universidade de são paulo - Faculdade de Odontologia - Unesp

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was collected from one donor or centrifuged longer and at a higher speed, no
significant differences were detected when they were compared to control. The
yeast-surface recognition systems involve different ligand-receptor mechanisms
based on protein or carbohydrate moieties existing in this interaction [11].
Moreover, it was suggested salivary mucins also bind to C. albicans, and they
promote yeast adhesion to polymethylmethacrylate [11]. Higher centrifugal forces
might separate significant amounts of the high molecular weight mucins [4, 32].
Thus, the centrifugation must be made without causing considerable effects on the
biochemical and biophysical properties of saliva. It has been observed that
centrifugation at 10000 g for 5 minutes at 4 °C had minimal impact normal saliva
protein profiling [40]. These may help explain, at least in part, the significantly
higher absorbance value of group G1 when compared to control. Another aspect
to be considered is that saliva composition varies greatly inter-individually [32].
Hence, the use of saliva collected from several donors and pooled may have
minimized this variation and, consequently, its influence on the adhesion results.
Differently from the results obtained by the XTT assay, the crystal violet
staining revealed that the adhered cell number was higher in group G 1 compared
to control and the other experimental groups, but the differences did not reach
statistical significance. It is important to emphasize that the two methods used in
this investigation for assessing C. albicans adherence to the denture base resin are
based on different principles. The XTT reduction assay is a method in which the
metabolic activity of viable cells is measured [22, 26, 33-35]. Mitochondrial
dehydrogenases of viable cells cleave the tetrazolium ring of XTT, yielding