[Efficacy of taurine haloamines and chlorhexidine against selected oral microbiome species].

Introduction: Uncontrolled bacteria of dental plaque generate formation of oral biofilm located on teeth and subgingival surfaces. It may induce local inflammation (gingivitis) with further development of periodontal diseases. A variety of oral bacteria such as Streptococcus mutans and Porhyromonas gingivalis are involved in pathogenesis of dental carries and periodontitis. Very often bacterial infections are associated with candidiasis (Candida albicans). Chlorhexidine (CHX) is the most commonly used antiseptic in dentistry due to its strong antibacterial activity and capacity to reduce the accumulation of oral biofilms. However, other antiseptics, especially endodontic irrigants, are still tested to improve their preventive and therapeutic effects in oral cavity infections. In this in vitro study we have compared antimicrobial activity of CHX with that of taurine chloramine (TauC1) and taurine bromamine (TauBr), natural taurine derivatives with known antibacterial and anti-inflammatory properties.

Methods: Antimicrobial activity of CHX, TauC1 and TauBr was tested by incubation of the compounds with S. mutans, P gingivalis and C. albicans. The agents were incubated in low (105/ml) and high (108/ml) density microbe suspensions, related to early and late biofilm infections, respectively. In some experiments bacteria were incubated with a combination of CHX + NaOCl and CHX + TauBr. MIC was determined by the pour-plate method.

Results: CHX showed the strongest antimicrobial activity against all tested pathogens. On the contrary, TauC1 was the weakest antiseptics used without effect on the growth of C. albicans. TauBr at non-cytotoxic concentrations inhibited the growth of S. mutans and P gingivalis with slight effect on the low density C. albicans. All tested agents showed weaker antiseptic properties in the presence of serum. Moreover, we have shown that interactions between CHX and sodium hypochlorite (NaOC1), the main endodontic irrigant, but not between CHX and TauBr,resulted in precipitation. Therefore, it may restrict their simultaneous application in root canal treatment. However, in spite of this unwanted reaction, the mixture of CHX with NaOCl kills pathogens more effectively then CHX alone.

Conclusions: The results confirmed CHX exceptional potential as primary antiseptic in dentistry, especially in prevention and treatment of dental carries, periodontal diseases and mouth candidiasis. Moreover, our study shows that TauBr may be used alternatively or in combination with CHX in killing of oral pathogens, due to its strong antibacterial and anti-inflammatory properties.