Probability of interface imperfections within SEM cross-sections of adhesively luted GFP

To calculate the probability of interface imperfections within SEM cross-sections of adhesively luted GFP depending on the level of analysis and the cement application method by means of LOM (light-optical microscopic evaluation method).

Four groups of artificial root canals received GFPs (n=5) under following experimental conditions: I=RelyX Unicem, applied with application aid, II=RelyX Unicem, III=Panavia F 2.0 and IV=Variolink II. In groups II-IV only posts were loaded with cement (i.e. conventional post cementation). After GFP cementation, standardized photographs were taken perpendicularly to post surface under light-optical microscope from two opposite sides. The length of homogenous cement interface areas were measured using surface-analyzing software. The homogenous areas were related to length of apical, middle, cervical post section and to complete post length to generate the probabilities (%) of hitting imperfections when using SEM cross-section analysis.

The probabilities (%) of hitting imperfections within SEM cross-sections for cervical, middle, and apical level of analysis were: I=78, 64, 82; II=89, 98, 99; III=72, 91, 99; and IV=85, 91, 97, respectively. For complete post length median values of probabilities (%) were: I=75; II=95; III=87; and IV=91.

The probabilities show, that SEM cross-section evaluation concerning detection of cement interface imperfections of adhesively luted GFPs depends on the cement application method and the level of analysis and seeming therefore not always unrestricted representative for the whole specimen.