Chlorhexidine-loaded bioactive glass for incorporation into adhesive systems: Mechanical properties, antibacterial activity, cell viability, and hydroxyapatite precipitation

To evaluate the effect of chlorhexidine-functionalized bioactive glass (45S5) addition on mechanical and bioactive properties of experimental self-etching adhesives. The bond of two-step self-etching adhesives were used in the following groups: (1) Magic Bond (commercial control – hydrophobic adhesive); (2) Experimental bond without bioglass (experimental control); (3) Experimental bond + 5% 45S5 glass (wt%); (4) Experimental bond + 20% 45S5 glass (wt%); (5) Experimental bond + 5% chlorhexidine-functionalized 45S5; (6) Experimental bond + 20% chlorhexidine-functionalized 45S5. Hourglass-shaped specimens were made to obtain data on mechanical properties (cohesive strength and elastic modulus). Adhesive discs were made for bacterial activity evaluation using Streptococcus mutans UA159 biofilms. The materials’ cell viability (%) was tested using the MMT assay technique. For the evaluation of mineral precipitation, adhesive discs were made, kept in PBS for 28 days and used for SEM/EDS analyses. The 45S5 CHX group (20%) presented the lowest values of mechanical properties (p