Microbiological analysis of glutaraldehyde after successive immersions of alginate impressions

Abstract

Aim: The objective of this work is to evaluate the efficacy of 2% glutaraldehyde solution after successive immersions of contaminated alginate impressions by analyzing its bacteriostatic and bactericidal activity. Materials and methods: Seven samples of the disinfectant were collected. Evaluation of bacteriostatic activity of the samples was performed by observing the presence of viable bacteria through Standard Methods Agar (Plate Count Agar). Plates were inoculated with Escherichia. coli, Pseudomonas aeruginosa, e Staphylococcus aureus in order to evaluate bactericidal activity. Wells with a 0.9 cm diameter at the centre of the plate received aliquots of 100 μL of glutaraldehyde in each sample. Then, the plates were maintained at 8-10oC for 16 hours to allow diffusion of the compound. Later, the plates were stored at 37oC in a stove for 24 hours. Antibacterial activity was evaluated by the presence of zone of inhibition in bacterial growth around the wells where the glutaraldehyde was placed. Results: Results show no bacterial growth in any sample, and all inoculated plates showed zone of inhibition in bacterial growth. Conclusion: With this study design, it is possible to conclude that at least 70 alginate impressions may be disinfected in 3L of 2% glutaraldehyde solution during 28 days.