Are cavities contagious?

Sweets are often blamed for kids getting cavities, but the real culprits are actually bacteria — Streptococcus mutans and Streptococcus sobrinus.

Time reports from AOL Health:

“Particularly, the easiest way to catch a cavity is when a mother is feeding a child,” Dr. Irwin Smigel, creator of Supersmile, told AOL Health. The mother will taste the food to check the temperature and then continue feeding the child. “Immediately, that’s how kids get cavities,” he says.”

“Kissing between couples can also cause the spread of harmful bacteria. Smigel has seen many patients, particularly women, who have clean, healthy mouths, discover a cavity or two after entering into a relationship with a man who has cavities, gum disease or hasn’t been to the dentist in several years.”

What? Kissing spreads cavities? Sharing food with your kids spreads cavities? I understand that it’s the bacteria eating away at the tooth but it just really goes against all that you are told – don’t eat sweets, brush, floss. (But you’re brushing away the bacteria is the point.)

The Time story continued:

“Infants and children are especially vulnerable to the bacteria. A 2007 study conducted at the University of Queensland’s School of Dentistry in Australia found that cavity-causing bacteria was found in the mouths of 30% of 3-month-old babies and more than 80% of 24-month-olds with primary teeth.”

I think that heredity and the shape and texture of your teeth also affect whether or not you get cavities. For 10 years the Giarrusso children have not had any cavities.

At Lilina’s first dental appointment last year, they told me her back tooth looked very susceptible to a cavity and to work really hard a cleaning it. Well we’ve tried our best and at this year’s check up she has a cavity. I think the back tooth had a lot of grooves in it that made it harder to get clean and more susceptible.  We are bummed out about the cavity. I think the other kids take after Michael’s side and their teeth are less susceptible based on shape and texture. (The hygienist said Lilina was doing a much better job brushing than Walsh was but Walsh didn’t have a cavity.)

Are you buying that cavities are contagious? Does that make you want to not share food or kiss? Do you think heredity has something to do with it as well? How long did your kids go without cavities?

12 comments Add your comment

Theresa Walsh Giarrusso

April 8th, 2011
11:18 am

So sorry guys. I had a technical malfunction. that was supposed to publish at midnight and I just realized it didn’t!! so sorry!! I have a second topic I am working on now.


April 8th, 2011
11:50 am

My oldest 3 have never had a cavity but my 3 year old has 3. It might have something to do with how lax I’ve gotten with oral hygiene for them. That’s my fault & I’m trying to do much better teaching her to brush (but still basically doing it for her.) I do think it has something to do with genetics too as the 3 yr old is the only one blood-related to my husband and his teeth have a lot invested in them (crowns, root canals, broken tooth, etc.) Who knows. Brush, floss, try to do your best. I’m not going to worry about passing cavities around casually. Trying to protect yourself from everything out there that can hurt you will only end up isolating you in a plastic bubble.


April 8th, 2011
12:02 pm

I think tooth structure has a big effect. My son (8) has already had at least 2 cavities due to his teeth having deeper crevices on the chewing surfaces, so being harder to clean well. The dentist put a sealant on the most susceptible permanent teeth last year, I think. You may want to ask about it for Lilina when she’s older. We also switched him to an electric brush with a timer, which has helped too.


April 8th, 2011
12:03 pm

BTW, I refuse to give up kissing!!!


April 8th, 2011
12:10 pm

I too think it has a lot to do with genetics. My brother got his first cavity when we was in his 20’s. He always drank soda, ate candy and was not consistant about brushing his teeth. I on the other hand seem to have very weak enamel. I chip teeth, have had way too many caities. I (even as a young child) was much more consistant about brushing my teeth and flossing. I carry floss picks and keep a tooth brush at my office. I am loving the new G.U.M. dental picks. I also use a water pick, mix the water with peroxide or mouthwash to help get a deeper clean.


April 8th, 2011
12:13 pm

I’m not buying this… Hubs has several fillings and I have never had any. I haven’t gotten any cavities (yet) in the decade+ we’ve been together. I think it’s more a product of early dental care – maintaining dental schedules and teaching kids early to take care of their teeth.

Other anecdotal evidence – people of my parents’ generation, including my parents – had a lot of cavities from when they were younger. They pretty much never went to the dentist (whether that was the attitude of their parents, or they were too poor) and had lots of fillings. With regular dental care, they haven’t had cavities in many years.

I do think tooth structure has something to do with no cavities, but I’m hoping a dentist or hygienist will dispel this ’spit-swapping’ business properly.


April 8th, 2011
5:48 pm

I think genetics has a lot to do with it. My husband never went to the dentist until he enlisted in the Navy as an adult. Hard to believe but true. My kids have been going since they were babies and neither has had many cavities. I never had one growing up but once I got to be an adult, have had 5 or 6. Plus caps and crowns….yikes.


April 9th, 2011
10:23 am

Hard to tease out cause and effect. My parents both had their teeth pulled at an early age, and my teeth have always been problematic. I have always avoided the dentist, as anesthesia doesn’t work well on me. (I was even slapped by a dentist when I was about 8 because he got frustrated at my jumping and crying!) It’s like I am resistant to the effects. My hairdresser told me it is because I am a red-head, that doctors know that red-heads are harder to put to sleep, numb up, etc. I know the stuff that was supposed to make childbirth easier did not work–I could have danced. I woke up on the operating table when I had my gallbladder out. I looked it up on the internet (cause I thought he was full of it) but there is evidence to suggest that it is true. I have found a dentist who is very cognizant of my difficulty so the dental work is better. They get me in quickly, have someone stay with me in the room (never leave me alone–I will bolt), hold my hand, and are prepared to give me however long I need to get numb enough. Even then, though, I have had a few “shocks” and jumped and made the dentist scream–pretty funny actually.

Like other things, I think it is a combination of genetics, care, diet, and bacteria. Some people are the perfect storm of these variables.


April 9th, 2011
11:49 am

People of my parents’ generation did not do preventative care, and they probably did not have treated water.


April 9th, 2011
6:01 pm

How did they have lots of fillings if they never went to the dentist?


April 10th, 2011
9:01 am

I’m with you catlady-I have to almost be knocked out to just get my teeth cleaned! I think cavities have a lot to do with genetics and the structure of the teeth. My oldest is my candy eater, soft drink lover, etc.-he’s 20 and has no cavities. My youngest is a very healthy eater, conscientious brusher, etc.-he’s 10 and has 2 cavities. Go figure!


April 11th, 2011
1:34 pm

Well, you all know my neighbor’s 3 year old granddaughter has 5 cavities…..

My daughter has NONE. She has the most beautiful set of teeth. I have good teeth, and so did her father. She’s never had a cavity and her teeth are perfectly straight, without the help from braces.

A few years ago, we had appointments back to back. I was waiting for her when the dentist walked out to talk to me. He said “she has her wisdom teeth”. I thought, oh no, here comes the bill for pulling them. He said NO, she has them in her mouth, they came in straight, and we don’t need to pull them”. She fell into that 3% that doesn’t have to have wisdom teeth pulled… my kid has 32 teeth in her mouth… wonder she can’t shut up….LOL.