Diversity and frequency of yeasts from the dorsum of the tongue and necrotic root canals associated with primary apical periodontitis

Abstract

To determine the frequency and diversity of yeasts from the dorsum of the tongue and necrotic root canals with teeth associated with primary apical periodontitis. Detailed medical and dental histories of 168 patients were recorded. The samples were collected from the dorsum of tongue and from 168 teeth with root canals contained necrotic pulps. Yeasts were isolated on Sabouraud agar with 100 mg L(-1) chloramphenicol, purified and characterized by standard methods. Identification was confirmed by EI1 PCR fingerprint technique. Yeast isolates of uncertain identity or with a different genetic fingerprint profile from the reference strains were identified by sequencing the D1/D2 variable domains of the large subunit rDNA. Yeasts were isolated from 22.6% of teeth sampled and from 45.8% of tongue samples. Candida albicans was the most frequently isolated species at both investigated sites but other species were also found. Saccharomyces cerevisiae and Kluyveromyces lactis were recovered from the tongue. Although the detection of yeasts in the root canal does not imply an involvement in the disease process, the study suggests a frequency of Candida spp. in primary endodontic infections that deserves further clarification.