Susceptibility of various microorganisms to chlorhexidine

Abstract

– The susceptibility to chlorhexidine of bacteria in aerobic, facultatively anaerobic and anaerobic isolates from clinical specimens of wounds, urine, saliva, and dental plaque was studied. Agar diffusion tests using 50 μg chlorhexidine discs and agar dilution tests were performed and the MIC values correlated with inhibition zone diameters, Anaerobic plaque strains were isolated and tested by the agar dilution method in an anaerobic glove box. Regression lines obtained for five agar media demonstrated a good correlation between zone diameters and MIC values. There was a broad range of susceptibility to chlorhexidine among both Gram‐positive and Gram‐negative strains. Low MIC values were noted for staphylococci, S. mutans, S. salivarius and E. coli, while strains of Proteus, Pseudomonas and Klebsiella were less susceptible. S. sanguis showed intermediate susceptibility with both low and high MIC values. Among the anaerobic isolates tested, the strains most susceptible to chlorhexidine were Propionibacterium and Selenomonas, while the least susceptible strains were Gram‐negative cocci resembling Veillonella.

Effect of chlorhexidine gluconate on porosity and compressive strength of a glass ionomer cement

“…According to Palmer et al 5 ., GICs have the potential of slowly releasing active agents, such as fluoride 24 , and the CHX incorporated into GICS can be similarly released into the oral cavity. This association is aimed at reducing severity and frequency of secondary caries by decreasing failures and unsuccessful use of these restorative materials 6,7,12,25 . Based on the observation of the presence of viable bacteria in the remaining dentin after removal of the infected layer and proper sealing of the cavity researchers observed that under in vitro conditions the addition of CHX to the GIC showed favorable antibacterial effect against microorganisms such as Streptococcus mutans, Lactobacillus spp., Candida albicans and Actinomyces naeslundii, acts on the biofilm act on the biofilm, which begins to show less pathogenic composition compared to acidogenic biofilm with a predominance of S. mutans, which would be formed without the presence of the antibacterial agent 3,9,[11][12][13][14]23,25 Türkün et al 3 demonstrated that GIC and CHX at a concentration of 0.5% have a long-term antibacterial effect without compromising the physical properties of the restorative material.…”

“…Nevertheless, the incorporation of antibacterial agents into restorative materials can result in changes in their physical properties depending the concentration used 3,5,6 .…”

“…It is known that chlorhexidine (CHX) can be released into the oral cavity 5 , thus being incorporated to GICs in order to potentialise the antibacterial effect of this material 5,6 . CHX stands out for its proven effectiveness against wide spectrum of pathogens oral cavity 7,8 and low toxicity 9 .…”

“…Studies have been carried out in order to incorporate antibacterial agents to GICs 3,5,6,7,[11][12][13][14] , such as CHX at different concentrations, showing effective results for certain microorganisms under in vitro conditions (Streptococcus mutans) 3,6,12 . Nevertheless, the incorporation of antibacterial agents into restorative materials can result in changes in their physical properties depending the concentration used 3,5,6 .…”

In Vitro Fluoride Release and the Antibacterial Effect of Glass Ionomers Containing Chlorhexidine Gluconate

“…[9][10] CHX has been shown to be the most suitable agent in reducing ms due to its increased susceptibility when compared to other oral microorganisms. 11 Since CHX is retained in oral structures from which it is slowly released, this is one reason that its antibacterial effect is significantly longer than other agents. 6,12 The antibacterial effect of CHX is concentrationdependent.…”