Ion release from a composite resin after exposure to different 10% carbamide peroxide bleaching agents

Objective

This in vitro study evaluated the influence of two 10% carbamideperoxide bleaching agents - a commercial product (Opalescence PF; UltradentProducts, Inc.) and a bleaching agent prepared in a compounding pharmacy - on thechemical degradation of a light-activated composite resin by determining itsrelease of ions before and after exposure to the agents.

Material and Methods

Thirty composite resin (Filtek Z250; 3M/ESPE) samples were divided into threegroups: group I (exposed to Opalescence PF commercial bleaching agent), group II(exposed to a compounded bleaching agent) and group III (control - Milli-Q water).After 14 days of exposure, with a protocol of 8 h of daily exposure to thebleaching agents and 16 h of immersion in Milli-Q water, the analysis of ionrelease was carried out using a HP 8453 spectrophotometer. The values wereanalyzed statistically by ANOVA, Tukey''s test and the paired t-tests. Thesignificance level was set at 5%.

Results

After 14 days of the experiment, statistically significant difference was foundbetween group II and groups I and III, with greater ion release from the compositeresin in group II.

Conclusions

The compounded bleaching agent had a more aggressive effect on the composite resinafter 14 days of exposure than the commercial product and the control (nobleaching).