CDA Essentials 2018 • Volume 5 • Issue 8

1) 2) 3) Face Mask Performance: Are You Protected? John A. Molinari, Ph.D. and Peri Nelson, B.S. Dental Consultants, Inc., Ann Arbor, Michigan Safe Mask ® Customized Comfort and Protection OBJECTIVES: The objectives of this study were to: Assess how extended use of different levels of uid-resistant mask affects microbial penetration; Evaluate the penetration resistance of Medicom Safe+ face masks during speci c intervals to aerosolized “red” spatter ( uid resistance), and resistance to aerosolized mixtures of water soluble red dye mixed with a representative bacterial species (bacterial ltration); and Compare the penetration effectiveness of the Medicom Safe+ masks to that demonstrated for similarly tested masks from other manufacturers. 1 2 3 ask resistance to bacterial penetration was studied using an enclosed, specially fabricated 4’ x 3.5’ x 3’ chamber around a dental chair (Figure 1). A mannequin head was mounted on a rod and tted with a test mask before each experiment. One investigator held the mannequin head in the chamber in front of a “patient” mannequin head (Dexter) with full dentition during testing. A mixture of water-soluble red dye and S. marcescens was placed in the mannequin’s oral cavity. This uid served as the “patient’s saliva.” The second mannequin head tted with the worn face mask was mounted approximately 12” in front of the mouth of the “patient.” This masked head represented a dental clinician using a high-speed handpiece during treatment. The mannequins were exposed to aerosolized preparations of the red dye/bacteria mixture for periods of either 5, 15, or 30 minutes. To accomplish this, a dental water-driven high speed handpiece was run by an investigator in the mouth of the patient mannequin, touching teeth and creating aerosolized spatter. The masked mannequin was positioned as a clinician would be during treatment, in order that airborne droplet spatter from the “patient’s mouth” would contact the test masks as per clinical procedures. Handpieces were run for 30-second intervals until total exposure times were reached. Masks were subsequently removed from the mannequin heads and visually inspected for detection of red spatter on the outside and inside portions of the mask. Sterile cotton swabs moistened in tryptic soy broth were also used to culture the outside and inside surfaces of the masks. Aerobic S. marcescens microbial growth was evaluated by culturing collected specimens onto tryptic soy agar plates at room temperature for 48-72 hours. Bacterial growth patterns were then observed for the experimental exposure intervals with each mask type tested. M This article is sponsored content from Medicom.