12-Month Bond Durability of Vertise Flow to Tooth Structure

Objectives: Vertise Flow is a self-adhering flowable composite that combines the essential components of an etchant, primer/adhesive and composite into one material, providing a simplified restorative protocol. To study the long-term bond durability of Vertise Flow (VF) by testing the shear bond strengths to dentin and enamel substrates after the bonded specimens are conditioned in de-ionized water for various times (up to 12 months).

Methods: Human dentin and bovine enamel surfaces were polished with 600 grit SiC paper, rinsed with water, and air-dried.  VF was then bonded directly to dentin and enamel substrates without further surface treatment following manufacturer’s instructions.  A bonding jig having a mold with an internal diameter of 2.38mm was used.  The shear bond strength was tested on an Instron mechanical tester after the bonded specimens (n=6) were stored in de-ionized water at 37C for 24 hours, 1 week, 1 month, 3 months, and 12 months.

Results:  ANOVA analysis revealed that there are no statistical differences (p > 0.05) among the dentin bond strengths at all storage times.   The enamel bond strength after 12-month storage time is not statistically different (p > 0.05) from that after 24-hour storage time, but significantly higher than (p < 0.05) those after 1-week, 1-month, and 3-month storage times.     

	Shear Bond Strength, MPa
Storage Time	Dentin	Enamel
24 hours	22.8±3.1a*	23.8±1.8ab*
1 week	20.5±2.3a	21.4±1.7b
1 month	25.0±5.2a	19.3±5.4b
3 months	20.6±4.0a	20.1±3.4b
12 months	26.1±4.4a	28.1±4.3a

   *Means with the same letter within the same column are not statistically different

Conclusions: The bond strength of VF to both dentin and enamel substrates is very stable and not negatively affected by 12-month storage time in water.