Effects of dentin surface treatments on shear bond strength of glass-ionomer cements.

Aim: The aim of this in vitro study was to evaluate the effect of different surface treatments on shear bond strength of a conventional glass-ionomer cement (GIC) and a resin-modified glass-ionomer cement (RMGIC) to dentin.

Materials And Methods: 80 bovine permanent incisors were used. 40 cylindrical specimens of a GIC (Fuji IX GP Extra) and 40 cylindrical specimens of a RMGIC (Fuji II LC) were attached to the dentin. The teeth were then randomly assigned to 8 groups of equal size (n=10), 4 for every type of glass-ionomer cement, corresponding to type of dentin surface treatments. Group 1: GC Cavity Conditioner; Group 2: 37% phosphoric acid gel; Group 3: Clearfil SE Bond; Group 4: no dentin conditioning (control). The specimens were placed in a universal testing machine (Model 3343, Instron Corp., Canton, Mass., USA) and subsequently tested for shear bond strength (MPa).

Results: ANOVA showed the presence of significant differences among the various groups. Post hoc Tukey test showed different values of shear bond strength for Fuji IX GP Extra and for Fuji II LC. The different conditioners variably influence the adhesion of the glass-ionomer cements tested. Conclusions. RMGIC shear bond to dentin was higher than GIC. The use of a Self-etch adhesive system improved the shear bond strength values of RMGIC and lowered the shear bond strength values of GIC significantly.