Dental dam

A dental dam or rubber dam (sometimes termed "Kofferdam"—from German), designed in the U.S. in 1864 by Sanford Christie Barnum, is a thin, rectangular sheet, usually latex rubber, used in dentistry to isolate the operative site (one or more teeth) from the rest of the mouth. It is used mainly in endodontic, fixed prosthodontic and general restorative treatments. Its purpose is both to prevent saliva interfering with the dental work (e.g. contamination of oral micro-organisms during root canal therapy, or to keep filling materials such as composite dry during placement and curing), and to prevent instruments and materials from being inhaled, swallowed or damaging the mouth. In dentistry, use of a rubber dam is sometimes referred to as isolation.^[1]

Dental dams may also be used as a safe sex technique to reduce the risk of sexually transmitted infections (STIs) during cunnilingus and other sexual activities.

Dentistry

Dental dam in place during a dental procedure.

Rubber dam isolation of upper left second premolar giving improved visibility during endodontic therapy.

The dam is held over individual teeth or groups of teeth by appropriate rubber dam clamps or threads (ligatures) along the edge of the gum. The tooth crown stands out from the rubber dam through individual holes made by a hole punch. An ink stamp is available to guide placement of the holes prior to application of the dam.^[2]

Advantages:

• Clean and dry operating field (saliva, blood). For dentistry procedures involving bonding with adhesives or cements it is to be encouraged as the operative field must avoid contamination in order to achieve maximum bond strength between restorative material, enamel and dentin. One of the main functions of saliva is to coat the oral tissues to protect them. When a jet of air from a dental hand-piece is used to dry a part of the mouth, this stimulates salivary flow and there is an instinctive reaction to lick the dry area to make it wet with saliva again. This is avoided as the tongue and the output of the salivary glands are on the other side of the dam.
• Corrosive endodontic irrigants such as sodium hypochlorite (bleach) are contained, which could damage the soft tissues of the mouth and be harmful if swallowed
• The oral mucosa, lips and perioral skin is afforded some degree of protection against injury from instruments or materials
• There is improved visibility of the operative site (retracts the lips and cheeks, more light, less saliva)
• Decreased (but not eliminated) chance of swallowing or inhaling instruments, debris or other items. Should this occur, hospital admission might be necessary for a chest x-ray, and potentially an operation to remove it.
• Use of a dental dam reduces aerosolized contamination (air-borne particulate matter e.g. generated by drilling tooth substance) by 98%. Use of rubber dam has been likened to wearing latex gloves during dental treatment with a similar impact on cross-infection.
• Some patients find it more comfortable to have treatment with a dental dam since there is no water in the mouth and they feel safer and more dissociated from the noise of drilling etc.
• Decreased contamination of the pulp system with oral micro-organisms in saliva
• In some parts of the world, use of a dental dam is mandatory for procedures such as root canal therapy, and if any injury that could have been prevented by its use occurs it is medicolegally indefensible.
• The dental dam significantly reduces the ability of the dental patient to communicate. This can be considered a disadvantage (see below), or an advantage, e.g. in over-talkative patients to facilitate faster treatment

Disadvantages:

• It takes extra time to apply (although with practice this becomes fast)
• The cost of dental dams and the kit to apply it. Although not expensive, this cost would not be incurred if it was not used
• Since it effectively blocks off the oral airway, the patient must be able to comfortably breathe through their nose. Of relevance are temporary causes of nasal airway obstruction such as the common cold, or persons who continually breathe through their mouth for whatever reason.
• To an extent, it may lead to visual distortion of tooth morphology since the other teeth and the rest of the mouth are hidden from view. This may lead to perforation if an access cavity is incorrectly angled during root canal therapy. For this reason, some endodontists routinely begin their access cavity before applying the dam, to ensure the correct orientation before the root canal system is opened up.
• The dam, which is usually brightly colored (blue or green), may alter the apparent color of the tooth, which can lead to incorrect choice of shade, e.g. during placement of a dental composite. For this reason, shades are normally chosen before the dam is applied.
• Latex allergy, depending upon the severity, may make the use of rubber dam uncomfortable afterwards (allergic contact dermatitis, allergic contact cheilitis, allergic contact stomatitis) or even life-threatening (anaphylaxis). Silicone versions are available for those with latex allergies.
• Some patients find the dental dam claustrophobic
• Reduced communication between patient and dentist may increase patient anxiety and make them feel more vulnerable.

Safe sex

Dental dams are promoted during safe sex campaigns for use during cunnilingus and anilingus, especially for men who have sex with men. After lubrication with a water-based lubricant, an unpunctured dental dam may be held over the vulva or anus, allowing oral stimulation of these areas without transmission of bodily fluids and direct physical contact.^[3]

References

1. Luca Martinelli, The rubber dam technique, Academia.
2. Bun San Chong, Shanon Patel, Bhavin Bhuva, Rubber dam in clinical practice, ENDO (Lond Engl) 2008;2(2):131–141.
3. "Tips for Using Condoms and Dental Dams - HIV/AIDS". www.hiv.va.gov. Retrieved 2016-03-12.