Microbiologic changes in subgingival plaque after removal of fixed orthodontic appliances.
OBJECTIVE
To evaluate changes that occur in the subgingival microbiota after removal of fixed orthodontic appliances using polymerase chain reaction (PCR).


METHODS
Thirty orthodontic patients (11 males and 19 females; aged 20 +/- 7.3 yr) were included in this study. Subgingival plaque samplings were gathered from the disto-buccal gingival crevice of the left upper central incisors and the left lower central incisors, and from the mesio-buccal gingival crevice of the left upper first molars and the left lower first molars, at two different times: 2 weeks before appliance removal (T1), and 3 months after appliance removal (T2). DNA was extracted from the samples and the 16S rRNA-based PCR detection method was used to determine the prevalence of Actinobacillus actinomycetemcomitans , Tannerella forsythia , Campylobacter rectus , Eikenella corrodens , Porphyromonas gingivalis , Prevotella intermedia , Prevotella nigrescens , and Treponema denticola , which are considered as putative periodontopathogens.


RESULTS
The frequency of positive sites at T1 and T2 was 65% and 43.3% for C. rectus , and 53.3% and 30.8% for E. corrodens , respectively. For the other bacteria, the frequency tended to be reduced between times.


CONCLUSIONS
Periodontopathogens during orthodontic treatment were significantly reduced within 3 months of appliance removal. However, how long it takes to return to the preorthodontic composition of the subgingival microbiota and whether it happens at all remain to be seen.
Choi
Dong-Soon
DS
Department of Orthodontics, College of Dentistry, Kangnung National University, Gangneung, South Korea.
Cha
Bong-Kuen
BK
Jost-Brinkmann
Paul-Georg
PG
Lee
Si-Young
SY
Chang
Beom-Seok
BS
Jang
Insan
I
Song
Jae-Seok
JS
D000293:Adolescent; D016976:Aggregatibacter actinomycetemcomitans / Q000302:isolation & purification; D001439:Bacteroides / Q000302:isolation & purification; D044883:Campylobacter rectus / Q000302:isolation & purification; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000032:analysis; D003773:Dental Plaque / Q000382:microbiology*; D016124:Eikenella corrodens / Q000302:isolation & purification; D005260:Female; D005500:Follow-Up Studies; D005881:Gingiva / Q000382:microbiology; D006090:Gram-Negative Bacteria / Q000145:classification*; D006801:Humans; D007180:Incisor / Q000382:microbiology; D008297:Male; D008963:Molar / Q000382:microbiology; D016910:Orthodontic Brackets; D016133:Polymerase Chain Reaction; D016966:Porphyromonas gingivalis / Q000302:isolation & purification; D018713:Prevotella intermedia / Q000302:isolation & purification; D045242:Prevotella nigrescens / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D048373:Treponema denticola / Q000302:isolation & purification; D055815:Young Adult
D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S