My daughter is very good about brushing her teeth, but I had noticed that she was sometimes missing the gum area of her teeth. So I went hunting for a very soft bristled toothbrush with a head large enough to always stimulate the gums.
On the advice of a Youtube friend I discovered the Radius toothbrush. I ordered the regular size for me to try and the childs size for my daughter.
After using this brush our teeth feel like they do after a cleaning at the dentist office. It gently stimulates the gums and my daughter no longer has any inflammation of her gums.
If you have a small mouth order the childs size.
The frugal side of these brushes is that they are made to last for 9 months without being replaced. If you feel that the brush needs sanitizing I would soak it in a peroxide and water bath.
I ordered mine from Vitacost, but they are also available through Amazon (link below).