compositeinstruments useful for posterior compositeplacement and adaptation (Fig. 6). Theseinstruments (Ash) are available with a rangeof tips which facilitate more easy access andpacking (Fig. 7).

More recently introduced ‘flowable com-posites’ (Revolution, Kerr) may also proveto be beneficial in restoring cavities in whichthere is restricted access.34 However physi-cal properties are inferior to conventionalcomposites and they would appear inappro-priate for larger posterior cavities or wherethere are heavy occlusal contacts.

Fig. 7 Adaptation of composite in a large posterior cavity

Fig. 6 ‘Non stick’ composite instruments

Type of sealant restoration Indications

Type 1 Stained and decalcified fissureFissure sealant alone No radiographic sign of dentine involvement Less than two other carious lesions in mouth

Type 2 Stained and decalcified fissureComposite plus sealant More than two other carious lesions in mouth Enamel biopsy shows lesion confined to enamel

Type 3 Enamel biopsy indicatedGlass-ionomer cement plus Cavity in dentine with minimal sealant lateral spread Margins not in occlusal contact

Type 4 Enamel biopsy indicatedLaminate restoration Lesion in dentine with lateral spread along EDJ Cavity margins in occlusal contact

Amalgam restoration Enamel biopsy indicated Large radiolucency in dentine Significant lateral spread along EDJ Few fissures remaining surrounding cavity

Table 2 Indications for the use of each of the four types of sealant restoration



With minimally invasive techniques suchas air abrasion and chemomechanical cariesremoval35–37 materials such as the flowablecomposites may allow easier restorationplacement where access is restricted.

ConclusionsWhilst the success of larger posterior com-posites appears to be inferior to amalgam38

success rates for sealant restorations are com-parable to those of amalgam restorations butwith the advantage that they are less invasiveand hence sound tooth tissue is not removed.

Dentist concerns regarding the reportedsuccess of sealant restorations appear to belargely unsupported by longevity studies.Possible fears over incomplete cariesremoval also appear to be unwarranted, withcaries appearing not to progress beneathintact sealants. Potential problems regardingthe marginal shrinkage of composites andrecurrent caries may be addressed by usingglass ionomer in the technique. The cost-effectiveness of the procedure may be influ-enced by the re-introduction of afee-for-service element into the capitationpayment system for children’s dentistry.

The use of the sealant restoration shouldbe encouraged because it represents a toothpreserving procedure, producing a moredurable restoration with the added benefitof protecting the remaining fissure patternfrom carious attack. It may have the poten-tial to improve the prognosis of a tooth in‘the repeat restoration cycle’.39 It is apparenthowever that the dentist has a duty of care toensure that the sealant restoration is regu-larly reviewed and maintained to ensurecontinued success.

The authors would like to thank the dentists whoparticipated in the study and the Dental PracticeBoard for their co-operation. The assistance of theDepartment of Medical and Dental Illustration atLeeds Dental Institute is appreciated. The funding ofthe Department of Health is acknowledged, but theviews expressed are those of the authors.

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