***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: OBJECTIVE To determine the effects of fixed orthodontic appliances on periodontal health and microbiological composition of subgingival dental plaque . MATERIAL AND METHODS This prospect i ve longitudinal self-controlled study was conducted on 32 adolescents ( 13 males , 19 females ) , who were scheduled for fixed orthodontic treatment between 2002 and 2005 .  Dental plaque accumulation , gingival inflammation and pocket probing depth were measured at the mesio-vestibular angle of the examined group of teeth followed by collection of subgingival dental plaque sample s in the same points . These periodontal indices and microbiological parameters were determined prior to the placement of fixed appliances and 1 , 3 and 6 months after the beginning of orthodontic treatment . RESULTS All values of both clinical and microbiological parameters started to increase after the placement of fixed appliances . Maximum values were reached 3 months after fixed appliance placement followed by their decrease in the last registration period of 6 months after the placement of fixed appliances . CONCLUSIONS Treatment with fixed appliances in adolescents may transitionally increase the values of all periodontal indices and stimulate the growth of periodontopathogenic bacteria , but without destructive effects on deep periodontal tissues 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 BACKGROUND Patients with fixed orthodontic appliances often experience an absolute increase in the number of Streptococci mutans colony-forming units ( cfu ) . The aim of this investigation was to study the development of biofilm and S. mutans cfu in connection with stainless steel ligatures and elastomeric rings in orthodontic patients treated with and without 0.4 % stannous fluoride gel ( SFG ) .  MATERIAL Forty-seven patients were divided into 2 groups : those treated with 0.4 % SFG for 4 minutes ( experimental ) and those without 0.4 % SFG ( control ) . In each patient , elastomeric rings were used for ligation on 1 side of the dental arch midline , and stainless steel ligatures were used on the opposite side . Saliva sample s were collected before and after appliance placement . At 15 and 30 days after appliance placement , biofilm sample s from the stainless steel ligatures and the elastomeric rings were collected and subjected to microbiologic procedures and scanning electron microscopy ( SEM ) analysis . RESULTS The numbers of S. mutans cfu in the saliva and biofilm were not statistically different between the teeth fitted with elastomeric rings and stainless steel ligatures , or between the experimental and control groups . SEM analysis showed biofilm formation on both ligature ties . CONCLUSIONS Topical application of 0.4 % SFG in orthodontic patients with elastomeric rings or stainless steel ligatures does not cause a significant decrease in S. mutans cfu in the saliva and biofilm Fixed or removable orthodontic appliances impede the maintenance of oral hygiene and result in plaque accumulation . Plaque retention surrounding orthodontic appliances leads to enamel demineralization caused by organic acids produced by bacteria in the dental plaque . Many studies have evaluated the effects of fixed orthodontic appliances on microbial flora and periodontal status , but only a few have evaluated the method of ligation as an additional factor . The aim of this study was to determine the changes in microbial flora and periodontal status after orthodontic bonding and to determine whether two different archwire ligation techniques affect these changes . A total of 21 orthodontic patients scheduled for fixed orthodontic treatment were selected for this split-mouth study . Two commonly used auxiliaries ( elastomeric rings and ligature wires ) for tying archwires were tested . Microbial and periodontal records were obtained before bonding ( T0 ) , one week later ( T1 ) , and five weeks after bonding ( T2 ) . Paired t-test and Wilcoxon signed rank test were used to compare the groups statistically . Although , teeth ligated with elastomeric rings exhibited slightly greater numbers of microorganisms than teeth ligated with steel ligature wires , the differences were not statistically significant and could be ignored . The two archwire ligation techniques showed no significant differences in the gingival index , bonded bracket plaque index , or pocket depths of the bonded teeth . However , teeth ligated with elastomeric rings were more prone to bleeding . Therefore , elastomeric ring use is not recommended in patients with poor oral hygiene The aim of this investigation was to evaluate the prevalence of C and ida and Enterobacteriaceae in a group of adolescents during fixed orthodontic appliance ( FOA ) therapy .  The experimental group was recruited from a larger sample of orthodontic patients who were clinical ly examined once to obtain baseline data before active treatment . The group comprised 27 subjects ; 13 males , 14 females ( mean age 15.5 + /- 2.3 years ) . Thereafter , the experimental group was examined three times during a 3 month follow-up period after insertion of the FOA . The whole mouth plaque score was obtained , and the oral cavity was then sample d for C and ida species and Enterobacteriaceae using three different microbiological culture techniques , namely the oral rinse , pooled plaque and the imprint culture . A significant increase in c and idal numbers was observed after FOA insertion when the imprint technique was used ( P < 0.001 ) , although the overall c and idal prevalence rates obtained using the oral rinse and pooled plaque techniques did not demonstrate such a change . The predominant C and ida species isolated was C. albicans and the number of coliform carriers significantly increased after the insertion of a FOA , as detected by the oral rinse ( P < 0.05 ) and the pooled plaque ( P < 0.05 ) techniques . In total , eight coliform species were isolated following FOA therapy compared with the three species isolated before insertion of the appliance . The results also revealed a significant increase in plaque index due to the introduction of a FOA . Taken together , these data imply that insertion of a FOA is likely to promote oral carriage of C and ida and coliform species . Furthermore , it appears that routine oral hygiene instruction and information on appliance hygiene given to these patients may not necessarily reduce plaque accumulation and possible attendant effects . Further work with a larger cohort is required to confirm these findings White spot or areas of decalcification are carious lesions of varying extent . The incidence and severity of white spots after a full term of orthodontic treatment were studied among patients in the separate private practice s of two of the authors . To establish a base line of comparison , the presence of white spots in a r and om sample of untreated persons was observed . The incidence of white spots among patients treated by a multibonded technique  was recorded at the time of debonding . In addition , white spots were sought in the before- and after-treatment Kodachrome slides of persons whose maxillary incisors had been h and ed . It was found that individual teeth , b and ed or bonded , exhibited significantly more white spot formation than was found in the control group . For the teeth studied , there was no difference in white spot formation in those that were b and ed or bonded . The labiogingival area of the maxillary lateral incisors had the highest incidence of white spots . When studied by segments , the highest incidence occurred among the maxillary incisors ; the lowest was in the maxillary posterior segment . No white spots were found on the lingual surfaces of m and ibular canines and incisors after prolonged use of a canine-to-canine bonded retainer . These findings suggest a relationship between resistance to white spot formation and the rate of salivary flow . Despite the lack of any preventive fluoride program among the study groups , 50 % of the patients demonstrated resistance to white spot formation . The obvious degree of latrogenic damage during orthodontic treatment suggests the need for preventive programs using fluoride . Further clinical research is needed 
    Output:
    
The literature revealed moderate evidence that the presence of  fixed  appliances influences the quantity and quality of oral microbiota