The Effects of Antibacterial Solutions on Microorganisms Isolated from Infected Root Canals In Vivo

ABSTRACT

Objective: This study assessed the in vivo antimicrobial activity of NaOCl, Chx, Ca(OH)₂, and H₂O₂ against five different microorganisms: Enterococcus faecalis, Porphyromonas endodontalis, Streptococcus salivarius, Lactobacillus sp., and S. aureus. Study design: Eighty infected teeth in seventy patients with pulpal or periapical pathology were studied. After preparing a standard access cavity. Sterilized paper points were used to take samples from the root canals. These were incubated in test tubes at 37°C for 72 hours. Of the resulting bacteria, the five most frequent strains were examined. The teeth were divided into four equal groups. After preparing the root canal using the step-back technique until a number 55 file, each group was subjected to one of the following irrigation solutions: 2% chlorhexidine gluconate (Chx), 5% NaOCl, Ca(OH)₂ in distilled-water, or 3% H₂O₂. After irrigation, a temporary filling was placed in each cavity. The same irrigation procedure was repeated three and six days later. Then, the microbiologic sampling was also repeated. The chi-squared test was used for statistical comparisons. Results: Of the irrigants tested in this in vivo study, chlorhexidine was the most effective against all the microorganisms isolated from infected root canals, followed by NaOCl, Ca(OH)₂, and H₂O₂. However, differences among the three groups were not statistically significant, except against Enterococcus faecalis (p>0.05). Conclusions: Our results did highly confirm the fact from previous studies that chx with 2% percent is the most effective antibacterial agent after three consecutive irrigations. Furthermore, in vitro and in vivo studies are necessary to assess whether the Chx imparted substantive dissolve organic material.