[Effects of 3 desensitizers on bond strength of luting agents]

To explore the effect of Hybrid Coat, Prime & Bond NT, and anti-sensitivity toothpaste on the bond strength of glass ionomer cement (GIC), polycarboxylat cement (PCC), resin cement (RC), and to provide reference for clinical operations.

A total of 96 isolated human premolar samples, which were prepared to expose dentine, were randomly divided into a GIC group, a PCC group, and an RC group. Each group was divided into 4 subgroups according different desensitizers: a control subgroup, a Hybrid Coat subgroup, a Prime & Bond NT subgroup, and an anti-sensitivity toothpaste subgroup (n=8 in each subgroup). After using Hybrid Coat, Prime & Bond NT, and anti-sensitivity toothpaste in the corresponding groups, the castings of cobalt-chromium alloy were bonded to dentine surfaces by GIC, PCC, and RC. All the dentinesurfaces were treated with selected desensitizers. Specimens were tested by a universal testing machine to obtain the shear bond strength of each specimen, and the data of the shear bond strength was analyzed by one-way analysis of variance.

The shear bond strength of GIC significantly was increased in the Hybrid Coat subgroups compared with that in the control subgroups, the Prime & Bond NT subgroups, and the antisensitivity toothpaste subgroups (P<0.05); the shear bond strength of PCC significantly reduced in the Prime & Bond NT subgroups compared with that in the control subgroups, and the antisensitivity toothpaste subgroups(P<0.05); the shear bond strength of RC was obviously enhanced in the anti-sensitivity toothpaste subgroups compared with that in a control subgroup, a Hybrid Coat subgroup, a Prime & Bond NT subgroup (P<0.05).

When GIC is adopted as adhesive agent, we shoud choose Hybrid Coat; if PCC is chosen, the Prime & Bond NT should be avoided; if RC is chosen to adhere crown, the antisensitivity toothpaste is applicable. Among the selected luting agents, GIC has the lowest shear bond strength while RC has the highest.