主催: The Japanese Society for Dental Materials and Devices
The aims of this study were to compare fluid flow rates across dentine surfaces treated with four conditioners, and the effect of conditioning and dentine permeability on micro-shear bond strengths of glass ionomer cement and resin-based adhesives. Under a simulated pressure of 1.3 kPa, two dentine conditioners (Dentin Conditioner and Cavity Conditioner), 37% phosphoric acid (Acid Etch Gel) and a self-etching primer (Clearfil SE Primer) were applied to the dentine surfaces. Dentinal fluid flows at baseline and after conditioning were recorded for 15 min each using the Flodec device. The conditioned surfaces were examined using a scanning electron microscope. The micro-shear bond strengths of a glass ionomer cement (Fuji IX GP) bonded to unconditioned and conditioned dentine, or two resin-based adhesives (Single Bond 2 or Clearfil SE Bond) bonded to dentine with simulated intrapulpal pressures of either 0 or 1.3 kPa were evaluated. Only the dentine surface etched with phosphoric acid showed a significant increase in dentin permeability. SEM images of dentine etched with Acid Etch Gel showed the smear layer and plugs were completely removed. In contrast, smear plugs in dentinal tubules were partially removed by the other conditioners. There was no significant difference in micro-shear bond strengths of Fuji IX GP between unconditioned and conditioned dentine with either conditioner, regardless of the simulated pulpal pressure (p>0.05). Effects on bond strengths of resin-based adhesives depended on the system used. The simulated positive intrapulpal pressure during bonding significantly affected the adherence of Single Bond 2 (p<0.0001), however, Clearfil SE Bond was not affected (p>0.05).
