Resin-Based Materials with Chlorhexidine-Loaded MCM-41: Surface Characteristics, Drug Release, and Antibiofilm Activity.

Poly(methyl methacrylate) resins containing chlorhexidine diacetate (CHX)-loaded mesoporous silicate MCM-41 have the ability to prevent biofilm adhesion and growth over time. With the aim of increasing knowledge of the drug release and surface properties of these materials and their relationship with antibiofilm activity, in this paper an acrylic-based resin containing CHX-loaded spherical and narrow size silanized MCM-41 was prepared. Resins containing CHX but no filler were prepared as well and compared. Samples were characterized for polymerization degree, water sorption, and drug release. The sample capacity of inhibiting biofilm adhesion and formation over time was evaluated. All samples were able to reduce the biofilm mass over time. The resin containing CHX loaded into silanized MCM-41 mesopores resulted in less activity during the first 4 h but was able to maintain antibiofilm activity for a longer time. This effect was correlated to the prolonged CHX release and to the sample surface modifications observed after treatment with water and artificial saliva, evaluated by X-ray photoemission spectroscopy, scanning electron, and atomic force microscopies.