Comparison of Antimicrobial Effects of Triple Antibiotic Paste and Calcium Hydroxide Mixed with 2% Chlorhexidine as Intracanal Medicaments Against Enterococcus faecalis Biofilm

Objectives: The purpose of this in-vitro study was to determine and compare the shortest period needed for a triple antibiotic paste (TAP) and calcium hydroxide (Ca(OH)2) plus 2% chlorhexidine (CHX) to eradicate the biofilm of Enterococcus faecalis (EF) from the root canal system. Materials and Methods: Sixty-five extracted single-rooted human teeth with straight root canals were selected. The crowns were cut from the cementoenamel junction (CEJ), and canal preparations were done by step-back technique. The smear layer was removed by 17% ethylenediaminetetraacetic acid (EDTA) and 5.25% sodium hypochlorite (NaOCl). Afterwards, the samples were sterilized with gamma ray and were placed inside microtubes for one week. During this week, the teeth were infected with EF. Then, a TAP and Ca(OH)2 mixed with 2% CHX were inserted into the canals. The roots were cut longitudinally, and dentin chips were collected from the apical part of the roots by a round bur to the depth of 400 μm. The vital bacterial load was assessed by counting the numbers of colony-forming units (CFUs). Results: The paste of Ca(OH)2 mixed with 2% CHX was able to eradicate the EF biofilm in three days. The TAP was able to eradicate the biofilm of EF in seven days. Conclusions: It seems that Ca(OH)2 mixed with 2% CHX is more potent than the TAP against EF biofilm.