After spending an inordinate amount of time studying computer restorations, I sometimes get sidetracked from basic dentistry.
Paul Feuerstein, DMD
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After spending an inordinate amount of time studying COMPUTER RESTORATIONS, I sometimes get sidetracked from basic dentistry. Many "digital practitioners" do almost all of their restorations, no matter how small, with in-office CAD systems, currently CEREC and E4D. The reason, they state, is that you cannot get a well-contoured ideal contact with direct resin restorations. Also, because these are retained by bonding, there is no need for GV Black restorations with retentive isthmus areas. These preparations can be much more conservative and prepared quickly.
For dentists who were trained on amalgam, this could be the answer to their frustrations. Many practitioners create the amalgam preps they were taught, put on a Tofflemire retainer and thin band, wedge it, squirt in or compress the composite, and somehow get open contacts and large gingival spaces. This is because it was easy to burnish a band and pack the amalgam with pressure. But even with condensable composites, they still are frustrated with the results.
Also, replacing an entire quadrant of amalgams with composite can be a long process since, unlike amalgam, it is unpredictable to do back-to-back restorations with bands in place. This is a sure recipe for disaster. The CAD systems allow the practitioner to make a "row" of MOD inlays that can be bonded in at once in a very short period of time.
Fortunately, there is another answer: low-tech, inexpensive, and practical. There is a world of sectional matrices and novel retainers and wedges. Palodent and contact rings blazed the path for this technique. But if the box preparation was too wide, there were issues with these rings. They caused indentations buccal and/or lingual, as well as a fair amount of flash that required finishing. The tines were widened to help with this.
But the concept of the rings using pressure for separation yielded tighter contacts than ever before. This concept has now come to new levels thanks to the ingenuity of Garrison Dental (garrisondental.com) and Triodent (triodent.com). The former, led by the late Dr. Edgar Garrison and his sons in Michigan, and the latter, spearheaded by Simon McDonald from New Zealand, have made direct posterior composites simple and predictable.
Each has a place in every general practice. The Web sites have complete graphics and instructions on how these systems work. Each system also has evolved and changed dramatically from its original designs of the rings, bands, and wedges. Both systems, the Garrison Composi-Tight 3D™ and the Triodent V3Ring, have engineered flexible materials that help the metal rings compress the sectional bands against the outer tooth walls.
There is little or no flash, and thanks to the band contours as well as clever flexible plastic wedge design, the emergence profiles and contacts rival nature. And rival those CAD restorations mentioned before. In fairness, these are still composite and are certainly not as dense and durable as those made from CAD blocks. But, if well designed, well bonded, and properly finished, they can yield a durable restoration.
There are numerous other aids to create better contacts, such as Contact Pro 2 (cejdental.com) and Trimax (addent.com). They can be used with traditional bands or the aids mentioned here for even greater contacts. Just be sure the patient can still floss.
Garrison and Triodent also have an array of products and instruments to help the restorative dentist. Garrison has introduced a clever line of clear matrices that are tinted blue. The blue color makes it easier to see where you have placed the band around the tooth, especially at the gingiva.
The matrices are also not easily lost on the setup table the way clear ones are (where is that matrix?), and they increase the contrast between the matrix and tooth structure. Garrison has added a thick little piece on the end of the "grip strips" that allows the dentist to easily anchor the band between other teeth in the arch. This allows full control of the pressure when pulling on it for placement. You just have to see this on the company's Web site.
Triodent has introduced the clever Grip tabs. These allow you to hold small restorations with a tacky bonding agent that releases from the occlusal (or facial of a veneer) with a quick twist. This is a marvel if you are trying to place an upper second molar inlay. The companies' Web sites are full of information, and representatives that are helpful. Plus, the companies appear at most dental meetings so you have opportunities for up-close looks.
Dr. Paul Feuerstein installed one of dentistry's first computers in 1978. For more than 20 years, he has taught technology courses. He was named "Clinician of the Year" at the 2010 Yankee Dental Congress. A general practitioner in North Billerica, Mass., since 1973, Dr. Feuerstein maintains a Web site (www.computersindentistry.com) and can be reached by e-mail at email@example.com.