Silver Point Endodontic Retreatment

The word “endodontic” comes from two Greek words meaning “inside” and “tooth”.  The first signs of human beings treating the “inside of the tooth” or the root canal system were believed to be around the second or third century B.C.  This notion is founded on the discovery of a skull found in Israel’s Negev Desert with a bronze wire inside a maxillary cuspid tooth.   Anthropologists believe this wire signifies early techniques to treat infected root canal systems.

Sundqvist outlined the three primary functions of a root canal filling material:  sealing against ingrowth of bacteria from the oral cavity, entombment of the remaining microorganisms, and complete obturation of the root canals system, at a microscopic level, to prevent stagnant fluid from accumulating and serving as nutrients for bacteria from any source.

From the early 1900’s through to the early 1970’s the endodontic filling material of choice was silver points, alone or in combination with gutta percha (GP).  Silver points had a number of characteristics which were appreciated by dentists of the day.  The rigidity of the points made them easy to handle and place.  They were inert and easy to sterilize, and due to their radiographic opacity were easy to see on a radiograph.

Unfortunately, silver points did not fulfill Sundqvist’s criteria especially well.  It was challenging to adequately gauge the size of the apical terminus often resulting in a poor apical seal.  The points had minimal taper from apical extent to the coronal orifice.  This left a large portion of the irregular canal unfilled or filled solely with cement failing to create a reliable long-term seal both apically or coronally. The silver point was also an impediment to the placement of a post should one become necessary.  To top it off, corrosion of the silver point, in the presence of interstitial fluids or saliva, and the resulting products were often very inflammatory.

Today silver point endodontic treatments are mostly an historic oddity, though they can present at your office with a failing endodontic result necessitating retreatment.  Silver point retreatment can be technically challenging.  The original obturation technique recommended leaving a ”tail” of the silver point 4-5 mm above the coronal orifice of the canal.  This allowed the operator to grasp the silver point with a fine hemostat should the endodontics fail and retreatment be indicated.  If this “tail” was eliminated in subsequent restorative treatment the dentist had to get very creative to extricate the sub-orifice point.  To compound this, the corrosion products made it almost a foregone conclusion that there would be an inordinate amount of post treatment discomfort.

Pre-op PA

Figure 1

A silver point retreatment case presented to Langley Endodontics in the summer of 2017.  The tooth was symptomatic with the signs and symptoms of chronic apical periodontitis and a lesion of endodontic origin (see figure 1).  Following access, I found that the silver point “tail” had been removed.  A combination of gentle ultrasonic disruption of the remaining cement, being careful not to inadvertently cut off the point with the ultrasonic tip, Hedstrom files to engage the silver point in the mid-point of the root, and specially crafted Steigitz pliers ultimately allowed for the removal of the obstructive silver point.  The tooth was then cleaned and shaped with copious irrigation with NaOCL prior to obturation with vertically compacted warm gutta percha.

PO PA Case Report

Figure 2

Figure 2 shows the final gutta percha obturation result.  Note the comparatively larger diameter of the apical foramen filled with GP compared with the silver point result.  The original silver point fill was never close to creating a seal at the apical terminus of the canal.  A further finding was the presence of a lateral canal in the apical third of the tooth which was revealed with the warm GP final fill and a likely contributor to the silver point failure.

Follow-up with the patient found they did have a persistent discomfort to biting on the tooth which lasted for about 10 days before finally resolving.  As with all endodontic treatment, time is the ultimate arbiter of healing to be revealed at the 12 month recall.  Hopefully full healing will occur but if a second surgical intervention should become necessary at least removal of the silver point will facilitate root end preparation and retrofilling.

ABOUT THE AUTHOR

Dr. Howard Bittner, DMD, CAGS

Dr. Howard Bittner, DMD, CAGS

Dr. Bittner was born and raised in the Surrey / Langley area. Following his pre-dental training at Simon Fraser University, he received his Doctor of Dental Medicine from the University of British Columbia in 1982 and his Certificate in Advanced Graduate Studies in Endodontics from Boston University’s Goldman School of Dental Medicine in 1995.
Dr. Bittner was in private practice in general dentistry for 11 years in Langley before his Endodontic specialty training. He has been practicing Endodontics since 1995.
In his free time, Dr. Bittner loves to participate in a variety of sports including golf. He also enjoys being a grandfather to 4, which if you ask him is just the best!