Nothing Lasts Forever
Robert C. Margeas, DDS
With the options for restoration becoming ever more complex, clinicians need to fully understand the considerations that drive material choices during treatment planning as well as the appropriate methods of removal if failure occurs. Although "doing it right the first time" is essential to ensuring longevity, there are generally multiple ways to approach treatment, so the question of which way to do it the first time is of paramount importance. The evaluation of patient-specific factors to guide treatment and material selection should include a risk assessment of any variables that could result in future failure and require the need for re-treatment.
This month, Inside Dentistry's cover story examines how advanced restorations can present greater challenges in the face of removal. We all think our restorations should last forever, but nothing lasts forever. I'd rather be faced with redoing a restoration than providing treatment for a catastrophic failure in which the patient loses the tooth. If this occurs, he or she will require an implant. Although we want to provide the strongest restoration that we can, in situations involving functional challenges or parafunction, making the restoration the weak link can serve to protect and preserve the tooth as well as the opposing dentition. For example, when I'm restoring a patient with excessive wear, I like to use composite for the overlays or lingual veneers, then come back and veneer the facial surfaces with porcelain to raise the esthetic value.
One way that we can be better prepared to handle restorative failure is to remain as conservative as possible. For highly retentive preparations, use traditional cementation instead of defaulting to bonding. If you need to bond, bonding to enamel instead of dentin leaves more natural tooth structure should re-treatment become necessary. That being said, the bonding of modern materials such as lithium disilicate to enamel results in the strongest restorations in dentistry. Back in 1986, when I was in dental school, I learned my lesson early on as I watched an instructor attempt to remove a bonded restoration by cutting it and using a spreader. The tooth fractured right to the pulp. If I need to remove a bonded veneer from a tooth that was prepared, I'll attempt to cut and gently separate it, but if it doesn't easily pop off, or in cases involving no-prep veneers, I refer the patient to a skilled laser dentist for conservative removal. I'm not in the business of grinding away at my patients' enamel in no-prep cases.
When selecting materials, clinicians should balance the need for strength with the potential need for removal. In order to best prepare for contingencies, we should be conservative when placing restorations as well as when removing them. In this manner, the amount of remaining natural tooth structure is always being maximized to accommodate future treatment.
Robert C. Margeas, DDS
Editor-in-Chief, Inside Dentistry
Private Practice, Des Moines, Iowa
Department of Operative Dentistry
University of Iowa, Iowa City, Iowa