OCT and SEM imagistic investigations of composite resin-IPS empress ceramic interfaces

The purpose of this in vitro study is to evaluate the quality of repaired all ceramic IPS Empress e.max crowns. Excellent esthetics of all ceramic crowns is well known. One disadvantage of all ceramic restoration is the susceptibility to fracture due to brittle character of ceramic materials. Fracture of ceramic veneer may be repaired with composite resin or special designed ceramic material. Twenty four all ceramic crowns were made with IPS Empress e.max system. Fracture of ceramic veneer happens in the cervical, incise or functional (occlusal) area of metal-ceramic and all ceramic crowns. For simulating the fracture of ceramic veneers, defects of 2×2cm were made with a grinding instrument in the 1/3 incise area, on facial surface of each crown. All defects were repaired with Filtek Supreme (3M ESPE) composite resin. Samples were imagistic investigated by Optical Computer Tomography- Time Domain and Scanning Electron Microscopy. The interested areas were ceramic- composite resin interfaces. Longevity of all repaired ceramic crowns depends on interfaces integrity. Apparently intact, the ceramic-composite resin interface may display microscopic material defects which may lead to failure. Optical Coherence Tomography and Scanning Electron Microscopy are identifying and validate the micro-defects.