While the application of pit and fissure sealants is into its sixth decade of use, there are some practitioners that consider it out-of-date and potentially dangerous to teeth. This latter claim is due to the discovery that secondary caries seems to be discovered with increasing frequency when "suspicious" areas under sealants are exposed through cavity preparation.
However, advocates of sealants maintain that, from a public health standpoint, they are still the best modality to noninvasively protect pits and fissures from carious attack. In addition, it is speculated that the reason many sealants seem to fail is due to their poorly controlled placement. Since sealants are usually applied by an auxiliary working alone, moisture control, essential to proper placement, has probably not been exemplary in many instances.
Criteria for Selection
Flow For a sealant to be effective, it must have adequate flow, but not be excessively liquid to restrict proper placement. Sealants are supposed to be placed in the pits and fissures — they are not intended to cover the entire occlusal surface. Conversely, if a sealant is too viscous, it will not flow adequately into the small recesses of the pits and fissures.
Dispensing Direct placement with a syringe or other instrument is most efficient, assuming you can control the volume of material being dispensed. If you dispense an excessive amount, you'll waste time removing the excess. The design of the dispensing instrument can be quite unique and whether you will like it or not is a personal preference choice. However, some of these applicators are difficult to clean, which can affect their long-term use.
Shade This is a matter of preference — some dentists want opaque sealants to allow easy identification during periodic examinations while others (dentists and patients) prefer "invisible" sealants.
Fluoride Release All things being equal, it certainly seems that fluoride release adds another aspect of prevention to sealants. Therefore, in general, we prefer sealants that release fluoride, although the amount of fluoride being released and its ability to reduce caries susceptibility is questionable.
Best Curing Time
We tested the hardness of these materials after curing for various times with a halogen and LED curing light. From these hardness measurements, you can see the differences between the various curing times. These times are listed in the commentary for each product.