Evaluation of three different concentrations of Chlorhexidine for their substantivity to human dentin

To evaluate the substantivity of different concentrations of Chlorhexidine (CHX) to dentin disks prepared in-vitro.

Sixty dentin disks were prepared from extracted human third molars and divided into three groups (each containing 20 disks). All the disks were partially demineralized, as per standard procedure. Group A specimens were then treated with 10 microliters of 0.02% Chlorhexidine, Group B specimens with 10 microliters of 0.2% Chlorhexidine, and Group C specimens were treated with 10 microliters of 2% Chlorhexidine. They were then incubated in 1 ml of Phosphatebufferedsaline PBS (pH 7.4). The substantivity was evaluated after 24 hours and one week of incubation. CHX concentration in the eluates was spectrophotometrically analyzed.

A significant amount of CHX was found retained on the dentin disks in Group B as compared to Group C. Also, Group A performed significantly better than group C. However, no statistically significant difference was observed between Group A and Group B.

Both 0.02% and 0.2% Chlorhexidine can be clinically recommended when being used for prolonging the durability of resin-dentin bond.