Effect of dentin-cleaning techniques on the shear bond strength of self-adhesive resin luting cement to dentin.

摘要

OBJECTIVE : This in vitro study evaluated the influence of different cleansing techniques on the bond strength of self-adhesive cement to dentin. METHODS AND MATERIALS : A total of 33 noncarious human molars were sectioned mesiodistally and embedded in chemically cured resin with the buccal or lingual surfaces facing upward. Superficial dentin was exposed and resin disk provisional restorations were cemented to the dentin surfaces with noneugenol provisional cement and were stored in distilled water at 37 degrees C. After seven days, the provisional restorations were removed and 13 specimens were randomly assigned to each of the five groups (n=13), according to the following cleansing treatments: G1-excavator (control); G2-0.12% chlorhexidine digluconate; G3-40% polyacrylic acid; G4-mixture of flour pumice and water; and G5-sandblasting with 50 mum aluminum oxide particles at a pressure of 87 psi. Resin composite disks (Filtek Supreme Plus, 3M ESPE Dental Products, St Paul, MN, USA) 4.7 (+/-0.1) mm in diameter and 3.0 (+/-0.5) mm in height were cemented with self-adhesive cement (RelyX Unicem, 3M ESPE), photocured, and stored in distilled water at 37 degrees C for 24 hours. Shear bond strength testing was conducted using a universal test machine at a crosshead speed of 0.5 mm/min until failure. RESULTS : Data were analyzed using analysis of variance (ANOVA) and the Tukey-B rank order test. Sandblasting with aluminum oxide (11.32 +/- 1.70 MPa) produced significantly higher shear bond strength values compared with any other treatment groups (p<0.05). No significant differences were found between G1-control (7.74 +/- 1.72 MPa), G2-chlorhexidine (6.37 +/- 1.47 MPa), and G4-pumice (7.33 +/- 2.85 MPa) (p<0.05).