Investigations on the prevalence and ratio of periodontal pathogenic bacteria by the pcr-hain test technique, before and after orthodontic therapy

Authors: Catalina Elena Danila, Ioana Rudnic, Silvia Martu


The aim of the study was to investigate the prevalence and ratio of the major periodontal pathogenic bacteria, by the polymerase chain reaction (PCR) technique, patent of F.Hoffmann-La Roche AG, Basel, Switzerland, for the establishment of a most rigurous periodintal diagnosis capable of assuring the success of the subsequently applied orthodontic therapy.The experimental group included 13 patients (6 women and 7 men) with ages between 23 and 47 years (average age: 41.3 years), selected from the patients treated at the Department of Periodontology and from the Danident dental surgery, all suffering from chronic or very aggressive forms of periodontitis, who came, in an initial stage, for routine orthodontic examination. Microbiological tests were performed to determine any possible modification in the percent of subjects showing average or increased pathogenic flora during fixed orthodontic appliance therapy. In 6 of the 8 microbial agents under investigation, the cases with a high number of pathogenic agents increased significantly after a 6 month treatment. Also, after a 12 month fixed orthodontic appliance therapy, a lower percent of pathogenic increase could be recorded. After the first 6 months, the pathogenic level slightly increased or remained constant, while major teeth displacement occurred, which could have led to periodontal pathogenicity. Equally, fixed orthodontic appliance may induce local changes, which will be to the advantage of pathogenic bacteria. After a 12 month treatment, the pathogenic level is lower, as compared to the one registered after 6 months. No significant difference was registered between the amount of pathogenic agents present in the beginning and end of the treatment. The results obtained demonstrate that therapy with fixed orthodontic devices in patients with periodontal diseases does not significantly influence microbial pathogenicity, if the corresponding measures of local hygiene are observed.

  • fixed orthodontic therapy
  • PCR technique
  • periodonto-pathogenic bacteria