What is a Dental Dam?

What is a Dental Dam?

Dental dam, sometimes known as rubber dam or Kofferdam is a thin rectangle of latex rubber or silicone material which is used in dentistry to isolate a tooth from the rest of the mouth to facilitate certain intricate dental procedures.


Uses And Benefits

Endodontist with microscope and using rubber dam

The dental dam helps to prevent contamination of a tooth which is especially important in root-canal therapy where the aim is to sterilize the canals of the tooth’s roots and avoid any re-infection. The rubber  is perforated in the center to allow the tooth being treated to poke through and is secured at the base of the tooth with a suitable metal clamp. The rubber is then slightly stretched on to a metal or plastic frame which holds it to cover the lower face and prevent splashes of saliva contaminating the open tooth.

The dental dam also protects the patient against swallowing or inhaling any small hand-held instruments such as files or reamers, such as are used by the dentist to systematically widen and clean the inside of the root canals. If a small instrument is inhaled it can end up somewhere in the lungs and cause an infection so it is a problem to be avoided at all costs. The rubber also protects the oral cavity from tooth debris produced by drilling, and from excessive amounts of water or caustic chemicals used during irrigation which is an essential part of root-canal treatment.

The rubber dam can be blue or green but is commonly of a dark color which contrasts well with the tooth and helps the dentist visualise the tiny area of tooth requiring treatment.

Rubber dam also provides protection against moisture contamination which can be important when placing white or tooth-colored fillings such as composites, since moisture can interfere with the bond between filling material and tooth, whilst blood could discolour the filling.


Common Worries

Some people have a fear of rubber dam because they are worried that they won’t be able to breathe and/or swallow properly. This is an unfounded fear of course, since there is plenty of air space around the dam and normal breathing is in no way impaired, either through the mouth or nose.

Swallowing is also not affected but to avoid the discomfort of lots of saliva building up in the mouth and the annoyance of having to swallow often the dental assistant usually uses a plastic suction tube to constantly remove saliva or may give the patient the suction tube to hold and control themselves.

In addition to the traditional type of dental dam there is also a smaller, self-contained type called quickdam. This is one without the frame, and also there is a rubbery material called paint-on dam which is used primarily to protect the gums when patients are having “power whitening” carried out in the dentist’s office. This form of teeth whitening uses a strong bleaching gel which can burn the gums so they need protection during treatment.

Some dentists are reluctant to use rubber dam since it can be fiddly and time consuming to put on correctly. But in certain circumstances most will use it because the advantages for easier, safer treatment are immense and outweigh the slight inconvenience of getting it in place.


As a patient do not fear the rubber dam since it is only slightly uncomfortable but makes for an easier and much safer job by the dentist.

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