Optical Coherence Tomography (OCT) is a non-invasive low coherence interferometry technique that includes several
technologies (and the corresponding devices and components), such as illumination and detection, interferometry,
scanning, adaptive optics, microscopy and endoscopy. From its large area of applications, we consider in this paper a
critical aspect in dentistry - to be investigated with a Time Domain (TD) OCT system.
The clinical situation of an edentulous mandible is considered; it can be solved by inserting 2 to 6 implants. On these
implants a mesostructure will be manufactured and on it a superstructure is needed. This superstructure can be integral
ceramic; in this case materials defects could be trapped inside the ceramic layers and those defects could lead to fractures
of the entire superstructure. In this paper we demonstrate that a TD-OCT imaging system has the potential to properly
evaluate the presence of the defects inside the ceramic layers and those defects can be fixed before inserting the
prosthesis inside the oral cavity. Three integral ceramic superstructures were developed by using a CAD/CAM
technology. After the milling, the ceramic layers were applied on the core. All the three samples were evaluated by a
TD-OCT system working at 1300 nm. For two of the superstructures evaluated, no defects were found in the most
stressed areas. The third superstructure presented four ceramic defects in the mentioned areas. Because of those defects
the superstructure may fracture. The integral ceramic prosthesis was send back to the dental laboratory to fix the
problems related to the material defects found. Thus, TD-OCT proved to be a valuable method for diagnosing the
ceramic defects inside the integral ceramic superstructures in order to prevent fractures at this level.