In vitro assessment of push-out bond strength of cold ceramic and mineral trioxide aggregate to root dentin.

Background: To provide a continuous seal of the root canal, root-filling material should bond to the root canal dentin, ensuring the integrity of both the root-filling material and dentin remains in a static and functional state. The present study assessed the push-out bond strength of mineral trioxide aggregate (MTA) and cold ceramic (CC).

Materials and methods: In this laboratory trial study, 20 single-rooted, extracted human teeth without caries and cracks were selected. Each tooth was mounted in cold-curing resin. Then, 3 mm slices of mid-root dentin were obtained from each tooth. The specimens were randomly divided into two groups (n = 10) and filled with MTA ProRoot and CC. All specimens were stored for 30 days in an incubator at 37°C and 100% humidity. The push-out bond strength of the test materials was measured using a cylindrical punch with a 1-mm diameter. The punch was pushed against the test specimen at a speed of 1.0 mm/min using a universal material testing machine, extruding the filling test material. The push-out force during the test was recorded, and then, the internal surface of the teeth was examined to evaluate the mode of failure. Independent t-test and Chi-square were used to analyze the data. P < 0.05 was considered a significance threshold.

Results: The mean push-out bond strength in the CC group was 24.58 (MPa), and in MTA ProRoot, it was 23.77. No significant difference was observed between the two groups. The most frequent mode of failure in both groups was adhesive failure.

Conclusion: The two materials have adequate push-out bond strength to root dentin, and there is no difference between the bond strength and mode of failure of the two materials.