The effect of different strong acids and silica‐coating on resin Ti adhesion

Abstract

<p>The presence of Si on the Ti surface is quintessential for a strong, durable silane-based adhesion utilized in several dental applications. Silica-coating and silanization form durable ≡Si-O-Si≡ bonds, which might have a positive effect on resin-Ti adhesion. This laboratory study studied the effect of strong acids, their blends, and silica-coating on Ti and resin-Ti bonding. One-hundred sixty-eight c.p. grade 2 polished Ti samples (10 mm × 10 mm × 1 mm), out of which 96 were etched with 9% and 12%HF, a blend of 35%HCl+85%H<inf/>PO<inf/> and a blend of 69%HNO<inf/>+35%HCl at 60°C, each for 2 min. One half was silica-coated (Rocatec™ Plus, 110 μm SiO<inf/>-coated-Al<inf/>O<inf/>). Sixty Ti samples were first silica-coated, and then, 48 of them were etched with 9%HF, 12%HF, a blend of 35%HCl+85%H<inf/>PO<inf/>, and a blend of 69%HNO<inf/>+35%HCl at 60°C for 2 min. SEM, EDX, XPS, and R<inf/> analyses were carried out. Polished Ti samples were controls. All silanizations were carried out with a blend of 0.3 vol% 1,2-bis-(triethoxysilyl)ethane+1.0 vol% 3-acryloxypropyltrimethoxysilane. Multilink™ Automix self-adhesive resin composite cement was used in adhesion testing, and the samples were artificially aged followed by enclosed-mold micro-shear test on day 1 and weeks 1, 4, and 8. Failure mode analysis and statistical analysis with one-way/two-way ANOVA (p &lt; 0.05) were carried out. HF etching produced the highest surface roughness. XPS analysis identified after etching with HF a variety of Ti and Si ions: Ti<sup/>, Ti<sup/>, Ti<sup/>, and Ti<sup/> and, on the other hand, Si<sup/>, Si<sup/>, and Si<sup/>. A gradual decrease in adhesion strength was observed after artificial aging. Adhesive and cohesive failures were observed.</p>