Jack had the same issue and I refused to put him under. Thankfully I found a small family owned pet supply store that offers teeth cleaning. He has a dental hygienist clean his teeth once a month and all she uses is a pick and a tooth brush but it does wonders! I also brush his teeth about twice a week (not as often as I should). Here is the website if you are interested
Canine Care - Home. I think this website is for California residents only but you may want to see if they offer anything of this sort in your area.