Coated dental floss as a novel instrument for drug delivery to the Gingival Mucosa: Development, characterization, and In vivo delivery

Gum disease is a polymicrobial tissue infection observed as a continuum of disease beginning with gingivitis evolving to more severe periodontitis. Advanced stages of the disease can lead to facial disfigurement and pose risk for development of heart disease and stroke. Treatment options consist of a variety of modalities including scalar root planning, systemic or localized medication, and surgery; however, no treatment is completely effective due to special conditions and bacterial persistence. The purpose of this dissertation is to introduce novel drug-coated floss to deliver therapeutics directly to the site of gingival bacterial infection. This modality is expected to provide the least invasive and most effective delivery of medication to the gingival pocket. First, different types of flosses and sutures were collated and characterized for use. This analysis elevated un-waxed nylon braided floss for advanced examination where floss was coated using a custom designed and fabricated coating system containing a coating solution reservoir and specialized floss-holder. Then floss was coated with drug in either free form or after encapsulation in poly(lactic-co-glycolic) acid nanoparticles (NPs). Initial study of drug coating delivery efficiency proved surface modification required before coating drug atop to improve drug delivery to the gum pocket. Upon surface modification, observations in delivery efficiency showed near complete coating debridement from floss and almost a doubling in the amount of drug delivered to the gingival pocket. Then, characterization of floss coatings showed that by varying the dip count or altering the coating formulation an increase coated drug mass and a change in coating thickness could be observed. The study in changing coating thickness proved a reduction in delivery efficiency upon reaching a thickness threshold indicating an optimum coating thickness for a high rate of drug delivery. Characterization of response of coating under load showed resiliency in drug coating proving coated floss could be manually manipulated and floss coatings were not so fragile to debride spontaneously or readily. Then testing of drug coating capability showed drugs possessing different physicochemical properties were capable of being simultaneously coated and delivered with similar efficiency as that of a single drug coating. Finally, coated floss was delivered in vivo without food or water being withheld and no special conditions applied. Results showed delivery efficiency to the pocket reached 72% and continued drug residency within the pocket at 8 h after application. In summary, the content of this dissertation shows floss can be coated with drug and drug coatings can be delivered to the gingival pocket. Results support this approach as evidence for practical application of drug coated floss for practitioners and individuals alike.

Embargo status: Restricted until 09/2024. To request the author grant access, click on the PDF link to the left.