Just wanted to update to say that we started the xylitol and a fluoride rinse (not Act- it's not sold here. I'm trying to get some) the day after I started this thread. A couple days ago, we got Crest, and ds has decided that it's not too "spicy" for him, so he's going to use it too. I'm going to try to keep track of our progress here. He has an appt to have a small cavity filled (the dentist said it wasn't urgent), so we're going to cancel the appt and have a checkup for him in 6ish mos, and see where we are.
We do the fluoride rinse (and he does diluted Listerine sometimes) and floss once a day, and brush twice a day, and I clean the toothbrushes once a day.
I put 1/4 tsp of xylitol in each cup of water ds drinks (he drinks 2-4 a day- it's easier to get him to drink his water with a bit of xylitol in it! It's been a struggle in the past). I also give him 1tsp of xylitol in a bowl that he eats (and sort of swishes around his teeth) through the day. He also gets xylitol gum sometimes, and I ordered some candies- so that's 6g of xylitol at a minimum, and usually 8g or more.
I put 1.5-2tsp of xylitol in 1/2c of water, and swish and spit 5+ times a day until it's gone. I tried to get ds to do the same (spit some of it out) but he's decided against that. lol.
So far, my teeth definitely feel cleaner. I notice a difference in the smoothness from before I swish the xylitol and after.
Ds says that his front teeth are whiter. He had "cavities" (no decay, just the enamel came off) on his front top teeth since he was 18mos old. They have fillings on them, but are noticably yellower than his other teeth. Apparently, kids in his class have asked him why they are yellow. Anyway, I haven't read anything about xylitol making teeth whiter, but I looked at them the other day, and they do seem less yellow. So who knows. Maybe the xylitol is making them smoother, which makes them look shinier and gives the illusion that they are whiter? Regardless, I'm happy that he's happy!
eta- just read the post that says that Act can make teeth whiter- maybe that's what's helping! Either way, yay!