F11. Identify the benefits of using a pit and fissure sealant and state the prerequisite properties and proper technique for its successful placement.

The benefits of using pit and fissure sealants are that it quite effectively prevents the pits and fissures from developing caries. If properly done, the failure frequency is around 5% per year.

The prerequisite is that the tooth can be kept dry during sealant placement. In other words, partly erupted teeth are poor candidates for a "permanent" sealant. However, under these conditions and when we are dealing with a high caries risk patient, a glass-ionomer (capable of releasing F-ions) can be used as a temporary sealant until the tooth is fully erupted.

Ideally, rubberdam should be used, but cotton rolls and efficient suction can also produce good results. If minor caries lesions exist, the fissure can be opened locally in these regions to remove the carious lesion.

Before the etching procedure is initiated, the tooth surface should be cleaned with pumice or a water-soluble prophy-paste. Some people say that such slurry should be free from fluoride, a recommendation that is not based on science. Clinical studies dealing with fluoride pretreatment have shown that the fluoride has no negative effect on the bonding ability.

When fissures are etched, it is important that low viscosity gels or pure liquids are used as etchants. This is because viscous gels will not be able to infiltrate the fissures. The etching procedure should include the cusp slopes to increase the bondable surface, and last for 15-30 s. After completed etch, rinse carefully for 20 s. If a regular sealant is used (hydrophobic resin), dry with air until the etched surface looks frosty. However, before the air is blown on the tooth surface, make sure that the air is not contaminated with oil. Such an oil contamination is not unusual, because oil can leak from the air compressor. The easiest way to check whether such a contamination exists is to blow the air against the glove covering the free hand.

After the enamel has been dried, place a sealant or a low viscosity composite (flowable composite). When this material is placed, it is important to place it in such a way that air is not entrapped. The advantage with using a flowable composite is that these materials shrink less than the unfilled sealants. Before the sealant is cured, make sure that its thickness is not such that it will interfere with opposing teeth in occlusion. In other words, do not use too thick layer of sealant. Then cure the sealant according to the manufacturer's recommendations. Wipe of the oxygen inhibited surface layer with a cotton pellet soaked in ethanol and check the final occlusion. If necessary, make occlusal adjustments.