The effect of dentin age on the microshear bond strength and microleakage of glass-ionomer cements

To compare the microshear bond strength (µSBS) and microleakage of glass-ionomer cements when bonded to aged and young dentin.

Glass-ionomer cement (GIC) is frequently used to restore root caries in elders. Many studies of GIC have been conducted using young dentin; however, few studies have assessed adhesion and microleakage of GICs to aged dentin.

Seventy-eight non-carious human molars (patient age 16-30 = 39; patient age ≥ 65 = 39) were tested with three GICs (Fuji II LC, Equia Forte Fil and Fuji BULK). For µSBS, teeth were horizontally sectioned, embedded in resin and three tubes attached to the sectioned surface. Materials were mixed and injected into the tubes, allowed to set and the tubes removed leaving the GIC cylinders. Specimens were stored in deionised water for 24 hours and tested in a universal testing machine. For microleakage, a buccocervical cavity was prepared, restored with GIC and stored in deionised water. The specimens were polished, coated with varnish, placed in 0.5% basic fuchsin for 24 hours, sectioned at the midpoint and evaluated for microleakage under a stereomicroscope and scanning electron microscope.

For µSBS, Fuji II LC showed the highest bond strength among three products. There was no significant difference between age groups. (P = .93) For microleakage, Fuji II LC had more dye penetration (P < .01) and there was significant difference between age groups.

After bonding of GICs, aged dentin showed no difference in µSBS but less microleakage when compared to young dentin.