The crucial role of S. mutans in the development of caries is well
authenticated and thus it has become the prime target for
prevention. Different antimicrobial drugs have been tested against biofilm formation and maturation. Use of these compounds also
shows a reduction in the number of viable micro-organisms in the
oral flora. Although effective, such antibacterial therapies have
several undesirable side effects [15]. In order to develop a novel
and effective chemotherapeutic approach (other than microbicides)
against dental biofilms, use of plants could be a very
promising way to thwart the pathogenesis of oral infectious
diseases such as dental caries.
Use of two fluorescent nucleic acid stains, SYTO 9 (green, live
cells) and PI (red, dead cells) demonstrated that CHX is capable of
causing membrane damage to mutans streptococci; this has been
illustrated by the presence of the enormous number of redfluorescent
bacterial cells within the CHX-treated biofilm. These
results strongly suggest that the membrane of CHX-treated S.
mutans was compromised, whereas the membrane of S. mutans
exposed to eugenol remained intact and cells were dispersed as
evidenced by the presence of many green-fluorescent bacteria. In
the presence of eugenol, S. mutans was unable to form a biofilm.
The data further confirm the results that eugenol exerts its effect
through a reduction in the virulence traits and not of bactericidal
activity (Fig. 2). The data clearly indicate that eugenol could
decrease the adherence of S. mutans to glass surfaces as well as GTF
activity [16,17]. As a result, eugenol appears to be an ideal drug to
prevent oral diseases.