STATEMENT OF PROBLEMChanges in the oral microbiota of new complete denture wearers are the main cause of oral candidiasis. The drawbacks associated with traditional antimycotic therapies, especially drug resistance, have led to the search for potent therapeutic and prophylaxis agents with less harmful effects, including probiotics. However, investigation of the prophylaxis and preventive effects of probiotics on new complete denture wearers are lacking.PURPOSEThe purpose of this randomized clinical trial was to assess the prophylactic efficiency of multistrain probiotics (Lactobacillus and Bifidobacterium) in combating oral candidiasis in new complete denture wearers. The Candida relapse after 4 weeks of intervention cessation was also evaluated.MATERIAL AND METHODSA total of 50 new maxillary and mandibular complete denture wearers with asymptomatic detectable levels of Candida were enrolled. The participants in the probiotics group received a daily dose of probiotic lozenges for 8 weeks versus placebo tablets taken by those in the placebo group. Collected mouth-rinse samples were microbiologically assessed to count Candida colonies and identify different species at different time intervals: baseline, 2 weeks after denture delivery, 4 and 8 weeks after the beginning of intervention, and 4 weeks postintervention follow-up. Data were assessed by performing the Shapiro-Wilk test to check the normality of the colony count, while the difference in the colony count between timelines was analyzed using the Freidman test followed by multiple comparison tests (α=.05).RESULTSTwo weeks after denture delivery, the Candida load had not risen significantly from the baseline count (P>.05). After the intervention, the probiotics had reduced the Candida count significantly in the fourth week and in subsequent follow-up periods, with the highest decrease observed in the eighth week, recording a median count of (0.00) compared with (2.74) at the baseline level (P<.001). Furthermore, in assessing the differential count of Candida species, a noteworthy decrease was found in the level of the most prevalent Candida albicans in the eighth week, with a relapse noticed in the twelfth week of posttreatment follow-up.CONCLUSIONSProbiotic lozenges had antimycotic efficiency in asymptomatic new complete denture wearers, with short-term extended preventive effects after intervention cessation.