you did say your with a private dentist now? dont you think this might be the reason theyve changed their ways? this is a company, and their out to make money! i totally agree theres no point in having to go back all the time just cuz your filling gets chipped. sounds to me like their getting as much money as they can from ya! I go to an NSH dentist, and he is actually very good, always giving me options and asking me what i think would be best, after all, their my teeth! his fillings used for me have always been silver and they have always worked very well.
one of my friends is private and even she says what a rip off they are. she doesnt just see a dentist, they make her oppointments with a load of other people and then she gets charged like 50 quid for, as far as shes concerned, them doing nothing other than looking!
like i said, because their private, their a business. their going to work on the assumption you dont know any different, otherwise, or better. if i were you, id do some reading/research, then approach them and ask why their doing the things they are the way they are. (wow that was a good example of extremely bad english in that last sentance eh!)