Microscopic Analysis of Dental Filling Materials

Specimen polished surfaces (n = 90, three surfaces for each tooth) were first examined under a digital microscope VHX-5000 (KEYENCE, Osaka, Japan), and one image was captured for each specimen at 100× magnification. The micrographs were coded by an expert examiner who was not involved in the experiment, displaying the canal wall surface of both groups at the coronal, middle, and apical thirds, for blinded analysis using the VHX-5000 software (KEYENCE, Osaka, Japan) to measure the total area of the filling materials and of the internal and external voids in µm³ following a previous study [28 (link)] (Figure 2). After that, the percentages of voids were calculated and statistically analyzed.