Table 2.

Comparison of standard polymerase chain reaction (PCR) and quantitative real-time PCR (qPCR) in detection of Streptococcus nutans and Aggregatibacter actinomycetemcomitans in dental plaque of a Haitian adolescent population

Study group	Gender		PCRa		qPCRb
			% positive for S. mutans or A. actinomycetemcomitans		% positive for S. mutans or A. actinomycetemcomitans
		%	S. mutants c	A. actinomycetemcomitans d	S. mutans c	A. actinomycetemcomitans d
Supra-gingival
N=54	All	100	38.8	59.2	67.3	67.3
	Male	57.1	42.9	67.9	67.9	75.0
	Female	42.9	33.3	47.6	66.7	57.1
Sub-gingival
N=98	All	100	8.l	44.0	36.6	85.1
	Male	56.0	7.0	43.1	39.0	83.7
	Female	44.0	9.7	45.0	33.3	87.1

^aPearson Chi-square test showed no differences in the prevalence of S. mutuns and A. actinomycetemcomitans detected by PCR between the males and the females. However, the prevalence were statistically significant higher in supra-gingival samples compared to that in sub-gingival samples for cither S. mutans (p< 0.001) or A. actinomycetemcomitans (p=0.031)

^bPearson Chi-squarc test showed no differences in the prevalence of S. mutans and A. actinomycetemcomitans detected by qPCR between the males and the females. However, the prevalence was statistically significant higher in supra-gingival samples compared to that in sub-gingival samples for S. mutuns (p<0.001), but marginally higher for A. actinomycetemcomitans (p 0.055)

^cThe prevalence of S. mutans was significantly higher when detected by qPCR compared to the results detected by standard PCR for cither supra-gingival samples (McNcmar's test, p<0.00l) or sub-gingival samples (McNcmar's test, p<0.001)

^dThe prevalence of A. actinomycetemcomitans was significantly higher when detected by qPCR compared to the results detected by standard PCR for sub-gingival samples (McNcmar's test, p<0.001), but not for supra-gingival samples (McNcmar's test, p=0.219)