Objective: The aim of this study is to compare the radiopacities of different types of materials with indications for application as a base under restorations and the microleakage of the final restorations with these materials applied as bases.
Methods: Standart Class I cavities were prepared in 90 caries-free molar teeth. The cavities were randomly divided into 9 groups according to the type of intermediate material to be applied (n=10): 1. High flowable composite, 2. Low flowable composite, 3. Fiber reinforced composite, 4. Giomer, 5. Ormocer, 6. Alkasite, 7. Bioactive composite, 8. High viscosity glass ionomer, 9. Glass carbomer. The base materials in each group were applied to the cavity floor and restoration was completed using a nanohybrid composite resin and an universal adhesive system. To evaluate radiopacity, radiographic images were taken using direct digital system and mean gray values were measured with ImageJ software. To analyse microleakage, specimens were subjected to thermocycling, immersed in 2% methylene blue solution for 24 hours, sectioned buccolingually and leakage values observed on the half-piece surfaces were examined under a stereomicroscope and recorded. Data were analysed using One-way Analysis of Variance, Tukey HSD Test and Pearson Chi-Square with Bonferroni-corrected Z Test (p˂0.05).
Results: In terms of radiopacity, while alkasite and low flowable composite showed the highest radiopacity, glass carbomer gave the lowest (p