New Approaches to Adhesive Interface Assessment

Objectives: The aim of the present study is to develop in vivo methods of visualization (V) and early-stage non-invasive diagnostics of the states of adhesive intetfaces (AI) between hard tooth tissues (HTT) and polymer material (PM).
Methods: In the course of our experiments 350 AI between HTT and PM were tested by 3 methods.
The 1st one was a standard clinical examination including diagnostics, restorative treatment and further 4-year observation. The state of restorations was examed in accoradance with the recommendations of FDI and by using the USPHS criteria.
The 2nd method of diagnostics of AI represented itself a high-resolution digital analysis (VD) of tooth photos including the areas of AI. We used a camera NiconD3 with a set of macrolens and the system of additional
lighting (with power-controlled LEDs) from oral cavity. The images of AI were digitally processed using PTC MathCAD Express software.The method made it possble not only to visualize AI but also perform quantitative calculations.
The 3d mehod of in vivo V of AI was based on the application of OCT. To visualize the defects and hidden caries lesions in the restoration volume the experimental set including Spectral Radar OCT Imaging System OCP 930 SR022 was assembled.
Results: Having developed extended USPHS criteria so that they might be suitable for the application of physical methods of diagnostics, the qualitative and quantitative analyses of the state of AI were carried out by using VD and OCT in comparison with standard clinical ones. The results of statistical analysis of experimental data of the standard method and OCT showed a singnificant correlation between these two; however, this correlation is much lower than that between the results obtained using standard methods and VD.
Conclusions: It has been revealed that the results of VD tests are in full agreement with the results of clinical observations, which makes it possible to use this method as a screening one for preventive clinical examinations.
The OCT method allows in vivo, in situ, non-invasive monitoring of the state of AI between HTT and composite PM as well as revealing of hidden carious cavities and defects of restorations. It has been shown that the OCT method is more informative and reliable in comparison with standard clinical diagnostics and with VD when determining the state of AI.