The role of salivary factors in persistent oral carriage of Candida in orthodontic patients

Abstract

AIM: Candida albicans is commensal oral yeast is observed in some 34 per cent of the healthy population. It has been shown that insertion of orthodontic appliances increase the Candida count in the majority of patients. However there is a wide variation in patient response. It is of importance to understand why different individuals react differently to the insertion of orthodontic appliances. In addition, there are no studies investigating the anti-candidal salivary constituents of healthy individuals with varying or nil candidal carriage rates. The aim of this study was to compare the composition and anticandidal activity in stimulated whole saliva of healthy ‘consistent’ oral Candida carriers with Candida-free individuals undergoing orthodontic treatment. SUBJECTS AND METHOD: A sub-sample of 22 consistent, Candida-free individuals and 10 consistent Candida carriers were recruited from a longitudinal study investigating oral Candida carriage in 97 healthy subjects. Unstimulated and stimulated saliva samples were collected. The salivary attributes including fl ow rate, pH, level of inhibition of blastoconidial viability, blastospore germination, lysozyme, lactoferrin and IgA concentrations of both groups were measured. RESULTS: Saliva from the Candida-free individuals showed a 20 per cent higher inhibition of blastoconidial viability (P < 0.05) of a reference strain of Candida albicans. No signifi cant differences between the other salivary attributes of the two groups were found. CONCLUSIONS: The saliva of Candida-free individuals signifi cantly inhibited the blastoconidial viability compared with saliva from carriers; this may help to explain the microbiological fi ndings from the effect of the orthodontic appliances.