IADR Abstract Archives
A Novel, Injectable Hydrogel for Endodontic Antimicrobial Delivery
Objectives: Microbial infection following root canal treatment is common: it is difficult to treat and, if allowed to progress, can lead to irreversible tissue damage and systemic infection. Hydrogels are used as therapeutic delivery systems due to their tuneable physical properties and good biocompatibility. These may have an application in endodontics as topical antimicrobial treatments, as systemic antibiotics are usually ineffective. This project aims to develop a novel, injectable, antimicrobial-loaded hydrogel for use in endodontic restorations with the aim of reducing the incidence of secondary microbial infections
Methods: Liposome MLVs and SUVs were prepared with the hydrophobic antimicrobial triclosan (50-500 µg/mL) and the encapsulation efficiency was measured using HPLC. Liposomes were incorporated into a methylcellulose solution and the rheological properties of the material were investigated, including viscosity, and viscoelasticity. The antimicrobial capability of the liposomes and the liposome-loaded hydrogels against clinical isolates of Enterococcus faecalis and Streptococcus anginosus was measured; both in vitro and in human root canals.
Results: Triclosan could be incorporated into liposomes (maximum concentration 120µg/mL) and liposome diameter showed a negative correlation with triclosan loading dose. The rheology showed that the polymer was a viscous solution at 25°C and formed a gel at temperatures above 35°C. This was unaffected by the addition of liposomes, irrespective of liposome size or concentration. Antimicrobial assays showed inhibited growth of S. anginosus and E. faecalis when cultured with antimicrobial liposomes in methylcellulose. Triclosan liposomes were shown to be more effective than free triclosan in some instances.
Conclusions: A potential hydrogel has been identified that has favourable physical properties for endodontic delivery and has an antimicrobial effect against common oral pathogens when combined with antimicrobial nanoparticles. This shows promise for a future application in restorative dental treatment, and further work aims to establish whether the material is suitable for vital pulp therapy.
Methods: Liposome MLVs and SUVs were prepared with the hydrophobic antimicrobial triclosan (50-500 µg/mL) and the encapsulation efficiency was measured using HPLC. Liposomes were incorporated into a methylcellulose solution and the rheological properties of the material were investigated, including viscosity, and viscoelasticity. The antimicrobial capability of the liposomes and the liposome-loaded hydrogels against clinical isolates of Enterococcus faecalis and Streptococcus anginosus was measured; both in vitro and in human root canals.
Results: Triclosan could be incorporated into liposomes (maximum concentration 120µg/mL) and liposome diameter showed a negative correlation with triclosan loading dose. The rheology showed that the polymer was a viscous solution at 25°C and formed a gel at temperatures above 35°C. This was unaffected by the addition of liposomes, irrespective of liposome size or concentration. Antimicrobial assays showed inhibited growth of S. anginosus and E. faecalis when cultured with antimicrobial liposomes in methylcellulose. Triclosan liposomes were shown to be more effective than free triclosan in some instances.
Conclusions: A potential hydrogel has been identified that has favourable physical properties for endodontic delivery and has an antimicrobial effect against common oral pathogens when combined with antimicrobial nanoparticles. This shows promise for a future application in restorative dental treatment, and further work aims to establish whether the material is suitable for vital pulp therapy.