Try the Sonicare toothbrush with the small brush (for children). Also,
Fragaria Vesca (homeopathic pellets to soften tooth plaque).You can find FV
at most health food stores, or order online. There are 90 pellets in a vial.

Google Fragaria Vesca to learn more; it's derived from the strawberry plant.
I've used it for 2 years with excellent result - no plaque. Designed for
humans, it's also popular in the dog and cat family, particularly with aging
pets where sedation dentistry/cleaning may pose a risk :)

I take 4 pellets twice a day for a few days, til plaque releases, then
simply repeat a cycle of a few days if plaque builds up again. I don't take
daily; it's really not necessary with effective brushing/flossing :)
I also brush my teeth with PLAX dental rinse - don't just rinse with it
pre-brushing. Also, don't rinse after brushing the teeth with PLAX, leave it
on the teeth to work away at plaque build-up.

Cheers!

Carla
http://home.netscape.ca/~terrier