Shear bond strength of resin-modified glass ionomer cement with saliva present and different enamel pretreatments

The purpose of this study was to evaluate the shear bond strength of resin-modified glass ionomer cement in a saliva-contaminated environment, using different enamel pretreatments. A total of 125 freshly extracted, bovine permanent inferior incisors were divided into five groups. Group I received 10% polyacrylic acid, moistened with saliva/Fuji Ortho LC (FOLC); group II received 37% phosphoric acid, moistened with saliva/FOLC; group III was moistened with saliva/ FOLC, without acid etching; group IV received 10% polyacrylic acid, not moistened with saliva/ FOLC; and group V was used as a control with 37% phosphoric acid/dry/Transbond XT. After the bonding procedures, all samples were thermocycled, tested in a shear mode on a testing machine, and the Adhesive Remnant Index was evaluated. One-way analysis of variance and Tukey's honestly significant difference (HSD) tests indicated that group V yielded the highest shear bond strength (4.09 MPa) but with no statistically significant difference from group II (3.88 MPa). There were no statistically significant differences between groups I, III, and IV (2.84, 2.90, and 3.22 MPa, respectively) (P > or = .05). In groups I, II, IV, and V, where enamel was etched, more than 50% of the samples showed that all material adhered to the teeth surfaces. This was opposed to group III, where the bond failure was mostly between the enamel interface and the bonding material. The results indicated that in a saliva-moistened environment, FOLC achieved higher shear bond strength when 37% phosphoric acid is used, with no statistically significant difference from Transbond XT.