***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: A sample of mentally retarded adolescents with moderate periodontal disease was given conventional treatment with and without adjunctive metronidazole therapy following consent of guardians . Antibiotics or placebo tables were taken 1 week following prophylaxis in a double blind clinical trial . Six months after the baseline examinations , there were no significant differences between the treatment and control groups in the mean attachment level or the proportions of microorganisms in subgingival pockets Sixteen patients diagnosed as having juvenile periodontitis were r and omly placed into one of two treatment groups . Group I received local and systemic tetracycline ( TTC ) , while Group II received no antibiotics . Osseous defects were grafted with allogeneic freeze-dried bone ( FDBA ) mixed with TTC powder ( Group Ia ) or FDBA alone ( Group IIa ) . Contralateral defects were debrided only in both Groups ( Ib and IIb ) . Direct reentry evaluation of 104 measurement sites demonstrated significantly greater bone fill ( mean = 2.8 mm ) and resolution of osseous defects ( mean = 72.7 % ) in the TTC/FDBA-treated group ( Ia ) as compared to the TTC plus debridement only ( Ib ) or no TTC-treated groups ( IIa and IIb ) . The results of this study indicate that of the modes of treatment investigated , the combination of local and systemic tetracycline coupled with freeze-dried bone allografts was the treatment of choice for defects associated with juvenile periodontitis The aim of the present study was to analyze the effect of systemic antimicrobial therapy and mechanical plaque control in patients with recurrent periodontal disease . 9 patients volunteered for the combined therapy . At a baseline examination they were r and omly distributed into 2 groups , one given tetracycline therapy for 2 weeks and the other metronidazole therapy for 1 week . A mechanical plaque control program comprising oral hygiene training , professional cleaning of all teeth and subgingival debridement at diseased sites was carried out at the baseline examination and at all recall visits , i.e. once every month during the first 6 months and then after 9 , 12 , and 18 months . The results demonstrated clinical ly and microbiologically that a combination of an initial antimicrobial and a continuous systematic mechanical plaque control program may be a valuable therapeutic approach in a strictly selected group of refractory patients . Recurrent periodontal lesions which still displayed severe inflammation despite renewed conventional therapy showed a marked reduction in probing depths , bleeding and suppuration from the pockets , and further , a reduced presence of spirochetes and motile rods during the trial . The results indicate that the level and longevity of success is also related to whether or not self-performed oral hygiene measures are sufficiently carried out . No superior effect of the combined program could be observed in cooperating patients receiving tetracycline as compared with those given metronidazole Periodontitis , a common cause of tooth loss in adult population s , is an inflammatory response to the overgrowth of anaerobic organisms such as spirochetes and bacteroides and , in some cases , micro-aerophilic organisms in the subgingival plaque . In the present investigation , using a double-blind clinical design , we sought to determine whether 1 week of metronidazole treatment plus debridement of the tooth surfaces was superior to 1 week of placebo treatment plus debridement ( positive control ) in reducing the subsequent amount of periodontal surgery given to the patients . Thirty-nine patients were r and omly assigned to either the metronidazole or placebo ( positive control ) groups . All patients were given the necessary scaling and root planing and were unsupervised in their usage of the medication . After the completion of this treatment , they were reexamined and it was found that the metronidazole regimen caused a significant reduction in surgical needs of about 5 teeth per patient compared to the positive control ( difference before and after treatment 8.3 + /- 6.8 teeth metronidazole versus 2.9 + /- 4.8 positive control , P = 0.007 ) . The difference between groups was maintained during the 2 to 3 years ' recall period . Metronidazole had a significant effect on the site specific reduction of spirochetes : 90 % of the sites in the metronidazole group versus 64 % in the positive-control group had a decrease in the percentage of spirochetes ( P less than 0.05 ) . We conclude that systemic metronidazole given 250 mg tid for 7 days in conjunction with debridement of the tooth surfaces can significantly reduce the need for periodontal surgery compared to the st and ard regimen which included only debridement BACKGROUND / AIMS The aim of this short-term open parallel longitudinal clinical study was to compare the clinical and microbiological efficacy of 2 different antibiotic regimes in the treatment of acute periodontal abscesses . METHOD After patient selection , a clinical examination was carried out recording the following variables : pain , edema , redness , swelling , bleeding on probing , suppuration , tooth mobility , lymphadenopathy , and probing pocket depth . Microbiological sample s were taken from the lesion and the patient was r and omly assigned to one of two antibiotic regimes : azithromycin or amoxicillin/clavulanate . Clinical variables were recorded , and microbiological sample s were taken , at 3 - 5 days , 10 - 12 days and 30 days . Additional mechanical treatment ( debridement and scaling ) was performed in the third visit ( 10 - 12 days ) . Blood and urine sample s were collected at baseline and after 10 - 12 days . Microbiological sample s were processed by anaerobic culturing , and isolated periodontal pathogens were tested for antibiotic susceptibility by means of the spiral gradient endpoint methodology . RESULTS 15 patients took azithromycin , and 14 amoxicillin/clavulanate . Subjective clinical variables demonstrated statistically significant improvements with both antibiotic regimes , which lasted for at least 1 month ( p<0.01 ) . Objective clinical variables also showed clear improvements , being statistically significant after 30 days with probing pocket depth in the azithromycin group ( p<0.01 ) . Microbiologically , short-term reductions were detected with both antibiotics , however fast recolonization occurred after the third visit . No significant differences were found between both treatment regimes . Antibiotic susceptibilities demonstrated no resistances for amoxicillin/clavulanate , while 2 - 3 strains of each studied pathogen were resistant to azithromycin . CONCLUSIONS However , both antibiotic regimes were effective in the short-term treatment of periodontal abscesses in periodontitis patients AIM To determine whether adjunctive metronidazole therapy would compensate for the poorer treatment response to scaling and root planing reported in smokers . METHOD A single-blind , r and omised clinical trial of 28 smokers and 56 non-smokers , stratified for periodontitis disease severity and r and omly allocated to 3 treatment groups : ( 1 ) Scaling and root planing using an ultrasonic scaler with local anaesthesia ( SRP ) , ( 2 ) SRP+ metronidazole tabs 200 mg tds for 7 days , ( 3 ) SRP + 2 subgingival applications of 25 % metronidazole gel .  Probing depths ( PD ) and attachment levels ( AL ) were recorded with a Florida probe at baseline , 2 months and 6 months post treatment by a single examiner who was unaware of the treatment modality . Results were analysed for all sites with baseline probing depths equal to or greater than Florida probe recordings of 4.6 mm using analysis of variance . RESULTS Reductions in probing depth at 6 months were significantly less ( p < 0.001 ) in the smokers ( mean 1.23 mm , 95 % confidence intervals = 1.05 to 1.40 mm ) than in the non-smokers ( 1.92 , 1.75 to 2.09 mm ) . Attachment level gains were approximately 0.55 mm and there was no statistically significant difference between smokers and non-smokers . There were no differences in any clinical measure in response to the three treatment regimens at 2 or 6 months for either smokers or non-smokers . A reduction in the proportion of spirochaetes was observed at 6 months which was less in smokers than in non-smokers ( p = 0.034 ) . Multiple linear regression analysis on probing depth at 6 months demonstrated that smoking was a significant explanatory factor ( p < 0.001 ) for poor treatment outcome , whilst the presence or absence of adjunctive metronidazole was not ( p = 0.620 ) . CONCLUSION This study confirms that smokers have a poorer treatment response to SRP , regardless of the application of either systemic or locally applied adjunctive metronidazole The present investigation was performed to study the effect of long-term , low dosage tetracycline therapy on advanced periodontal disease in humans . 14 volunteers participated in the trial . Each of the participants had at least 4 pairs of diseased sites around contralateral premolars and incisors with deep pockets and advanced bone loss . The trial extended over a 50-week period and was design ed as a double-blind split-mouth study . A Baseline examination included assessment s of oral hygiene , gingival conditions , probing depth , attachment level and analysis of the composition of the subgingival microbiota in sample s obtained from 8 selected diseased sites . All participants received oral hygiene instruction . In each patient 2 quadrants of the mouth , chosen at r and om , were treated by scaling and root planing . The 2 remaining quadrants were left unscaled . Following the Baseline examination the patients were r and omly distributed into 2 groups of 7 members each . In one of the groups the patients received tetracycline on a daily basis during a 50-week period . The participants of the control group received placebo . Reexaminations were performed 2 , 10 , 20 , 30 and 50 weeks after the Baseline examination . The findings demonstrated that in patients with advanced periodontal disease long-term tetracycline therapy in the absence of scaling result ed in the establishment of a subgingival microbiota almost devoid of motile bacteria and in markedly reduced signs of gingivitis , probing depth and attachment loss . In fact , the alterations observed as a result of tetracycline administration to patients with excellent self-performed plaque control were similar to those obtained by conventional scaling and root planing in the control group BACKGROUND The prevailing concept is that little or no clear benefit is derived from antibiotic therapy in chronic periodontitis . Studies to determine the effect of metronidazole plus amoxicillin ( M+A ) on adult periodontitis are question able because st and ard design for clinical trials was usually not used . In addition , there is no information about the effect of M+A as the sole therapy for periodontitis . METHODS A r and omized , triple-blind , controlled clinical trial was used to determine the effect of systemic administration of M+A , as the sole therapy , in progressive adult periodontitis . Forty-six subjects with moderate to advanced adult periodontitis who showed > or = 2 mm attachment loss in at least 2 sites in the previous 2 months were entered in the study . Subjects were r and omly distributed to a group who received 21 tablets of metronidazole 250 mg plus amoxicillin 500 mg , or to a group receiving a placebo ( 1 tablet every 8 hours for 1 week ) . Patients were examined every 2 months for 12 months . The M+A or placebo regimen was repeated at 4 and 8 months . No effort was made to change the oral habits of patients and they received no additional therapy . Differences between groups were assessed using the Mann-Whitney U test . The differences at every 2-month interval within each group were assessed using the ANOVA test . RESULTS Seven subjects ab and oned the study ; at 12 months the M+A group had 20 subjects and the placebo group 19 . There were no significant differences in the clinical parameters at baseline between the 2 groups . After 2 months and thereafter , the M+A group showed significant clinical improvement while the placebo group showed a progressive deterioration of periodontal status . At 12 months compared to baseline , subjects of the M+A group showed : 1 ) a significant overall mean attachment gain of 0.43 mm ( P = 0.005 ) ; 2 ) a significant decrease of active sites ( P < or = 0.03 ) ; 3 ) a significant increase of sites gaining attachment level ( P < or = 0.01 ) ; 4 ) a significant reduction of pocket depth ( P < or = 0.00006 ) ; and 5 ) a significant decrease in percentage of bleeding on probing sites ( BOP ) ( P < or = 0.0005 ) . Significant differences between both groups at all 2-month evaluations were found in overall mean attachment level ( P < or = 0.000004 ) , in percent of active sites ( P < or = 0.03 ) , and in percent of BOP sites ( P < or = 0.02 ) . Sites exhibiting > or = 2 mm of attachment loss in 2 successive or alternate evaluations , and periodontal abscess were noticed only in the placebo group . CONCLUSIONS A 1-week course of systemic M+A every 4 months , as the only therapy , arrests the progression of adult periodontitis and significantly improves the clinical parameters of the disease Abstract . The healing process following periodontal surgery for advanced adult periodontitis is described . Of the various indicators , tooth  mobility  ( TM ) is considered , and its relation to surgical treatment and the time lapse from the flap surgery is quantitatively modeled by non-parametric regression . Mobility 
    Output:
    
The systemic antibiotics were uniformly beneficial in providing an improvement in AL when used as adjuncts to scaling and root planing ( SRP ) and were consistently beneficial , although of borderline significance , when used as adjuncts to SRP plus surgery or as a st and alone therapy .
5 .
When examining the effects of individual or combinations of antibiotics , it was found that there were statistically significant improvements in AL for tetracycline , metronidazole , and an effect of borderline statistical significance for the combination of amoxicillin plus metronidazole .
6 .
Improvements in mean AL were consistent for both chronic and aggressive periodontitis subjects , although the aggressive periodontitis patients benefited more from the antibiotics .
REVIEW ERS ' CONCLUSIONS 1 .
The use of systemically administered adjunctive antibiotics with and without SRP and /or surgery appeared to provide a greater clinical improvement in AL than therapies not employing these agents .
2 .
Due to a lack of sufficient sample size for many of the antibiotics tested , it is difficult to provide guidance as to the more effective ones