PSI - Issue 28

Vesela Hristova et al. / Procedia Structural Integrity 28 (2020) 1002–1009 Author name / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 1. As prepared teeth, filled with restorative materials and covered with lacquer.

3. Results The dye penetration, defining the ratio of the microleakage, can be clearly seen during observations of the filled V-shape tooth defects with light microscopy. Fig. 2 shows that in the cavity, filled with GIC, the dye has penetrated more than one third of the obturation depth. While in the teeth, treated with FPC, the dye penetration is in lower depth, predominantly at the cervical areas (Fig. 3). The observation of the cavities, filled with UPC, has shown only traces of dye penetration (indicated by arrows on Fig.4) in the occlusal and cervical regions along the border of the obturation. In this group two teeth (one incisor and one premolar) with no microleakage are found. The investigation of the relative microleakage confirms the results of the observations of V-shape tooth defects, filled with different restorative materials. Quite big differences in the values of the relative microleakage in the three groups are revealed (Fig. 5). The teeth, filled with GIC, are characterized with highest microleakage - 38.1%, followed by the group of FPC – 24.5% and the lowest is in the cavities, filled with UPC – 18.2%. In the groups, treated with GIC and UPC, the relative microleakage in the occlusal area is higher than that in the cervical area (41.3%/33.9% in GIC and 19.7%/16.4% in UPC). While in the cavities, filled with FPC, the relative microleakage in the occlusal area is lower compared to the

Fig. 2. Cavity of tooth, filled with GIC (magnification x8).