IADR/AADR/CADR location:San Diego date:6-9 march 2002
Recently, the use of laser technology as an alternative to mechanical rotating instruments for cavity preparation has been introduced. Objectives: The hypothesis tested was that laser irradiation is equally effective to pre-treat enamel and dentin as acid-etch procedures. Methods: Buccal/oral enamel and mid-coronal human dentin was laser-irradiated using an Er:YAG laser (λ=2.94 µm; Fidelis, Fotona Medical Lasers) set to 10 Hz and 120 mJ for enamel, and 10 Hz and 80 mJ for dentin (settings for enamel and dentin ‘conditioning'). A total-etch adhesive (OptiBond FL, Kerr) with (AE) and without (N-AE) acid-etching and a self-etch adhesive (Clearfil SE Bond, Kuraray) were applied and a composite build-up was made (Z100). Micro-tensile bond strength (µTBS) specimens (2x2x9 mm) were trimmed into a round cross-sectional interface (± 1 mm2). The µTBS (MPa) was determined after 24 hours of storage in water at 37°C.
Conclusions: The total-etch adhesive bonded significantly less effective to lased than to bur-cut enamel/dentin. Laser ‘conditioning' was clearly less effective than acid-etching, by which the hypothesis was rejected. Moreover, acid-etching lased enamel and dentin significantly improved the bonding effectiveness of OptiBond FL. The self-etch adhesive bonded equally well to lased as to bur-cut enamel, but significantly less effective to lased than to bur-cut dentin. It is concluded that cavities prepared by laser appear less receptive to adhesive restorations than conventional bur-cut cavities. email@example.com