THE EFFECT OF SALIVA OR SERUM ON STREPTOCOCCUS-MUTANS AND CANDIDA-ALBICANS COLONIZATION OF HYDROXYLAPATITE BEADS

Objective: Several recent reports imply the possibility of cariogenici ty of denture plaque containing Candida albicans. Hence the purpose of this study was to investigate the effects of salivary and serum pelli cles on C. albicans and Streptococcus mutans colonization on hydroxyla patite beads. Methods: The colonization of three isolates of C. albica ns and two isolates of S. mutans was examined by the use of a biolumin escent adenosine triphosphate (ATP) assay based on the firefly lucifer ase-luciferin system. Results: In the preliminary study, a good correl ation was observed between the cell number and ATP amount of each isol ate tested, and the results yielded a level of significance (P<0.001; Student's t-test), confirming the validity of this method. When the re lative ATP content of the 48 h colonization of both isolates of S. mut ans were compared, a saliva pellicle was significantly more effective in promoting bacterial colonization than either uncoated or serum pell icle (ANOVA; P<0.01). In contrast, in the case of colonization of C. a lbicans isolates, a serum pellicle was significantly more effective in promoting the colonization of C. albicans GDH 18 and GDH 19, than bot h uncoated specimens and saliva pellicle (ANOVA; P<0.01). Similar tren ds were observed with C. albicans GDH 16, though significant differenc es were not observed (ANOVA; P>0.05). Conclusion: The results suggest that the mechanism involved in fungal colonization on hydroxylapatite (HAP) should be different from that of mutans streptococci. (C) 1997 E lsevier Science Ltd.