Dr. Chal's Commitment to Quality Dental Laboratory Work
This page of the website explores the laboratory work that prompted the endorsement by Dr. deLeeuw. Motivated by his passionate pursuit of excellence in dental care, Dr. Chal has made sure that his office has the necessary laboratory equipment to produce the highest quality of dentistry for his patients.
Most dental laboratory work starts with an impression of your teeth and oral tissues. If the impression isn't perfectly accurate, nothing done later can make up the discrepancy, and the final restoration will be compromised.
Dr. Chal has purchased the finest impression equipment and materials available, namely Permadyne polyether impression material, as mixed by the Penta-mix machine. This gives absolutely consistent mixing every time and reproduces the finest detail.
The two Penta-Mix machines we use
Permadyne polyether impression material is the material of choice for the German master dentists and technicians
such as Willi Geller and Klaus Muterthies.
For the production of TMJ orthotics and for models of opposing teeth, however, a different type of impression material is optimal. In those cases, we use a warm hydrocolloid material. This requires special baths to keep the material at a uniform, fixed temperature until the moment it is placed in the mouth. Below is the machine used for that purpose:
After the impression is taken, it needs to be poured up in a gypsum material. There are many types of dental gypsum. Many dentists will use simple laboratory plaster—it's simple and inexpensive. But when it sets it is relatively soft. This makes it easy to work with, but it also makes it susceptible to
chips and fractures. And when it is mixed in a simple plaster bowl, it is again easy and convenient, but it will get bubbles incorporated into the model.
Dr. Chal uses resin-rock stone for his models. This is exceptionally hard—so hard that it has to be trimmed with a diamond abrasive wheel. And all mixing is done on a vibrator and under a vacuum to insure the elimination of bubbles.
Here is the vacuum mixing apparatus on top of the digital scale. Powders are measured to the fraction of a gram to insure accuracy and consistency.
The precision liquid dispenser, pictured below, insures that the liquid portion of the mix is also accurate. Most dentists will mix their gypsum products with plain water. Again, this is simple, inexpensive, and convenient. But resin-rock stone requires the use of water plus a liquid with special modifiers in it. Not as convenient, true, but it won't chip and is exceptionally accurate.
Below is the vacuum mixer sitting on top of its mobile stand:
Below is the Foster heavy-duty vibrator that helps eliminate any entrapped air in the mix.
This is the diamond grinding wheel that is used to trim the resin-rock stone. A conventional dental grinding wheel is insufficient for trimming this material.
The end product is these models, pictured below. They have been mounted on a sophisticated articulator (engineering instrument) that reproduces the motions of a patient's jaw.
  
Even though dental schools teach the use of articulators, a recent
survey by the trade journal, Laboratory Management Today revealed
that fewer than 5 percent of cases submitted to dental laboratories in
the United States are submitted on articulators. Fewer dentists still use articulators with this degree of sophistication.
To see the following steps, showing how these highly accurate models are used in the production of final restorations of ultimate quality, please see page two.
|
