ENAMEL AND DENTIN SHEAR BOND STRENGTH OF 2 RESIN MODIFIED GLASS IONOMERS AND 2 RESIN-BASED ADHESIVES

Objectives. The purpose of this in vitro study was to compare the shea r bond strength to enamel and dentine of two resin modified glass iono mers (Fuji Bond L.C. and Vitrebond) and two resin based adhesives (Pri me&Bond 2.1 and Scotchbond Multi-Purpose). Methods. A total of 120 bon d sites were prepared on either enamel (n = 60) or dentine (n = 60) on human molars by grinding the teeth flat with a 600 grit sandpaper. Ea ch tooth substrate group was divided into four groups (n = 15) to matc h each material. Each of the four material systems was applied, accord ing to the manufacturers instructions, to the bond sires. On top of th e placed material, a microfilled composite was placed in a 2.5 mm diam eter matrix and light-cured for 40 s. All specimens were thermocycled 500 times (5-55 degrees C). Shear bond strength values were determined 120 h after bonding using a Zwick testing machine. One-way ANOVA was used to determine whether significant differences (p < 0.05) existed a mong the material groups on enamel and dentine. Pairwise comparisons w ere used to determine significant differences (p < 0.05) among the fou r products. Results. The ANOVA revealed strong significant differences on enamel (p = 0.0001) and dentine (p = 0,0172). The enamel bond stre ngth values of the two resin based adhesives were significantly higher than one of the resin modified glass ionomers (Vitrebond), while the other resin modified glass ionomers did not differ from Scotchbond Mul ti-Purpose. On dentine, however, Vitrebond performed significantly bet ter than the two resin based adhesives. Conclusions. The investigated resin modified glass ionomers bonded better to dentine surfaces than t o enamel surfaces, while the investigated resin based adhesive systems bonded better to enamel than to dentine. (C) 1998 Elsevier Science Lt d. All rights reserved.