Effect of etching on leakage of sealants placed after air abrasion.

PURPOSE: The aim of the present study was to assess the microleakage of pit and fissure sealants in: 1) air-abraded molars with and without etching and 2) in preventive resin restorations (PRR) prepared with air abrasion or mechanically with a bur. METHODS: Forty molars with no or minimal occlusal caries were cleaned with pumice, washed, and assigned to four groups of 10 teeth each. In group A, the teeth were air-abraded and Helioseal was applied directly to the fissures without previous treatment. Group B was air-abraded and etched for 20 s prior to sealant application. In group C, caries was excavated with air abrasion, etched, and restored with Scotchbond Multipurpose, Z-100 and Helioseal. Group D was similar to C except that the fissures were prepared mechanically with a carbide bur at high speed. RESULTS: Group A was significantly different in both Y1 and Y2 measurements from all the other groups. No differences were observed between all the other groups. Acid etching should be a precondition before sealant application. Air abrasion and mechanical preparation resulted in the same amount of microleakage following acid etch.