A Novel Combined Silica-Coating and Etching Protocol for Titanium for Improved Adhesion

Abstract

Durable adhesion between resin composite cement and Ti prostheses is critical for a long clinical life in dentistry. A rough surface is a prerequisite for mechanical interlocking and a special coating method, silica-coating must be followed by silanation for chemical adhesion. Commercially pure grade-2 Ti specimens were modified by silica-coating and silanized with an experimental silane blend primer or two commercially available silane primers. Specimens were assigned randomly: Group-A (control; polished only Ti), Group-B (polished Ti + silica-coating + primers), Group-C (polished Ti + etching with HNO3 + with or without primers), Group-D (polished Ti + silica-coating + etching with HNO3 + with or without primers), Group-E (polished Ti + etching with HCl+H(3)PO4 + with or without primers), and Group-F (polished Ti + silica- coating + etching with HCl+H3PO4 + with or without primers). Next, Ti specimens were analyzed for their atomic concentration by electron dispersive spectroscopy (EDX). BisCem(TM) resin cement was used to build up enclosed mold stubs onto the Ti specimens. Enclosed mold micro-shear bond strength (EM-mu SBS) was measured after storage in distilled water for 1 day, 1 week, 4 weeks, and 8 weeks. A combined treatment employing silica-coating + the blend HCl+H3PO4 had a more substantial effect on Ti surface roughness when compared to other surface pretreatments. Whereas, the highest EM-mu SBS values were observed in Group-D from week 1 to week 8. A novel combined dual surface modification creates higher surface roughness on Ti, and this might significantly improve the durability of resin-Ti adhesion.