While full mouth comprehensive care is sometimes the best treatment option, quadrant dentistry frequently provides both the patient and the dentist with outstanding opportunities to reach the goals of excellent patient care. High quality, life-like esthetics, improved occlusion, time efficiency and cost effectiveness exemplify goals that both the doctor and the patient can agree on. This article discusses these worthwhile advantages of quadrant dentistry.
Laboratory fabricated restorations provide an excellent restorative option for replacement of oversized, old, defective amalgams that have recurrent caries; and the vast majority of the posterior quadrant dentistry that is diagnosed is amalgam replacement. There are a number of extraordinarily talented and highly trained dentists who can do an incredible job of replacing an MODBL amalgam with a direct resin restoration. These dentists create excellent dental anatomy to precise function. However, for the vast majority of dentists in practice, 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 is already lost. In these situations, a highly skilled 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 to proper function only. When function is the only consideration, materials such as gold and silver-mercury amalgam suffice. Gold in particular provided a long lasting, supportive restoration which, when onlayed over the cusps of the teeth, prevented fracture.
Silver-mercury amalgam served the profession well for over a hundred 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, so this stresses the tooth day to day. The mercury evaporates over the years so the restoration is not dimensionally stable and this allows leakage. Corrosion and oxidation of amalgam causes it to expand, not daily as with hot and cold, but over the long run, which leads to fracture. Some research says that the mercury in amalgam is safe while 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 the 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 this allows the laboratory technician to precisely match all of these teeth with the same restorative material. There are many excellent restoratives available today, including Empress, Belleglass, Sinfony, Cerec, Cercon, and others, which bond to the tooth, effectively reinforcing it. Choosing materials is beyond the scope of this article, but should be investigated thoroughly by reading articles and by taking continuing education courses at postgraduate centers such as LVI. With the high level of color accuracy of digital photography, dentists can effectively communicate the exact color combination of the teeth to be matched by taking digital images of shade tabs next to the teeth. Most up to date labs can receive emails of these images and view them on their computer monitors during fabrication of these restorations, helping 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 concerning the relation of the upper jaw to the lower jaw, teeth-to-teeth bite problems in that quadrant can definitely be addressed. Before beginning any significant treatment plan, a comprehensive exam should be accomplished which should include TMD screening. Just as a simple bite adjustment can relieve a “high” filling, new dental work can turn a dormant TMD problem into an acute one. First, do no harm. Oftentimes, patients are used to living in pain, thinking it is normal, so patients should be given an opportunity to answer pertinent question about potential TMD such as:
- Do you get frequent headaches?
- Do you have muscle tension in your jaw?
- Do you have facial pain?
- Do you clench or grind your teeth?
- Do your teeth feel sensitive?
- Do your TMJs click or pop?
- Do you get vertigo or dizziness?
- Do you get tinnitus?
- Do you get ear congestion?
- Do you have an overbite or over jet?
- Are you a mouth breather?
- Do you have neck pain?
- Do you have posture problems?
Patients should also be examined for tenderness in the muscles of mastication. Many of these muscles can be palpated-and tenderness is an indication of TMD. If the bite is not correct, muscles will not be balanced and rested. This causes tenderness, which dentists can discover on clinical exam. Patients appreciate the attention to detail when dentists take the time to palpate muscles that have likely never been examined. Masseters, pterygoids, temporalis, digastrics, sternocleidomastoids and trapezius muscles should all be tested. When these muscles are tender, it is strongly advised to “keep the handpiece in the holster” until a definitive TMD solution is planned. Other signs to watch out for are:
- joint sounds
- abfraction lesions
- lingually inclined teeth
- bicuspid drop-off
- chipped teeth
- worn enamel
- scalloped tongue
- abnormal head posture
- high palatal vault
When the dentist is not trained to treat TMD, referral to a properly trained neuromuscular dentist is indicated. Using TENS therapy and guided by tomography, sonography, electromyography and jaw tracking kineseography, neuromuscular dentists can find an ideal craniomandibular position to which the teeth can be restored. Neuromuscular dentists can be found at www.leadingdentists.com.
If TMD screening is unremarkable, the quadrant can be restored with the goal of improving the cusp to fossa relationships and eliminating pathologic bite interferences. All incline interferences should be eliminated, leaving only functional cusp tips contacting opposing fossae in function. Function should be tested by chewing real food or chewing gum on one side with articulating paper on the opposite side, rather than with parafunctional grinding that is typically used at chairside. Skilled dental laboratory technicians understand the importance of these bite issues and will create restorations that meet these criteria. By making restorations for an entire quadrant, the dentist and the technician have an opportunity to improve an entire area, with the potential of relieving symptoms that may have been caused by pathologic tooth-to-tooth contact.
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 should be avoided in this instance as well. 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 sequallae. When restoring a quadrant, one goal should be to improve the occlusion, not cause TMD, and this goal can be accomplished with careful attention to meticulous protocol.
Time is a precious commodity to dentists and patients alike and should therefore not be wasted. Restoring the 4 posterior teeth in a quadrant can take as many as 8 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 laboratory using full mouth casts mounted on an articulator. It is up to each dentist in consultation with each patient to decide which approach is most appropriate. This much is certain-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 always a consideration for everyone. Dentists can only provide outstanding services if they are profitable and patients must get value for their health care dollar. 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 to come in for multiple appointments when dentistry is accomplished one tooth at a time. Each time the patient comes in, they must be anesthetized which is also 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, diminishing 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, which are currently available, the out of pocket costs can become even less objectionable.
From the dentist’s perspective, quadrant dentistry is a clear winner. Two two-hour appointments to restore 4 teeth in a quadrant cost the practice far less in overhead than eight one 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, less staff labor, less everything.
In summary, it is clear that 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 the dentist gives one patient undivided attention, doing a highly productive procedure, rather than running from room to room doing smaller procedures on larger numbers of patients-and you cannot put a price on peace of mind.
Dr. Bernstein is a Clinical Instructor at LVI. In 2002, The Richards Report awarded Dr. Bernstein “Practice of the Year.” He is widely published and lectures throughout the U.S.A. Dr. Bernstein practices in Piedmont, California, focusing on comprehensive cosmetic dentistry, TMD, sedation and exceptional guest services. He can be reached at firstname.lastname@example.org .