Prevalence of cariogenic streptococci on incisor brackets detected by polymerase chain reaction.
BACKGROUND
Streptococcus mutans and Streptococcus sobrinus are the main causative organisms for enamel demineralization during orthodontic treatment. In this study, we analyzed the prevalence of cariogenic streptococci adhering to incisor brackets.


METHODS
Four incisor brackets from both the maxilla and the mandible were collected from 80 patients at debonding, immediately after the visible plaque index and the gingival bleeding index were measured from the incisors. The genomic DNA of adhered cariogenic streptococci was extracted and amplified by using polymerase chain reaction, and the prevalence of cariogenic streptococci was determined and compared with oral hygiene indexes in the incisor area.


RESULTS
The results showed that the prevalence of S mutans on incisor brackets was higher than that of S sobrinus, and the maxillary incisor brackets were colonized by both cariogenic streptococci to a somewhat higher degree than were the mandibular brackets. The prevalence of S mutans was 50.0% on the maxillary incisor brackets and 33.8% on the mandibular incisor brackets, but that of S sobrinus was 17.5% and 15.0%, respectively. At least 1 species of cariogenic streptococci was detected on the incisor brackets of 51 subjects (63.7%). However, the prevalence of cariogenic streptococci was not significantly associated with the oral hygiene indexes at debonding.


CONCLUSIONS
Cariogenic streptococci can adhere to orthodontic brackets. Careful hygiene control around orthodontic brackets is important.
Ahn
Sug-Joon
SJ
Department of Orthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Korea.
Lim
Bum-Soon
BS
Lee
Shin-Jae
SJ
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001422:Bacterial Adhesion; D004269:DNA, Bacterial / Q000032:analysis; D006801:Humans; D007180:Incisor; D008875:Middle Aged; D009911:Oral Hygiene Index; D016910:Orthodontic Brackets / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D018709:Statistics, Nonparametric; D013295:Streptococcus mutans / Q000302:isolation & purification; D016986:Streptococcus sobrinus / Q000302:isolation & purification
D004269:DNA, Bacterial