422H
Fig. 9.7 This molar is just at the correct stage to apply fissure sealant. The very
small operculum of gingival tissue can be held away from the tooth gently with a flat
plastic.
9.5.2 Clinical technique
Pretreatment prior to sealant application
Tooth preparation with pumice and a rotary brush results in a good clinical retention
rate. Dry brushing achieves similar results. Air polishing, using a 'Prophy-Jet', an
early air abrasion system that uses sodium bicarbonate particles as the abrasive
medium, provides good bond strength and sealant penetration but has not received
general acceptance, probably, because most dental surgeries do not possess this
equipment.
Some researchers have advocated the use of 'Enameloplasty', a more aggressive
intervention into the tooth, that is, mechanical enlargement of the fissures with a bur
or with air abrasion, to improve sealant penetration and reduce micro-leakage.
Although some studies have confirmed these claims, the authors feel that this is an
unnecessary extra procedure to subject the child to, and do not recommend it.
Etching
All the methods of cleaning the tooth, discussed above, should be accompanied with
etching of the enamel surface. Etching for just 20 s with a range of concentrations of
acid but most often, 35-37.5% phosphoric acid is the tried and tested method. Its one
drawback is the susceptibility of the etched surface to saliva or moisture