Terminology, technology, and troubleshooting for the dental assistant.

Today's dental technology changes so fast that one cannot keep up with it. Dental manufacturers sometimes use terms or words we, the members of the dental health team, may not recognize. This is the reasoning behind this article and many more to come. The more we know about the products and procedures the easier our lives will be. In many cases when I have talked with doctors and asked them what they are currently using for a product, their response is, "I just use what my assistant hands to me." Adhesive dentistry is done every day in every dental office. It is important for the dental assistant to completely understand what they are using and why they are using it.

One rule to always follow: do not assume. All products are created differently and therefore have different directions. Please read and understand all directions before using any product. If you have questions, please don't hesitate to contact the manufacturer or their local representative.

We will start with some terms used in adhesive dentistry.

BisGMA Resins

This refers to the type of chemistry used in all light-cured resins. BisGMA-based resins include the bonding adhesive and the filled composites you use in your practice every day for performing all bonded restorations, sealants or direct veneers. Because all light-cured resins are BisGMA, you can mix and match from whatever manufacturer you wish. For example, your bonding resin could be a 3M product and your filling material could be from Ultradent. Because they are BisGMA based, they will all work together.

Oxygen Inhibition Layer (OIL)

This layer is the top layer of resin/composite that does not cure. It looks shiny or oily. It is necessary for resins to bond to each other, sort of like chains linked together.

As stated above, the OIL is necessary for bonding resin to resin. Sometimes, however, it needs to be removed or prevented. When placing a block-out resin to create reservoirs in custom-fit whitening trays, wiping off the OIL is recommended. The tray will have a better seal if the OIL is removed before vacuuming down the tray material. If the OIL is not removed, you will notice a residue in the tray. If this happens, just wipe the residue off with a cotton tip applicator.

It is also a good idea to prevent an OIL from forming when luting veneers. Studies have shown that there is a chance of microleakage at the margin if an uncured layer of resin is present. Once again, this is easy to prevent. Once the veneer has been tacked, the luting agent removed and the contacts opened, the doctor will have you do a final cure. Just place a glycerin-based material--like DeOx from Ultradent Products, Inc. (Photo 1)--along the margin before curing. This will prevent the OIL from forming and help to prevent future staining and breakdown at the cervical margin.

Photo Initiator 

Photo initiators are used in resins to "cure" the material. A commonly used photo initiator is camphorquinone. After curing camphorquinone, the material has a bit of a yellowish tint. Since today's new esthetic resins or composites are being used to mimic lighter or translucent enamel shades, some manufacturers have incorporated a clear photo initiator instead of camphorquinone. One example of this is PPD, or phenyl propanedione. Without a photo initiator, the resin will not cure unless it is a chemical-cured resin system.

Super-Adaptive Layer

A super-adaptive layer is a layer of composite--usually flowable--that is placed directly after curing the bonding resin and before placing a heavy-bodied composite filling material (Photos 2, 3, 4). Super-adaptive layer placement is especially recommended in a deep Class II preparation. Placing a super-adaptive layer will help prevent any voids or air pockets in the restoration. This layer also provides peace of mind for many clinicians concerned with composite shrinkage.

latrogenic Damage

What a fun word! This means "self-inflicted." latrogenic damage can occur when preparing a Class II, III, or IV. Basically, when breaking through the contact area, the bur can nick or touch the adjacent tooth. The nick may not be noticeable to the human eye, but over time, bacteria will easily stick to that area and may become the start of a carious lesion. To prevent iatrogenic damage, the clinician can place a small, almost matrix-like band called the InterGuard (Photo 5) in the interproximal area before prepping the contact area. The InterGuard is available only through Ultradent Products, Inc., and comes in two sizes, 4mm and 5.5mm.

I hope that this has helped you to better understanding of some of the newer, important aspects of adhesive dentistry.

If you have a topic you would like to know more about, or have questions you would like answered, just e-mail me at [e-mail] and I will see if I can help.

Happy assisting ... It's a Great Career!

Victoria L. Wallace, CDA, RDA, has a varied dental assisting career which includes general dentistry, cosmetic/esthetic dentistry, lecturing and consulting. Currently she is Western U.S. University Relations Manager for Ultradent Products, Inc., and an independent practice organizer for dentists starting their own practices. Ms. Wallace is President of the Nevada Dental Assistants Association and a director of the ADAA Foundation