Question about fluoride regarding tooth decay

I think that xylitol is an excellent product to use to help fight tooth decay. From what I understand, it inhibits the bacteria that decays teeth. I’m surprised that my dentist didn’t know about this although he did mention the usual important aspects of oral hygiene (brushing twice a day with a fluoride toothpaste, etc.). If it weren’t for my own research, I would never have even heard about it. More people should know about this product. It should be as routine knowledge as the fact that fluoride helps strengthen enamel.

Which brings me to my question. I had very bad oral hygiene in the past and now I have had many root canals, fillings, and crowns. Sometimes when I’m brushing with a fluoride toothpaste over these porcelain/metal crowns, I wonder if I’m not wasting my time. Of course, it’s just easier to spread the toothpaste all over the mouth instead of carefully brushing the real teeth with fluoride and the artificial, covered ones without. But what if someone has no exposed enamel in his or her mouth. Say someone has crowns, bridges, and implants on all of his molars, his front top teeth are crowned for aesthetic reasons, and the bottom front teeth (for argument’s sake) are crowned or bridged too. So this hypothetical patient has most or all of his teeth, but they are all covered by artificial restorations. That is, no enamel is exposed anywhere in his mouth. Would it still be necessary to go out and buy a fluoride toothpaste? In other words, would fluoride still be necessary in this person’s oral hygiene? And if so, what purpose would it serve (since I’ve always understood that fluoride’s main purpose is to strengthen enamel).

I would imagine that such a patient should stick to the xylitol (so it could continue to kill bacteria that might cause recurrent decay) but flip a coin as to whether or not to use the fluoride treatments when brushing teeth.

I’m woefully underinformed about how much of a tooth’s surface is covered by the dental work you talk about, but I suspect there are still quite a few places where the tooth enamel is exposed, like between adjacent teeth, or along the gumline (where slivers of food (bits of potato chip, fragments from of shell from M&M’s, etc.) can sometimes lodge.

I had always thought xylitol was a less-hazardous substitute for sugar.
Does it actually have an additional positive benefit, or is it just less bad for you?

Either way, there’s no reason to avoid fluoride in toothpaste.
You aren’t supposed to be swallowing it anyway, so your pineal gland is safe.

From what I understand, it’s very good in that it kills the hell out of that crappy bacteria that causes tooth decay. You’re supposed to take a certain amount a day (too much isn’t good in that it might cause diarrhea) according to studies.

As for the fluoride matter, I don’t mean to start a debate about how it might be dangerous. I don’t put much stock in the alarmist notion that it’s a communist plot to brain damage us or anything like that. I’m just curious if an hypothetical person with no exposed enamel in his restored teeth is wasting his time with fluoridation (not that it’s really that big a deal to go through the motions while cleaning away the bacteria that might seep under the restorations and cause failures).

The main benefit of xylitol is that it is not fermentable, and therefore does not promote caries. Large amounts of xylitol will actually cause decay-causing bacteria to starve to death, but this requires several grams a day, which you won’t get from toothpaste. Xylitol is also capable of transporting calcium through the gut and promoting remineralization, but again, you won’t get this benefit from toothpaste. Xylitol toothpastes therefore have no greater benefit than other sugar-free toothpastes, and even xylitol lozenges do not compare with fluoride toothpaste as an anti-caries measure.

I’ve got that all covered. I buy mints that I chew on throughout the day and then have a xylitol mouthwash that I use once a day. I haven’t found any xylitol toothpaste but I don’t really feel that I need it since I get it from other sources. And I also put xylitol in my coffee in the morning (I’ve got a big bag of it that I keep handy) but I stupidly use sugar if I go to a coffee place around town (I need to buy some portable xylitol packets that I can carry around with me to take care of that issue). I just need to make sure I take the 5 to 10 milligrams a day. I’m just sick of my teeth rotting so much. At least I still have most of them and I’d like to keep it that way.

As for the fluoride, obviously I still need to use it. I’m just curious what a dentist would say to a patient who’s got no exposed enamel in his or her mouth. Is fluoride necessary in that situation? Brushing is always necessary to kill bacteria but does fluoride serve any other purpose besides strengthening enamel?

I just want to make sure that no one misunderstand me. I’m not saying I don’t want to use fluoride. It’s very useful and in fact I’m using super-strength prescription fluoride at this moment. I don’t intend to replace fluoride with xylitol. I think they can work very well together (fluoride for making enamel strong and the xylitol for killing that damned cavity-causing bacteria). I was just thinking if someone has, say, thirty dental implanted crowns in his mouth (or root canals, etc.) and no exposed enamel, is the fluoride obsolete for his purposes or does it still serve a very critical purpose in some other way?

Yes, it still serves a purpose. Even with a crown, there’s still always at least some environmental exposure where the crown meets the underlying tooth.

I don’t see any purpose if you’ve got a full set of dentures, though.

Dentist here. This is correct. Where crowns meet the tooth is seldom on enamel anyway. Because of how the teeth are preped, the crown usually is supported on dentin or cementum, neither of which is as hard as enamel. All the more reason to use flouride.