Performance differences of two potentiometric fluoride determination methods in hard dental tissue

A comparison between two ion selective electrode (ISE) potentiometric methods is reported for determining the amount of fluoride in hard dental tissue after placement of fluoride-releasing dental restorations. The two methods are: (1) the direct method involving linear calibration (LC), and (2) a spiking method involving multiple standard additions (MA). Results showed that measurements performed by the LC method underestimate the amount of fluoride released by up to 30%. Recovery tests demonstrated that the use of MA and blank correction procedures is useful for an accurate and sensitive ISE determination of fluoride in hard dental tissues.