Evaluation of adhesive systems in primary dentin by nanoleakage: effects of aging

Resumo

Nanoleakage evaluation by silver uptake in permanent
teeth provides good spatial resolution of submicron defects at the
hybrid layer, which have not been tested in primary teeth. Objective:
This study evaluated the nanoleakage at the dentin-adhesive interface
in primary teeth by two methods, for three adhesive systems,
immediately (IM) and six months (6M) after adhesive procedures.
Material and methods: Crowns of primary molars were occlusal flat
grounded and divided into three groups according to the adhesive
system tested (n = 6-7). Scotchbond Multi-purpose/SMP, Single
Bond/SB and Clearfil SE Bond/CSB adhesive systems were applied
with a composite resin (Filtek Z-250). Crowns were sectioned so
that 0.8 mm² sticks were obtained and subdivided depending on
the time of evaluation: IM or 6M. They were immersed into silver
nitrate solution and evaluated by SEM-EDS. Data (%) were analyzed
by ANOVA (p < 0.05) and the scores by Kruskal-Wallis and U
Mann-Whitney tests (p < 0.05). Results: There was no difference
between groups regarding to the evaluation time (aging) percentage.
In terms of scores, there was a significant difference for the adhesive
variable: SMP and SB showed similar results with less leakage,
while CSB demonstrated higher leakage. Conclusion: Nanoleakage
was not influenced by aging, but noticeable difference was observed
between total-etch and self-etching adhesives. Total-etch showed
better performance.