***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: INTRODUCTION Bacterial plaque is an etiologic factor in the development of gingival inflammation and periodontitis . The presence of orthodontic b and s and brackets influences plaque growth and maturation . The purpose s of this research were to monitor microbiologic and periodontal changes after placement of orthodontic attachments over a 1-year period and to link these changes to alterations in cytokine concentrations in the gingival crevicular fluid ( GCF ) . METHODS This longitudinal split-mouth trial included 24 patients .  Supragingival and subgingival plaque composition , probing depth , bleeding on probing , and  GCF flow and composition  were assessed at baseline ( Tb ) and after 1 year ( T52 ) . A statistical comparison was made over time and between the b and ed and bonded sites . Prognostic factors for the clinical reaction at T52 in the GCF at Tb were determined . RESULTS Between Tb and T52 , the pathogenicity of the plaque and all periodontal parameters increased significantly , but intersite differences were not seen , except for bleeding on probing . The cytokine concentrations in the GCF did not differ significantly between the sites or between Tb and T52 . The interleukin-6 concentration in the GCF at Tb was a significant predictive value for the GCF flow at T52 ( P < 0.05 ) . The same relationship was found between the interleukin-8 concentration at Tb and the increase in probing depth at T52 ( P < 0.05 ) . CONCLUSIONS Interleukin-6 and interleukin-8 concentrations before orthodontic treatment were shown to be significant predictive factors for some potential inflammatory parameters during treatment The objective of this study was to investigate the effect of bracket type ( conventional and self-ligating ) on the levels of Streptococcus mutans and total bacterial counts in whole saliva of orthodontic patients . Thirty-two male and female patients were selected using the following inclusion criteria : adolescents ( mean age 13.6 years , range 11 - 17 years ) , fixed appliances in both arches , non-smoker , and no reported oral habits . Demographic and oral hygiene characteristics were determined for each subject . The patients were subdivided into two groups with r and om allocation of bracket type ( conventional or self-ligating ) . An initial saliva sample was obtained before the initiation of treatment ( T1 ) and a second sample 2 - 3 months following appliance bonding ( T2 ) . Salivary S. mutans and total bacteria were enumerated and analysed after growth in culture . The demographic and clinical characteristics of the sample s were analysed with a t- or chi-square test , where applicable , to assess the r and om allocation of bracket group to participants . The results of S. mutans and total facultative bacterial counts were log transformed and statistically analysed with analysis of covariance with bracket ( conventional versus self-ligating ) as the categorical variable and initial total bacterial counts or initial S. mutans levels serving as the covariate . No difference was found in the demographics and oral hygiene indices between the two groups , verifying the r and om assignment of brackets to the population sample . The levels of S. mutans in whole saliva of orthodontically treated patients do not seem to be significantly different between conventional and self-ligating brackets . The pre-treatment levels of S. mutans are significant predictors of the levels of S. mutans after placement of orthodontic appliances , while this was not the case for total bacterial counts Background : Orthodontic therapy has oral ecological changes causing increased numbers of mutans streptococci in saliva and plaque . The purpose of this study was to estimate counts and colonization pattern of Streptococcus mutans after application of fixed orthodontic appliances . Material s and Methods : Plaque sample s of r and omly selected sixty patients were collected before placement of orthodontic appliances from buccal and labial aspects of the anterior teeth and four first molars and readings were recorded as T0 . After placement of appliances ( 0.22 MBT preadjusted Gemini ) , i.e. , 2nd and 3rd month , the plaque sample s were collected again from same site and readings were recorded as T1 and T2 , respectively . Counts of S. mutans in these patients were determined by using DM Strips ( Orion Diagnostic , Espoo , Finl and ) . Kruskal – Wallis test and Mann – Whitney U-test were used to find out significant differences between different time interval for Dentocult score for S. mutans in orthodontic patients ( P < 0.001 ) . Results : Prior to the treatment , 46 patients ( 76 % ) showed mild and 14 patients ( 24 % ) showed moderate colonization of S. mutans . After treatment , the severity of colonization increased showing fifty patients ( 84 % ) moderate and six patients ( 10 % ) showing severe colonization of S. mutans at T1 , which further increased in severity at T2 with 54 patients ( 90 % ) showing severe colonization with S. mutans . Conclusion : Results showed that fixed orthodontic appliance increases colonization of S. mutans during orthodontic treatment 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 Objective Lingual orthodontics is becoming more popular in dental practice . The purpose of the present investigation was to compare plaque formation on teeth bonded with the same bracket onto buccal or lingual surface , with non-bonded control teeth , via an in vivo growth experiment over a 30-day period . Material and Methods A r and omized controlled trial with split-mouth design was set up enrolling 20 dental students . Within each subject sites with buccal and lingual brackets and control sites were followed . Clinical periodontal parameters ( periodontal pocket depth : PPD ; bleeding on probing : BOP ) were recorded at baseline and on days 1 , 7 and 30 . Microbiological sample s were taken from the brackets and the teeth on days 1 , 7 and 30 to detect colony-forming units ( CFU ) . Total CFU , streptococci CFU and anaerobe CFU were measured . Results No significant differences ( P>0.05 ) were found between buccal and lingual brackets in terms of clinical periodontal parameters and microbiological values . Conclusion Bracket position does not have significant impact on bacterial load and on periodontal parameters 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 Background This study compared the oral hygiene and caries risk of patients treated with labial and lingual orthodontic appliances  throughout a prospect i ve evaluation of the status of the oral environment before and after bracket placement . Methods A total of 20 orthodontic patients aged 19 to 23 years were included in the study and were divided into two groups : 10 patients wore Roth labial appliance  ( American Orthodontics , Sheboygan , WI , USA ) and 10 patients wore STb lingual appliance  ( Ormco Corporation , Glendora , CA , USA ) . Plaque index ( PI ) , gingival bleeding index ( GBI ) , salivary flow rate , saliva buffer capacity , salivary pH , and Streptococcus mutans and Lactobacillus counts in saliva were determined at three time points : before orthodontic appliance placement ( T 0 ) , 4 weeks after bonding ( T 1 ) , and 8 weeks after bonding ( T 2 ) . After appliance placement , all patients were periodically educated to the oral hygiene procedures . Wilcoxon rank and Mann-Whitney U tests were used to determine intragroup and intergroup differences as regards qualitative data . To compare quantitative data between the groups , chi-square and Fisher 's exact tests were undertaken , while intragroup differences were tested with McNemar test . The level of statistical significance was set at p < 0.05 . Results Statistical analysis of the data obtained revealed a statistically significant difference between the data of T 0 and T 1 and the data of T 0 and T 2 of the PI scores and between T 0 and T 2 of the GBI scores in the group treated with the lingual appliance . The GBI value increased significantly between T 0 and T 1 but decreased significantly between T 1 and T 2 ( p < 0.01 ) in the group treated with labial appliance . S. mutans counts increased significantly between T 0 and T 2 in the saliva sample s of patients treated with lingual appliance . No statistically significant differences were found between S. mutans and Lactobacillus counts at the three terms of saliva collection in patients treated with labial appliance . No statistically significant differences were found between the two groups at the three time points as regards the salivary flow rate and saliva buffer capacity . Conclusions Lingual and labial orthodontic appliances showed a different potential in modifying the investigated clinical parameters : patients wearing STb lingual orthodontic appliance had more plaque retention 4 and 8 weeks after bonding , while there were more gingival inflammation and more S. mutans counts 8 weeks after bonding . No differences were found between the two groups as regards the Lactobacillus counts , the salivary flow rate , and saliva buffer capacity Background : To compare changes in the amount and distribution of dental plaque associated with placement of elastomeric modules over a self-ligating bracket during orthodontic treatment and to relate these changes to the periodontal inflammation . Material s and Methods : A cross-arch r and omization trial was carried out at Bristol Dental School , United Kingdom . Clinical measurements of periodontal inflammation and plaque accumulation and microbiological test were done on 24 patients aged 11 - 14 years [ Mean ( SD ) age = 12.6 ( 1.01 ) years ] wearing fixed appliances ( Damon 2 brackets , Ormco , Orange , CA , USA ) at the start and 3 months into fixed orthodontic treatment . Results : In the first 3 months of treatment there was no statistically significant difference in bleeding on probing between incisors with and without elastomeric modules ( P = 0.125 and 0.508 , respectively ) . The difference in plaque accumulation was not statistically significant ( P = 0.78 ) . The difference in probing depths between the incisors was not statistically significant ( P = 0.84 ) . The microbiological analysis showed no difference . Conclusions : Based on this preliminary 3 months study , elastomeric modules were not significantly associated with any increased risk during treatment when compared to self-ligating brackets . The longer term studies are needed to further confirm the findings of the present study INTRODUCTION The rough surface of Hawley removable appliances provides an environment for plaque accumulation , leading to enamel demineralization . The aim of this study was to evaluate the effect of silver nanoparticles incorporated into acrylic baseplates of orthodontic retainers on Streptococcus mutans colony-forming units . METHODS Sixty-six orthodontic patients at the debonding stage were r and omly assigned to 2 sex-matched groups with stratified block r and omization : group 1 received conventional removable retainers ; group 2 received 
    Output:
    
Results : Orthodontic appliances influence the oral microbiota with an increase in the counts of S. mutans and Lactobacillus spp .
and in the percentage of potentially pathogenic gram-negative bacteria .
Conclusions : There is moderate/high evidence regarding the association between orthodontic appliances and changes in the oral microbiota .