Use of an oxygen planar optode to assess the effect of high velocity microsprays on oxygen penetration in a human dental biofilms in-vitro

Abstract

Background: Dental plaque biofilms are the causative agents of caries, gingivitis and periodontitis. Both mechanical and chemical strategies are used in routine oral hygiene strategies to reduce plaque build-up. If allowed to mature biofilms can create anoxic microenvironments leading to communities which harbor pathogenic Gram-negative anaerobes. When subjected to high velocity fluid jets and sprays biofilms can be fluidized which disrupts the biofilm structure and allows the more efficient delivery of antimicrobial agents. Methods: To investigate how such jets may disrupt anoxic niches in the biofilm, we used planar optodes to measure the dissolved oxygen (DO) concentration at the base of in-vitro biofilms grown from human saliva and dental plaque. These biofilms were subject to "shooting" treatments with a commercial high velocity microspray (HVM) device. Results: HVM treatment resulted in removal of much of the biofilm and a concurrent rapid shift from anoxic to oxic conditions at the base of the surrounding biofilm. We also assessed the impact of HVM treatment on the microbial community by tracking 7 target species by qPCR. There was a general reduction in copy numbers of the universal 16S RNA by approximately 95%, and changes of individual species in the target region ranged from approximately 1 to 4 log reductions. Conclusion: We concluded that high velocity microsprays removed a sufficient amount of biofilm to disrupt the anoxic region at the biofilm-surface interface.

A Combination of Zinc and Arginine Disrupt the Mechanical Integrity of Dental Biofilms

“…Saliva-plaque inoculum collection. Saliva plaque was collected from healthy individuals according to protocols approved by the Ohio State University (OSU) Institutional Review Board (IRB) (number 2017H0016, 03/22/2017) (39). Collected samples were pooled and separated into 1 mL aliquots supplemented with 30% glycerol.…”

ROS-scavenging biomaterials for periodontitis

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Detection and Characterization of Bacterial Biofilms and Biofilm-Based Sensors

“…Optical imaging systems based on confocal and fluorescence microscopy involving planar optodes (i.e., polymeric films embedded with oxygen-sensitive luminescent probes) and labeled micro- and nanoparticles have been used to detect changes of oxygen and pH in the biofilm. Since planar optodes are 2D polymer films on which the cells adhere to form the biofilm, they cannot reveal information inside the biofilm, − , whereas micro- and nanoparticles doped with fluorescent or luminescent dyes (that are sensitive to pH or oxygen changes in the biofilm) can be dispersed inside the EPS matrix, thereby providing 3D mapping of the oxygen concentration and pH inside the biofilm. Their nondestructive nature also offers reduced stress for in situ studies of the biofilm. − Fluorescent probes have also been used to detect heavy metal (Fe 3+ , Cu 2+ , Zn 2+ , and Hg 2+ ) adsorption by bacterial biofilms that are relevant to bioremediation applications …”