MOD RESTORATIONS

Working in Tight Spaces With Rotating Instruments: Informed Consent

Another important item to mention here is that we are simply dealing with rotating instruments in a very small and confined space. This carries with it an associated risk for human error. Accidents do happen, even though we all we try to the best of our abilities to be careful and not damage adjacent teeth. This risk should be noted in an informed consent to the patient before any restorative procedure. Yes, we do mean that seriously. A patient should have an informed consent for every single procedure that is done on them, just like they do for every procedure that is done in a physician’s office or in a hospital. There are certainly risks and benefits to every procedure that we do, and it is our duty to properly inform the patient of what could happen, even when it is a remote possibility. Feel free to visit commonsensedentistry.com to download current informed consent form for dental procedures.

Magnification
There are numerous ways to prevent damage to adjacent teeth during teeth preparation, especially for restorative procedures. The absolute first requirement for any dental restorative procedures these days would be the use of magnification glasses, surgical telescopes, or surgical microscopes. Magnification glasses will help somewhat, but they do not allow the clinician to see all the details that are required for proper teeth preparation. Surgical microscopes, with their ability to literally almost take you on a journey down the endodontic canal, are an incredible advancement. Unfortunately, for most general dental restorative practices, they are cost prohibitive at this time. Generally, the best choice for everyday magnification use in general dentistry is the surgical telescope.
There are a number of manufacturers who provide some excellent surgical telescopes (such as Orascoptic, Designs for Vision, SurgiTel, and others). There are a myriad of features and designs, and every dental practitioner should do their due diligence when deciding which surgical telescope is best for them and their practice. What is the bottom line? The use of magnification is required as the absolute minimum step to take to prevent damage to adjacent teeth during teeth preparation procedures.

Preventing Soft-Tissue and Osseous Damage in the Interproximal Zone 
A major operative risk, as the preparation design approaches the gingival area, is possible trauma to both the soft tissue and the osseous structures. This can often result in the damage or even loss of the gingival papilla. When this type of trauma occurs, many times the end result can be an aesthetic restoration with good margins, but the patient may now experience a food trap between the teeth because of loss of the interproximal gingival structure. This so-called “black triangle” effect is one of the most frustrating aesthetic and functional complaints to dentists due to the lack of adequate treatments for this challenge. While there are new and successful techniques available which we have developed using laser biostimulation (with a diode laser such as Picasso [AMD Lasers]) and dermal filler materials, the best way to prevent this problem from happening is to place a physical barrier that will protect the tissue and bone.

Placing an Interproximal Barrier 
Another way to prevent damage to adjacent teeth during preparation is by placing a physical barrier between the teeth. The most common way to do this in the past was to create this “barrier” with a tofflemire matrix band. The advantage of using a tofflemire band, or any appropriately thick metal strip for that matter, was the ability to at least absorb minor scratches and damage. In addition, it also gave the operator some “warning” to pull away from the interproximal area.
Today, metal matrix bands are often not regularly found in dental offices, especially if the dental office does not currently use amalgam. Furthermore, one must consider that the matrix band metal is a flimsy, soft metal that does not allow for much protection. Metal matrix bands also encircle the entire tooth, and many times the operator does not have a clear path of sight into the interproximal area that is being prepared. In addition, other matrix systems used today cannot double as protection for the adjacent tooth, primarily because they are made from clear matrices and will shred upon first contact with a rotating carbide bur or high-speed diamond.
Another choice that has been available for some time now is the use of a metal shield that was especially designed for this purpose, the InterGuard protective interproximal shield (Ultradent Products). These disposable shields (available in 4.0 and 5.5 mm vertical heights to accommodate varying teeth) do not encircle the tooth, and are adequately thick/tough enough to help protect the adjacent tooth from iatrogenic damage during preparation. If you are not using a rubber dam, or the shields are not adequately wedged properly and continually supervised using a high volume evacuation tip, the manufacturer advises that the clinician thread an ample length of floss through the hole provided in the side of the shield. The floss allows the clinician or assistant to easily retrieve an accidentally loose interproximal shield, thus preventing the patient from accidentally swallowing or aspirating it. (Note: The floss should be of a length to hang no less than 7 inches outside of mouth.)
In the clinical case example that follows, we will introduce a new and novel multipurpose, single-product option that was designed to help the clinician prevent interproximal and soft tissue damage during restorative preparation, while fulfilling all of the requirements of MID.