A Tooth-binding PEG-Based Molecular Brush for Dental Plaque Prevention

Objective: To develop a tooth-binding poly(ethylene glycol) (PEG) molecular brush for dental plaque prevention, using biodegradable pyrophosphate as the binding moiety. The hydrophilic PEG chain will effectively bind to the tooth surface and prevent saliva protein adsorption and thus inhibit pellicle glycoprotein-mediated S. mutans adhesion and biofilm development.

Method: The tooth-binding PEG brush was synthesized using acetylene modified PEG2000 and a diazide linker bearing pyrophosphate as building blocks through click chemistry. The tooth-binding kinetics of the PEG-based molecular brush were analyzed using hydroxyapatite (HA) as the model tooth surface. For in vitro S. mutans adhesion prevention studies, HA discs were pretreated with the tooth-binding PEG brush prior to incubation with saliva or saline. HA discs were then incubated with S. mutans UA159 for 1h, and subsequent S. mutans adhesion was assessed by calculating the colony forming units (CFU) recovered per disc. Specific differences between the log-CFU/disc of each experimental group were analyzed using the Student t-test. A p-value of < 0.05 was considered as statistically significant.

Result: The tooth-binding kinetics of the PEG-based molecular brush on HA was found to be fast (<1 min). In a S. mutans adhesion prevention study, the PEG brush successfully prevented bacterial adhesion on an HA surface after treatment with saline or human saliva when compared to controls which were not treated with tooth-binding PEG brush (4-fold and 2-fold reduction in CFU respectively, p<0.05).

Conclusion: This tooth-binding PEG brush demonstrated high HA binding capacity and fast HA binding kinetics. It was also successful in inhibiting initial S. mutans adhesion to clean and saliva treated HA surfaces in vitro. Collectively, these results suggest that this antimicrobial-free tooth-binding PEG-based molecular brush could provide an effective and safe tool for the prevention of dental plaque formation.