Q. I have been given a kit called ‘day white excel 3’ from my dentist in Australia. I used the kit last week for 9 days straight and was meant to leave it on for half an hour, but sometimes left it for over an hour. I had very sensitive teeth afterwards and felt that diet coke or anything acidic afterwards was attacking my teeth. It looks like some enamel may have been eroded the root s of some of my teeth, is this possible or could the whitening highlight a problem that may already be there? In addition do fizzy drinks and sparkling water erode the enamel on teeth over time? Thanks in advance.