30 single edge-notched (SEN) samples were prepared and divided into three groups. 10% (mass) Chlorhexidine and 10% (mass) Diflucan powder (4.5% mass Fluconazole) were added to heat cured PMMA respectively to create the two study groups. A third group of conventional heat cured PMMA was prepared as the control group. Fracture toughness (3-point bending test) was carried out for each sample and critical force (Fc) and critical stress intensity factor (KIC) values measured. Data were subject to parametric statistical analysis using one-way ANOVA and Post hoc Bonferroni test (p = 0.05).
Fluconazole had no significant effect on the fracture toughness of the PMMA while Chlorhexidine significantly reduced the KIC and therefore affected the fracture toughness.
When considering addition of a bioactive material to PMMA acrylic, Chlorhexidine will result in reduced fracture toughness of the acrylic base while Fluconazole has no effect.