IADR Abstract Archives
The Effect of Hydration on the Stability of Oral Plaque Morphology and Mechanics
Objectives: Oral plaque biofilms exhibit varying dynamic, de- and re-hydration cycles in the oral cavity, due to intermittent periods of salivary flow, the consumption of drinks and conditions such as sjrögens syndrome. Their state of hydration can influence morphology and mechanical properties, with those that are dry exhibiting flattened structures with greater mechanical properties than those that are hydrated (Powell et al. 2013, Lau et al. 2009). Before the mechanical effects of such hydration cycles on biofilms can be determined, researchers must identify how different biofilms behave through drying and subsequent hydration, in-vitro. This change in structural and mechanical properties has yet to be mapped as a function of hydration time.
Methods: Mixed species plaque biofilms (n=12), with low (0.1% w/v) and high (5% w/v) sucrose concentrations were grown on hydroxyapatite (HAP) disks and incubated for 5 days. Optical coherence tomography (OCT) was used to observe biofilm morphology after 1 hour air drying and for 100 minutes at 110s intervals under liquid conditions. Atomic force microscopy was then employed to monitor their mechanical properties in terms of Young’s Modulus (Es) and adhesion (Ad) at 1 minute intervals for 100 minutes under liquid conditions.
Results: OCT showed increased biofilm heights with increasing sucrose concentration across the hydration regime. AFM showed significant differences in biofilm Es and Ad at baseline with increased sucrose concentration exhibiting significantly lower Es and higher Ad compared to those with low sucrose. Lower sucrose fed biofilms exhibited a faster stabilization of mechanical properties (60 minutes) compared to those fed with higher sucrose (90 minutes).
Conclusions: While most studies use hydration times of approximately 30-60 minutes before monitoring a biofilms mechanical properties, this study has shown that different biofilms exhibit different stages of stabilization. Those with higher sucrose diets have been shown to require longer stabilization times than those with lower sucrose.
Methods: Mixed species plaque biofilms (n=12), with low (0.1% w/v) and high (5% w/v) sucrose concentrations were grown on hydroxyapatite (HAP) disks and incubated for 5 days. Optical coherence tomography (OCT) was used to observe biofilm morphology after 1 hour air drying and for 100 minutes at 110s intervals under liquid conditions. Atomic force microscopy was then employed to monitor their mechanical properties in terms of Young’s Modulus (Es) and adhesion (Ad) at 1 minute intervals for 100 minutes under liquid conditions.
Results: OCT showed increased biofilm heights with increasing sucrose concentration across the hydration regime. AFM showed significant differences in biofilm Es and Ad at baseline with increased sucrose concentration exhibiting significantly lower Es and higher Ad compared to those with low sucrose. Lower sucrose fed biofilms exhibited a faster stabilization of mechanical properties (60 minutes) compared to those fed with higher sucrose (90 minutes).
Conclusions: While most studies use hydration times of approximately 30-60 minutes before monitoring a biofilms mechanical properties, this study has shown that different biofilms exhibit different stages of stabilization. Those with higher sucrose diets have been shown to require longer stabilization times than those with lower sucrose.