Jindo Mix’s Dental Health?

Hi everyone!

I was wondering what everyone’s dental routine is like for their jindo? I adopted my jindo mix about 1 year ago. Even at adoption, his teeth were very brown. It’s gotten slightly more brown as this year has gone by. We regularly brush his teeth almost every night with an enzymatic toothpaste and a soft toddler toothbrush. And we also regularly give him a daily greenie. But the brown spots never went away… everywhere online says a recommended dental cleaning but we really do not want to put him under. Any advice? TYIA!