Are dental cavities contagious?

[miguelbgood]

I think I heard somewhere that some study proposed and proved the idea that if one person has cavities they can pass bacteria to their mate (through kissing and such) which can cause their mate to also get cavities.

I wouldn't have thought this was true, or thought about it at all, except that my wife recently had cavities, and then I suddenly started getting one.

Coincidence? Or are cavities contagious?

[Darwin's Finch]

It certainly appears that way:

http://abclocal.go.com/kabc/health/090401_hs_cavities.html
Kissing doesn't only spread colds; one local dentist says it can also spread cavities. He uses a new type of test that can help answer why some people get tons of cavities and others don't.

http://danr.ucop.edu/news/Jan-June2001/cavities.html
Dental cavities are contagious, like the common cold or flu, Ramos-Gómez said. It is caused by a bacterium, Streptococcus mutans, which is passed usually from mother to child by kissing, sharing utensils or any other activity that transmits any minute particle of saliva from one mouth to the other.

[scm1001]

I know that if a friend is eating chocolate then I have to have some of theirs. In that way yes

[miguelbgood]

This sounds like one of those new age things like mercury vapor poisoning. I'm still not convinced. If cavities are contagious, why have I never heard a dentist utter a word about it?

[Acsenray]

If cavities are caused by bacteria, why would it be so hard to believe they might be contagious?

[AETBOND417]

http://www.odontocat.com/angles/cavities_description.htm
[Disclaimer: pictures of cavity-riddled teeth also on this page]

This states cavaties are infectious, but (not unlike other things) also has an aspect concerning genetic predisposition.

[handy]

Your friends, the dental bacteria family :-) :
1. Lactobacillus acidophilus bacteria reside in the pits and fissures of the chewing (occlusal) surfaces of teeth. These bacteria can cause rampant tooth decay in young children ages 3-12, causing cavities in both baby teeth and the first permanent molars that erupt around age 6.
2. Six species of streptococcus bacteria attack the smooth surfaces on the sides of the teeth. These sides are usually touching adjacent teeth, and cavities arising on these sides can be difficult to detect visually. These cavities are best detected by the use of x-rays.
3. Odontomyces viscoses bacteria live on the back of the tongue and attack exposed cementum. Cementum is the hard outer layer of the tooth root (the bottom two thirds of tooth that is normally buried in dental bone). In older patients and in patients with gum disease, the tooth root and cementum become exposed and vulnerable to attack by these bacteria.
http://www.medicinenet.com/Script/Main/Art.asp?li=MNI&ArticleKey=316

[Nametag]

It seems unlikely that anyone grows to adulthood without aquiring most or all of these bacteria; caries may well be infectious (in the sense of transmission from mother to child), but I doubt that the OP got his cavity from his wife.

[Markxxx]

Cavities must spread though. At least within your mouth.

I got mugged and got 9 teeth broke. Because I didn't have dental insurance it took me about 3 1/2 years to get it fixed. I didn't have any cavities before. I wound up not only having 9 root canals but every tooth but one eventually developed a cavity in it that had to be filled.

[miguelbgood]

I read the links given in the first answer, and they are not at all convincing. First of all, both links are just opinions of 2 individual dentists; they do not provide any research references at all.

I don't doubt that bacteria that causese tooth decay could cause spreading of cavities from husband to wife, for example. However, there may be some reason why this doesn't happen, and I've seen no good evidence that it DOES. Certainly nothing posted in this thread is convincing.

I'm going to ask my dentist about it and do some further searches here on the net. But so far, I see no convincing evidence and have to put it in my "potentially true but probably not" box along with the existence of faeries and angels.