Bone powder enhances the effectiveness of bioactive glass S53P4 against strains of Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans in suspension

Abstract

Objective. To assess whether bone powder in suspension enhances the antimicrobial efficacy of bioactive glass S53P4 against Gram-negative microbiota commonly associated with peri-implant disease. Methods. Standardized suspensions of Porphyromonas gingivalis ATCC 33277 and YH 3, as well as Actinobacillus actinomycetemcomitans ATCC 29523 and KK 2 were added to 24-h suspensions of bioactive glass S53P4 with ground bovine bone powder, decalcified bone, or hydroxylapatite powder. Recovery of viable bacteria was assessed using anaerobic culture methods. As a reference, the antibacterial effect of an inert borosilicate powder with a particle size corresponding to that of the bioactive glass was tested. Counts of bacteria suspended in a pure unbuffered saline solution served as controls. Results. A significant drop in viable microorganisms was observed in suspensions of bioactive glass and bone powder compared to counterparts of pure bioactive glass. In contrast, neither the presence of hydroxylapatite powder nor the presence of decalcified bone in suspension caused any increase in bioactive glass killing efficacy on the microorganisms under investigation. Inert borosilicate glass showed no antibacterial effects per se or in combination with bone powder. Conclusion. The antimicrobial effect of a combined bioactive glass-ground bone powder suspension was an in vitro observation which should be confirmed using adequate in vivo models.