A Pilot Investigation of Sub-gingival Yeast Spp. in Untreated Periodontitis

Yeasts may play an important yet undefined role in periodontal disease.Aim: to examine the prevalence of yeast species in the sub-gingival biofilm of healthy and diseased periodontal sites of patients with untreated periodontal disease.Methods: Twenty patients with untreated periodontal disease and meeting the inclusion criteria, underwent a medical and dental history and clinical examination including a periodontal examination. Patients rinsed with 10 mls of sterile distilled water for thirty seconds and emptied the rinse into a sample container. Sub-gingival sites selected included the two deepest sites displaying bleeding on probing (Disease Site) and one shallow site with an absence of bleeding on probing (Healthy Site). Sampling sites were isolated, supra-gingival plaque removed with cotton wool pellets and samples obtained using three no. 35 sterile paper points. Also a curette sample was taken of the sub-gingival plaque deposits. Sub-gingival paper point and curette samples were transferred separately to the laboratory in Yeast Peptone Dextrose Broth and processed within twenty-four hours. Samples were cultured on chrome agar, identified visually, number of colony forming units counted and their identity confirmed using the ID32 test.Results: Candida spp. were isolated from both the oral rinse and sub-gingival samples. Candida spp. isolated from periodontal sites included C. albicans, C. kefyr, C. dubliniensis, C. parapsilosis. Candida spp. were present in 36% of Disease Sites and 0.05% of Healthy Sites (at a density of greater than 100 c.f.u.). Presence of candida spp. were highly statistically significantly related to disease state (Fisher's exact test: p=0.02). Differential colonization patterns were observed between the oral rinse and sub-gingival samples.Conclusion: 1.Candida spp. were present in the subgingival biofilm of patients with untreated periodontal disease at a prevalence of 36%. 2. The presence of Candida spp. within the sub-gingival site was significantly associated with the clinical signs of periodontal disease (p=0.02).