More recent studies using molecular methods and a retrievable enamel chip model have revealed a new line-up of initial colonizers though the early dental plaque microflora varies at subject-specific basis (Diaz et al., 2006; Kolenbrander et al., 2005). In initial plaque on the chip at four to eight hours, Streptococcus spp. was dominant while Veillonella, Gemella, Prevotella, Niesseria, Actinomyces and Rothia were also frequently found. Among streptococci, S. oralis, S. mitis, S. infantis, S. sa