Mark Peters RDT, published in the Journal of the Toronto Academy of Cosmetic Dentistry
Volume 1, Issue 3
Over the past forty-five years, we have seen dentistry progress in
leaps and bounds especially in cosmetic restorations:† from the advent of all-ceramic jacket crowns,
to ceramic crowns cemented to a gold sub-structure, to the first Ceramco
porcelain fused to metal crown. Ceramic technology has evolved to such a degree
that we have come full circle. These particular restorations are becoming our
main staple of work these days.
As consumers become better informed and educated about what options are
available to them, as well as, being influenced by the media on the importance
of being a beautiful person, the decisions that the patient will take in
regards to their restorations is of a more critical nature.
As more and more patients desire a cosmetic change to improve their lives, it seems that many dentists as well as dental laboratories are jumping on the cosmetic dentistry bandwagon. It is at this point that one must reflect upon what one is truly undertaking to change a personís smile cosmetically. By fulfilling a patientís desire for whiter and brighter teeth, possibly longer or shorter, and, wider or narrower, could we be creating a recipe for disaster? Most definitely if a well thought out treatment plan is not carried out!
†We must remember that we are usually dealing with multiple units of teeth that are being cosmetically re-designed and engineered to fit the confines of the patientís head. These restorations must be able to function harmoniously with the rest of the teeth, TMJ, as well as, the ligaments and muscles. If these criteria are not met the case is destined for failure.
My philosophy is simple. Achieve the ultimate aesthetics for the patient while maintaining the occlusal sanity for both the dentist and technician. By combining the progressive knowledge of both the dentist and technician, and using the best technology at our disposal, these cosmetic cases become very predictable and enjoyable.
Most patients that I have talked to during a consultation are definitely looking for more than a mouth full of white generic teeth. What they are asking for is a customized restoration that mimics natural teeth. Over the years we have developed a system with our dentists that approaches and treats every case in a decisive logical manner. We have coined it the Art Ceramica technique.
Communication between the dentist, patient and the laboratory is essential. Understanding the patientís expectations and concerns is the only way we can determine whether these are reasonable expectations, and will the restorations withstand a realistic lifetime of use. How many times have you seen veneers or crowns fracture or debond after a short period of time? It is very important to have a clear understanding of the patientís present condition, and to have a clear understanding of the patientís ďwantsĒ before any other steps are taken.
Following the preliminary consultation, the dentist proceeds with a full clinical examination, which includes x-rays, periodontal probing, etc. Each case will then be assessed from a gnathological point of view by taking maxillary and mandibular impressions for full arch study models. I would suggest using a good impression material such as poly-vinyl , silicone or hydrocolloid. We are looking for an accurate representation of the present condition. These impressions are then poured with a low expansion type 4 die-stone or resin stone. Upon our recommendation, we have had clinicians use an Arcus Facebow transfer. They have all found this facebow to be a joy to use. It takes less than two minutes to take the transfer, and requires only two hands. Let us remember that recording the patientís anatomical data is the basis for quality and precise function of the dental restoration.
Then a centric occlusion, right and left mediotrusion and protrusive check-bites are taken. These are sometimes difficult to take since the patient has the tendency to slide around. It was with this in mind several years ago that we purchased a functional three-dimensional computerized pantograph called the Condylocomp LR3 for the laboratory. This service is performed at the laboratory to record the accurate movements of the TMJ.
The procedure is relatively simple, and takes approximately forty-five minutes to complete. A paraocclusal clutch is fabricated and fixed to the patientís lower anterior teeth. This clutch is then attached to the specialized headgear. While the headgear and clutch are mounted, the patient wears an Aqualizer splint to deprogram the muscles. This headgear is connected to a computer with† sophisticated software. The Aqualizer is removed from the patientís mouth and the patient is taken through a specific registration sequence. The patient is asked to move into protrusion unguided, into right and left mediotrusion unguided in the discluded position. We ask the patient to open from a closed position and then close to first occlusal contact (touch). The same movements are performed again, but with tooth contact throughout the excursions. The final step is a series of phonetic exercises, which are recorded into the program.
The Condylocomp LR3 then analyzes all the collected data. This data provides us with accurate information so that we can programme these values into a fully adjustable articulator, such as the Protar7 or Protar 9 articulators. What is even more amazing is that the Condylocomp LR3 has recorded centric relation electronically allowing us to hook up a special articulator called the CAR Transfer, which enables us to ďwalkĒ the mounted models from centric occlusion into centric relation. This in turn will allow us to fabricate the restoration with centric relation in mind offering an extra built in buffer into the occlusal scheme.
Why go through all this? It gives us an accurate means of capturing the present occlusal scheme, and the way the TMJ is functioning before any tooth reduction is performed. It allows us to see what the tolerances and limits are for each patient, and it gives us the capability of staying within these limits for any occlusal modifications that may take place. In short, it gives us an accurate reference point if we lose control of the case somewhere along the way. We know exactly where we need to be. Any major alteration from these tolerances will affect the integrity of the restoration and will probably lead to discomfort for the patient since the TMJ, muscles and ligaments are being strained. The study models are now mounted in a fully adjustable articulator.
Following the Condylocomp LR3 registration, a full digital photographic session will be done to record facial characteristics, the dentition, and smile. A custom shade is taken and discussed. It is also important to listen to what the patientís needs and expectations are at this point in order to cross-reference with the notes provided from the dentist.
With all the preliminary information gathered, a very accurate aesthetic wax-up is constructed showing final contour and texture (figAC4). Strict guidelines are used for correct tooth morphology. Since the articulator is fully programmed, it dictates what cosmetic changes are possible. If the patientís desire was to have longer teeth, it is at this point that we can determine how much longer (if at all possible) these teeth can be. Going outside the limits increases the chances that the patient might not tolerate the restoration. The wax-up accurately shows what the true and realistic possibilities could be. To further this end-result we incorporate translucent waxes to the wax-up to provide a sense of depth and aesthetics. At this point many of our dentists ask us to show how much tooth reduction is required to achieve these results accurately. We routinely duplicate the model and prepare the teeth. Some clinicians request a vacuum form reduction stent of the diagnostic wax-up so that while they are reducing the teeth they can see exactly where they are within the confines of the wax-up.
Once the patient accepts the proposal, we can all proceed with confidence. Final full arch impressions are taken, a new Arcus Facebow transfer and a centric occlusal record. The technician can now concentrate on the task at hand. All this correlated information is a blueprint from which the ceramist can let his/her creative energies flow. Using the most advanced synthetic porcelains on the market, we are able to build up the crowns or veneers in multi-layers incorporating opalescent porcelains. What this means is that the final restoration offers the highest degree of fluorescence, opalescence and clarity combined with long lasting performance. The aesthetics and function of these restorations are true works of art. (Fig AC01,AC02)
Using the Art Ceramica technique allows us to maintain control of any case, from the simplest to the most complex, to the fabrication of TMJ splints, crowns, bridges, veneers, implant cases, etc. Also, by using a device such as the Condylocomp LR3 pantograph, it is a way for us to maintain the occlusal records of the patient on hand in a database forever.
I know that our dentists take great pride in restoring cosmetic cases, which they do with relative ease by following a technique that is predictable. We can all achieve the† peace of mind that comes with this type of planning along with the use of† the progressive technology.