Table 1.

Combinations of low and high caries risk and bacterial challenge as a function of log MS and log LB by three levels of salivary fluoride

log LB, CFU/ml	log MS, CFU/ml
	<4	4–5.9	≥6
Low fluoride [F] in saliva: [F] < 0.03 ppm
<1	low risk	high risk	high risk
	low challenge	medium challenge	high challenge
1–2.9	high risk	high risk	high risk
	medium challenge	medium challenge	high challenge
≥3	high risk	high risk	high risk
	medium challenge	high challenge	high challenge
Medium fluoride [F] in saliva: 0.03 ppm ≤ [F] < 0.079 ppm
<1	low risk	low risk	high risk
	low challenge	low challenge	high challenge
1–2.9	low risk	high risk	high risk
	low challenge	medium challenge	high challenge
≥3	high risk	high risk	high risk
	medium challenge	high challenge	high challenge
High fluoride [F] in saliva: [F] ≥ 0.08 ppm
<1	low risk	low risk	high risk
	low challenge	low challenge	high challenge
1–2.9	low risk	low risk	high risk
	low challenge	low challenge	high challenge
≥3	low risk	high risk	high risk
	low challenge	high challenge	high challenge