Th 132771

Under the microscope

May 1, 2003
Cross contamination, disease transmission, bloodborne pathogens, microbial populations, germs, bugs U what can an operator do to reduce the transference of germs from one person to another when taking alginates? Begin by asking yourself, when obtaining alginates do youU.

When was the last time you examined your alginate technique?

By Ellen Gambardella, CDA, M.Ed and Rita Johnson, CDA, COA, RDH, MA

Cross contamination, disease transmission, bloodborne pathogens, microbial populations, germs, bugs U what can an operator do to reduce the transference of germs from one person to another when taking alginates? Begin by asking yourself, when obtaining alginates do youU.

  • always wipe the rubber bowl clean prior to storage?
  • wipe down the spatula after each use?
  • use an antimicrobial alginate powder to substitute for disinfecting?
  • clean the water-measuring devices between patients?

If you have answered "yes" to any of these questions, stop and re-examine your infection-control protocol.

Operators often neglect to properly disinfect rubber bowls, spatulas, and water/powder measuring devices between patients. This inadequate decontamination habitually takes place due to time constraints or because the operator overlooks the likelihood of disease transmission by these items.

Some clinicians question the need to disinfect alginate equipment between patients. The following scenario is typically seen in offices:

The clinician examines the oral cavity for palatial height, size, debris, tori, removable appliances, etc. Gloves are now contaminated with bioburden. Trays are then tried in the mouth for sizing, subsequently becoming contaminated by unclean gloves. Rubber bowls, spatulas, water, and powder-measuring devices are held by the operator's contaminated gloved hands. Thus, a domino effect occurs and everything becomes contaminated which increases the likelihood of disease transmission.

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Today's marketplace offers products that improve infection-control protocol. For example, the multi-purpose disposable system, Bowl-Away™ and Spat-Away™ (seen below, phone number for more information is (888) 910-4490), is used for mixing alginate impression material as well as preparing plaster and stone for pouring models. The bowl is manufactured with built-in water measuring lines for alginate, plaster, and stone, thus eliminating the need for a water-measuring device that will subsequently require disinfection. This convenient feature is also a time-saver. Hold the bowl under the faucet and fill to the appropriate water level line for one, two, or three scoops of alginate. Plaster and stone water lines are also indicated for pouring models. This feature forces the operator to place the water in the bowl first before adding the alginate or gypsum powder. This textbook version of sequencing will create a homogenous mix easier than if the reverse is done, i.e. powder in the bowl first and then adding water.

Disposable bowl liners are also available, but these do not eliminate the need to disinfect the rubber bowl, since the operator still touches the exterior of the rubber bowl with contaminated gloves. At best, liners reduce the microbial population only on the interior surface of the bowl. Moreover, it is still necessary to use a water-measuring device that will become contaminated during the procedure with the liner method. Although Bowl-Away™ is intended to be used alone, it may be inserted inside a rubber bowl and used as a liner. It is also compatible for use with the Alginator.

Spatulas present another source of disease transmission. The typical wooden handle riveted to a stainless steel blade is not conducive to disinfection or sterilization. The wooden handle is porous and capable of harboring microbes. It cannot withstand heat or chemical sterilization without compromising the integrity of the wood. Furthermore, the area where the wooden handle is joined to the steel blade provides an ideal location for harboring microbes.

An ideal choice for spatula use is the disposable wooden spatula designed with one end for mixing alginate and the opposite end for mixing plaster and stone. These spatulas are discarded at the end of the procedure and contribute to a germ-free environment. The cost-saving benefits of Spat-Away™ include no clean-up, no disinfecting, and no repetitive hand/wrist motion.

One-piece molded plastic spatulas are an alternative choice for a mixing instrument, although they must be sterilized in a chemical sterilant or autoclave after each use. Important note: Autoclaved plastic spatulas may acquire an unappealing yellow-brownish appearance, which may leave patients "thinking" they are dirty. Check with the manufacturer to confirm that heat sterilization is recommended for the brand of plastic spatula being used.

You can see the built-in water measuring lines for one, two, and three scoops of alginate powder, as well as the S & P water measuring lines for Stone and Plaster Spat. This also shows the wide end for mixing alginate and the narrow end for mixing stone, plaster, and rubber base.
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Another benefit to these one-piece molded spatulas is their smooth surfaces. Their sleek design prevents microbes from adhering to uneven areas.

Some alginates are manufactured with antimicrobial agents in the powder to reduce the number of microbes present on the impression. This procedure does not substitute for disinfection, but rather enhances the decontamination process. Impressions should be inspected, rinsed quickly under cool running water to visibly eliminate blood and saliva, and then sprayed with an approved disinfecting solution. Acceptable disinfectants are intermediate-level products capable of killing Mycobacteriun Tuberculosis. The disinfectant should be sprayed onto the alginate impression tray and tray handle prior to leaving the treatment room. A paper towel moistened with disinfectant is wrapped around the entire tray and transferred to a plastic bag that has been labeled with the patient's name for identification purposes. Labeling with a waterproof marker minimizes errors between the office and dental laboratory. The impression is stored and poured with plaster or stone as soon as possible. Important note: If disinfection of the impression is inadequate, the poured model will be contaminated and capable of transmitting disease.

The "dunking" or submersion method is an alternative to spraying the impression with a disinfectant. Check the directions on the product for the minimum amount of exposure time needed to accomplish tuberculocidal disinfection, usually no longer than 10 minutes. Although opinions vary on the choice of disinfectants, glutaraldehydes may be used with the submersion method. However, this method is not recommended by the authors because of the chemical's toxicity. Important note: Keep glutaraldehydes in a covered container to prevent toxicity from fumes. Avoid skin contact with the solution as tissue irritation and discoloration of cuticles may result.

Today's marketplace offers new infection-control products and creates choices for the astute operator. Choose techniques such as the Bowl-Away/Spat-Away that save time and permit auxiliaries to perform more income-producing procedures, i.e. fabricating whitening trays, athletic mouthguards, attending to more patients, etc., rather than paying the auxiliary to clean up. No wasted time equates to more profit for the practice! The ultimate benefit is the elimination of cross-contamination. In addition, costly plumbing charges are saved as alginate, plaster, or stone are thrown in the waste receptacle and not down the sink! Moreover, those individuals who suffer from carpal tunnel syndrome reap the benefit of reduced hand-wrist strain because the clean-up process is obviated.

Today's patients are educated, informed, and inquisitive. Use these techniques to market your practice as going "one step beyond" to promote a safe, aseptic environment. Patients will appreciate hearing about what you do to protect them. In turn, they will pass the word on to family and friends who may become future patients!

In conclusion, ask:

  • Can my infection-control technique be improved?
  • Would you personally be comfortable as the next patient during alginate procedures?

Reevaluate your protocol when taking alginates and pouring models. It is the obligation of all auxiliaries to continually implement constructive changes towards improving infection-control procedures to keep the public safer.

Editor's Note: A similar article appeared in "The Dental Assistant" ADAA, Nov/Dec 2000

Ellen V. Gambardella, CDA, M.Ed. is the director of Dental Assisting at the Minuteman School of Applied Arts and Sciences in Lexington, Mass.

Rita J. Johnson, CDA, COA, RDH, MA is a Dental Associate/Treatment Coordinator in Medford, Mass. Ellen and Rita are international speakers, authors, dental educators, recipients of Excellence in Education awards, Veterinary Dental Technicians, and inventors of dental products. They are the cofounders of Dynamic Dental Seminars and Consulting Services (P.O. Box 1008, Concord, MA 01742) and can be reached by e-mail at [email protected].