The Crown Holding My Partial Fell Out. Can You Please Make A New One?
Crown replacement is another common request that I hear in my office. It can be necessary when one of the anchor teeth that helps hold a partial or removable bridge (as it is often called) falls out. Either a tooth cracks or a crown that has been there for years has come off and no longer fits. This tooth or crown allows the partial to fit over it with a complex array of metal or non-metal arms. These arms, which we call ‘clasps’, allow the removable teeth to be stable in the mouth. It and a few of its friends that look similar create a steady base that allows functional movements and speech. These functional movements we shall call chewing. Without the tooth or crown, and the clasps on top and around it, the removable bridge would flop all over the mouth.
My readers know that I have spent time discussing crowns in the past. It is something that we do on a regular basis. So when the tooth that holds the partial denture, breaks and needs a crown, let’s just make a crown. When the old crown falls off and no longer fits because of decay, let’s make a new crown. These new crowns will fit under the existing partial denture and we can all go on our merry way – right?
Once Upon A Time, Reverse Engineering Teeth to Fit Inside Crowns Was Nearly Impossible.
Unfortunately, crown replacement is not always that simple. I would like to illustrate it with a story from my years in dental school. When in school everything moves along at a snail’s pace. That’s okay, as the students are learning new skills and practicing to create a perfect result. Let me tell you about what happened in my second year, to one of my classmates. We were in our dental lab working on plastic teeth in a model of the mouth. We were making crowns and bridges as a full term project. We worked on this for weeks and months. Long hours both during and after school were invested by all of us. After all, this single project accounted for 70% of our grade. The night before the project was due, many of us were working in the lab and putting the final touches on our work. I noticed one fellow in particular who was not very happy. He was in his work area, laboring diligently with a notable frown on his face. I went over to him to find out what was wrong. He promptly showed me his finished work. It looked great. I congratulated him and asked him as to why he appeared to be upset. He proceeded to tell me that he although he has his project, he could not find the plastic model of the teeth upon which he made the project. It was lost! He has to work backward! He was attempting to shape the teeth to fit inside the crowns. The key to our grading was the fit of the project on the plastic teeth.
Modern Dental Technology & Techniques to the Rescue
Under normal circumstances, we take an impression of a natural tooth or a crown and then make the partial denture over the tooth. When the patient walks in the door with a partial and the supporting tooth underneath is compromised through breaking or falling off, we, just like my dental student friend, have to work backward. This is beyond difficult as we need to make the underneath tooth fit inside the partial denture. In truth, in the past, there were a variety of techniques to accomplish this but they were really hit or miss. Finally, after years of struggling, computers, scanners and advancements in dental technologies have come to the rescue. I can now take an impression of the original tooth and use this to create a scan which can be superimposed to create an exact copy of what was there. This exact duplication of the way the tooth was allows me to make a replacement crown that will fit into and under the partial that is already there. I can not tell you what a cost and time saver this is for everyone involved. The patient does need to have their removable bridge replaced and can return to normal life in just a couple of appointments.
This is just another way where modern dental techniques have turned a nightmare of the past into a very predictable and affordable procedure in the present. Do you have an issue with a tooth or teeth, which you think that there is no solution? Please call me and run the predicament by me. You never know what simple solution that I may have to suggest. I can be reached at 440-951-7856 and I look forward to hearing from you.
Jeffrey Gross, DDS, FAGD is an Ohio licensed general dentist and is on the staff of Case Western Reserve School of Dental Medicine.