Soaking Plastic Impression Trays in Cold Sterile Solutions Leaves a Bad Taste in Patients’ Mouths

Updated November 2024

Maybe they won’t complain to you, but dental patients don’t like it.

Plastic impression trays are crucial to your successful practice, but most are not meant to be reused. Doing so can cause irritation and, literally, a bad taste in their mouths. 

The result is your patients may have an experience that is less than ideal…and they’ll likely tell others about it. 

Most plastic impression trays are made from polystyrene, polycarbonate, or polyacrylate (acrylic). These materials are relatively inexpensive, stable, and depending on the engineering behind the mold, can even be made rigid enough for VPS impressions used for aligner tray records.

Most plastic trays, however, are designed and manufactured as single-use items. Because CDC guidelines permit disinfectant processing of semi-critical items that are heat sensitive, some offices will clean, disinfect, and reuse disposable impression trays.

Absorption Issues: Are your disposable plastic trays absorbing chemicals?

The primary problem with this practice is that plastics used in impression tray manufacturing are hydrophilic. In other words, they absorb water. While water is no big deal, other liquid chemicals can also be absorbed in these materials.

Acrylic plastics can, in fact, absorb between .15% and .30% of their weight in aqueous solutions. When we look for formulas that provide high-level disinfection, we are in the category of aggressively toxic liquids that can also be used as cold sterilants. The most common chemicals in this category are glutaraldehyde and OPA (Ortho-Phthalaldehyde).

Label warnings state that direct contact with glutes and OPA is corrosive to exposed tissue and warn to avoid contact with eyes, skin or clothing. Using butyl rubber or nitrile gloves is recommended when handling, and when using latex gloves, to double up if contact with these materials is expected.

Residual Chemical Residue Can Cause Irritation

It is true that plastics can be effectively disinfected with these products, but everything immersed in these liquids will have residual amounts absorbed into the plastic. This absorbed portion is impossible to completely remove during the post-disinfection rinse.

The result is that disinfected plastic trays contact mucosal tissue and can cause serious irritation, literally leaving a bad taste in the mouth of your patient. Not good. Not only is this an issue with impression trays, but with anything else that is plastic, is disinfected, and is eventually used in the mouth. Bite sticks are another good example of a product that will retain toxic chemical residues if not disinfected with the right stuff.

The Hidden Cost of Reusing Disposable Items

Yes, the cost of supplies is significant and can substantially eat away at your practice’s profits, but taking short cuts can actually be more damaging in the long run.

As we mentioned above, some offices may try to sterilize and reuse items like plastic impression trays that are only intended for one use. 

But according to the Food and Drug Administration, any single-use device that has been reprocessed is required to be as safe as it was when it was originally created.  Of course, it’s impossible for your dental practice to return the device back to its pristine condition as it was when it was initially crafted. 

If you do reuse disposable items, you could be opening your practice up to liability if your patients get sick or a procedure results in cross-contamination. In addition, trying to sterilize items that were meant to be used only once actually inhibits the efficiency of your practice, as it takes more effort to clean these items.

Solutions for Your Plastic Impression Trays

The good news is that plastics are now available for manufacturing these “disposable” items that can be steam-sterilized. We carry a complete line of autoclavable impression trays that are very economically priced, as well as bite sticks that can not only be steam-sterilized but even a model that can be dry heat sterilized.

The bottom line is to look at what you are disinfecting that is plastic and see if you can find an alternative that is sterilizable.

Maybe at some point, you will be able to get rid of the really toxic disinfectants in your office and give everyone a “good taste” about your practice.

What Are Some of the Advantages of Using Plastic Impression Trays?

But are plastic impression trays the right choice for your practice? Now that you have the option of autoclavable impression trays that can be reused, what are their advantages? We’ll review a few reasons why this small adjustment can make a big difference in patient satisfaction.

They Are More Comfortable For Your Patients

Metal trays are hard and don’t stretch. Plastic trays can accommodate oral cracks easily. This makes your patients more comfortable. As a result, you’re more likely to get a better impression and your patients are more likely to return.

They Reduce the Risk of Tissue Damage

Again, the softer flexibility of plastic impression trays means there’s a reduced chance of tissue irritation. This is particularly beneficial for your patients who have oral sensitivity. 

They Give an Accurate Impression

Flexibility is a key advantage not only for your dental patient, but your staff as well. Plastic trays can mold better to the subtleties in anatomy, meaning you’re more likely to have an accurate impression without the need for “retakes.”

Diatech Has the Solution With Reusable Plastic Impression Trays

You don’t have to sacrifice the ease of plastic trays in the name of efficient sterilization. Soaking plastic impression trays can absorb chemicals, the better option is to invest in our autoclavable reusable impression trays. You’ll provide your patients with the comfort they desire while still staying in compliance with all regulations. 

Remember: When you order directly from Diatech, there are no required contracts and no minimums—only the best in customer service.