Long-term nanomechanical properties and gelatinolytic activity of titanium tetrafluoride-treated adhesive dentin interface.

•TiF4 did not affect the nanomechanical properties of dentin–resin interface.•The underlying dentin showed significant degradation after 6 months of storage time.•TiF4 did not inhibit gelatinolytic activity at the adhesive–dentin interfaces over time.•The gelatinolytic activity at the interfaces was higher after 6 month for all the groups.