Microleakage of class V composite restorations following Er:YAG and Nd:YAP laser irradiation compared to acid-etch:...

This study compared microleakage at enamel/composite and dentine/composite interfaces following Er:YAG laser, Nd:YAP laser, or acid-etch preparation. Class V cavities produced on the lingual and buccal surfaces of 20 extracted carie- and restoration-free human teeth were randomly assigned to four groups of 10 cavities. Teeth were treated with 37% phosphoric acid and primer (group 1), irradiated with an Er:YAG laser (group 2) or an Nd:YAP laser (group 3), or served as controls (group 4). The specimens were restored with Scotchbond Multipurpose/Z100 (3M), stored in physiological solution at 37 degrees C for 7 days, thermocycled 500 times between 5 degrees C and 55 degrees C, placed in a 0.5% solution of basic fuchsin for 48 h, embedded in resin, and sectioned. Microleakage was assessed according to the depth of dye penetration along the restorative composite. The results showed that irradiation with Er:YAG and Nd:YAP lasers did not produce a good seal. Mean microleakage was greater than with acid-etch and statistically comparable to that of control cavities (Kruskal-Wallis test).