Morphologic assessment of dental surface/ glass ionomer cement interface: influence of Er:YAG laser pretreatment

Resumo

The aim of this study was to assess the
surface and the substrate/glass ionomer cement (GIC) interface after
Er:YAG laser irradiation by means of scanning electron microcopy.
Material and methods: Thirty human third molars were selected
and had their roots removed. Crowns were sectioned to obtain
discs that were randomly assigned to three groups according to the
surface pretreatment: 40% polyacrylic acid (control); Er:YAG laser
irradiation (80mJ/2Hz) or Er:YAG laser followed by 40% polyacrylic
acid. Two discs of each group were put aside to the surface analysis
and the others were bisected. One half received Ketac-Fil and the
other received Fuji II LC. Specimens were prepared for SEM and
were analyzed under different magnifications. Results: Er:YAG laser
group showed no adhesive interface for both enamel and dentin,
but strongly damaged the interface build-up for dentin/Fuji II LC.
The application of laser irradiation followed by the polyacrylic acid
exhibited gaps and irregularities for both substrates. Conclusion:
Er:YAG laser irradiation combined or not with 40% polyacrylic acid
produced a surface unfavorable for GIC interaction, especially for
the resin-modified ones.