Antifungal efficacy of routine and newer irrigants on candida albicans biofilm colonization in young and old human root canal dentin

The purpose of this study was to evaluate the effect of routine and newer endodontic irrigants on Candida albicans biofilm colonization in Young and Old human root canal dentin. Eighty intact mandibular premolars were used in this study and divided based on Age into two groups. Forty teeth were from young subjects (Group I) and the remaining 40 from old subjects (Group II). Dentin disc samples of 4mm were prepared from each tooth, standardized using gates glidden drill #2 and autoclaved for sterility. The forty samples each in the young and old group were divided into 4 subgroups with various irrigation protocols. The experimental irrigants were: A) 17% EDTA +5.25% NaOCl, B) 100% Octenisept, C) 17% EDTA +5.25% NaOCl + 1% Clotrimazole and D) Phosphate buffer saline. After the irrigation the experimental samples were inoculated with C.albicans and incubated for 72hrs. Out of the 10 samples in each subgroup, 8 samples were analyzed by the Colony forming unit method and 2 samples were analyzed by the Confocal laser scanning microscope. In the CFU method, aliquots from the experimental samples were plated on Sabouraud dextrose agar plates and the colony forming units were counted as a measure of antifungal activity. In the CLSM method, fungal viability was demonstrated using special dyes SYTO 9 and Propidium iodide. The results showed that Octenisept was the most effective irrigant against C.albicans followed by addition of 1% Clotrimazole to 17% EDTA+5.25% NaOCl in both age groups. The other irrigant subgroups were less effective in both age groups. The results of this study also indicates that higher amount of fungi are found in old root dentin as demonstrated by the CFU method and confirmed by the CLSM method.