Comparison of Dentinal Microleakage of Class II Composite Restorations Using Universal Bonding: Self-Etch and Selective-Etch of Enamel, with and without Liner

Microleakage is one of the most important causes of failure in restoration and secondary caries. This study was conducted in order to compare dentinal microleakage of class II composite restorations using Universal Dental Adhesive, with and without liner.

In this laboratory study, two Class II cavities were prepared in the mesial and distal surfaces of 48 healthy premolar teeth. Then, the samples were divided into 6 groups of 8 according to the application method of Single Bond Universal adhesive and liner: selective etching of enamel (SEE), self-etch (SE) technique, SEE technique and resin-modified glass-ionomer (RMGI) liner, SE technique and RMGI Liner, SEE technique and Flow Liner, and SE technique and Flow Liner. Restoration was done with Filtek Z250 composite. Microleakage was evaluated and compared using 2% fuchsine based on intensity 0 to 3.

In the SEE group, 56.2% of restorations did not have microleakage. 31.2% had grade 3 microleakage and 12.5% had grade 1 microleakage. However, in the SEE+RMGI group, 81.25% and the SEE+Flow group, 81.2% of the restorations had no microleakage. In the SE group, 18.7% of restorations showed zero microleakage, 50% showed grade 3 microleakage, and 31.2% showed grade 2 microleakage. However, in the SE+RMGI group, 81.25% and in the SE+Flow group, 93.7% of the restorations did not have microleakage. The distribution of dentinal microleakage intensity between SEE and SE methods (p=0.067) and between SEE+RMGI and SEE+Flow groups (p=0.194) was not significant. However, in the SE+Flow and SE+RMGI groups, this difference was significant (p<0.001).

The results of this study showed that in the method of using a liner with Universal adhesive, dentinal microleakage in class II composite restoration decreased.