SCHOOL OF DENTISTRY
Fissure sealing is a technique whereby pits and fissures that occur principally on the occlusal
surfaces of molar and premolar teeth are occluded by the application of fluid materials, which
are then polymerised in situ. Currently used methods are based on the principle that the
adhesion of acrylic and composite resins to enamel is greatly increased if the tooth surface is
first etched with acid (1). The resins used are two main types: those that polymerise after
mixing two components, and those that polymerise only after exposure to an appropriate light
source. The majority of sealants are “unfilled”, that is, they do not contain filler particles as do
composite resin restorative materials. Since the incorporation of filler increases abrasion
resistance there is some logic in using a filled resin for fissure sealing, although there is
insufficient evidence to suggest that such materials are superior to unfilled resins.
Many trials have shown that fissure sealants are effective in preventing occlusal caries,
although the results reveal wide variations between the proportion of teeth remaining fully
sealed after approximately four years (2). During the more recent of these studies there is a
greater awareness of the need for a meticulous technique and the results improved to give a
mean of 75% of teeth fully sealed after 3 years (3). This latest group of studies produced an
overall percentage effectiveness index (4) of 70 and a teeth saved index (5) of 33. The latter
indicates that 33 teeth out of every 100 sealed would otherwise have suffered from occlusal
caries during the duration of the study, a benefit to-effort ratio of 1:3. This is much better than
the ratios of 1:8 and 1:7 derived by Horowitz from earlier studies (6).
When interpreting the results of clinical trials it is important to bear in mind that patients were
selected in a variety of ways and that the results may have been influenced by caries rates not
applicable today, certainly the dental condition of children in the UK is improving. For
instance in 1973 the proportion of 10 year old children in England and Wales who had suffered
decay was 87%; in 1984 it was 65% and in 1993 it was 32%. However, many children still
have too much dental decay that ought to be prevented. This largely occurs in newly erupted
molar teeth so that only 38% of 10 year olds in the UK have all four first molars sound.
Fissure sealants could prevent much of this decay, although in 1993 only 37% of 10 year olds
in the UK had received this treatment (7). Underutilization of sealants has also been reported
in the USA and reasons suggested include unfamiliarity with the technique, fear of sealing in
decay, and a belief that amalgam restorations are better (8).
Since “basic” and clinical research supports the extensive use of sealants and technique details
are well understood (8) it is difficult to understand why there are still dentists who feel
insufficiently informed about sealants. Similarly, the consequences of sealing in small
amounts of decay have been studied and found not to present a significant problem, provided
that the surface integrity of the sealants remains intact (9).
It is difficult to compare the cost effectiveness of sealants and amalgam because of the
essential difference that sealant placement avoids tooth destruction. However, studies have
shown that application time and durability are similar for the two techniques (10). The cost-
effectiveness of fissure sealants could be improved by an accurate method of identifying
patients who stand to benefit most.
Recommendations of United States NIH Consensus Development Conference
The conclusion of the panel at the National Institutes of Health Consensus Development
conference was that the placement of sealants is a highly effective means of preventing pit and
fissure caries. It was felt that a greater use of sealants would substantially reduce the
occurrence of dental caries beyond that already achieved by fluorides and other preventive
measures. The current underusage of sealants was regretted and the dental profession
encouraged to use the measure more widely.
Certain population groups have an especially urgent need for preventive measures, including
sealants. These groups include children medically at risk, children with learning or physical
disabilities and those children in families with a low income. Fissure sealing is effective only
against pit and fissure caries. The control of smooth surface caries that is provided by fluorides
is of critical importance to the overall success of a preventive programme.
Recommendations of the British Society of Paediatric Dentistry
The British Society of Paediatric Dentistry strongly supports the use of fissure sealants as a
primary preventive measure. The decision to fissure seal should be made on clinical grounds,
based on a thorough clinical examination, supported by radiographs where appropriate, taking
into consideration past caries experience and family environment. Children with special needs
are at disproportionate risk from the consequences of dental disease (8, 12) and those from
disadvantaged social backgrounds have a higher caries prevalence (7).
As far as the selection of individual teeth to be sealed is concerned, it has been shown that
molar teeth are more caries susceptible than premolars, and that when one molar tooth becomes
carious there is an increased probability of the remainder developing caries (7). The following
guidelines are therefore suggested in order to help the clinician target the application of fissure
sealants in the most cost effective way.
1. Patient Selection
a. Children with special needs, for example, for those who are medically
compromised, have learning or physical disabilities or come from a
disadvantaged background who might be at high risk from developing extensive
dental caries:- fissure sealing of all occlusal surfaces should be considered.
b. Children with extensive caries in their primary teeth should have all first
permanent molars sealed.
c. In children with caries free primary dentition, first permanent molars do not
need to be sealed routinely, rather these teeth should be reviewed at regular
2. Tooth Selection
a. Fissure sealants have the greatest benefit on the occlusal surfaces of permanent
molar teeth. The sealing of primary molars is not normally advised.
b. Sealants should normally be applied as soon as the selected tooth has erupted
sufficiently to permit moisture control.
c. Any child with occlusal caries in one permanent molar should have the
remaining sound first permanent molars fissure sealed.
d. Occlusal caries affecting one or more first permanent molars indicate the need
to seal the second permanent molars as soon as they have erupted sufficiently.
e. Teeth to be sealed should be free of approximal caries.
3. Clinical Circumstances
a. When there is a doubt about the integrity of an occlusal surface on clinical
examination, bitewing radiographs should be taken. If no sign of dentine
involvement can be seen radiographically, the surface should be sealed as a
preventive measure and kept under close radiographic and clinical review.
b. If early involvement is suspected, the fissure should be investigated using small
burs and a minimal composite restoration placed incorporating a fissure sealant
to protect the rest of the occlusal surface.
c. If extensive caries is discovered on investigation a standard dental restoration
should be inserted.
4. Long Term Follow Up
a. Sealed teeth should be monitored clinically at appropriate intervals supported by
radiographs if indicated.
b. Defective sealants should be investigated and fresh sealant applied in order to
1. Buonocore MG A simple method of increasing adhesion of acrylic fillings to enamel.
J Dent Res 1955; 849-853.
2. Rock WP. The effectiveness of fissure sealant resins, Dent Educ. 1984; 48
3. Rock W P Potential use of fissure sealants in the NHS. Brit Dent J 1984: 157;
4. Horowitz HS, Heifetz SB, Poulsen S. Retention and effectiveness of a single
an adhesive sealant in preventing occlusal caries: final report after 5 years. J Am Dent
Associ 1977: 95: 113-1139.
5. Going RE et al. Four year clinical evaluation of a pit and fissure sealants. J AM Dent
Assoc 1977: 95: 113-1139.
6. Horowitz HS Cost-value analysis in dentistry. J Pub Health Dent 1981; 41: 281-286.
7. Todd JE, Dodd T. Children’s Dental Health in the United Kingdom 1983, London: Her
Majesty’s Stationery Office, 1985.
8. National Institute of Health Consensus Development Conference Statement. Dental
sealants in the prevention of tooth decay. J. Dent Educ 1984; 48: No 2 (Supplement)
9. Handelman SL et al Two year report of sealant effect on bacterial in dental caries. J
Am Dent Associ 1976; 93: 967-970.
10. Dennison JB, Straffon LH. Clinical evaluation comparing sealant and amalgam - 4
year report. J. Dent Res. 1981; 60l Special Issue A, 520.
11. Report of the Joint BDA/DHSS Working Party. Fissure Sealants Brt Dent J; 1986.
12. Hobson P. The treatment of medically handicapped children.
Int Dent J. 1980: 30, 6-13.