Table 1. Pairwise bacterial coaggregation.

	S. oralis			S. sanguinis			S. mitis			S. downei
	t1	t2	t3	t1	t2	t3	t1	t2	t3	t1	t2	t3
A. naeslundii	0	0	0	0	1	1	2	3	3	0	0	0
S. downei	0	0	0	0	0	0	0	0	0	-	-	-
S. mitis	0	0	0	0	0	0	-	-	-	-	-	-
S. sanguinis	0	0	0	-	-	-	-	-	-	-	-	-

Pairwise coaggregation of A. naeslundii AK6, S. downei HG 594, S. mitis SK24, S. sanguinis SK150 and S. oralis SK248. Coaggregation was determined 15 min, 2 h and 24 h after mixing in 1/10 diluted Todd Hewitt Broth. t1 = 15 min; t2 = 2 h; t3 = 24 h. Grade 0: No visible aggregates in cell suspension. Grade 1: Small uniform aggregates in suspension. Grade 2: Definite coaggregates easily seen, but suspension remained turbid without immediate settling of coaggregates. Grade 3: Large coaggregates which settled rapidly leaving some turbidity in the supernatant fluid. Grade 4: Clear supernatant fluid and large coaggregates which settled immediately.