In situ Evaluation of Acrylic Resin Containing Chlorhexidine

Objectives: The objective of the present study, considering the importance of biofilm control in teeth or implants, was to evaluate in situ the influence of incorporation of chlorhexidine diacetate (CDA) in acrylic resins based on PMMA.
Methods: Firstly, 32 volunteers were selected, all of whom used an intraoral device that contained specimens without and with chlorhexidine (1%) over the course of 24 hours. After that, the microbial adhesion to both materials’ surface was measured by the plate count. The samples were plated in triplicate in the following culture mediums: Blood agar to evaluate the total number of bacteria (aerobic bacteria) and Mitis salivarius agar containing 0.25 units of bacitracin/mL plus 20% sucrose, to determine Mutans Streptococci. In addition, biofilm morphological differences were also observed in the scanning electron microscopy of the control acrylic resin versus the acrylic resin incorporating CDA. Finally, the chemical composition of the test specimens were tested using X-ray fluorescence
Results: The results showed that the antimicrobial effect did not differ between the control acrylic resin and acrylic resin incorporating CDA (p>0.05). Furthermore, the presence of the chlorhexidine was detected before and after the insertion of the specimens with CDA in the oral cavity.
Conclusions: It was concluded that the presence of the drug in the acrylic resin after 24 hours was verified. However, no results were found to confirm the presence of an antimicrobial potential of the drug at the concentrations used in situ specimens.