Evaluation of the Antimicrobial Effect of Pre-synthesized Novel Antibiotic Electrospun Nanofibers as an Intracanal Delivery Strategy for Regenerative Endodontics A Randomized Clinical Trial

Title: Evaluation of the Antimicrobial Effect of Pre-synthesized Novel Antibiotic Electrospun Nanofibers as an Intracanal Delivery Strategy for Regenerative Endodontics - A Randomized Clinical Trial

Rationale Regenerative endodontics technique outcome depends on microbial elimination because apical repair will not happen in the presence of infected tissues. It is well established that bacteria are essential for the development of pulpal and periapical pathosis. Eradication or control of bacteria may provide optimal treatment outcome. However, elimination of bacteria from infected root canal systems is challenging. Numerous measures have been described to reduce the number of bacteria in the root canal system, including the use of various instrumentation techniques, irrigation regimens and intra-canal medicaments. There is no definitive evidence in the literature that all these measures result in a bacteria-free root canal system.

Therefore additional methods such as the use of intra-canal medicaments are required in order to maximize disinfection of root canal system and kill as many bacteria as possible. Antibiotics have been proposed as intracanal medicament but any single antibiotic is unlikely effective to sterilize diverse flora in root canal infection.

Recently, triple antibiotic mixture (TAP) has been reported for successful disinfection of infected root dentine. This mixture consist of ciprofloxacin (CIP), metronidazole (MET) and minocycline (MINO) which consistently sterilize bacteria of infected dentine and infected pulps . Specifically, MET is a bactericidal imidazole that is highly effective against obligate anaerobic bacteria, CIP is a bactericidal broad-spectrum synthetic quinolone and MINO is a bacteriostatic broad-spectrum tetracycline.

However, as minocycline binds to dentin and causes tooth discoloration, it is recommended to remove minocycline from TAP and use only MET and CIP, or to use modified TAPs containing cefaclor or clindamycin (CLIN). CLIN is a bacteriostatic lincosamide known for its efficacy against a broad spectrum of endodontic bacteria.