Haemophili in developing dental plaque.

Evidence for a possible role played by oral haemophili in the development of dental plaque was sought by studying the occurrence of these bacteria in early dental plaque of smooth surfaces and occlusal fissures in six dental students. The mean number of haemophili per 10(3) anaerobes in early smooth surface plaque (18 h) and fissure plaque (7 d) was 95 and 22 respectively. Examination of 988 Haemophilus isolates revealed that H. parainfluenzae was the only species in samples of fissure plaque, whereas some samples from smooth surfaces, in addition to the predominating and ubiquitous H. parainfluenzae, yielded growth of the two species H. segnis and H. aphrophilus. It is concluded that haemophili are among the primary colonizers of smooth surfaces of teeth.