The laboratory comparison of shear bond strength and microscopic assessment of failure modes for a glass-ionomer cement and dentin bonding systems combined with silver nanoparticles

Purpose: More than half of the cavity restorations are replaced due to bacterial microleakage. A need for disinfection agents arises. Application of silver nanoparticles (AgNPs) may be beneficial, yet their impact on the adhesives' shear bond strength to dentin remains unknown. Methods: The aim was to assess the shear bond strength to dentin of different dental materials combined with AgNPs. Failure modes were also examined using SEM/FIB, SEM/EDS and endodontic microscopes. Results: The results showed no impact of AgNPs addition to dental materials in terms of shear bond strength to dentin. A change of the failure mode of the self-etch bonding system, Clearfil SE Bond, combined with AgNPs was observed. The new failure modes depended upon the order of application of the materials onto dentin. Conclusions: The microscopic evaluation of the samples showed the presence of AgNPs agglomerations gathered on the dentin's surface. AgNPs connection with self-etching dentin bonding system may have a serious clinical impact.