I was worried about the whole dummy thing with DD1, but eventually I decided 'why mess around with what works?'. She also wanted it during the day all the time and around 18 months we made it for sleep only. She still uses it for sleep. I think we are at the point that we will wait til she's old enough to understand the concept of a a dummy fairy (or similar) to give it to. She's always been such a good sleeper that I haven't wanted to mess with it.
DD2 won't take a dummy