Protein content of human mixed saliva of subjects with different caries risk

This study was aimed to investigate the correlation between the protein composition of human mixed saliva from participants of a caries risk assessment study. The participating schoolchildren exhibited a caries incidence from 0.34 to 0.71 while ageing from 8 to 10 years. Three unstimulated mixed saliva samples of 111 subjects were collected during 2 years and 50 µl were analysed by reversed phase HPLC (RPLC) (Hewlett-Packard ChemStation LC 1100, Zorbax 300 SB-C8 column (4.6 x 150 mm, 3.5 micron) at 35 °C, UV detection at 215 nm). The protein content of nine fractions was determined using bovine serum albumin (BSA) as an internal standard. A cluster analysis (Ward method) with the protein contents of the nine protein fractions was performed, which allowed a separation of the subjects into two distinct cluster groups, distinguished to the two- or three-fold of the protein content for one group (Tab. 2). The number of test persons assigned to cluster 2 decreased dramatically with increasing age of children. Keywords: saliva, protein, caries risk, hplc, cluster analysis