Effect of seating forces on cement-ceramic adhesion in microtensile bond tests

The aim of this study was to evaluate the effect of different seating forces during cementation in cement-ceramic microtensile bond strength (μTBS).

Forty-five blocks (5 × 5 × 4 mm(3)) of a glass-infiltrated alumina-based ceramic (In-Ceram Alumina) were fabricated according to the manufacturer's instructions and duplicated in resin composite. Ceramic surfaces were polished, cleaned for 10 min in an ultrasonic bath, silica coated using a laboratory type of air abrasion device, and silanized. Each treated ceramic block was then randomly assigned to five groups (n = 9) and cemented to a composite block under five seating forces (10 g, 50 g, 100 g, 500 g, and 750 g) using a dual-cured resin cement (Panavia F). The ceramic-cement-composite assemblies were cut under coolant water to obtain bar specimens (1 mm × 0.8 mm(2)). The μTBS tests were performed in a universal testing machine (1 mm/min). The mean bond strengths values were statistically analyzed using one-way ANOVA (α ≤ 0.05).

Different seating forces resulted in no significant difference in the μTBS results ranging between 13.1 ± 4.7 and 18.8 ± 2.1 MPa (p = 0.13) and no significant differences among cement thickness.

Excessive seating forces during cementation seem not to affect the μTBS results.

Excessive forces during the seating of single all-ceramic restorations cementation seem to display the same tensile bond strength to the resin cement.