The effect of treatment of radicular dentin on colonization patterns of C. albicans

The aim of this study was to observe the colonization pattern of C. albicans on treated and untreated radicular dentin.

Root sections of 10 human mandibular premolar teeth were longitudinally separated into halves. The 20 halves were separated into 2 groups and each half served as its own control. In Group 1, only gross pulpal remnants were removed with pliers. Root canal walls in the corresponding 102 halves (Group 2) were instrumented with Gates-Glidden burs and treated with sequential use of 15% EDTA solution for 3 minutes and 2.5% NaOCl solution for 3 minutes. Finally, all teeth were washed with distilled water. Each specimen was placed individually in each well of a 24-well cell culture plate. After the assembly was sterilized with ethylene-oxide, the root canal of each specimen was inoculated with 20 microL of C. albicans (1-1.5 x 10(6) cfu/mL) that was kept in place for 24 hours for initial attachment. Then, 2 mL of SDB was added to each well and the assembly was placed in an incubator at 37 degrees C for 10 days. Following the incubation period, the specimens were washed, fixed, dehydrated, and processed for scanning electron microscopy.

C. albicans was present on the root canal surfaces of all specimens; however, the colonization pattern was different. In the untreated group, the main growth pattern was a dense mass of yeast cells forming biofilm layers while hyphal structures were not common. On the other hand, pseudohyphae invaded all root canal surfaces in Group 2 and yeast cells were occasionally observed.

The treatment procedures of root canal dentin have a strong influence on the colonization pattern of C. albicans. This fact should be considered when planning and evaluating in vitro Candida adhesion and/or penetration studies.