Table 2.

Subgroup analysis of the effect of topical fluorides on caries incidence by intervention parameters and control type

Subgroup	Caries Incidence(OR, 95% CI, p value)
Note: OR < 1 favours topical fluoride because the event was defined as the development of dental caries. The 5% NaF varnish study was not pooled in this subgroup table because only one study used this high-concentration professionally applied varnish and the control group received delayed varnish during follow-up.
Intervention frequency
High-frequency intervention (≥ 2 times/week)	OR = 0.45, 95%CI: 0.33–0.61, p < 0.00001
Low-frequency intervention (< 2 times/week)	OR = 0.62, 95%CI: 0.48–0.80, p = 0.005
Intervention duration
Short-term intervention (< 18 months)	OR = 0.56, 95%CI: 0.42–0.74, p < 0.00001
Long-term intervention (≥ 18 months)	OR = 0.39, 95%CI: 0.28–0.54, p < 0.00001
Age group
Children (3–10 years)	OR = 0.48, 95%CI: 0.34–0.68, p < 0.00001
Adolescents (10–19 years)	OR = 0.60, 95%CI: 0.46–0.79, p < 0.00001
Fluoride type
Sodium fluoride	OR = 0.47, 95%CI: 0.35–0.62, p = 0.003
Monofluorophosphate	OR = 0.55, 95%CI: 0.41–0.74, p = 0.01
Type of control group
Placebo/No Intervention	OR = 0.49, 95%CI: 0.38–0.64, p < 0.00001
Active control	OR = 0.58, 95%CI: 0.42–0.80, p = 0.001