An invitro Study to Evaluate the Microleakage at Interface Between Combined Amalgam/Composite Resin Restorations in Class II Cavities

Abstract

Objective: The aim of this invitro study is evaluation of the microleakage of dye penetration at the interface between amalgam-composite resin restorations using different bonding systems.

Material and Methods: In this in-vitro study, standard class II cavities were prepared on 60 human maxillary premolars. The axial and gingival floor depths of the cavities were 2 mm and 1 mm below (cementoenamel junction), respectively. In all cavities, a layer of 1-mm thick amalgam was used as a coating for the initial part of the gingival floor. Then, samples were divided into 4 groups (n = 15) according to the type of bonding system used. Group 1 (control): no bonding system was used for amalgam restoration, group 2: G-Premio Bond was applied, group 3: G-Premio bond + alloy primer were used and in group 4: single bond + alloy primer were used. The rest of the cavities in all groups were then restored using composite (FiltekZ250). The samples were thermocycled at 500 rpm and immersed in 1% methylene blue solution for 24 hours to allow dye penetration. Once cut, the samples were placed under a stereomicroscope (40X) to determine the microleakage rate. Data analysis was carried out using post-hoc and Chi-square tests (p<0.05).

Results: The highest and lowest microleakage rate was related to groups 1 and 3, respectively. There was a significant difference between another groups (p<0.05).

Conclusion: The use of alloy primer and bonding could reduce the microleakage between the two restorations in class 2 cavities.