Antifungal and antibacterial effect of Eucaliptus oil added to tissue conditioner

Contamination of soft denture lining materials and tissue conditioners with microorganisms is a common clinical problem. The aim of the study was to determine the effect of adding eucalyptus (E) oil to viscogel tissue conditioner against bacterial and fungal growth on it. In this experimental study MIC (Minimum Inhibitory Concentration) of E. oil against Candida albicans and Staphylococcus areus was determined, then experimental specimen disks (diameter, 15mm, thickness: 2mm) with the amount of 1MIC, 2MIC and without E. oil were fabricated under aseptic conditions. The samples were divided to 11 groups each group contained 5 samples. One group was considered as control. The samples immersed into 1 ml of saline. After 24 hours 1ml of bacterial or fungal suspension with BHI broth medium was added. The growth of microorganisms was investigated after another 24 hours. This test was done for the samples at the concentration of 2 MIC of E. oil. The data were analyzed with Fisher's exact test. The samples which were mixed with 1 MIC of E. oil showed antimicrobial effect in comparison with the controls (P= 0.024) after 72 hours. Samples of 2 MIC didn’t show a significant inhibitory effect against S. areus (P=0.08) after 24 and 48 hours, but this effect was significant against C. albicans after 24h (P=0.024) and 48h in comparison with control samples (P=0.004). Addition of Eucaliptus oil significantly reduced the growth of microorganisms. The study showed that Eucaliptus oil leached out of tissue conditioner in 72 hours which is too short for clinical usage.