PSI - Issue 28

Vesela Hristova et al. / Procedia Structural Integrity 28 (2020) 1002–1009 Vesela Hristova, Tsanka Dikova, Vladimir Panov / Structural Integrity Procedia 00 (2019) 000–000

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cervical area – 22.7% and 25% respectively. Therefore, it can be summarized that the V-shape tooth defects, obturated with photo-cured composite material are characterized by a lower microleakage compared to those filled with GIC.

Fig.3. Cavity of tooth, filled with FPC (magnification x15).

Fig. 4. Cavity of tooth, filled with UPC (magnification x15).

4. Discussion The FUJI VIII GP glass-ionomer cement, used in the study, belongs to the group of resin modified GIC . It is recommended for application in repair of root lesions as well as Class III and V lesions (GC Fuji VIII GP (2020). The setting reaction of the GIC starts immediately after the mixing of the solid (powder) and liquid phases in 3.4/1 (77% powder/23% liquid) ratio and runs homogeneously throughout the volume, which determines the centripetal nature of the shrinkage. The cement used is characterized with 3% shrinkage and no adhesive system is applied in obturation of the cavities in the study. As it belongs to the group of resin modified GIC, its adhesion to the hard dental tissues is

100

Relative micro‐leakage Relative micro‐leakage in oclusal area Relative micro‐leakage in cervical area

80

60

41,3

38,1

33,9

40

25,0

24,5

22,7

19,7

18,2

16,4

20

Relative microleakage, %

0

GIC

FPC

UPC

Fig. 5. Relative microleakage in V-shaped cavities, filled with GIC, FPC and UPC.