Objectives: Dentin desensitizers can inhibit the bonding between dentin and resin cements. This study examined the effect of the previous application of desensitizers on the shear bond strength of one resin cement using self-etching primer to dentin.
Materials and methods: One hundred and twenty-five dentin exposed teeth were randomly assigned to four experimental groups and one control group of 25 teeth each. Four dentin desensitizers were applied to the four experimental groups, respectively. The dentin desensitizers used were SuperSeal (Phoenix Dental, Inc., USA), MS-Coat (Sun Medical Co. Ltd, Japan), Gluma (Heraeus Kulzer, Germany), and Copalite Varnish (Cooley & Cooley Ltd, USA). Panavia F (Kuraray Co. Ltd, Tokyo, Japan) was attached to the top of each experimental and control group teeth using an Ultradent testing jig (Ultradent Product, Inc., Utah, USA), and the shear bond strength was measured using a Universal testing machine (Model 6022, Instron Co., Canton, MA, USA). The tooth surface was examined by scanning electron microscopy (SEM, JSM-T2000, JEOL, Tokyo, Japan).
Results: The control group showed the greatest shear bond strength (14.74 MPa) followed by SuperSeal (12.33 MPa), Gluma (5.28 MPa), MS-Coat (4.44 MPa) and Copalite Varnishtrade mark (3.14 MPa). There was no significant difference in shear bond strength between the control group and the experimental group treated with Superseal. The shear bond strength in the other experimental groups treated with Gluma, Varnish, and MS-Coat was similar to each other but significantly lower than control or Superseal. SEM showed revealed resin tags in most of the dentinal tubules in the experimental group treated with the Superseal.
Conclusion: Among the four dentin desensitizers, Superseal was the only one that did not interfere with the process of resin bonding. The other dentin desensitizers that contained a resin ingredient interfered with resin retention.