Effect of air abrasion and acid etching on sealant retention: an in vitro study

This in-vitro study evaluated shear bond strength and analyzed, via scanning electron microscopy, enamel prepared for pit and fissure sealant placement. Various surface pretreatment methods were conducted prior to short-term (72-hour) and long-term (120-day) analysis.

Six treatment groups of 14 teeth, having 28 bonding surfaces (buccal and lingual) were treated. Cylinders of Delton pit and fissure sealant were placed on the prepared buccal and lingual surfaces and light-cured for 60 seconds. One-half of each group's specimens were stored in distilled water for 72 hours and the other half were stored in water distilled for 120 days followed by thermocycling. All specimens were subjected to shear bond strength analysis as determined on an Instron testing machine.

All acid treated groups were equivalent and greater than air abrasion alone after 72 hours of water storage. Scanning electron microscopy of air-abraded and combination treated enamel surfaces revealed a more detailed retentive pattern in the combination treatment than in either treatment alone.

Based on in-vitro shear bond strength values, air abrasion with 50 micron alumina is an effective pre-etch treatment for sealant placement and in concert with phosphoric acid treatment significantly enhanced the long-term bond of a sealant to enamel. The clinical relevance of this has not been established.