<prompt> Active fluoride concentration in the cavity varnish duraphat is:22,900 ppm7,600 ppm22,600 ppm11,600 ppm  <response>: Duraphat, the first fluoride varnish developed in Germany.It is a viscous yellowish material, containing 22,600 ppm fluoride as sodium fluoride in a neutral colophonium base NaF varnish containing 2.26 fluoride in organic lacquer. Duraphat has shown caries reduction between 30 and 40 in the permanent dentition and in between 7 and 44 in the primary dentition.Essentials of preventive and community dentistrySoben Peter5th editionpage no. 255 