In vitro antibiofilm activity of eggshells derived nano-hydroxyapatite (nHA) against Staphylococcus aureus and Streptococcus mutans

Dental caries, a highly prevalent oral health condition worldwide, is primarily driven by the biofilm-forming abilities of Staphylococcus aureus and Streptococcus mutans. The interest in eggshell extracts has grown in recent years due to their potential benefits for oral health. Therefore, this study investigated the potential of nano-hydroxyapatite (nHA) derived from eggshells in combating bacterial infections and inhibiting biofilm formation by the selected cariogenic bacteria. The antibacterial activity of the nano-hydroxyapatite extract was initially assessed using the agar well diffusion method. Subsequently, biofilm inhibition was evaluated through crystal violet assays, and the disruption of biofilm structure was visualized under a light microscope. The findings indicated that the nano-hydroxyapatite extract lacked antibacterial activity in inhibiting the growth of both S. aureus and S. mutans. However, the extract demonstrated antibiofilm activity against mono-species biofilms, with observed disruption of biofilm formation upon treatment. As a result, nano-hydroxyapatite extracts derived from eggshells may hold potential as agents for inhibiting biofilm formation associated with dental caries.