Performance Profile of Different Self-adhesive Resin Cements

OBJECTIVES: The purpose of this in vitro investigation was to compare different self-adhesive resin cements regarding the degree of neutralization, exogenic staining (coffee) and bond strength to enamel, dentin and zirconia to create a comprehensive performance overview.

METHODS: Materials tested were Maxcem™Elite (Kerr), SmartCem™2 (Dentsply), iCem® (Heraeus Kulzer) and universal self-adhesive resin cement RelyX™ Unicem Clicker™ (3M ESPE).

For shear bond strength (SBS) testing bovine teeth were ground, polished (600grit sandpaper), water-rinsed and air-dried. In case of zirconia (Lava, 3M ESPE), discs (15 x 3.5 mm) were pre-treated as recommended by manufacturers. Stainless steel rods were cemented under pressure (20 g/mm²) onto teeth and zirconia discs. After light-curing (lc) following the manufacturers' instructions, specimens were stored for 24h at 37°C and 100% relative humidity. SBS was measured using a universal testing machine (Zwick Z010, crosshead speed: 0.75 mm/min). Exogenic staining was tested using lc (20s each side + 7min light furnace) cement discs (15 x 1.5 mm). After storing in a coffee solution for 72 h at 36°C, color of the discs was determined with a 0°/45°C-color measuring device (Hunterlab LabScan) and ΔE values were calculated. The degree of neutralization was determined by measuring the increase of pH of the mixed cement within 24h (ΔpH) using pH indicator sticks (Fisherbrand).

Data obtained were analyzed using Multiple Range Test (Fisher's LSD; p<0.05).

RESULTS: see table

CONCLUSION: RelyX Unicem Clicker shows the best performance profile with excellent results in all tested material properties compared to all other cements in this study. A high degree of neutralization as indicated by a high ΔpH-value contributes to the longevity of the cementation.