Table 2.

Correlation coefficients (95% confidence interval).

	Pearson	Spearman
Sample source	R2A with SimPlate for HPC
All	0.607 (0.421, 0.744)	0.475(0.256, 0.648)
Handpiece	0.103 (−0.356, 0.522)	0.174 (−0.291, 0.572)
Air/water	−0.068 (−0.486, 0.375)	−0.268 (−0.627, 0.185)
Source water	0.481 (0.062, 0.756)	0.521 (0.115, 0.778)
	Millipore with SimPlate for HPC
All	0.650 (0.474, 0.776)	0.598 (0.406, 0.740)
Source water	0.573 (0.188, 0.805)	0.624 (0.263, 0.832)
	R2A with Millipore
All	0.871 (0.793, 0.921)	0.734 (0.592, 0.832)
Source water	0.795 (0.554, 0.913)	0.797 (0.557, 0.914)