LPS removal from hydroxyapatite disks by Sonicare^TM or manual toothbrushes

Objective: An in vitro assay was utilized to compare the ability of a sonic and a manual toothbrush to remove Lipopolysaccharides (LPS) from hydroxyapatite (HA) disks. LPS or endotoxins are components of Gram-negative bacteria that are pyrogenic and comprise a portion of the salivary pellicle. The presence of LPS-laden pellicle on tooth surfaces is believed to contribute to the binding of oral bacteria in the formation of plaque. In addition, the presence of excess LPS is associated with inflammatory responses leading to tissue damage and eventually bone loss. Removal of LPS from tooth surfaces by conventional methods may greatly improve oral health and prevent disease. Methods: Hydroxyapatite disks were coated with 0.02 microgram/microliter of fluorescently labeled LPS in a pooled saliva solution and allowed to incubate 45-60 minutes in the dark. HA Disks (n=22) were brushed with either a sonic toothbrush or a manual toothbrush for 15 seconds while submerged under Ringer’s solution in a petri-dish. Digital microscopic images of the fluorescent disks were captured before and immediately after brushing each disk. The change in fluorescence was determined using an image analysis system. Results: HA disks brushed with the sonic brush resulted in a mean 47% reduction in fluorescence, as opposed to a 32% reduction in mean fluorescence resulting from using a manual toothbrush. These results were determined to be significantly different using a standard t-test (p=0.005). Conclusion: The data suggest that the sonic toothbrush removes LPS from the surface of hydroxyapatite disks more effectively than the manual toothbrush.