***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background Malocclusion is a common disease of oral and maxillofacial region . The study was aim ed to investigate levels changes of periodontal pathogens in malocclusion patients before , during and after orthodontic treatments , and to confirm the difference between adults and children . Method One hundred and eight malocclusion patients ( 46 adults and 62 children at the school-age ) were r and omly selected and received orthodontic treatment with fixed orthodontic appliances .  Subgingival plaques were Porphyromonas gingivalis ( P.gingivalis ) , Fusobacterium nucleatum ( F. nucleatum ) , Prevotella intermedia ( P. intermedia ) and Tannerella forsythensis ( T. forsythensis ) collected from the observed regions before and after treatment . Clinical indexes , including plaque index ( PLI ) , gingival index ( GI ) , sulcus bleeding index ( SBI ) , probing depth ( PD ) and attachment loss ( AL ) of observed teeth were examined . Results The detection rates of P.gingivalis , F. nucleatum , P. intermedia and T. forsythensis increased from baseline to the third month without significant difference , and then returned to pretreatment levels 12 month after applying fixed orthodontic appliances . Adults ’ percentage contents of P.gingivalis , F. nucleatum , P. intermedia and T. forsythensis were significantly higher than those of children at baseline and the first month , but not obvious at the third month . PLI and SBI were increased from baseline to the first and to the third month both in adults and children groups . Besides , PD were increased from baseline to first month , followed by a downward trend in the third month ; however , all patients were failed to detect with AL . Conclusions Periodontal and microbiological statuses of malocclusion patients may be influenced by fixed orthodontic appliances in both adults and children , more significant in children than in adults . Some microbiological indexes have synchronous trend with the clinical indexes . Long-term efficacy of fixed orthodontic appliances for malocclusion should be confirmed by future research es OBJECTIVE To evaluate the effect of different bracket types on the levels of Streptococcus mutans ( SM ) and Lactobacillus ( LB ) in saliva , in plaque , and on the periodontal condition . MATERIAL S AND METHODS Forty patients aged 14 to 16 years , who had Angle Class I malocclusion with minimal crowding , were nonsmokers , were without systematic disease , and did not use antibiotics or oral mouth rinses during the 3-month period before the study were r and omly selected . The patients were subdivided into two groups with r and om allocation of bracket type : conventional brackets ( CB ; Avex Mx , OPAL orth . ) with steel wire ligature or self-ligating brackets ( SLB ; F1000 , Leone S.p . A. ) . Microbial and periodontal records were obtained before bonding ( T1 ) and 1 month after bonding ( T2 ) . Microbial sample s were collected from the stimulated saliva and the plaque from the labial surfaces of the upper and lower lateral incisors . To estimate the number of colony-forming units of SM and LB , Dentocult SM and LB kits were used . The plaque index ( PI ) , gingival index ( GI ) , and pocket depth ( PD ) values were recorded to evaluate the periodontal condition . Paired t-test and Mann-Whitney U-test were used to compare the groups statistically . RESULTS No significant differences occurred in SM or LB colonization between the groups . In the SLB group , PI , GI , and PD values increased significantly ( P < .05 ) . A greater increase was found in PD value in the SLB group ( 0.98 mm ) compared with the CB group ( 0.04 mm ; P < .05 ) . CONCLUSIONS The F1000 SLB do not have an advantage over Avex Mx CB with respect to periodontal status and colonization of SM and LB The aim of this longitudinal study was to monitor patients ' microbiological and clinical parameters from bracket placement up to 3 months post-treatment . Twenty-four patients ( 10 males and 14 females , aged 14.6 ± 1.0 years ) were included in this investigation . Microbiology ( sub- and supragingival ) , periodontal probing depth ( PPD ) , bleeding on probing ( BOP ) , and gingival crevicular fluid ( GCF ) flow were assessed at baseline ( T1 ) , at bracket removal ( T2 ) , and 3 months post-treatment ( T3 ) . A statistical comparison was made over time and between the b and ed , bonded , and control sites . Repeated measurements on patients were taken into account by modelling the patients as a r and om factor . Except for PPD and BOP , values were log-transformed before analysis . Corrections for simultaneous hypothesis testing were performed via simulation . The results demonstrated that sub- and supragingival colony-forming units ratio ( CFU ratio aerobe/anaerobe ) decreased significantly ( relatively more anaerobes ) at T2 compared with T1 . Between T2 and T3 no significant increase in CFU ratio was seen , result ing in a significantly lower CFU ratio at T3 compared with T1 for subgingival plaque . The difference concerning supragingival plaque between T3 and T1 was not significant . Clinical parameters PPD , POB , and GCF flow showed a significant increase between T1 and T2 . Between T2 and T3 these variables decreased significantly but remained significantly higher than at T1 [ except for BOP values at the bonded sites ( P = 0.0646 ) ] . Placement of fixed orthodontic appliances has an influence both on microbial and clinical periodontal parameters , which were only partly normalized , 3 months following the removal of the appliances The goal of this study was to evaluate the clinical and microbiological factors associated with orthodontic appliances during an episode of gingival inflammation and the impact of appliance removal on periodontal health . This prospect i ve study included 10 patients , aged 12 to 20 years , with clinical signs of gingival inflammation at the final phase of orthodontic treatment ( appliance removal ) . Plaque index , gingival index , and probing depth were evaluated , and microbiological sample s were collected from teeth 16 , 11 , and 26 at 2 times : during the gingival inflammation ( baseline ) and 30 days after the removal of the appliance and professional prophylaxis . Polymerase chain reaction analysis was used to detect Porphyromonas gingivalis , Bacteroides forsythus , Actinobacillus actinomycetemcomitans , Prevotella intermedia , and Prevotella nigrescens . A statistically significant improvement of the plaque and gingival indexes was seen , as well as a reduction in probing depth ( P < .05 ) . Periodontal pathogens were associated with gingival inflammation during orthodontic treatment . The improvement in periodontal health at 30 days was concomitant with a reduction of sites positive for A. actinomycetemcomitans and B. forsythus ( P < .05 ) . Periodontal pathogens associated with gingival inflammation during orthodontic treatment can be significantly reduced by orthodontic appliance removal and professional prophylaxis OBJECTIVES Fixed orthodontic appliances cause plaque accumulation around b and s and brackets . Since the microbiological composition of dental plaque is closely connected to periodontal tissue health , the aim of this study was to determine the effects of fixed orthodontic appliances on subgingival microflora and periodontal status . METHODS This prospect i ve study was carried out on 32 adolescents scheduled for fixed orthodontic treatment . Subgingival dental plaque sample s and periodontal records ( pocket probing depth and clinical attachment level ) were obtained in four recording times : before bonding of fixed appliances ( T0 ) , 1 ( T1 ) , 3 ( T2 ) and 6 ( T3 ) months after the beginning of orthodontic therapy , in order to detect the changes in periodontopathic anaerobe microbial flora and its effects on periodontal status . RESULTS The values of pocket probing depth , total number of microorganisms and number of patients with positive findings of Prevotella intermedia and other periodontopathic anaerobes increased from T0 to the maximum obtained in T2 recording time . Both clinical and microbiological values decreased 6 months after the beginning of orthodontic therapy . CONCLUSIONS The therapy with fixed appliances may transitionally increase the growth of periodontopathogenic bacteria and consequently result in gingival inflammatory response but without destructive effect on deep periodontal tissues OBJECTIVES The aim of this prospect i ve study was to monitor patients ' microbiological and clinical periodontal parameters prior and up to 2 years after orthodontic treatment . MATERIAL AND METHODS Twenty-four adolescents were treated with brackets .  Fourteen of them received b and s on upper first molars for extra-oral force application before bonding brackets to the remaining teeth . Microbiology , periodontal probing depth , bleeding on probing ( BOP ) , and gingival crevicular fluid ( GCF ) flow were assessed at baseline ( T1 ) , bracket removal ( T2 ) , and 2 years post-treatment ( T3 ) . A statistical comparison was made over time and between b and s and brackets . RESULTS A significant increase from T1 to T2 and a decrease from T2 to T3 in pathogenicity of plaque were noted . No significant difference was observed concerning supragingival colony-forming units ( CFU ) ratio ( aerobe/anaerobe ) between T3 and T1 . However , the subgingival CFU ratio ( aerobe/anaerobe ) at T3 did significantly differ from the ratio at T1 . Periodontal probing depth , BOP and GCF flow showed a significant increase between T1 and T2 and a reduction between T2 and T3 , result ing in the absence of significant differences between T3 and T1 , except for BOP at b and ed sites . CONCLUSION Placement of fixed appliances has an impact on periodontal parameters . The results showed that not all parameters were normalized at T3 , indicating that the changes are only partially reversible To determine a possible influence of two different hormonal contraceptives on bacterial microflora of gingival sulcus , subgingival plaque sample s of 29 healthy women aged between 20 and 32 years were investigated bacteriologically before subjects took a contraceptive and 10 and 20 days after subjects started the medication . In 14 women , and oral contraceptive containing 0.02 mg ethinyl estradiol and 0.15 mg desogestrel ( preparation A ) was used , and 15 women took a contraceptive containing 0.03 mg ethinyl estradiol and 2.00 mg dienogest ( preparation B ) daily over 21 days . There were no changes in clinical parameters of the teeth investigated during 3 weeks of the study . The periodontopathogenic bacteria Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans were never detected throughout the study . On the other h and , the periodontopathogenic species Prevotella intermedia was found in plaque sample s of 22 women . The content of this microorganism showed only a little change between the pretreatment period and plaque sampling after 10 days of contraceptive treatment , but a striking increase occurred after 20 days of contraceptive treatment , especially in the preparation A group . In this respect , there was a significant difference between preparations A and BACKGROUND The outcome of microbiological diagnostics may depend on the sampling technique . It was the aim of the present study to compare two widely used sampling techniques for subgingival bacteria using quantitative real-time polymerase chain reaction . METHODS Twenty patients with chronic periodontitis were r and omized into two groups . In group A , sample s were taken first with a paper point and then with a curet at the same site ( single-rooted teeth with probing depth > 5 mm ) before scaling and root planing and after 10 weeks . The sampling sequence was reversed in group B. The analysis enabled the quantification of Actinobacillus actinomycetemcomitans , Fusobacterium nucleatum , Porphyromonas gingivalis , Prevotella intermedia , Treponema denticola , and Tannerella forsythensis and total bacterial counts ( TBCs ) . Statistical analysis included t test , kappa , and Spearman correlation . RESULTS Higher TBC was harvested with curets than by paper points ( P = 0.008 ) . The plaque composition with regard to total target pathogens was similar for both sampling techniques . A strong positive correlation was found between curet and paper point sample s for TBC and single target bacteria . CONCLUSIONS Overall , there was a relatively good agreement for the results of paper point and curet sampling . Thus , both techniques seem to be suitable for microbiological diagnostics Abstract Objective . The aim of this prospect i ve longitudinal study was to assess and compare the microbiological and clinical parameters of patients wearing a fixed orthodontic appliance  , as opposed to 10 days after the bracket had been removed following treatment . Material s and methods . In total , 122 patients participated in this study ; 61 of the subjects were assessed at baseline ( wearing a fixed orthodontic appliance : T1 ) and 10 days after bracket removal ( T2 ) . The other 61 individuals had never worn an orthodontic appliance  before and these subjects served as controls ( CT ) . Subgingival plaque sample s were assessed for bleeding on probing ( GBI ) and plaque index ( VPI ) . PCR of 16s rDNA , followed by reverse species-specific hybridization for Aggregatibacter actinomycetemcomitans , Porphyromonas gingivalis , Prevotella intermedia , Tannerella forsythia and Treponema denticola were performed . A descriptive analysis was conducted ; chi-squared , Student ’s matched and unmatched t-tests , the point biserial correlation coefficient and the McNemar test were used to test for differences between groups ( p <  
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Conclusion The levels of subgingival pathogens presented temporary increases after orthodontic appliance placement , and appeared to return to pretreatment levels several months later .
This indicates that orthodontic treatment might not permanently induce periodontal disease by affecting the level of subgingival periodontal pathogen levels .