Inhibitory Effects on Selected Oral Bacteria of Antibacterial Agents Incorporated in a Glass Ionomer Cement

Abstract

The objectives of the study were to investigate the antimicrobial efficacy, over time, of combining antibacterial agents with a glass ionomer cement (GIC). This was assessed using an agar diffusion test. Chlorhexidine hydrochloride, cetylpyridinium chloride, cetrimide and benzalkonium chloride were added to Fuji IX GIC at 0, 1, 2 and 4% w/w. Antibacterial-GIC specimens were placed onto agar plates inoculated with one of six bacterial species (Streptococcus, Lactobacillus and Actinomyces, two each) and the area of inhibition calculated after 24 h incubation. The experiment was repeated weekly and at week 11 the surface of the specimen was abraded prior to replacing on inoculated agar plates. Control specimens of the GIC produced no bacterial inhibition. The antibacterial-GIC combination specimens showed significant inhibition which decreased at different rates over the test period. Resurfacing of the specimens showed a dramatic increase of antibacterial action similar to levels produced on week 1. CT-GIC showed the greatest (p < 0.005) inhibitory effect throughout the experimental period for 4 out of 6 test bacteria. The addition of antibacterial agents to Fuji IX creates a GIC material with significant antimicrobial action in vitro which is dependent on concentration and type of antibacterial agent, and appears to be associated primarily with a release of the antibacterial from the surface layer of the specimen.

Antibacterial effects of conventional glass ionomer cement

“…The largest number of studies analyse the antimicrobial effect of the chlorhexidine compound in the form of diacetate, gluconate, digluconat, hydrochloride or dihydrochloride, incorporated in conventional and modifi ed glass-ionomer cements, most often in the powder of the glass-ionomer cements (14,16,17,18,29,31). The antimicrobial effect against the cariogenic microorganisms Streptococcus mutans, Lactobacillus casei and Actinomyces viscosus is most often analysed (16,18,29,31).…”

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

“…The generalised and inherent formation of pores within the GIC reduces its strength to flexion and cohesion 20,11 . These pores are regions of high concentration of stress, which increased the likelihood of fracture of the material 22 .…”

“…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. However, concentrations at 1.25 and 2% weaken the material by compromising its physical properties, such as resistance to erosion, compression, diametrical traction, flexion, setting time, and surface hardness 3 .…”

“…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 .…”

Does 2% chlorhexidine digluconate cavity disinfectant or sodium fluoride/hydroxyethyl methacrylate affect adhesion of universal adhesive to dentin?

“…When shear bond test was used, other studies also showed that the application of CHX did not have a negative effect on the bond strength of adhesive systems [25,26]. On the other hand, one study even reported increased shear bond strength when CHX was used [27].…”