The effect of chemotherapeutic agents on titanium-adherent biofilms

To assess the effectiveness of different chemotherapeutic agents on biofilm-contaminated titanium surfaces.

This study used a recently described biofilm model. In experiment 1, Streptococcus mutans biofilms grown on titanium discs were treated with (1) EDTA, (2) citric acid (CA), (3) cetylpyridium chloride, (4) Ardox-X, (5) hydrogen peroxide (H(2) O(2) ), (6) chlorhexidine (CHX) and (7) water. In experiment 2, polymicrobial biofilms were treated with (1) CA, (2) Ardox-X, (3) H(2) O(2) , (4) Ardox-X followed by CA, (5) H(2) O(2) followed by CA, (6) CHX and (7) water. Aliquots of the suspended biofilms were plated and incubated anaerobically to enable counts of the total remaining viable bacteria, which were expressed as CFUs. Following incubation, the amount of protein remaining in the treated S. mutans biofilms was quantified to assess the removal potency of each treatment agent.

H(2) O(2) , Ardox-X and CA killed significantly more S. mutans compared with the other treatments. H(2) O(2) and CA removed significantly more protein than water. CA and the combination treatments were significantly more effective against the polymicrobial biofilms than CHX, H(2) O(2) and Ardox-X. The difference in the killing efficacy between CA alone and the combination treatments was not statistically significant.

Among the chemicals tested, CA demonstrated the greatest decontamination capacity with respect to both the killing and the removal of biofilm cells. This combination of effects is clinically desirable because it promotes biocompatibility and healing around a previously contaminated implant surface. These results should, however, be validated in in vivo studies.