by Richard Mounce, DDS
For more on this topic, go to www.dentaleconomics.com and search using the following key words: rubber dam, root canal therapy, tactile control, Twisted File, Dr. Richard Mounce.
I recently received this letter from a clinician who asked a clinically relevant question:
"You indicate that a rubber dam must always be used for root canal therapy, and if a rubber dam cannot be tolerated, the tooth should be extracted.
I'm aware that rubber dam use is the standard of care in Canada and the U.S. for endodontic treatment, and as a general dentist I always use a rubber dam during the procedure. What I wonder is if rubber dam use is a standard of care arising from a dramatically worsened prognosis for treatment carried out without a dam due to microbiological contamination, or to material hazards such as NaOCl tissue damage, or risk of aspiration of tiny files, etc.
Though I've not encountered this situation, as a general dentist there may be occasions when a patient requires endodontic treatment but cannot tolerate a rubber dam; however, the tooth is either strategic or the patient wishes to ‘throw the book' at a tooth. In either case it would be less than ideal to extract. If the patient declines sedation (or referral due to finances or rural dwelling), might it be acceptable to work without a rubber dam and use careful isolation and material application, provided the patient was fully consenting to a worsened prognosis and other hazards regarding treatment without a rubber dam?
I'm asking this for the sake of interest, not from a medical-legal perspective. I understand that rubber dams are necessary but I've never questioned why. Thanks for your expertise."
First of all, depending on the literature consulted, it is still not the global standard to use the rubber dam routinely in endodontics, even though the rubber dam is the clinical and legal standard of care in North America. If the tooth cannot accept a rubber dam clamp, the tooth requires a crown lengthening to make it restorable or the tooth should be removed.
Why would someone not use a rubber dam? The only reason I can think of is an emphasis on speed and a perceived saving of time. Does working without a rubber dam really save time? If we are honest with ourselves, given the factors listed, I believe not. I would not want a root canal without a rubber dam, nor would I want anyone in my family to have one. What's good enough for the family is good enough for all my patients.
The benefits of using the rubber dam are myriad and include:
- It is inexpensive, technically simple, and rapid to apply.
- True tactile control is difficult if not impossible to obtain without it. Tactile control is simple with a rubber dam, especially with enhanced lighting and magnification.
- The tooth is at risk of almost certain bacterial contamination during the procedure without it. Asking a patient not to swallow or to tolerate cotton rolls or other devices for an hour or more without risking saliva entering in the access is not reliable.
- The risk of irrigants being swallowed and instruments being aspirated is high despite precautions.
- The degree of patient cooperation is diminished without a rubber dam.
- The lighting and magnification that can be brought to focus on a tooth with a rubber dam far surpasses the tooth without.
- The placement of the coronal restoration after endodontic treatment is faster and far more controlled from every perspective with a rubber dam than without.
Clinically, I use the thinnest rubber dams and a No. 14 Hu-Friedy clamp for the majority of my cases, and if possible, clamp the tooth behind the one I am treating. I often use Ora Seal caulking to seal the rubber dam (Ultradent, South Jordan, Utah) and all of my cases are treated under the surgical operating microscope (Global Surgical, St. Louis, Mo).
The rubber dam also provides improved management of the access and as a result, improved control over apical canal preparation. Control the access, control the apex; lose control of the access (access is inadequate), and lose control of the apical shaping and microbial control of the case. Any deviation from the highest standards of straight-line access and removal of the cervical dentinal triangle translate into perforations and iatrogenic events of all types, especially with Gates Glidden drills. Problems in the coronal third shaping of the root translate to compromises in the apical third.
Alternatively, excellent straight line access and removal of the cervical dentinal triangle will allow a rotary nickel titanium shaping file like the Twisted File (SybronEndo, Orange, Calif.) to not just shape the orifice, but if used correctly, shape the canal to the point of first curvature, very quickly and efficiently, and often do so in one insertion.
I welcome your feedback.
Dr. Mounce offers intensive, customized, endodontic single-day training programs in his office for groups of one to two doctors. For information, contact Dennis at 360-891-9111 or write RichardMounce@MounceEndo.com. Dr. Mounce lectures globally and is widely published. He is in private practice in endodontics in Vancouver, Wash.