title: Profiling of bacterial flora in crevices around titanium orthodontic anchor plates.
abstract: OBJECTIVE
  The aims of this study were to characterize the microflora in crevices around titanium orthodontic anchor plates using anaerobic culture and molecular biological techniques for bacterial identification, and to compare the microbial composition between crevices around anchor plates and gingival crevices.
  
  
  METHODS
  Samples from crevices around titanium anchor plates and healthy gingival crevices of 17 subjects (aged 20-29) were cultured anaerobically, and isolated bacteria were identified by 16S rRNA sequencing.
  
  
  RESULTS
  The average logarithm colony-forming units/ml were 6.84, 7.51 and 8.88 in healthy anchor plate crevices, inflamed anchor plate crevices and healthy gingival crevices, respectively, indicating that the bacterial density of anchor plate crevices was lower than that of healthy gingival crevices. Of 184 strains isolated from healthy anchor plate crevices of seven subjects, 108 (59%) were anaerobic bacteria, while 73 (40%) were facultative bacteria. Predominant isolates were Gram-negative rods, such as Campylobacter (12%), Fusobacterium (10%) and Selenomonas (10%), and Gram-positive facultative bacteria, such as Actinomyces (17%) and Streptococcus (8.2%). Of 133 strains isolated from inflamed anchor plate crevices of three subjects, 110 (83%) were anaerobic bacteria, while predominant isolates were Gram-negative rods, such as Prevotella (47%), Fusobacterium (33%) and Campylobacter (16%). On the other hand, of 146 strains isolated from healthy gingival crevices of seven subjects, 98 (67%) were facultative bacteria, while 45 (31%) were anaerobic bacteria. Predominant isolates were Gram-positive facultative bacteria, such as Actinomyces (37%) and Streptococcus (20%).
  
  
  CONCLUSIONS
  These results suggest that the environment in crevices around titanium orthodontic anchor plates is anaerobic and supportive of anaerobic growth of bacteria, which may trigger inflammation in the tissue around the plates.
authors.affiliation: Division of Orthodontics and Dentofacial Orthopedics, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors.forename: Renya
authors.initials: R
authors.lastname: Sato
authors.forename: Takuichi
authors.initials: T
authors.lastname: Sato
authors.forename: Ichiro
authors.initials: I
authors.lastname: Takahashi
authors.forename: Junji
authors.initials: J
authors.lastname: Sugawara
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Takahashi
mesh_terms: D000190:Actinomyces / Q000145:classification; D000328:Adult; D001421:Bacteria, Anaerobic / Q000145:classification* / Q000235:genetics; D002167:Campylobacter / Q000145:classification; D015169:Colony Count, Microbial; D003764:Dental Materials; D005260:Female; D005673:Fusobacterium / Q000145:classification; D005881:Gingiva / Q000382:microbiology; D005888:Gingival Pocket / Q000382:microbiology; D005891:Gingivitis / Q000382:microbiology; D006801:Humans; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D018720:Prevotella / Q000145:classification; D012329:RNA, Bacterial / Q000032:analysis; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D020357:Selenomonas / Q000145:classification; D013291:Streptococcus / Q000145:classification; D014025:Titanium
chemical_list: D003764:Dental Materials; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D014025:Titanium