Caries is one of the dental diseases which seriously damage the human health by progress of the disease from enamel defect to tooth eruption.
Fluoride has been efficiently used for the prevention of caries which is the most prevalent in children and population and harmful for the human body.
Since the application of fluoride was known to be effective for the caries prevention, the most frequently used fluoride has been acidulated phosphate fluoride gel(APF gel).
In APF gel, the pH is acidic for the purpose which raises the chemical reactivity of NaF. This gel has high anticaries effect and stability, however, because of acidic pH of this gel, the use of this gel can lead to the decay of teeth and ceramic denture.
From this, we tried to develop a new type of fluoride which can improve the anticaries effect and minimize the limitation of APF gel.
Recently, we manufactured 0.5%, 1.23% NaF-HF gel. This fluoride is subacidic fluoride which contains NaF and HF.
According to the results of in-vitro test and microscopic pattern of the enamel surface, this fluoride showed higher acid endurance than APF gel.
We assessed anticaries effect according to times of application (once, 3 times, 5 times, 7 times)in sound teeth. And anticaries effect of 1.23% NaF-HF gel when applied once a year was also assessed.
Caries development reduction when a child applied 0.5% NaF-HF gel himself/herself once, 3 times, 5 times, 7 times was 28.34%, 61.22%, 69.02%, 71.36%, respectively. In group of 1.23% NaF-HF application showed high caries development inhibiting effect. In this group, caries development reduction when applied once a year was 64.57%.
These results showed higher anticaries effect of NaF-HF gel than that of 4 times application of 2% NaF.
We also assessed the anticaries effect of NaF-HF gel in teeth with caries compared with that of control group.
The proportion of teeth with more than D1 caries in group of 0.5% NaF-HF gel was lower than that of control group. Caries progression reduction when applied once, 3 times, 5 times, 7 times was 37.94%, 66.78%, 75.35%, 76.62% respectively.
And the high caries progression inhibiting effect was also seen in once application group of 1.23% NaF-HF gel. Caries progression reduction in this group was 63.12%, was similar to the value of 0.5% NaF-HF gel, 3 times application.
No side effect was noticed after application of this gel.
NaF-HF gel can be effectively used for the prevention of caries.
