1. Department of Pediatric Dentistry and Institute of Oral Bioscience, Chonbuk National University, Duckjingu, Jeonju-si, Jeollabuk-do, Korea.
2. Department of Oral Microbiology, School of Dentistry, Chonbuk National University, Duckjingu, Jeonju-si, Jeollabuk-do, Korea.