SEM analysis of hybrid layer and bonding interface after chlorhexidine use.

OBJECTIVE

To evaluate the appearance of the hybrid layer of one total-etch and one self-etch bonding agent on human teeth with and with-out the application of 2% chlorhexidine after water storage.

MATERIALS AND METHODS

Twelve human maxillary teeth (molars and premolars) had two Class II cavities (MO-OD) prepared. Teeth were separated in two groups (n=6) to receive either Adper Single Bond 2 or Adper SE Plus (3MESPE). In one cavity, the dentin donding agent was applied following manufacturer's instructions. On the adjacent cavity, 2% chlorhexidine was applied for 30 seconds before the application of the bonding agent. Teeth were sectioned mesiodistally with a slow-speed diamond disk and stored in water at 37°C for four months. The teeth were prepared for scanning electron microscope observation.The appearance of the hybrid layer was ob-served and measured by two variables: clear image of hybrid layer and presence of resintags in tubules. Data were analyzed with a Kruskal-Wallis test calculated at a 0.05 significance level.

RESULTS

All groups treated with chlorhexidine had the clear presence of a hybrid layer,whereas only half the specimens without chlorhexidine had a clear hybrid layer. Chlorhexidine did not affect the presence of resin tags.

CONCLUSIONS

The use of 2% chlorhexidine be-fore the application of a dentin-bonding agent reduced the deterioration of the hybrid layer when exposed to water.