[Composite retention area produced by CO2 laser beam]

Laser effect on enamel is manifested as consequence of temperature changes. Enamel melts, vaporises and a crater, and fissures are formed. Retention surface for anchoring of composite resin was obtained in intact approximal surfaces of premolars with CO2 laser (0.5, 1 and 3 W, sport size 1 and 1.5 mm, 0.2 and 0.5 s). The study results reveal composite and lased enamel interfaces are stronger then composite and inlased enamel (p less than 0.01) but weaker than composite and acid pretreated enamel interface (p less than 0.01).