Metal Mouth Message Board

Study Finds Potentially Pathogenic Microbes Growing on 50% of Retainers

Researchers at the UCL Eastman Dental Institute, London, have found that insufficient cleaning could allow build-up of microbes on orthodontic retainers. The study found potentially pathogenic microbes growing on at least 50% of the retainers it looked at. The findings have been published in the Society of Applied Microbiology’s journal Letters in Applied Microbiology.

For the study, the researchers took samples from the mouths of people without retainers and those wearing either of the two most widely used types. They were looking for microbes which are not normally found in the oral cavity, with particular interest in Candida (a type of yeast) and Staphylococcus (including MRSA).

The team, lead by Jonathan Pratten , PhD, found that species of these microorganisms were present on 66.7% and 50% of retainers respectively, regardless of the retainer type. These microbes were also present on the interior cheeks and tongue of retainer wearers.

Candida and Staphylococcus rarely cause problems in healthy individuals, but are potentially highly problematic in people with a compromised immune system. The bacteria on the retainers live in biofilms, which are communities of bacteria living together covered in a layer of slime. Once these biofilms form they are very difficult to remove and often have high levels of resistance to antimicrobials.

The researchers point out that hygiene is key to reducing the transmission of these bugs. Anyone handling a retainer should wash his or her hands before and after use, and employ careful tooth brushing followed by mouthwash.

Parents, don't show this article to your kids, they will never wear their retainers again!

Sure is much ado over nothing:

rarely cause problems in healthy individuals

Yes, that would be a problem for immuno suppressed/compromised people, but they are usually pretty careful anyway.

I have had some mouth guards and camel back hoses turn into biology experiments and am not any worse for wear. I'm sure that the usual rinses and cleaning tablets will be fine for most people.

Actually, it is speculated that people are getting sick from their Invisalign aligners because they are not keeping them clean enough (not properly killing all the bacteria).

I just got my braces removed today, and I've been given a retainer. I find a certain irony in this article since the dental nurse had a bit of a huff when I wanted to wash my hands before checking whether I could take my retainer in and out or not! (I did wash them in the end, and my orthodontist let me use his alcohol scrub stuff, so I think I should be ok )

Although on a related topic, retainer or not, people have a lot of bacteria in their mouths (although most will be non-pathogenic, at least to their host). I'd like to see the safari which could compare with dental plaque under a microscope (I have actually seen my own dental plaque under a microscope... it's quite a fascinating sight).

Fascinating article, thanks for posting!

Take it from someone with a background in Toxicology....It is a "Big Deal", and parents do need to share this information with their children....

yeah, my mom got an oral thrush (candida/yeast) infection this way. she doesn't have a "compromised immune system" in any sever way, the yeast just happened to take over at a time when she also had a cold and perhaps some gum irritation and therefore her body was busy fighting off something else.

the mouthwash you have to use for thrush is NASTY! this is important and relevant. thanks for the reminder.

Very interesting. I clean my retainers with hot water and Listerine every morning and night.