Hi,
I came across this video and the dog was so co-operative so I think you should start brushing your puppy when it is still young so that it will get use to it.
If you cannot see the video, go to http://www.youtube.com/watch?v=m-KIgPYguV4
I am still brushing Ruby's front teeth and just realised that I should not be givng her a treat immediately after the brushing but at least after 1/2 hour later!
David