Investigating the impact of flowable composite liner on the fracture strength and microleakage of large composite resin restorations of primary anterior teeth.

Purpose: To investigate the effect of pre-cured and co-cured flowable composite liner on fracture strength and microleakage of primary anterior teeth with extended composite resin restorations.

Methods: In the current in vitro experimental study, the crowns of 54 extracted primary canine teeth were cut 1 mm above the CEJ, and a pulpectomy procedure was performed. The samples were randomly divided into three groups to restore the coronal part up to 4 mm above the CEJ.