En face OCT imagistic evaluation and laser microspectral analysis for assessing microleakage at the prosthetic interfaces

The microleakage at the prosthetic interface, for example between the metallic framework and the veneering part of the fixed partial prostheses (FPP's) is a common problem in dentistry. Optical tomographic techniques are of particular importance in the medical imaging field, because these techniques can provide non-invasive diagnostic images. En-face OCT is preferred for microscopy as it can provide real time images with similar orientation as that of microscopy images. The purpose of this study is to detect and analyze the possible defects at the interface of several FPP's using en face optical coherence tomography (efOCT) and laser microspectral analysis, a method which allows to investigate small quantities of materials of around 0.1 μg and to establish the content of atoms and molecules and to perform semi-quantitative and quantitative analysis. By this method it is possible to establish trace elements, i. e. with concentration of ppm (parts per million). The advantages of the OCT method consist in non-invasiveness and high resolution. En face OCT investigations permit to visualize a more complex stratified structure at the interface metallic framework/veneering material.