I would like to review an issue from Dr. Gordon Christensen’s September column, "Post Concepts Are Changing." While I use many fewer custom-cast posts than I did 10 or 20 years ago, I think they are still an important part of our armamentarium and deserve more constructive and detailed discussion.
In his 40-year practice, I am sure Dr. Christensen would note that most custom-cast posts are still successful at 10, 20, 30 or more years, while many of the new and exciting prefabricated systems have not been on the market for more than five to 10 years. The fact that there are dozens of prefabricated systems, in addition to the custom-cast post, is a statement that there is no universal or perfect post and core system. Dentists may find it useful to have several techniques and systems available for treating specific clinical tooth presentations, including custom-cast post systems.
Dr. Christensen states that one disadvantage of custom-cast posts is that they require more removal of tooth structure than do prefabricated posts and cores. I disagree. Older technical education may have recommended that, but I have used a very conservative approach for years with success.
It is also possible in many situations to cement both the separate custom-cast post and crown on the second appointment successfully, with the proper laboratory and clinical technique. In these situations, I also have found that it takes less chair time to take an impression for the separate custom-cast post and crown; as opposed to constructing a prefabricated post, or core buildup first, and then taking the impression for the crown. The saved chair time for me is a more valuable commodity than any small difference in cost between the systems.
I do not consider the construction of the provisional restoration for the custom-cast post to be any more difficult than that for a crown with a prefabricated post, or core buildup. In most cases, dentists can use their preferential material and extend the acrylic or acrylic and provisional post into the internal pattern, and make a dowel temporary crown in the same amount of time as a regular temporary crown.
That brings up a more controversial point that Dr. Christensen did not discuss at all. Dr. Christensen discussed using posts on endodontically treated teeth missing all of the coronal tooth structure, therefore giving the tooth a questionable prognosis. Many such situations make it difficult, or impossible, to place prefabricated posts, or are even a result of the failure of a prefabricated post, or core buildup, system. In many of these cases crown lengthening, orthodontic extrusion, or extraction and an implant, are not indicated or practical for the patient.
For these presentations, I have found the dowel crown to be an effective and efficient tool to save a tooth in properly chosen cases. The dowel crown is the inclusion of the custom-cast post with the crown as one piece. In many instances, inclusion of the pattern of the external and internal tooth structure into one restoration can give a restoration a more ideal retention and resistance form, thus salvaging a decimated tooth for many years.
The objections that the dowel crowns make re-treatment of the crown or root canal difficult are mute, since the dentist and patient are facing no treatment, or loss of the tooth, anyway. Also, modern ultrasonic and electric handpiece devices make re-treatment of all post systems somewhat easier. I agree with Dr. Christensen that patients should be advised about the questionable longevity of restorations for all teeth in these situations.
A more detailed discussion of updated laboratory and clinical techniques, indications and contraindications, and advantages and disadvantages of custom-cast systems is in order. I would like to emphasize that, like Dr. Christensen, I am also impressed with many of the advantages, indications and efficiencies of the new prefabricated systems. My suggestion here is that the custom-cast post systems deserve more constructive and detailed discussion as a tool for the dentist’s clinical arsenal.
