Dental disaster

Rolled up for my dental check up today to find my ( good) dentist with I pad in hand. Seemingly I was being questionaired about my dental hygiene. So far so good and after the usual poking and scraping sat up expecting the usual about flossing more and " we wills see you in 6 months ".
Bit surprised to be handed a print out which tells me my teeth are literally wearing away. Something to do with too much acid so looks like its cheerio to the diet coke and fruit juice. Wasn't nagged about the flossing though.