Coaggregation occurred between Porphyromonas gingivalis and mutans streptococci. The coaggregation was completely inhibited by L-arginine, Na-p-tosyl-L-lysine chloromethyl ketone (TLCK), and a trypsin inhibitor, and weakly inhibited by L-lysine, N-ethylmaleimide, lysozyme, and human whole saliva. The results of heat and proteinase K treatment suggested that a heat-labile proteinaceous substance of P. gingivalis and a heat-stable substance of mutans streptococci may play a role in the coaggregation. Mutans streptococci also aggregated in the presence of the heatlabile factor in the supernatant of P. gingivalis. The aggregation was also inhibited by L-arginine, TLCK, and a trypsin inhibitor.

The vesicles of Porphyromonas gingivalis ATCC 33277 strongly aggregated Streptococcus cricetus, S. rattus, and S. mutans, but poorly aggregated S. sobrinus. The adherence of S. mutans OMZ 70 to hydroxyapatite (HA) coated with whole saliva was increased in parallel with the quantity of the vesicles. The significant increase of adherence of S. mutans OMZ 70 by the vesicles was also observed on the HA coated with parotid saliva, submandibular saliva, serum, and type I collagen. These findings suggest that the vesicles may act as a bridge between mutans streptococcus and the tooth surface.

No abstract

The purpose of this study was to elucidate 19 enzymatic activities in whole mixed saliva and their changes in men without oral hygiene.Ten healthy, unmedicated male students with excellent oral hygiene and clinically normal gingiva, between the ages of 22 and 26 years, were the experimental subjects. At the start of the experimental period, whole mixed saliva and parotid saliva were collected and the clinical parameters were recorded for each of them. Then, the experimental no-cleansing period of 7 days was started, and whole mixed saliva was collected and the clinical parameters were recorded every day. Enzymatic activities were determined using API ZYM systems (MONTALIEU VERCIEU, France).Alkaline phosphatase, butyrate esterase, caprylate esterase-lipase, myristate lipase, leucine aminopeptidase, valine aminopeptidase, and trypsin activities in whole mixed saliva supernatant were significantly higher at the end of the no-cleansing period than at the start of experiment. Myristate lipase, valine aminopeptidase, and trypsin were detected in whole mixed saliva sediment, but not in parotid saliva.This suggests that these enzyme activities in whole mixed saliva are useful in estimating the oral hygiene status.