Bonding performance of dispersed filler resin composite CAD/CAM blocks with different surface treatment protocols

Abstract

The effect of various pretreatments on the bonding of a resin cement to resin-composite CAD/CAM blocks (RCBs) was examined. The surface of dispersed-filler RCBs (DF-RCBs) and a polymer infiltrated ceramic network RCB (PICN-RCB) was roughened using hydrofluoric acid etching (HF) or sandblasting, and followed by silanization and/or universal adhesive (UA) application. Microtensile bond strength (µTBS), surface roughness parameters (arithmetical mean height (Sa); developed interfacial area ratio (Sdr)), and critical surface energy (γc) were determined. For most DF-RCBs, the highest µTBS was obtained using HF+UA. UA application to DF-RCBs resulted in similar or higher µTBS compared to silanization, which indicates that silane treatment is not crucial for DF-RCBs, especially after HF. In contrast, the highest µTBS to PICN-RCB was obtained with silanization. Both roughening pretreatments significantly increased the surface roughness parameters and the γc of all RCBs. The γc was positively correlated with Sa (r=0.756, p<0.001) and Sdr (r=0.837, p<0.001).

Shear Bond Strength of a Direct Resin Composite to CAD-CAM Composite Blocks: Relative Contribution of Micromechanical and Chemical Block Surface Treatment

“…Sandblasting significantly increased the SBS values for the dispersed filler composites and PICN. The aim of air abrasion is to increase the surface roughness of the material by creating random irregularities in the matrix, thereby increasing the surface energy [ 2 , 29 ]; this also improves the wettability of the resin composite, which leads to better anchoring by micro-retention [ 30 ]. Sandblasting a CAD-CAM resin also has other advantages, such as cleaning the bonding surface after saliva contamination due to a try-in simulation by providing a fresh and clean surface [ 31 ].…”

Shear‐bond strength and optical properties of short fiber‐reinforced CAD/CAM composite blocks

“…These findings are in line with previous studies [31][32][33], which proved that air-particle abrasion seems to be the best surface treatment option for indirect composites. On the other hand, some studies suggested that, hydrofluoric acid etching is the best surface treatment method for certain types of CAM/CAM composites [34,35]. Other investigations have proved that air-particle abrasion could cause damage to the surface and cracks to the subsurface, which compromises restoration long-term durability; moreover, the exposure of restoration margins to air-particle abrasion could result in marginal gap, which is unacceptable clinically [36].…”

MDP Salts: A New Bonding Strategy for Zirconia

“…The surface topography was assessed with a 3-dimensional confocal laser scanning microscope (VK-X150; Keyence) with a red semiconductor laser (658 nm) at a 50× lens (scanning area, 205 × 273.3 μm) for 9 specimens per group. The roughness parameters (Sa, arithmetical mean height; Str, texture aspect ratio; Sdr, developed interfacial area ratio; Abdou et al 2021) were measured for each specimen 3 times, and the average value was used as the sample mean for statistical analysis. The scanned surface plots were processed with a MultiFile Analyzer (version 1.3.1.120; Keyence).…”

“…Additionally, universal adhesives with MDP acidic monomer and silane were recommended to achieve effective bonding not only to tooth structure but also to glass ceramics, zirconia, and alloys (Xie et al 2016; Yoshihara et al 2016; Van Meerbeek et al 2020). The application of pure MDP on the air-abraded zirconia surface with alumina particles is the essential pretreatment to achieve the required reliable ceramic-resin bond (Attia and Kern 2011; De Souza et al 2014; Inokoshi, De Munck, et al 2014; Koko et al 2020; Khanlar, Abdou, et al, 2021; Khanlar, Takagaki, et al 2021). The MDP molecule has a phosphoric acid group at one end of the molecule, which acts as an adhesion promoter for metal oxides such as alumina and zirconia, as well as a vinyl group at the other end, which facilitates polymerization with unsaturated carbon bonds in the resin matrix (Nagaoka et al 2017; Yoshihara et al 2019).…”