Bactericidal Efficacy Of Antibiotic Combinations Against Enterococcus Faecalis – An In Vitro Study

Endodontics plays a major role in the eradication of pulpal inflammation, the primary goal includes the treatment of apical periodontitis and maintaining the pulpal health. An immature necrotic tooth poses various challenges in the management of pulpal necrosis which traditionally aims at the formation of calcific barrier that aid in the obturation. The prolonged duration of the procedure with multiple review appointments, and the risk of cervical fracture have posed a challenge in the conventional apexification procedures1. Regenerative endodontics is a biological based procedure designed to replace damaged structures such as dentin, root structures, and cells of the pulp-dentin complex. The evolution of the method of biologically replacing dental tissues by regeneration has overcome the challenges by increasing the root length and thickness of the root canal walls, inducing apexogenesis 2. The outcomes of regenerative procedures rely on the complete elimination of bacteria, facilitation of root development, and closure of sinus tracts3. The infection of the root canal system is polymicrobial, consisting of predominantly facultative anaerobes and anaerobic bacteria. The existence of bacterial species results in the persistence of apical periodontitis and inflammation4. The virulence of the bacteria on causing disease and tissue damage is proportionate to the type and the numbers of bacteria present5. The microbial flora in failed endodontic teeth normally include varied microorganisms of which Enterococcus faecalis is the most prevalent and highly resistant to intracanal medicaments6. It is an established fact that regeneration of the pulpal tissue of an infected immature tooth with open apex and apical periodontitis was considered to be impossible due to the presence of various microorganisms. Local antibiotics application has been widely used in the eradication of intracanal infection, hence the systemic routes of administration have been greatly reduced 7. To encounter the diverse flora in the root canal system, combinations of antibiotics are used known as the TRIPLE ANTIBIOTIC PASTE which comprises of combination of Ciprofloxacin, Metronidazole and Minocycline 8. The synergy of antibiotics used in the triple antibiotic paste is used to efficiently combat the polymicrobial environment in the infected root dentin 9. Minocycline is known for its broad-spectrum activity but has the disadvantage of discoloration of teeth which has led to the necessity of finding an alternative antibiotic. In this study in the triple antibiotic combination minocycline is replaced with clindamycin. This study aimed at comparing and evaluating the antibacterial efficacy of double or triple antibiotic combinations used as intracanal medicament. A standard strain of Enterococcus faecalis is used as a indicator organism to test the efficacy. The primary objective was to compare the efficacy of clindamycin over minocycline in combination with other antibiotic