Spend less time adjusting restorations received from the lab.
Ashley C. Johnson, III, J.D.
If I could show you ways to reduce the amount of time you spend adjusting the restorations you receive from your laboratory, I would have your attention, wouldn`t I? Well, I can do just that! The number of phone calls that I get from dentists who are apprehensive about placing the restorations they have received from their laboratories astounds me. I have come to realize that this is a common occurrence in the dental community. Using some of the communication tools I mentioned in last month`s article could relieve most of this tension.
How much do you really enjoy grinding porcelain? One of the biggest chairtime wasters is the unnecessary grinding of porcelain. How many times have you looked at a crown on a working model that seemed to have the correct interproximal contacts, only to find out that, when you took it to the mouth, it would not come close to seating?
When a crown and bridge model is fabricated, it is done in stages and with different materials for each stage. If the coefficient of expansion is different between the types of stone, there will be a torque factor placed on the dowel pins that are fixed in the die side of the model and imbedded in the base portion. When the dies are sawed out, they will move because of this torque. A few microns on each side make a huge difference chairside. The use of a solid contact model (a model that has not had the dies sawed out) should eliminate the need to adjust interproximal contacts.
Ideally, your laboratory should use two solid models for each case. One should be used to verify the interproximal contacts after the crown has been fitted to the working model. However, at this stage, the technician still is working with unglazed porcelain, which is very abrasive. No matter how careful he or she is, the technician will abrade the contact areas. The second solid model should be used only for a contact check after the porcelain has had its final-glaze bake. By using this system, your technician can reduce the time you spend adjusting your interproximal contacts.
These solid models can be poured from your original impression (not from Hydrocolloid material), so there is no additional work for you or inconvenience to your patient. An additional use of these solid-contact models is to check the internal fit of your restorations. You technician can use any spray-fit checker to make the necessary adjustments and, by checking the fit on all three models, an accurate fit virtually is guaranteed. These are steps normally done at chairside, so having the technician do them at the bench reduces your placement time.
You can increase the restoration predictability in your practice if you start taking and mounting study models. I know that you were going to do that with Mrs. Smith`s case last Friday, but Joe called and wanted to play golf so you didn`t get around to it. The models still are sitting in the lab, unmounted, and Mrs. Smith is your first patient tomorrow. "Oh, well, I will ad lib and get through the presentation." Does that sound like someone you know? The problem here is that this works enough of the time for us to believe that we can do it all of the time. I find this to be true in many areas of dentistry.
For complex cases, or cases that involve anterior restoration, mounted study models are very important. A technician must be able to examine all the teeth and their relationship to one another. He or she needs to know where the incisal edge of the pre-op or provisionals are in order to reproduce what the dentist and the patient have approved.
With these mounted study models, the technician can make an incisal-guide table. The table can be used to duplicate the anterior guidance the patient had or to copy the anterior guidance that you have worked out in your provisionals. These incisal-guide tables are easy to make and should eliminate the time you spend working out anterior guidance at chairside.
The technician also can use these mounted models to make a putty-silicon index of the incisal-edge position and facial contours of the teeth to be restored. This putty-silcon index allows the technician to copy exactly the correct incisal-edge position and facial contours that you want. This also will help you with the correct incisal-edge position for phonetics. No longer do you have to find ways to convince your patients that, with the passage of time, they will adjust to their new teeth. The restorations will look, feel, and function better automatically.
Photographs are one of the most important forms of communication that you can send to your technician. Although a photograph will not accurately depict the shade of the teeth, it will show the technician several key factors. How do you describe a tooth type or shade over the phone? How can you relate a patient`s lip line? You cannot tell a technician about the layering of color in a tooth or describe the surface texture in a conversation. What does "add a little orange or yellow" at the gingival really mean? These things will show up in a photograph. If you hold the shade tab you have chosen against the unprepared teeth in the photo, the technician can see how the shade tab relates to the natural dentition and be able to determine where there is incisal translucency or interproximal staining. He or she will be able to see craze lines and areas of random color changes.
Personal contact between the patient and the technician never will be replaced by photography, but photographs are the next best option for now. In the future, as more and more of us use intraoral photography and the Internet for video-conferencing, the geographical distance between the dentist and the technician will become a moot point.
In future articles, I will go over more of these tools, but it is up to you and your lab technician to take advantage of them. If your lab technician is not willing to use them, it may be time for you to make a change.
Dr. Peter Dawson has been teaching us how to put these tools to use for years. One suggestion I frequently make is that you take your technician to a Dawson-type seminar. Then, the two of you can discuss what you have heard together.
Remember, these are some of the tools that, when used together, provide the necessary visual aids for good communication between the dentist and the technician. The use of these tools practically guarantees predictability in your restorative work, which pleases you, the technician, and your patients. You know that if you keep doing what you have been doing, you are going to keep getting what you have been getting. We seem to believe that we can continue doing the same thing and that, at some point in time, we are going to start getting something better. It isn`t going to happen!
The first thing you have to do is to stop procrastinating. I saw a bumper sticker the other day that read "procrastinators will rule the world - someday." I started thinking about how procrastination affects us in the dental world. I wondered why we sometimes refuse to use the tools that have been given to us. There are so many things to say about procrastination, I don`t even know where to start. I`ll tell you about them later. See! It`s just that easy.