Microleakage in fiber-reinforced versus conventional composite restorations

Composite restorations are prone to hybrid structure degradation and microleakage over time, which causes destruction and discoloration of the restoration's margins, caries recurrence, postrestoration sensitivity, and pulp irritation. New fiber-reinforced restorations may reduce some of the disadvantages of conventional composite restorations. This study aimed to compare microleakage of fiber-reinforced and conventional composite restorations.

In this in vitro experimental study, 40 healthy extracted permanent premolars were included. The teeth were randomly divided into two groups: the first group consisted of teeth restored with fiber-reinforced composite and the second group consisted of teeth restored with conventional composite. In the teeth of both groups, two class II cavities were prepared, and then, according to the grouping, they were restored with composite or composite and fiber. Each cavity had a mesiodistal length of 2 mm, a buccopalatal width of 4 mm, and a depth of 5 mm, with proximal locations in the premolars. In the next step, the apex of all samples was sealed with adhesive wax, and the tooth surfaces were covered with two layers of nail polish and placed in 0.5% Fuchsin solution at room temperature for 24 h. Finally, the teeth were cut in half, and the extent of dye penetration was determined with a stereomicroscope equipped with a digital camera. The Mann-Whitney test was used to compare microleakage between groups. P ≤ 0.05 was considered statistically significant.

The median of microleakage score was 1 (interquartile range [IQR] = 2) in the intervention group and 2 (IQR = 1) in the control group. The difference between groups was statistically significant (P = 0.012).

This study revealed significantly lower microleakage with fiber-reinforced composite compared to conventional composite.