Growth and/or acid production of Candida albicans on soft lining materials in vitro

Effects of soft lining materials on the growth and/or acid production of Candida albicans were investigated using a simplified method monitoring the pH change in the growth medium. Reverse sigmoidal pH curves were observed with all samples and, as compared with acrylic, all soft lining materials inhibited fungal growth or acid production in the following way, i.e. delay of the beginning of a rapid and linear decline in pH, decreases in the rate of linear change in pH and increases in minimum pH. Further examinations using a surface-modified glass tube revealed that the order of Candida growth agreed with the relative hydrophobicity and adherence capacity of substrates, suggesting that this adherence capacity affected the yeast growth on their surfaces. Besides adherence capacities of substrates, the powder, liquid and plasticizer of some soft lining materials directly inhibited Candida growth. Thus, the results obtained here revealed that several factors within soft lining materials affected Candida growth and/or acid production.