1. Department of Operative Dentistry, Nihon University School of Dentistry at Matsudo , Matsudo, Japan
2. Department of Oral Microbiology, Nihon University School of Dentistry at Matsudo , Matsudo, Japan
3. Department of Biological and Medical Sciences, Rochester Institute of Technology , Rochester, NY, USA
4. Department of Pediatric Dentistry, University of Alabama at Birmingham , Birmingham, AL, USA
5. Department of Microbiology, University of Alabama at Birmingham , Birmingham, AL, USA