While full-mouth comprehensive care is sometimes the best treatment option, quadrant dentistry frequently provides the patient and dentist with opportunities to reach the goals of excellent patient care. High quality, lifelike esthetics, improved occlusion, time efficiency, and cost effectiveness exemplify goals with which both the doctor and patient can agree. This article will discuss the advantages of quadrant dentistry.
Laboratory-fabricated restorations provide an excellent restorative option for replacement of oversized, old, defective amalgams that have recurrent caries. The vast majority of posterior quadrant dentistry diagnosed is amalgam replacement. There are a number of talented and highly trained dentists who can successfully replace an MODBL amalgam with a direct resin restoration. These dentists create dental anatomy to precise function. However, for the vast majority of dentists, it is not practical to take the time to place these large, direct restorations, nor is it the standard of care to place a direct restoration when a significant amount of tooth structure already is lost. In these situations, a master technician can provide a much higher level of quality at the lab bench working with properly mounted models on an articulator.
Today’s discriminating dental consumer demands outstanding esthetics. In the past, the focus of dentistry for posterior restorations was limited only to proper function. When function is the only consideration, materials such as gold and silver-mercury amalgam suffice. Gold, in particular, provides a long-lasting, supportive restoration which - when onlayed over the cusps of the teeth - prevents fracture.
Silver-mercury amalgam served the profession well for more than 100 years, and saved many teeth. But amalgam has significant limitations. The tooth supports the amalgam, not vice versa. It expands and contracts with hot and cold, similar to the mercury in a thermometer. This stresses the tooth daily. The mercury evaporates through the years so the restoration is not dimensionally stable. This allows leakage. Corrosion and oxidation of amalgam cause it to expand, not daily as with hot and cold, but over the long run. This leads to fracture. Some research says that the mercury in amalgam is safe. Other studies disagree. Finally, under the best of circumstances, the esthetics of a highly polished amalgam is far from tooth-colored while many old amalgams are nearly black.
Replacing a quadrant of old amalgam restorations with one of today’s esthetic alternatives significantly increases the overall esthetics of a patient’s mouth. Posterior teeth are not nearly as invisible as we would like to believe. Laughing, yawning, smiling, and talking reveal these unsightly restorations in numerous daily interactions. The advantage of replacing a whole quadrant of amalgams is that it allows the laboratory technician to precisely match all of these teeth with the same restorative material. There are many excellent restoratives available today. These include Empress, Belleglass, Sinfony, CEREC, Cercon, and others. Each of these bond to the tooth, thus effectively reinforcing it. Choosing materials is beyond the scope of this article but should be investigated by reading articles and by taking continuing education courses at postgraduate centers. With the high level of color accuracy of digital photography, dentists can effectively communicate the exact color combination of teeth to be matched by taking digital images of shade tabs next to the teeth. Most up-to-date labs can accept e-mails containing these images, and view them on computer monitors during fabrication of these restorations. This helps skilled technicians create restorations that defy detection by the naked eye.
While replacing a single quadrant of old amalgams will not correct a bite problem in regard to the relation of the upper jaw to the lower jaw, teeth-to-teeth bite problems in that quadrant can be addressed. Before beginning any significant treatment plan, a comprehensive exam should be accomplished.
It is highly recommended to use complete upper and lower casts mounted on an articulator for anything but a single-unit restoration. However, if the single-unit restoration is a second molar, a triple tray impression also should be avoided in this instance. Whenever a quadrant or a second molar is being restored, it is critical to maintain the bite relationship by relining a bite registration during the preparations. By preparing the second molar last, the craniomandibular relationship is preserved as the bite registration is relined. Once the second molar is prepared, the bite registration is relined one last time. To preserve the bite during the provisional stage, a temporary should be fabricated using an impression of the quadrant, waxed to ideal occlusion.
While this protocol may sound overly cautious, cutting corners can cause harm. If the second molar relationship is not preserved, the condyle will collapse superiorly into the glenoid fossa. This places pressure on the vital structures surrounding the fossa and changes the resting length of the muscles of mastication with the potential of initiating all manner of TMD sequelae. When restoring a quadrant, one goal should be to improve the occlusion, not cause TMD. This goal can be accomplished with careful attention to meticulous protocol.
Time is a precious commodity to dentists and patients, and should not be wasted. Restoring the four posterior teeth in a quadrant can take as many as eight or more appointments when accomplished one tooth at a time with laboratory-fabricated restorations. An entire quadrant can also be restored in one visit using CAD/CAM technology, such as CEREC, or in two visits when the restorations are made by a master technician in a lab using full-mouth casts mounted on an articulator. It is up to the dentist and patient together to decide which approach is most appropriate. But it is far more time-efficient to restore an entire quadrant at a time rather than one tooth at a time. Quadrants require fewer visits, and less time in the chair. For busy dentists and busy patients, quadrant dentistry makes good sense.
Cost is also a consideration. Quadrant dentistry is cost-efficient for dentists and patients. Some dentists even charge less for quadrants than they do for the same number of teeth restored individually. For patients, it is more expensive to take time off for multiple appointments when dentistry is accomplished one tooth at a time. Each time the patient comes in, he or she must be anesthetized. This can be a disincentive for many patients. While it can be argued that patients who are covered by insurance only qualify for about one crown per year, the insurance benefits for porcelain restorations grow smaller each year in proportion to a realistic fee. This diminishes the importance of benefits in considering treatment options. Many patients find that the benefits of fewer visits outweigh the out-of-pocket costs. With the large number of third-party financing options currently available, these out-of-pocket costs can become even less objectionable.
From the dentist’s perspective, quadrant dentistry can be an effective treatment option. Two, 2-hour appointments to restore four teeth in a quadrant cost the practice far less in overhead than eight, 1-hour appointments to do the same thing one tooth at a time. Time isn’t the only consideration in dollar cost either.
With quadrant dentistry, there is less anesthetic used, less bonding material used, less room turnover, less sterilization involved, and less staff labor.
In summary, quadrant dentistry provides many advantages to both dentists and patients. High-quality, excellent esthetics, improved occlusion, less chair time, and lower costs make quadrant dentistry mutually beneficial. It is also less stressful for everyone involved when a dentist can give one patient undivided attention performing a highly productive procedure rather than running from room to room doing smaller procedures on more patients. And, you cannot put a price on peace of mind.
Dr. Josh Bernstein is a clinical instructor at the Las Vegas Institute. In 2002, The Richards Report awarded Dr. Bernstein "Practice of the Year." He is widely published and lectures throughout the United States. Dr. Bernstein has a practice in Piedmont, Calif, that focuses on comprehensive cosmetic dentistry, TMD, sedation, and guest services. He can be reaced via e-mail at [email protected]
