How are his gums?

This link has some good info..Sounds like treatment at home is crucial...

http://www.peteducation.com/article.cfm?cls=2&cat=1633&articleid=379>

What types of aftercare and home care are needed for pets with Grade I or II disease?

Owner commitment to home care is crucial.

Pets with Grade I or II disease will be placed on a regular brushing and home dental care program to control plaque. Measures include the mechanical removal of plaque through brushing and chewing; the chemical removal of plaque through toothpastes, gels and rinses; and proper nutrition with the possible use of specially formulated foods which reduce the amount of plaque and stain on teeth.