The year is 1864. Dr Sanford C. Barnum, a New York dentist, is becoming increasingly frustrated with the problem of saliva messing up his gold foil restorations. His solution is to invent the rubber dam, also known as dental dam. While we no longer use gold foil to restore teeth, rubber dam has endured as a useful tool for dentists all over the world. I still get patients asking me, "Is this a new thing? I've never seen it before!" So, even though rubber dam is old hat to dentists, I thought I'd spend a bit of time introducing it to the wider world.
What is it exactly? Picture a thin sheet of coloured latex, about 10 x 10cm square. A small hole is punched in it for the tooth being worked on. The tooth pokes through the hole, and the rest of the sheet covers the outside of the mouth. The result is a clean, dry, easily visible tooth which is surrounded by latex rather than cheeks, lips, saliva, and a tongue. That may sound uncomfortable, but many patients actually prefer to have their dental work completed with rubber dam.
Patient comfort is a big advantage. The rubber dam stops water, restorative materials, bits of tooth etc. from going in the mouth. The patient also has less need for concern about what they are doing with their tongue during treatment, as the dam provides a barrier and keeps the tongue retracted out of the way. Many patients also report feeling more comfortable during treatment because they feel separated from what is going on, and can psychologically externalise the sensations better than if rubber dam was not used. Not only can it be more comfortable, it's also safer. Sometimes strong chemicals and very small tools are used in dentistry, which can be dangerous if swallowed or inhaled. Rubber dam protects the patient from this happening.
On the flip side, a few patients are not able to tolerate it. People prone to claustrophobia don't tend to like the sensation of having their mouth covered. Another group of people who don't do well with rubber dam are those who can't breathe well through their nose, or those who have problems swallowing. It's also extremely difficult to speak comprehensibly with rubber dam in place, so communicating with patients during a procedure can be challenging. I usually try and stick to questions that only require a "thumbs up, thumbs down" response!
There are other benefits that make it worthwhile though. In an era where aesthetic adhesive dentistry is the cutting edge, dentists everywhere are bonding tooth-coloured restorations to teeth. This means the filling material is not just plugged into the cavity, it actually adheres to the tooth. Unfortunately, adhesive dentistry doesn't work underwater. Anyone who's ever read the instructions on a tube of glue will be familiar with the concept of a "clean, dry surface". Rubber dam keeps saliva, blood, and oral microbes off of the tooth surface so proper bonding can occur. Keeping the bugs out is also an essential part of root canal therapy. The whole point is to rid an infected tooth of germs, so it's important that no hitchhikers find their way into the tooth via saliva.
Some dentists find rubber dam annoying to use, they feel it takes up too much time to put on. There are others like myself though, who find the rest of the procedure goes much more quickly and smoothly for a little bit of time invested in putting rubber dam on at the start. Used well, rubber dam can be a great tool for both dentists and patients alike. So next time you hear your dentist call out, "Dam!", don't assume something has gone wrong!