Antibacterial effect of bactericide immobilized in resin matrix

Abstract 

Objective

Biomaterials with anti-microbial properties are highly desirable in the oral cavity. Ideally, bactericidal molecules should be immobilized within the biomaterial to avoid unwanted side-effects against surrounding tissues. They may then however loose much of their antibacterial efficiency. The aim of this study was to investigate how much antibacterial effect an immobilized bactericidal molecule still has against oral bacteria.

Methods

Experimental resins containing 0, 1 and 3% cetylpyridinium chloride (CPC) were polymerized, and the bacteriostatic and bactericidal effects against Streptococcus mutans were determined. Adherent S. mutans on HAp was quantitatively determined using FE-SEM and living cells of S. mutans were quantified using real-time RT-PCR. The amount of CPC released from the 0%-, 1%- and 3%-CPC resin sample into water was spectrometrically quantified using a UV–vis recording spectrophotometer.

Results

UV spectrometry revealed that less than 0.11ppm of CPC was released from the resin into water for all specimens, which is lower than the minimal concentration generally needed to inhibit biofilm formation. Growth of S. mutans was significantly inhibited on the surface of the 3%-CPC-containing resin coating, although no inhibitory effect was observed on bacteria that were not in contact with its surface. When immersed in water, the antibacterial capability of 3%-CPC resin lasted for 7 days, as compared to resin that did not contain CPC.

Significance

These results demonstrated that the bactericidal molecule still possessed significant contact bacteriostatic activity when it was immobilized in the resin matrix.

Keywords: Adhesive resin, Antibacterial effect, Bacteria, Bactericide, Cetylpyridinium chloride, CPC, Immobilization, Streptococcus mutans