Question 1

How soon after brushing does Duraphat start working?

Accepted Answer

Fluoride begins binding to enamel immediately during brushing. The protective effect begins within minutes and lasts for hours.

Question 2

How long does Duraphat stay on teeth after brushing?

Accepted Answer

Fluoride remains in saliva for 2‑3 hours, providing a reservoir. Some fluoride incorporates permanently into enamel, but the topical level declines after a few hours.

Question 3

How long does it take for Duraphat to be absorbed if swallowed?

Accepted Answer

Absorption is rapid – peak blood levels occur 30‑60 minutes after ingestion. The fluoride is then distributed to bones and teeth or excreted in urine.

Question 4

How long does Duraphat take to work for cavity prevention?

Accepted Answer

While some protection is immediate, maximum caries reduction requires 2‑3 weeks of regular thrice‑daily use as fluoride accumulates in plaque and saliva.

Question 5

How long does it take for fluoride to leave the body?

Accepted Answer

Fluoride not deposited in bone is excreted in urine within 24‑48 hours. Bone‑bound fluoride remains for years; however, it does not pose a risk at therapeutic levels.