Application of priming agents containing hydrophobic phosphate monomer (MDP) yielded the durable bond strengths of resin-based luting agents to a translucent zirconia material.

This study investigated bond strength of CAD/CAM-manufactured composite resin and ceramic veneers to a zirconia framework and analyzed the effect of treatments of veneer surfaces. A CAD/CAM resin-based (AVE) composite or lithium disilicate ceramic (IEC) block was used as the veneer material. AVE and IEC specimens were assigned to receive one of three surface treatments (n = 22): no surface treatment, acid-etching with 9.5% hydrofluoric acid gel, and airborne-particle abrasion with alumina particles. Zirconia disks and AVE or IEC specimens in each group were bonded with a resin-based luting agent, and shear bond strength of the specimens was measured at 0 and 20,000 thermocycles. Significant differences were assessed by the Steel-Dwass test for multiple comparisons and Mann-Whitney U-test (α = 0.05). As compared with other surface treatments, bond strengths were significantly higher at 0 and 20,000 thermocycles in the airborne-particle abraded AVE and acid-etched IEC specimens. Airborne-particle abrasion of the surface of AVE specimens increased bond strength between AVE veneers and zirconia frameworks, while hydrofluoric acid treatment enhanced bond strength between IEC veneers and zirconia frameworks.

This study examined the effect of silane and phosphate functional monomer on bond strengths between a resin-based luting agent joined to a lithium disilicate ceramic (IPS e.max) and silica (quartz) materials. The e.max and quartz specimens were assigned to 6 groups with different priming/bonding agents, namely, Clearfil Porcelain Bond Activator, Clearfil Photo Bond, Clearfil Photo Bond Universal with Clearfil Porcelain Bond Activator, Clearfil Photo Bond Catalyst with Clearfil Porcelain Bond Activator, Clearfil Photo Bond with Clearfil Porcelain Bond Activator, and unprimed. The corresponding specimens were bonded by using a resin-based luting agent (Panavia V5). Shear bond strengths were determined before and after 5,000 thermocycles. For both the e.max and quartz specimens, the Clearfil Photo Bond Universal with Clearfil Porcelain Bond Activator group had the highest pre- and post-thermocycling bond strength values. Combined use of silane in the acidic environment of a phosphate functional monomer and initiators enhances bond strength of a resin-based luting agent to e.max ceramic and quartz materials.

This study evaluated shear bond strengths of two gingiva-colored layering resin composites to zirconia frameworks coated with feldspathic porcelain. Airborne-particle abraded porcelain-coated zirconia disks were treated with one of the following primers: Clearfil Photo Bond, Clearfil Photo Bond with Clearfil Porcelain Bond Activator (CPB+Activator), Estenia Opaque Primer, Porcelain Liner M Liquid B (PLB), or no primer. A light-polymerizing (CER) or a photo/heat-polymerizing gingiva-colored indirect resin composite (EST) was bonded to the porcelain-coated zirconia disks in each group (n=11). Shear bond strength was measured. For both CER and EST specimens, bond strengths in CPB+Act group were significantly higher than those in the other groups. In all priming groups, bond strength was significantly higher for EST specimens than for CER specimens. Combined application of a phosphate monomer and silane enhanced initial bond strength of light-polymerized and photo/heat-polymerized gingiva-colored layering resin composites to porcelain-coated zirconia ceramics.

Characteristics of oxide inclusions in steel weld metals with varying acicular ferrite (AF) fractions, which were produced by gas metal arc welding using controlled CO2 (10%, 30%, and 50%) and titanium contents (by placing ultra-fine Ti wire), were statistically investigated. The correlation between identified phases in the oxide inclusions and AF formation was discussed from the viewpoint of AF formation mechanism. For high AF fraction samples, we confirmed that all oxide inclusions include Mn-Si-Al-Ti-O amorphous phases. By contrast, an amorphous phase was never observed for low AF fraction samples. Additionally, we confirmed that a few of the amorphous oxides created a Mn-depleted zone (MDZ), which suggested that the MDZ formed by Mn-Si-Al-Ti-O amorphous phase stimulates AF formation.