Adhesive-Cement Incompatibility: When Universal Adhesive is Not Universal

Objectives: It has been reported that aidic adhesives had low or no bond strength with self-cured cements, when used without a dual-cure activator. New universal adhesives are less acidic, and two of them (All-Bond Universal; Adhese Universal) are designed to be used without dual-cure activator. The purpose of this study is to evaluate the compatibility between universal adhesives and self-cured cements, without dual-cure activator.
Methods: Human dentin was polished, blot dried and treated with 2 different universal adhesives according to manufacturer’s instructions. Shear bond strength on dentin was tested using the ultradent jig method (bonding area 4.5mm²). Dual-cure resin cements which were either light cured (40sec/500mW/cm²) as a control or self-cured (15min/37C), were used to fabricate the posts (2mm-high). The specimens were stored in de-ionized water (37C/24hours), and tested by Instron tester (crosshead-speed 1mm/min). The data were analyzed statistically by two-way ANOVA and Student-t Tests. Two representative bonded interface were examined by SEM.
Results: Results are shown in Table 1 and Figure 1
Conclusions: All-Bond Universal is compatible with self-cured resin cements without a dual-cure activator, while Adhese Universal is not compatible with self-cured resin cements, resulting in lower bond strength and big gap formation.