Oral cleaning habits and the copy number of periodontal bacteria in pregnant women and its correlation with birth outcomes: an epidemiological study in Mibilizi, Rwanda oleh Hiroaki Arima, Akintije Simba Calliope, Hideki Fukuda, Theoneste Nzaramba, Marie Goretti Mukakarake, Takayuki Wada, Takashi Yorifuji, Leon Mutesa, Taro Yamamoto