I have home cooked but ONLY used a diet formulated by a veterinary nutritionist. One size fits all is not the way to go imho.
You can get a free diet that is balanced at:
www.balanceit.com What you are doing is not balanced.
As for the teeth...the diet may be deficient and affecting them, but that diet will affect other parts of the body as well. You REALLY need to get a well balanced diet plan for them.
Much of what happens in terms of periodontal issues in small dogs is genetic and also due to their tiny mouths. Most small dogs need dentals done by the vet ...even if you brush them, they still need them. Not doing dentals will lead to major organ diseases and quite possibly failure.
Info on dogs oral health here:
Veterinary Oral Health Council