ABSTRACT
Objectives: To develop a mature biofilm of Enterococcus faecalis inside the root canal
system and to test its susceptibility to some antimicrobial medications in vitro.
Methods: Single rooted premolars were mechanically enlarged, sterilized, and then
infected with a clinical isolate of E. faecalis. Biofilm formation and maturation
was monitored using SEM. Biofilm bacteria were exposed to Amoxicillin+clavulanate,
Ciprofloxacin, Clindamycin, Doxycycline, and calcium hydroxide as intracanal medications
for 1 week. Finally bacterial samples were collected, and colony-forming units were
enumerated.
Results: SEM examination confirmed the formation of a mature biofilm at the end of
the incubation period. All the chemotherapeutic agents used were significantly better
than Calcium hydroxide in elimination of biofilm bacteria. The antimicrobial effect
of Amoxicillin + clavulanate, Ciprofloxacin and Clindamycin was significantly better
than Doxycycline (P=.05). However the difference in the antimicrobial effectiveness
among them was statistically non-significant (P=.05).
Conclusions: The method used for bacterial biofilm development and maturation is reliable
and can be used to assess the anti bacterial potential of endodontic materials. Also,
the local application of antibacterial agents can be beneficial in resistant cases
of apical periodontitis but only after careful culture and sensitivity testing to
choose the appropriate agent for the existing flora. (Eur J Dent 2012;6:43-50)
Key words Endodontics - E. faecalis - biofilm