Silane-coupling effect of a silane-containing self-adhesive composite cement

Objective: Hydrofluoric-acid etching followed by silanization is a routine clinical protocol for durable bonding to glass ceramics. Simplifying ceramic-bonding procedures, new technological developments involve the inclusion of a silane coupling agent in a self-adhesive composite cement. To investigate the effectiveness of the incorporated silane coupling agent, shear bond strength (SB) to ceramic and dentin, contact angle of water (CA), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Si-29 nuclear magnetic resonance (NMR) assessments were correlatively conducted. Materials and Methods: SB to glass ceramic was measured without ('immediate') and with ('aged') 50K thermocycles upon application of (1) the silane-containing self-adhesive composite cement Panavia SA Cement Universal ('SAU'), being light-cured: 'SAU_light', (2) 'SAU_chem': chemically cured SAU, (3) 'SAP_light': light-cured Panavia SA Cement Plus ('SAP'), and (4) 'SAP_CP': SAP light-cured after separate silanization using Clearfil Ceramic Primer Plus ('CP'). CA was also measured on glass ceramic. The cement pastes before and upon mixing were characterized using Si-29 NMR. SB of SAU or SAP onto dentin was measured. Finally, the cement-dentin interface was characterized by TEM and XRD. Results: The immediate and aged SB to glass ceramic of SAU did not significantly differ from those of SAP_CP, while they were significantly higher than those of SAP. CA of SAU did not significantly differ from that of SAP_CP, but it was significantly higher than CA of SAP. Si-29 NMR revealed siloxane bonds after mixture. SB of SAU and SAP to dentin did not show any significant difference. SEM, TEM and XRD confirmed tight and chemical interaction, respectively. Significance: Incorporating silane in a 10-MDP-based self-adhesive composite cement combined efficient silane-coupling ability at the ceramic surface with effective bonding ability at dentin. (C) 2020 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.