Effect of resin coating on dentin bond durability of a resin cement over 1 year

Abstract

Purpose: To evaluate the effect of resin coating of bonded dentin on the micro-tensile bond strengths of a resin cement to dentin over 1 year. Methods: Human molars were ground to obtain flat dentin surfaces and divided into three groups. The dentin surfaces were left as a control, or resin-coated with a combination of a dentin bonding system, Clearfil SE Bond (SE), and one of two lining materials: Protect Liner F (PLF) (SE/PLF) or Ionosit Micro Spand (IMS). The dentin surfaces with or without resin coating were covered with a temporary filling material (Cavit-G) and stored in water for 1 day. After removal of Cavit-G, an indirect composite block (Estenia) was bonded with Panavia F following the manufacturer's instructions. The specimens were stored in water for 1 day, 6 months or 1 year in 37°C water. Micro-tensile bond strength was measured at a crosshead speed of 1 mm/minute. There were 10 slices each group. Data were analyzed with two-way ANOVA and Fisher's PLSD test (P< 0.05). Results: ANOVA indicated that resin coating and storage period significantly influenced the micro-tensile bond strengths (P< 0.0001). The bond strengths of SE/PLF, SE/IMS and the control after 1 day were 27.5 ±5.1, 15.7 ±3.2 and 10.6 ±4.9 MPa, respectively. The bond strengths of SE/PLF significantly decreased over 1 year (P< 0.05), while there were no significant differences in bond strengths for SE/IMS (P> 0.05). The bond strengths of SE/PLF were significantly higher than those of the control over 1 year (P< 0.05).