Keeping things clean

Calcium sulfate dihydrate-commonly known as gypsum-and the associated products used in the dental laboratory industry are considered to be non-hazardous materials. However, there are health concerns regarding the inhalation of such materials especially if silica is used as an additive to these products.

Even gypsums containing no silica can cause irritation to the respiratory system. Over time dermatitis and dehydration also occur upon contact with unprotected skin. In addition there are a few studies of possible chronic health impacts from long-term exposure to gypsum products. If silica is added, inhalation can prove much more serious leading to silicosis, which is an irreversible condition.

The process of manufacturing dental gypsums involves heating gypsum to approximately 302° F to drive off 75% of the water contained in the chemical structure. The process is called calcination. The resulting powder when combined with water again returns to a hardened form through an exothermic chemical reaction, thus setting to a relatively strong gypsum-crystal latticework.

In the dental laboratory much work is done using dental gypsums. For example handling gypsum powder prior to mixing, grinding and trimming dental casts creates fine gypsum dusts that can contaminate the air in the laboratory. Typically, this dust and the effects of it are lessened by the use of laboratory grade evacuation systems such as dust collectors, air purification systems and respirators. Still it is likely some of this dust inevitably ends up in the air of dental laboratories.

In addition to this, there is the finishing of acrylics, and the resulting dust and fumes. In fact, there is a large range of materials in dental laboratories that produce unwanted and possibly unhealthy fumes and dust. For me, the use of evacuation alone has proved unsatisfactory.

A new solution

My personal concerns, combined with concerns about the health of laboratory personnel and the health of patients who may visit the dental laboratory for shade matching, led me to a search for a different and more thorough solution to this problem. During my quest to find what I deemed a “clean box” for my laboratory, I came across many products.
Here I am highlighting what I have found to be the best solution to the problem, which is a clean box made by Dan Voiculescu of Danvo, a company that also produces RC racing boats (Fig. A).

“The clean box looks like a great way to eliminate any airborne gypsum dusts, which in my experience, can contribute to the cleanliness of laboratories and the overall health of dental technicians working with gypsums and other dental materials day in and day out,” said Mark Hester, BS, President of Hi-Tec Dental Products Inc.

The box comes with lighting (Fig. B), a port for dust evacuation and collection, a variety of bur holders for large and small burs, and an air puffer to keep the site of adjustment clean and free of debris. This can be particularly helpful when trimming dies and a variety of other laboratory tasks (Figs. C & D). I further customized the box by connecting the puffer to a compressed air line with an on/off valve I added. This allows me to control the amount of air pressure directed at the adjustment site.

This box works particularly well for me as I have found it to be nearly airtight. Combining this with a good suction unit, and an air purification system, I have virtually eliminated all dust and fumes from my laboratory. Below the bench top I added PVC fittings to tie together two evacuation ports that terminate into a Vaniman dust collection unit with an Accumulator (Fig. E).

The box also has enough room to house a handpiece and a small Foredom bench lathe (Fig. F). These tools have proven to be more than adequate for my finishing and trimming purposes. The lathe is bolted directly through the bottom of the box and securely fastened to the bench top further stabilizing the entire unit.

In fact, after setting the box up with the intended purpose of using it for gypsum dusts only, I found it to work so well I started finishing all of my acrylics in the box. The positioning of the arm access (Figs. G & H) makes it ideal for fine finishing right up to the point of polishing, thus eliminating acrylic and other dust and shavings that might otherwise be missed by the typical suction hood accessories for either front or rear evacuation from the dental laboratory bench. It also should be noted that the clean box can be used for collecting gold dust when grinding gold or other metals, and the remnants can be saved and recycled.

I have found this box to be a great addition to my lab. It is set up where I can sit comfortably and work with my hands in the box for a range of tasks I need to complete (Fig. I). The clean box makes me feel like I am protecting my health as much as I possibly can while providing an ideal workspace for the work I do in my lab. 

About the author

Arian Deutsch, CDT, is a member of the Dental Technician’s Alliance of the American College of Prosthodontists and of the Arizona Dental Association. He has been involved with removable prosthetics for more than 18 years and owns Deutsch Dental Arts in Youngtown, Ariz.