IADR Abstract Archives
In Vitro Oral Biofilm Model to Assess the Efficacy of Antimicrobial Additives to Dental Restorative Materials
Objectives: Our study is aimed at developing a robust in vitro oral biofilm model to determine the effectiveness of enhancing dental restorative materials with antimicrobial additives. It is focused on the antibacterial and mechanical properties of novel silver formulations that have been combined with glass ionomer cement.
Methods: Three out of nine bacterial species considered to be early colonizers (Streptococcus oralis, Streptococcus mutans, & Neisseria subflava) were inoculated at 0.1 OD600 into wells containing sterile glass-ionomer discs. The established artificial saliva media DMM (Defined Medium Mucin) was used for 24 hours studies conducted under aerobic & anaerobic conditions. Following incubation the discs were washed with PBS (Phosphate Buffer Saline) in a series of 12 minute up to five steps. The bacterial community within the well, the loosely attached to the well surface and the disc, and finally the intimately attached to the surface were determined using Colony Forming Unit Count (CFUs), MTT metabolic assay, SEM and qPCR.
Two silver solutions were developed with different ionic concentrations, 5mg/ml and 10mg/ml. MIC/MBC and the effect on the ability of the bacterial species to survive and colonize a disc was determined.
In addition compressive strength, hardness and adhesive shear bond strength of each glass-ionomer silver disc was assayed and compared with the base line glass-ionomer.
Results: The biofilm model favoured survival of S. oralis under aerobic conditions & N. subflava and S. oralis under anaerobic conditions. Silver formulations proved to have effects on strength and antimicrobial activity. Specifically 5mg/ml proved more antibacterial than a 10mg/ml silver.
Compressive strength was enhanced for both additive, however bond strength became compromised at the higher concentration
Conclusions:
This model proved its efficiency to test the antibacterial activity of restoratives materials in the presence of artificial saliva and the extra washing steps which mimic the sheer force of saliva.
Augmentation of glass ionomer cement with silver and having a stable formulation with enhanced antibacterial and strength within our biofilm assay will form the basis for further studies.
Methods: Three out of nine bacterial species considered to be early colonizers (Streptococcus oralis, Streptococcus mutans, & Neisseria subflava) were inoculated at 0.1 OD600 into wells containing sterile glass-ionomer discs. The established artificial saliva media DMM (Defined Medium Mucin) was used for 24 hours studies conducted under aerobic & anaerobic conditions. Following incubation the discs were washed with PBS (Phosphate Buffer Saline) in a series of 12 minute up to five steps. The bacterial community within the well, the loosely attached to the well surface and the disc, and finally the intimately attached to the surface were determined using Colony Forming Unit Count (CFUs), MTT metabolic assay, SEM and qPCR.
Two silver solutions were developed with different ionic concentrations, 5mg/ml and 10mg/ml. MIC/MBC and the effect on the ability of the bacterial species to survive and colonize a disc was determined.
In addition compressive strength, hardness and adhesive shear bond strength of each glass-ionomer silver disc was assayed and compared with the base line glass-ionomer.
Results: The biofilm model favoured survival of S. oralis under aerobic conditions & N. subflava and S. oralis under anaerobic conditions. Silver formulations proved to have effects on strength and antimicrobial activity. Specifically 5mg/ml proved more antibacterial than a 10mg/ml silver.
Compressive strength was enhanced for both additive, however bond strength became compromised at the higher concentration
Conclusions:
This model proved its efficiency to test the antibacterial activity of restoratives materials in the presence of artificial saliva and the extra washing steps which mimic the sheer force of saliva.
Augmentation of glass ionomer cement with silver and having a stable formulation with enhanced antibacterial and strength within our biofilm assay will form the basis for further studies.