Tensile Bond Strength of New Filling Systems

Objectives: The purpose of this study was to compare and evaluate the adhesion strength of five different filling systems including newly developed PrimeFil, which consisted of flowable resin composite and self-etching primer.

Methods: Five different filling systems in two categories: bonding-less system: PrimeFil (PF, Tokuyama Dental), Fusio (FU, Pentron), and Vertise Flow (VF, Kerr), and the conventional system (light-cured adhesive and resin composite): Bond Force (BF, Tokuyama Dental) with Estelite Sigma Quick (ESQ, Tokuyama dental) and SE Bond (SE, Kuraray) with ESQ, were bonded to bovine enamel and dentine prepared with 600-grit SiC paper, according to manufacturer's instructions. The tensile bond strength was measured after immersion in water at 37 degree Celsius for 24 hours.

Results: Means (n=5) of tensile bond strength are summarized below.

Filling system	Category	Pre-treatment of tooth surface	Tensile bond strength / MPa (SD)
PF	Bonding-less	Self etching primer	Enamel	21.9(1.9)
			Dentin	21.6(4.4)
FU		Not required (Self adhesive)	Enamel	9.6(2.0)
			Dentin	8.4(1.6)
VF			Enamel	6.7(1.9)
			Dentin	8.5(2.6)
SE & ESQ	Conventional	Self etching primer	Enamel	21.2(3.5)
			Dentin	22.6(3.3)
BF & ESQ		Not required (All-in-one)	Enamel	21.9(2.6)
			Dentin	23.3(3.1)

Conclusions: PrimeFil showed a high bonding strength comparable to the conventional systems.