A Clinical Study on the Plaque Formation and Its Propagative Process

Abstract

In the present study, 12 dental students at Nihon University School of Dentistry were used. They were instructed to brush their maxillary and mandibular anteriors thoroughly for 10 minutes and, subseqently, their teeth remined unbrushed for 48 hours, in which time the formational processes of dental plaque were observed at 6 different intervals.In the initial time interval, the individual differences were particularly noted with the rate of plaque formation being anywhere form 21 to 27% after 4 hours. After the passage of 48 hours, however, the rate of plaque formation was just 4 to 10%. In terms of different teeth and surfaces, the labial surface of maxillary lateral incisors was the soonent in plaque formation in 13 to 16 hours after the brushing. followed by that of mandibular lateral incisors in 15 to 17 hours. The lingual surface of maxillary central incisors was the latest in plaque formation with the time lapse of 24 hours.Although there was no appreciable difference between the maxilla and mandible with regard to the labial surface, the mandible hed a tendency of a sooner plaque formation as regards the lingual surface.Propagative processes were not directly connected with an inadequate toothbrushing, and, in many cases, the tips of propagative plaques presented round appearances.