The use of overlays in restorative dentistry

The Use of Overlays in Restorative Dentistry*
By Edward Feinberg, DMD The following synopsis is based on lectures given by Dr. Feinberg to the Academy in October, 2001 and May, 2002. A successful approach for full mouth restorative dentistry includes contingency plans in the event of future trouble. Success is, in essence foreseeing where failure might occur, and the better the practitioner, the better prepared he or she is to handle potential complications. The ancient Greek myth of Deadalus and Icarus illustrates this idea perfectly. Deadalus and his son Icarus were imprisoned in an island Labyrinth by King Minos. To escape, Deadalus invented a system of flight using wax and feather wings so that he and his son Icarus could fly home. He warned Icarus that flying too close to the sea would cause the feathers to dampen and rot, while flying too close to the sun would cause the wax to melt and the wings to fail. Icarus, of course, did not heed the warning and defiantly flew too close to the sun. The wings failed, as predicted, and Icarus fell headlong from the sky into the sea. “Deadlus forsaw”, Henry Petroski explains in his book To Engineer is Human,1 “as all engineers must foresee, the ways in which his structure could fail, for it is only by recognizing the possible ways of failure that a successful structure can be designed to resist the forces that might tear part from part. Had Icarus used the wings within the proper altitude, they would to this day be declared a success”. Restorative Dentistry is very akin to engineering. Engineered structures must be designed to withstand stresses and forces on a foundation. Dental Restorations must likewise be structured to withstand stresses and forces on the periodontal foundation—the teeth (or implants) and alveolar bone. Indeed one of the main goals of restorative dentistry is to minimize the forces on the periodontal foundation to promote health and longevity. Overlay (or Telescopic) restorations, when properly