Tuesday, August 28, 2007
Have you ever wonder what it takes to remove a separated file? The position of the separated instrument has a lot to do with our ability to retrieve it. The closer it is to the apex, the more difficult it is to remove. Removing a separated instrument is a balancing act between removing enough tooth structure to dislodge the file and removing too much tooth structure and weakening or perforating the root.
This video shows the removal of a separated rotary file using an ultrasonic instrument. (watch closely and you will see the instrument fly out) The separated instrument has been located, coronal access to the separated file has been increased using Gates Gliddens. Under the microscope, the ultrasonic tip is used to trough around the separated instrument. One of two things will happen:
1. The instrument will loosen & sometime fly out
2. The instrument will break again & the procedure starts over again.
Removing a separated instrument can be a difficult procedure which requires alot of patience from the operator and the patient.
For helpful tips to prevent file separation, click here.
Monday, August 20, 2007
This patient came in 18 months ago. Tooth #30 was diagnosed with Prior RCT & Phoenix Abscess. Retreatment was recommended. As you can see, there is an apical radiolucency on the mesial roots, which appear to be filled short of the apex.
An amalgam was placed into the canal orifaces for retention of the core build-up. During the treatment, some amalgam shavings were pushed apically. However, I was pleased that we were able to open the canals better and get to the apex.
This patient returned today for a 18 month recall. The lesion has healed. The tooth is asymptomatic, fully functional & with normal periodontal probings. Endodontic retreatment is a valuable (and economical) treatment option that has helped this patient retain this tooth and the bridge.
Monday, August 13, 2007
Implants have long been accepted as a predictable treatment option for the replacement of missing teeth. However, recently, there are those who have begun to indicate that extraction and an implant may be preferred over endondontic treatment. There are those who argue that implants have a higher long term survival rate than teeth treated with endodontics. This is not an evidence based argument.
Until recently, there was no research directly comparing the survival rate of endodontics and implants. The endodontic literature defined "success" as complete radiographic healing, absence of symptoms, & full function. (A tooth that had incomplete radiographic healing at the time of re-evaluation would not be considered a "success" by this definition even if it was asymptomatic and fully functional.) In contrast, the implant literature defines their success as "survival". An implant was categorized as "surviving" if it was still in the mouth at the time of re-evaluation. (An implant with a draining sinus tract that had not been removed would be considered "surviving".) This difference in definitions has caused much confusion and mis-interpretation of the endodontic & implant literature.
The recent study by Doyle et. al. directly compared the NSRCT with single tooth implants. The retrospective study compared 196 NSRCT cases and 196 single tooth implant cases for success, survival, survival with intervention & failure. This definition of outcomes allows a more accurate comparison of the outcomes of endodontics & implants.
Their results were very interesting.
Their study found that NSRCT (when restored properly) and single tooth implants have similar failure rates over time. They also found that the implant group has a longer average and median time to function.
This study directly comparing implants and endodontics, while one of the first of its kind, will not be the last. Dr. Walter Bowles, associate professor at the University of Minnesota, will be leading a team of researchers to conduct a similar retrospective study on a much larger scale. Dr. Bowles and his associates from the University of Alabama, University of California, San Francisco, & Ohio State University, will be evaluting 10,000 patients and use the data to provide a timeline for outcomes over a 10 year period. The project which recently began will take two and a half years to complete.
Evidence based dentistry helps us to make treatment decisions based on the best available clinical evidence, individual factors of each particular case, the clinician’s expertise & patient’s informed consent. The decision to restore a tooth with endodontic treatment or remove and place an implant should be based on other factors than long term survival rates.
Doyle S, Hodges J, Pesun I, Law A, Bowles W. Retrospective Cross Sectional Comparison of Initial Nonsurgical Endodontics Treatment and Single Tooth Implants. J Endod 2006; 31.
Hoffman, J. AAE-Funded Study to Compare Implants, Endo. The Endo Tribune 2007; 2:8, 2-3.
Monday, August 6, 2007
Today I had the chance to see one of the very first root canals I did after dental school. If I had to guess, I would say it was my 20th root canal. My friend was traveling to Arizona from Washington, D.C., and needed a root canal on #14. I had completed the root canal on #15 in my AEGD residency following dental school. This gave me the unique opportunity to look back in time at my own development as an endodontist.
When I first saw #15 my thought was, "I did that?" My second thought was, "thank goodness for second chances". Since his flight out of town left in a few hours, we quickly got to work. #14 was diagnosed with an irreversible pulpitis & acute apical periodontitis. #15 was diagnosed as a prior RCT with phoenix abscess.
With my friend's help, I recalled the situation. He was a huge dental phobic, he arrived in tears, the tooth was abscessed, I was working without a microscope & I had less than 2 dozen root canals under my belt.
What a difference of few years of practice (several thousand RCTs) and a microscope can make. We were able complete the RCT #14 and retreat #15 easily.
I expect the periapical lesion on the MB root to heal and that my friend will have both of these teeth for a long time.
Thank goodness for 2nd chances!