Microleakage of Class II Posterior Composite Restorations with and Without use of Liners - A Comparative Study.

Aim: This study aims to compare the effect of liner on microleakage in Class II restorations at the occlusal and gingival levels when restored with a nanocomposite.

Methodology: A total of 60 mandibular molars were selected and divided into three groups. Cavities in Group A were restored with posterior nanocomposite without liner, samples of Group B were restored with posterior nanocomposite with flowable composite liner and in Group C samples were restored with posterior nanocomposite with resin-modified glass ionomer cement (RMGIC) liner. Samples were stored at 37°C in 100% humidity for 14 days. Samples were subsequently immersed in 0.5% methylene blue dye and then placed under water for 15 mins. Teeth were sectioned mesiodistally with a diamond disc and examined under a stereomicroscope.

Results: All the cavities exhibited dye penetration along the occlusal and gingival margins of the restored cavities. Group A showed maximum leakage compared to Groups B and C, which was statistically significant ( P = 0.001 and P < 0.0001). No significant difference in microleakage was observed between Groups B and C. Microleakage was more in gingival margins as compared to occlusal margins in all the groups.

Conclusion: Based on the results of the present study, it may be concluded that the placement of liner beneath nanocomposite restoration results in a significant reduction in microleakage.