Journal of Dental Research, Vol 66, 761-765, Copyright © 1987 by International & American Associations for Dental Research Online Journals
A 30-month longitudinal study of the effects of some oral hygiene measures on Streptococcus mutans and approximal dental caries
P. Axelsson, K. Kristoffersson, R. Karlsson and D. Bratthall
The effects of some oral hygiene measures on Streptococcus mutants and
approximal dental caries were evaluated. One hundred and eighty-seven
13-year-old individuals with high levels of salivary S. mutans (greater
than 10(6)/mL) were selected. They were randomly distributed into three
groups. Group I initially received professional mechanical tooth-cleaning,
tongue-scraping, chlorhexidine treatment, and oral hygiene instructions
concentrated on the approximal surfaces most colonized by S. mutans. The
treatment was given four times with intervals of two days, followed by one
single treatment every six months throughout the experimental period. The
initial treatment period for group II, also consisting of four visits,
included the same oral hygiene instructions as for group I. The
instructions were repeated every six months. Group III was maintained in
the preventive program provided by the local Dental Health Office, based on
mechanical plaque control and topical use of fluorides and chlorhexidine at
individualized intervals. Group I showed a significant immediate reduction
of S. mutans in saliva as well as an approximal tooth surfaces. After six
months, there were no differences among the three groups regarding these
variables. Compared with baseline, there was a significant reduction of S.
mutans in all groups. There was no significant difference in caries
progression among the three groups. However, the selected "high-risk"
individuals in group I developed 0.25 new manifest caries lesions
approximally/year, compared with 0.27 for all children of the same age
group in the area. Seventeen individuals had approximal surfaces with
consistently high or consistently low S. mutans levels. Forty-six percent
of the surfaces with high values developed new or progressive caries,
compared with 2% of the surfaces with low values.
