| 2019–present | Thomas W. Evans Centennial Professor, Dept. of Basic and Translational Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA |
| 2015–2019 | Thomas W. Evans Centennial Professor, Dept. of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA |
| 2012-2014 | Professor, Dept. of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA |
| 2010- 2011 | Professor and Distinguished University Scholar, Dept. of Oral Health and Rehabilitation, Associate Director, Center for Oral Health and Systemic Disease Oral Health and Systemic Disease Research Group, University of Louisville School of Dentistry; Joint appointment to Dept. of Microbiology and Immunology, School of Medicine, University of Louisville, Louisville, KY |
| 2008-2010 | Professor and University Scholar, Dept. of Periodontics, Endodontics, & Dental Hygiene, Oral Health and Systemic Disease Research Group, University of Louisville School of Dentistry; Joint appointment to Dept. of Microbiology and Immunology, School of Medicine, University of Louisville, Louisville, KY |
| 2005-2008 | Associate Professor (tenured) and University Scholar, Dept. of Periodontics, Endodontics, & Dental Hygiene, Oral Health and Systemic Disease Research Group University of Louisville School of Dentistry; Joint appointment to Dept. of Microbiology and Immunology, School of Medicine, University of Louisville, Louisville, KY |
| 2003-2005 | Assistant Professor, Dept. of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center (LSUHSC), New Orleans, LA |
| 2002-2003 | Research Assistant Professor, Dept. of Oral Biology, SUNY at Buffalo, School of Dental Medicine, Buffalo, NY |
| 2000-2002 | Research Fellow, Dept. of Oral Biology, State University of New York (SUNY) at Buffalo, School of Dental Medicine, Buffalo, NY |
| 1997-1999 | Research Assistant Professor, Dept. of Oral Biology, School of Dentistry, UAB, Birmingham, AL |
| 1996-1997 | Research Associate, Dept. of Microbiology, UAB, Birmingham, AL |
| 1994-1996 | Post-doctoral Research Fellow, Immunology, Dept. of Microbiology, UAB, Birmingham, AL |
| 1990-1994 | Graduate Student, Cellular & Molecular Biology Program, Dept. of Microbiology, UAB, Birmingham, AL |
