| Abstract [eng] |
Relevance of the problem: The global ageing of the population has led to a growing number of elderly individuals residing in long-term care facilities. Seniors wearing removable dentures represent a particularly vulnerable group due to age-related systemic diseases, reduced salivary flow, impaired manual dexterity, and limited ability to maintain adequate oral hygiene. These factors contribute to an increased risk of opportunistic oral infections, especially those caused by Candida species. Denture surfaces provide a favourable environment for microbial adhesion and biofilm formation, facilitating fungal colonisation of both oral mucosa and prosthetic materials. Data on the prevalence and species distribution of oral Candida among institutionalised elderly populations in Lithuania remain scarce. Therefore, this study aimed to evaluate the species composition and prevalence of oral Candida spp. among seniors living in social care homes and wearing removable acrylic dentures. Material and methods: A pilot cross-sectional study was conducted in 2025 among seniors residing in two social care homes in Vilnius, Lithuania (ethics approval No. 2024/1-1563-1024). All participants who met the inclusion criteria voluntarily agreed to participate and signed informed consent forms. Concentrated oral rinse samples as well as samples from the internal and external surfaces of upper and/or lower removable acrylic dentures were collected. Samples were cultured on chromogenic medium (Chromo®Bio Candida, Biolab, Hungary) and incubated aerobically at 37 °C for 48 hours. Colony-forming units (CFU) were quantified. Yeast species identification was performed using microscopy, germ tube testing, growth at 37 °C and 42 °C, and matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI TOF MS). Data processing and statistical analysis were performed using IBM SPSS Statistics 27.0 (IBM, USA) and Microsoft Excel (Microsoft 365, USA). Results: A total of 51 social care home residents were included in the study; 78.4% (n = 40) were women, and 66.7% (n = 34) were aged 85 years or older. Most participants wore removable dentures in both jaws: 98.0% (n = 50) wore upper dentures and 88.2% (n = 45) wore lower dentures. Oral Candida spp. were detected in most participants (88%). High-level oral Candida colonisation (> 2–3 × 10³ CFU/mL in oral rinse) was observed in 84% of cases. Eight different Candida species were identified in oral rinse samples, including C. albicans, C. glabrata, C. dubliniensis, C. parapsilosis, C. tropicalis, C. lusitaniae, C. guilliermondii and C. norvegensis, along with four non-Candida yeast species (Saccharomyces cerevisiae, Kluyveromyces marxianus, Cyberlindnera fabianii and Cryptococcus gattii). The most frequently isolated species were C. albicans (62%), C. glabrata (46%) and C. dubliniensis (26%). Nine Candida species were identified on denture surfaces, eight of which were also detected in oral rinse samples; C. krusei was found exclusively on the internal surface of the lower denture. Higher Candida CFU counts were observed on upper dentures compared to lower dentures. Lower Candida CFU counts were associated with storing dentures dry overnight compared to keeping them moist or leaving them in the mouth. Participants with iron-deficiency anaemia tended to exhibit higher oral Candida CFU/mL counts. Conclusions: This study demonstrates a high prevalence and intensity of oral Candida colonisation among elderly denture wearers living in social care homes. Upper removable acrylic dentures were more heavily colonised than lower dentures, and inadequate denture hygiene practices were associated with increased fungal burden. These findings highlight the importance of targeted oral hygiene education and denture care strategies to improve oral health and quality of life in institutionalised elderly populations. |
