***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: The purpose of the study was to assess the anti-plaque effect of chlorhexidine ( CHX ) in chewing gum . The 0.80 g pieces of test gum contained 5 mg chlorhexidine acetate with or without a hydrogen peroxide releasing agent . The gum base with flavouring agents but containing neither CHX nor H2O2 was used as a control . 12 dental hygiene students volunteered to participate in the 3 x crossed-over double blind clinical trial . During the 4-day test periods , no other oral hygiene measures were allowed than chewing 2 pieces of gum at the time for approximately 10 min , 5 times daily . Between test periods , meticulous mechanical oral hygiene measures were practised for 3 days . At the beginning and at the end of each test period , the quantity of plaque was assessed using the plaque index , plaque wet weight , and the area of plaque on the tooth surface as criteria . The results indicated that both CHX gums completely inhibited the increase in plaque index and plaque weight . With regard to area of plaque , the difference between the 2 test gums and the control gum was less marked but still present . The test persons subjectively assessed the gum base to have a poor cleansing effect but also the least unpleasant taste . It was concluded that use of both the chlorhexidine gum and the gum-containing chlorhexidine in addition to the hydrogen peroxide releasing agent had an excellent plaque growth inhibiting effect during the 4-day test periods Chewing gums may be suitable vehicles for the delivery of xylitol ( X ) and chlorhexidine acetate ( CHX ) , both of which can aid oral health . The aim of this study was to determine the clinical effectiveness of chewing gums containing X or a combination of X and CHX in a double-blind , r and omised , cross over , 5-day clinical trial , with a 9-day washout period in a group of participants over 40 years old . After professional tooth cleaning , 8 subjects ( mean age 51.3+/-10.4 years ) used in a r and om order 2 pieces of ACHX ( a liquorice flavoured CHX/X ) gum , 2 pieces of BCHX ( a chocolate mint flavoured CHX/X ) , 2 pieces of X ( a liquorice flavoured X gum ) and 1 piece of ACHX . Gums were chewed 2x daily for 15 min and volunteers refrained from all other oral hygiene procedures . Data were analysed using Friedman nonparametric analysis of variance . Plaque indices for chewing 2 pieces of ACHX gum ( 0.78+/-0.15 ) and BCHX gum ( 0.52+/-0.15 ) were significantly lower ( p<0.0006 ) than for X gum ( 1.57+/-0.08 ) . The gingival index was significantly greater ( p<0.05 ) for X containing gum than for the other chewing regimes . The subjects ' attitudes to the gums were also assessed by structured question naires which showed that all gums were easy to chew , did not adhere to dentures , teeth or restorations and that the subjects preferred to chew 2 pellets rather than 1 BACKGROUND Studies in vitro showed that eucalyptus extracts possess antibacterial activity against cariogenic and periodontopathic bacteria ; however , the clinical effects with respect to periodontal health in humans remain unproven . The objective of this study was to evaluate the effect of chewing gum containing eucalyptus extract on periodontal health in a double-masked , r and omized , controlled trial . METHODS Healthy humans with gingivitis but not deep periodontal pockets were r and omly assigned to the following groups : high-concentration group ( n=32 ) : use of 0.6 % eucalyptus extract chewing gum for 12 weeks ( 90 mg/day ) ; low-concentration group ( n=32 ) : use of 0.4 % eucalyptus extract chewing gum for 12 weeks ( 60 mg/day ) ; and placebo group ( n=33 ) : use of chewing gum without eucalyptus extract for 12 weeks . Plaque accumulation ( PLA ) , gingival index ( GI ) , bleeding on probing ( BOP ) , periodontal probing depth ( PD ) , and clinical attachment level ( CAL ) were measured at weeks 0 , 4 , 8 , 12 , and 14 . Significance was analyzed with repeated- measures two-way analysis of variance followed by the Games-Howell pairwise comparison test . RESULTS The interaction between the effects of eucalyptus extract chewing gum and the intake period was statistically significant for PLA , GI , BOP , and PD but not for CAL . The low- and high-concentration groups exhibited statistically significant ( P < 0.05 ) improvements compared to the placebo group for PLA , GI , BOP , and PD . CONCLUSIONS Eucalyptus extract chewing gum had a significant effect on PLA , GI , BOP , and PD . The use of eucalyptus extract chewing gum may promote periodontal health Previous studies showed that Persica extracts have antibacterial activity against cariogenic and periodontopathic bacteria and can develop periodontal health ; however , the clinical effects of gum as a delivery device for Persica to periodontal health in human , have not yet been investigated . The objective of this study was to evaluate the effect of chewing gum containing Persica extract on periodontal health in a double-masked , r and omized trial . From a high school in Babol , 72 cases with plaque induced moderate gingivitis were r and omly assigned to the 2 weeks trial in the following groups : S+/P+ ( n = 18 ) : use of Persica extract chewing gum for 2 weeks and two sessions of scaling ; S+/P- ( n = 18 ) : use of placebo chewing gum two sessions of scaling ; S-/P+ ( n = 18 ) : use of Persica extract chewing gum ; and S-/P- ( n = 18 ) : use of placebo chewing gum .  Plaque index ( PI ) , gingival index ( GI ) , and bleeding index ( BI ) , were measured at days 0 , 7 , and 14 . Data was analyzed with t test or Mann-Whitney U test . Seven patients from Persica scaling group and five patients from Persica no scaling ( S-/P+ ) group were excluded for complaining about the taste and irritation . The effects of extract chewing gum was statistically significant in reduction of GI , and BI but not for PI in Persica groups compared with the placebo groups in the days of 7 and 14 after the beginning of trial . Persica extract chewing gum had a considerable effect on GI , and BI . The use of Salvadora persica extract chewing gum may promote periodontal health The purpose of this study was to evaluate the inhibitory effect of funoran containing chewing gum ( FG ) and eucalyptus extract- containing chewing gum ( EG ) on plaque formation .  Fifteen dentists or dental students were assigned a r and om order of use of either FG , EG or a control gum . All subjects received professional tooth cleanings before the experiment . During the four-day test periods , no oral hygiene measures were allowed other than chewing three pieces of gum for approximately 10 min daily . Chewing gum was used following each morning , noon and evening meal . Plaque formation was evaluated by the Quigley and Hein index . The FG ( 1.83 + /- 1.1 ) and EG ( 1.97 + /- 1.1 ) significantly reduced plaque compared to the control gum ( 2.57 + /- 1.2 ) . Our results suggest that FG and EG may be useful in inhibiting dental plaque formation UNLABELLED Sugar-free chewing gum has been cl aim ed to be a useful means of reducing dental plaque accumulation . The incorporation of additives , such as enzymes , abrasives and divalent metal ions , into gum formulations might improve their antiplaque activity , particularly at the buccal and lingual surfaces of the teeth . OBJECTIVES The aim of this study was to investigate the plaque inhibitory effects of three sugar-free chewing gums each containing lactoperoxidase ( LP ) , micro granules of silicon dioxide ( SD ) , and zinc gluconate ( ZG ) . METHODS The study was an observer-masked , r and omized cross-over design balanced for carryover effects , involving 12 healthy volunteers in a 4-day plaque regrowth model . An additive-free ( AF ) gum served as positive/negative control for occlusal and smooth surfaces , respectively . On day 1 , subjects received professional prophylaxis , suspended oral hygiene measures , and commenced chewing their allocated product . Gum chewing was one piece chewed for 30min 4 times a day . On day 5 , subjects were scored for disclosed plaque . RESULTS There were no significant differences in antiplaque activity of the gums tested , neither for the smooth nor for the occlusal surfaces ( P=0.447 and P=0.418 , respectively ) . Similar results were obtained for the anterior and posterior sites of smooth surfaces ( P>0.05 ) , and for the lower and upper sites of occlusal surfaces ( P=0.451 and P=0.53 , respectively ) . CONCLUSIONS These findings suggest that the chewing gums containing LP , SD and ZG would provide no plaque inhibitory effects on smooth surfaces . The gums containing these additives , therefore , should not be recommended as adjuncts to mechanical oral hygiene ETHNOPHARMACOLOGICAL RELEVANCE Salvadora persica shrub has been used traditionally in folk medicine for different medical condition treatments . The habitual use of Salvadora persica roots ( chewing sticks ) for dental hygiene is still wildly spread throughout parts of Asia , Africa , and Middle . It is one of the most important species with its reported strong antibacterial , antifungal , and antiviral effects . Mechanical removal of dental plaque is regarded as an effective mean of controlling progression of periodontal disease . AIM OF THE STUDY To evaluate the effect of active and inactive miswak on dental plaque , subgingival microbiota and gingival inflammation in patients with gingivitis . MATERIAL S AND METHODS In this double blinded r and omized controlled trial 68 gingivitis patients were r and omly assigned to either active or inactive miswak group , and were instructed to use only issued miswaks for oral hygiene during 3 weeks experimental period . Registration of plaque , gingival inflammation , and plaque sample s were taken at baseline and on completion of the study . Plaque sample s were analyzed by DNA-DNA hybridization technique . RESULTS Active miswak significantly reduced dental plaque ( p = 0.007 ) . There were no differences between active and inactive miswak in reduction of approximal plaque and composition of subgingival microbiota . CONCLUSIONS Miswak has an overall effect on dental plaque and gingival inflammation scores . Similar results were achieved by active and inactive miswak in difficult to reach areas , indicating miswak has limited chemical effects on this study population . Therefore , miswak can be used as a dental hygiene method in conjunction with interproximal cleaning aides A double-blind 3-treatment crossover design employing a 6-day trial period with out mechanical oral hygiene measures was used to compare dental plaque formation following use of chlorhexidine ( CHX ) acetate- , xylitol- , and sorbitol-containing chewing gum .  Fourteen dental students were assigned a r and om ordering of the chewing gum products  and received professional tooth cleaning at the start of trial periods . For each trial period , subjects were instructed to use 5 pieces of the unlabeled chewing gum daily ( containing 5.0 mg CHX acetate/piece ; 0.8 xylitol/piece ; or 1.0 g sorbitol/piece ) . Two pieces of chewing gum were used following each morning and evening meal and one piece following the noon meal . The subjects were instructed to use the products for 20 minutes at each occasion . A 7-day washout-period between trial periods was used . The Turesky modification of the Quigley and Hein index was used to assess plaque formation . Differences between treatments were evaluated using a repeated measures ANOVA with Newman-Keuls multiple comparisons . The CHX-containing chewing gum showed significantly reduced plaque values ( 0.7 + /- 0.4 ) compared to the sorbitol-(2.7 + /- 0.4 ; P < 0.01 ) and xylitol-product ( 1.7 + /- 0.3 ; P < 0.01 ) . Furthermore , the CHX-product significantly reduced plaque levels compared to the study subjects ' regular plaque control routines ( 1.3 + /- 0.04 ; P < 0.05 ) . The xylitol-product exhibited significantly lower plaque-values than the sorbitol-product ( P < 0.01 ) . Our results suggest that regular use of CHX-containing chewing gum appears useful to control dental plaque formation AIM A r and omised , controlled , double-blind , clinical trial was conducted to investigate the effect of a chlorhexidine acetate/xylitol gum ( ACHX ) on the plaque and gingival indices of 111 elderly occupants in residential homes . A gum containing xylitol alone ( X ) and a no gum ( N ) group was included . Participants ' opinions about chewing gum were also investigated . METHODS Subjects chewed 2 pellets , for 15 min , 2x daily for 12 months . RESULTS In the ACHX group , the plaque and gingival indices significantly decreased ( p<0.001 ) over the 12 months . In the X group , only the plaque score significantly decre 
    Output:
    
Most of the chewing gums with antimicrobial agents or herbal extracts were shown to have a positive effect with respect to plaque and gingivitis scores .
The most compelling evidence was provided for chewing gum containing chlorhexidine .
Meta- analysis and individual results indicate a beneficial effect of chlorhexidine on plaque inhibition .
However , GRADE evidence profile shows that the recommendation to use CHX-gum to reduce plaque scores in the absence of brushing is considered to be ' weak ' .
Other ingredients with positive outcomes on plaque scores are eucalyptus , acacia , funoran , Pycnogenol and mastic .
Limited data with respect to gingivitis scores were available , and the following agents showed a positive effect : magnolia , eucalyptus and CHX