Redoing Procedure Necessary
Dear Dr. Mady: I had a root canal done on one of my teeth about 30 years ago and now the tooth is infected. My dentist said it is because my root canal was done by some old technique using some sort of silver filler inside the roots. He wants to take that stuff out and redo the procedure. Do you think this really necessary and can it even be done? J.G. in Lakeshore
Dear J.G.: Silver points were commonly used in the past to fill and seal the roots of the teeth during root canal therapy, especially during the '50s and '60s. They were more popular as an obturating (root filling) material as opposed to gutta purcha (a rubber-like material) that is widely used today. They are composed of pure silver.
Their use has declined to a point where few dentists even use them anymore. Virtually no dental schools in North America are teaching the routine use of silver points in endodontic (root canal) treatment.
Many of the reasons for this decline in use are justified and some are not. Most failures of silver points are usually associated with leakage and corrosion. It is the inability of silver points to seal irregularly shaped root canals that allows leakage of the tissue fluids into the canal, thus harbouring bacteria and causing potential reinfections.
The contact of these fluids with the silver point may result in corrosion and thus the release of products including silver carbonates and silver sulfates. It is these culprits that can be extremely damaging to the tissues around the root(s)of the tooth.
If and when silver point root canals fail, the best thing that your dentist or endodontist (root canal specialist) can do is attempt re-treatment. During this, the most challenging, but necessary dilemma is to retrieve or remove the point from the root canal. The points cannot be extracted unless they are accessible, so your dentist will have to take care in the removal of surrounding fillings and restorations so that the head of the point does not get severed in the process. If this occurs it makes retrieval much more difficult and sometimes impossible. If your dentist or specialist uses ultrasonic tools and/or enhanced magnification and lighting, the chances of success are greater.
It sounds like this is the necessary procedure for you and it can be done most of the time with minimal consequences. After the failing point(s) are removed, your dentist will clean and flush the inside of the root(s) and refill them usually with a rubber-like material called gutta purcha. This material tends to seal the end of the root and the inside walls very well due to its adaptability and capability of being heated and melted. This, in conjunction with a good sealer, may get you better service out of your tooth for a number of years to come, once the tooth is properly restored.
This column is reprinted with the permission of the author and The Windsor Star. "Ask the Dentist" is written by Windsor dentist (and ECDS member), Dr. David Mady Jr.. The column appears the first Thursday of each month in the Windsor Star. Readers with questions can write to "Ask The Dentist", c/o The Windsor Star, 167 Ferry St., Windsor Ontario, N9A 4M5