ABSTRACT
This research paper documents the current performance of an advanced CAD/CAM system. Patients with CAD/CAM Empress glass-ceramic or Aristeé composite machined complete crowns were retrospectively evaluated using U. S. Public Health Service criteria at least two years after placement. The composite restorations had unacceptable wear and surface loss. Development continues.
Subject(s)
Computer-Aided Design , Crowns , Dental Prosthesis Design/instrumentation , Dental Restoration Wear , Adolescent , Adult , Bicuspid , Ceramics , Composite Resins , Humans , Middle Aged , Molar , Retrospective Studies , Treatment OutcomeABSTRACT
Most coronal radicular reconstructions are made of cast inlay core metals or prefabricated posts covered in composite. The differences in the mechanical properties of these elements create a heterogeneous mass with inconsistent mechanical behavior. Studies using the Finite Element Method have shown the biomechanical disturbances caused by the inclusion of materials with a modulus of elasticity that is superior to that of dentine (i.e., nickel, chrome, zircon, etc). The use of materials with a modulus of elasticity close to that of dentine does not disturb the flow of stress inside the root. To our knowledge, only a composite material structured with programmable mechanical properties would be capable of producing both high mechanical performance and a modulus of elasticity adapted to dentine values. The C-POST, made of carbon epoxy, accommodates the demands of the dentine, as well as the in vitro stress linked to the prosthesis. The internal structure, consisting of long high-performance carbon fibers, unidirectionally and equally stretched, confers a totally original behavior that is adapted to clinical objectives. In addition, the C-POST has a fracture resistance superior to most metals.
