An Analysis of the Periodontopathic Bacteria Involved in Extrinsic Discoloration of Teeth

Recent dental esthetics are paying attention to whitening. Many people take an interest in tooth color, and wish to remove extrinsic discoloration. While a relationship between tooth discoloration and periodontopathic bacterial prevalence has been suggested, such a relationship has not been clearly elucidated. The aim of the present study was to clarify the relationship between the periodontopathic bacteria present in plaque and tooth discoloration. Plaque samples were taken from 54 subjects whose tooth color was evaluated using a shade guide. The subjects were then divided into a white group (30 women) and a discolored group (24 women). Using bacterial DNA prepared from the plaque samples as a template, polymerase chain reaction was performed with specific primers to identify the presence of five periodontopathic bacteria ( Aggregatibactor actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola and Prevotella intermedia ). The numbers of the bacterial species were counted and the percentage of the subjects that were carriers of each bacterium was calculated. In addition, the mean number (± SE) of periodontopathic bacterial species per person was calculated as 1.23 (± 0.15) and 2.04 (± 021) in the white and discolored groups, respectively, and there was a significant difference between these two groups ( p < 0.01). We thus found a positive relationship between superficial tooth color and the number of periodontopathic bacterial species.