Antibacterial Activity of Calcium Hydroxide Combined with Chlrohexidine or Sodium Hypochlorite against Gram Positive and Gram Negative Bacteria

Abstract

The most significant current goal in endodontology is the maximum reduction of the microorganisms because they play a fundamental role in the etiology of pulpo-periapical pathosis and may escape from tooth and circulate throughout the body to cause an infection in distant part. Numerous materials have been used to achieve this goal. Calcium hydroxide [Ca(OH)2]with its unique properties, need to be mixed with other agents to fulfill its antimicrobial requirement. However, to the best of authors knowledge , no report has been found so far investigates the antimicrobial efficacy of Calcium hydroxide / chlorhexidine [CHX ]combination  against  klebsiella spp..The aim of this study is to evaluation of the effect of adding CHX or sodium hypochlorite[NaOCl] on the antibacterial activity of Ca(OH)2 against gram positive and gram negative bacteria. The tested samples were grouped into 5 groups of 20 samples for each group: G1:Ca(OH)2  mixed with H2O. G2:2% CHX solution. G3: 2.5% NaOCl solution. G4: combination of Ca(OH)2   and 2% CHX. G5:combination of Ca(OH)2  and  2.5% NaOCl. 10 samples from each group had been inoculated with streptococcus spp. and the other 10 had been inoculated with klebsiella spp. Microbial growth was verified and number of plates which show growth or no growth for bacteria were counted and analyzed statistically. As a result Ca(OH)2  and 2.5% NaOCl had antibacterial effect on both tested bacteria while 2% CHX appeared to be less effective . Pastes of Ca(OH)2   and 2% CHX were effective on klebsiella spp., while mixing of Ca(OH)2 with 2.5% NaOCl had significant effect on both types of bacteria and it was more effective against streptococcus spp.

Key words: Calcium hydroxide, Chlorhexidine, Sodium hypochlorite, klebsiella, Streptococcus .