I had that for a while, maybe few years. Is this permanent?
The edges of your front teeth are composed of enamel which is a translucent material. Enamel has optical properties that include luminescence, fluorescence and opalescence. It is those light properties and the way the light gets absorbed and reflected from the surface of the tooth that gives the color characteristics to a tooth. The bluish hue is a sign of healthy enamel, actually young enamel that has not been worn away and is intact. So its is a sign of youth and is perfectly normal. Dentists sometimes fight to try to recreate this in veneers and bonding. If you don't like it, it can be corrected with applying an opaque color composite over it, but this may require the removal of some healthy enamel.
