***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 / AIM Tobacco use reduces the effect of non-surgical periodontal therapy . Host-modulation with low-dose doxycycline ( LDD ) might favour repair and promote an improved treatment response . The aim of this study was to investigate the effect of LDD in smokers on non-surgical periodontal therapy .  MATERIAL AND METHODS This was a parallel arm , r and omized , identical placebo-controlled trial with masking of examiner , care-giver , participant and statistician and 6 months of follow-up . Patients received non-surgical therapy and 3 months of test or control drug . Statistical analysis used both conventional methods and multilevel modelling . RESULTS Eighteen control and 16 test patients completed the study . The velocity of change was statistically greater for the test group for clinical attachment level -0.19 mm/month ( 95 % CI=-0.34 , 0.04 ; p=0.012 ) and probing depth 0.30 mm/month ( 95 % CI=-0.42 , -0.17 ; p<0.001 ) . However , no differences were observed for absolute change in clinical or biochemical markers at 6 months . CONCLUSIONS This study does not provide evidence of a benefit of using LDD as an adjunct to non-surgical periodontal therapy in smokers BACKGROUND / OBJECTIVE Subantimicrobial dose doxycycline ( SDD 20 mg bid ) plus scaling and root planing ( SRP ) significantly improved clinical attachment level ( CAL ) and reduced probing depth ( PD ) compared with placebo plus SRP in a double-blind , placebo-controlled , multicenter study of patients with adult periodontitis ( AP ) . In a study conducted as a follow-up , the post-treatment effects of SDD were assessed in patients who completed the SRP study . METHODS The SRP study was a 9-month , active-treatment study and the follow-up was a 3-month , no-treatment study . In the SRP study , tooth sites in qualifying quadrants were scaled and root planed and patients were r and omized to receive twice daily SDD 20 mg or placebo . In the follow-up , patients received no study drug ; investigators and patients remained blinded to the previous treatment group assignments . Efficacy measures included the change in CAL and PD from baseline values determined at the start of the SRP study in tooth sites stratified by baseline PD ( i.e. , 0 - 3 mm , 4 - 6 mm , > or = 7 mm ) . Safety was evaluated using adverse event data and the results of clinical laboratory tests , oral pathology examinations , and microbiological assessment s. RESULTS Within each disease stratum , the incremental improvements in PD and CAL demonstrated in the SDD group over 9 months of active treatment were maintained through 3 additional months of no treatment . Treatment cessation did not result in an accelerated regression of periodontal health . No differences in the incidence of adverse events ( including those related to infection ) or laboratory or microbiological parameters were noted between the SDD group and the placebo group . CONCLUSIONS The administration of SDD 20 mg bid for a period of up to 9 months is not associated with rebound effects or delayed or negative after-effects for a 3-month period after cessation of therapy OBJECTIVES The therapeutic effects of doxycycline and other tetracyclines in the treatment of periodontitis involve , at least in part , mechanisms that are unrelated to their antimicrobial activity . Previous clinical studies have shown that doxycycline administered orally , at doses below those needed for antimicrobial efficacy , to human subjects with adult periodontitis result ed in significantly reduced collagenase activity in gingival crevicular fluid ( GCF ) and in extracts of inflamed gingival tissues . The purpose of the present study was to identify clinical ly effective dosing regimens using subantimicrobial dose doxycycline ( SDD ) as an adjunctive therapy in patients with adult periodontitis . MATERIAL AND METHODS A total of 75 adult men and women qualified for enrollment into the three-part , placebo-controlled , double-blind , parallel-group study . Patients were stratified based on repeatedly exhibiting pathologic levels of periodontal attachment ( ALv ) and GCF collagenase activity at several appointments prior to baseline . Patients were administered a scaling and prophylaxis , then 1 of 5 treatment schedules for 12 weeks ( part I ) , followed by a 12-week period of no drug therapy ( part II ) , a second scaling and prophylaxis , and 12 additional weeks of treatment ( part III ) . Primary determinants of efficacy included reductions in GCF collagenase activity and changes in relative ALv . RESULTS 66 patients completed the 1st 12 weeks ( part I ) of the 3-part , 36-week study ; 51 patients completed the entire 36-week study . From baseline to week 12 ( part I ) , treatment with specially formulated SDD capsules ( 20 mg ) 2x daily ( 1 x every 12 h ) for up to 12 weeks was shown to significantly reduce GCF collagenase activity and to improve ALv , effects not seen in patients treated with placebo . Continuous drug therapy over the 12-week treatment period was needed to maintain and maximize the reduction in GCF collagenase and the improvement in ALv . Improvements in periodontal disease parameters occurred without the emergence of doxycycline-resistant micro-organisms . In patients administered an " on-off-on " regimen of SDD over 36 weeks ( parts I-III ) , essentially no attachment loss occurred in patients receiving the highest of these SDD regimens ( 20 mg 2x daily during part I and 20 mg 1 x daily in part III ) , whereas patients administered placebo capsules experienced a mean attachment loss of approximately 0.8 mm at the 24- and 36-week time periods . CONCLUSIONS Doxycycline administered at subantimicrobial doses led to improvements in disease parameters , with no apparent side effects , and appears to have significant potential as an oral adjunctive therapy in the long-term management of adult periodontitis BACKGROUND The present r and omized , double-masked , placebo-controlled , parallel-arm study examines the impact of adjunctive subantimicrobial-dose doxycycline ( SDD ) on the local inflammatory response through cytokine and chemokine levels in gingival crevicular fluid ( GCF ) sample s from patients with chronic periodontitis . METHODS Forty-six patients with chronic periodontitis received scaling and root planing with or without adjunctive SDD . GCF sample s were collected and clinical parameters including probing depth , clinical attachment level , gingival index , and plaque index were recorded every 3 months for 12 months . GCF tumor necrosis factor-α , interleukin (IL)-6 , IL-4 , IL-10 , IL-13 , IL-17 , macrophage inhibitory protein 1α , macrophage inhibitory protein 1β , monocyte chemoattractant protein 1 , and regulated on activated normal T-cell expressed and secreted protein levels were determined by xMAP multiplex immunoassay . RESULTS Significant improvements were observed in all clinical parameters in both groups over 12 months ( P < 0.0125 ) , whereas the SDD group showed significantly better reduction in gingival index , probing depth , and gain in clinical attachment compared to the placebo group ( P < 0.05 ) . Decrease in IL-6 in the SDD group was significantly higher compared to the placebo group at 6 and 9 months in deep pockets ( P < 0.05 ) , whereas tumor necrosis factor-α was significantly reduced in moderately deep pockets ( P < 0.05 ) . SDD result ed in a stable IL-4 and IL-10 response while reducing the monocyte chemoattractant protein 1 levels at 3 months ( P < 0.05 ) . CONCLUSIONS These results show that SDD , as an adjunct to non-surgical periodontal therapy , stabilizes the inflammatory response by promoting the suppression of proinflammatory cytokines and increasing the anti-inflammatory cytokines . The chemokine activity would account for the regulation of the inflammatory response to SDD therapy BACKGROUND This study evaluated the efficacy and safety of a subantimicrobial dose of doxycycline ( SDD ) in conjunction with scaling and root planing ( SRP ) . METHODS The study was a 9-month , double masked , r and omized , placebo-controlled , parallel-group trial . A total of 41 patients with moderate chronic periodontitis who received SRP were r and omly allocated to receive either a doxycycline hyclate or a placebo 2 weeks after SRP .  Clinical attachment level ( CAL ) , the probing depth ( PD ) , gingival crevicular fluid ( GCF ) levels , and matrix metalloproteinase (MMP)-8 and -13 levels were measured throughout the study . The effect of SDD in conjunction with SRP on the dynamics of the periodontal microflora was also assessed using dark-field microscopic and culture analysis . Information on adverse events was collected throughout the study . RESULTS During the treatment period , per-patient reductions in PD and CAL were demonstrated for both treatment groups , with a significantly greater reduction for the SDD group . The mean value of per-patient change in the GCF was much greater for the SDD group . Microbial analysis showed there were a general tendency for cocci , non-motile rods , and aerobes to increase with increasing treatment duration and a general decreasing tendency for spirochetes , motile rods , and anaerobes and black pigmented bacteria in both treatment groups , but no significant difference between the groups . The MMP-8 and -13 levels of the SDD group gradually reduced with time , and the mean perpatient average was significantly higher than in the placebo group . The adverse events in the SDD group were similar to those in the placebo group . CONCLUSION This study suggests that a su bmi crobial dose of doxycycline as an adjunct therapy with SRP might be safe and effective in the long-term management of chronic periodontitis AIM Diabetic patients have more severe periodontal destruction , but periodontal therapy can improve metabolic control . Recently , interest has focused on the use of subantimicrobial dose doxycycline ( SDD ) as a treatment paradigm . Therefore , this study was undertaken to evaluate clinical efficacy of SDD with scaling and root planning ( SRP ) in chronic periodontitis patients with diabetes . METHODS AND MATERIAL S Twenty chronic periodontitis patients with diabetes mellitus were r and omly allocated to either a test and a control group . Clinical measurements were recorded at baseline and at six months for probing pocket depth ( PPD ) , clinical attachment level ( CAL ) , and gingival recession ( GR ) . After SRP , patients in the test group were instructed to take SDD 20-mg capsules twice a day while patients in the control group took a placebo twice a day . Both groups were on this regimen for a six-month period . RESULTS A greater reduction in mean PPD was demonstrated in patients in the test group compared to the control group . The mean CAL increase observed in the test group was significantly greater ( 0.67 mm ) than that in the control group . CONCLUSION It can be concluded that SRP , in conjunction with the SDD therapy described , is more effective then SRP alone in terms of CAL gain and PPD reduction in diabetic patients with severe periodontal disease . CLINICAL SIGNIFICANCE Given the widespread prevalence of both chronic periodontitis and diabetes , the proposed treatment approach will prove to be of great value and contribute significantly to the overall health of the patients In this study , the clinical efficacies of systemic doxycycline ( SD ) and local doxycycline ( LD ) in the treatment of chronic periodontitis were compared . Forty-five patients were studied in 3 main groups with 5 treatments : SD alone , SD+scaling-root planing ( SD+SRP ) , LD alone , LD+SRP and SRP alone . Antibiotic-treated patients were given doxycycline treatment alone in 1 quadrant of their upper jaws , and doxycycline+SRP was given in the contralateral quadrant . The areas included at least 4 teeth with > or = 5 mm pockets . Probing depth ( PD ) , clinical attachment level , gingival index , sulcular bleeding index and plaque index values were recorded at baseline and the 7th week . The results were statistically analyzed . All of the clinical parameters were significantly reduced by all treatments ( P < or = 0.05 ) . The SD and LD treatments alone provided significant clinical healings . The significant differences among the groups were only in PD at the 7th week . The LD treatment provided significantly higher PD reduction than the SD treatment ( P < or = 0.05 ) . No significant difference was found between the SD+SRP and the LD+SRP treatments . There was no significant difference between SD+SRP and SRP alone treatment ( P > 0.05 ) . The SD group showed lower PD reduction than SRP group ( P < or = 0.05 ) , while no significant difference was found between LD and SRP treatments . The LD alone treatment seemed more effective than SD alone treatment on PD reduction , but no significant difference was found between them when combined with the SRP . LD may be more preferable than SD as an adjunct to mechanical treatment since LD seems more effective than SD on PD reduction and does not have the side effects of SD BACKGROUND Previous studies have shown that subantimicrobial dose doxycycline ( SDD ) is of clinical benefit in the treatment of chronic periodontitis ( CP ) . The aim of this study was to further assess the role of SDD as an adjunct to scaling and root planing ( SRP ) in the treatment of CP . METHODS A double- 
    Output:
    
Significant differences were observed for all investigated clinical parameters in favor of the SRP + SDD group .