Introduction:

Currently, the market offers Bulk Fill resins that are used with the monobloc or single-increment technique (up to 4 or 5 mm).

These resins are characterized by a lower filler content and larger filler particles, improved translucency, and a different chemical structure of the monomers in the filler compounds, which-when placed in a single block-reduce polymerization stress.

Objective:To evaluate the level of marginal microleakage of two Bulk Fill resins using the deproteinization technique prior to acid etching.

Methods:

This is an invitro study in which 64 extracted premolars underwent standardized cavity preparations. The teeth were randomly divided into four groups and subjected to a manual thermocycling process of 500 cycles.

All samples were immersed in a 2% methylene blue solution for 24 hours. Microleakage was then observed with a stereomicroscope.

Results:

For the Aura Bulk Fill resin, microleakage in enamel was observed in 25% of the deproteinized samples and in 18.8% of the non-deproteinized samples. For the Filtek Bulk Fill resin, 31.3% of the samples exhibited microleakage in enamel with the deproteinization technique and 25.0% without deproteinization. No statistically significant differences were found.

Conclusions:

All samples presented microleakage, with similar levels in both brands of Bulk Fill resins, and no significant differences were observed with the application of the deproteinization technique.