***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: UNLABELLED Glass ionomer cement with addition of chlorhexidine used as a varnish on tooth surfaces has been shown to reduce the number of interproximal mutans streptococci ( ms ) . The effect of a single application of such a varnish containing 2.5 % chlorhexidine on occlusal caries development of the first permanent molars on 6-year-old children in a high caries incidence area was investigated . The children were examined according to WHO criteria and 262 children with 2 caries free contra-lateral molars were selected for treatment . Salivary ms sample s were collected using the Strip-mutans ( SM ) method . After brushing the occlusal surfaces with a toothbrush and pumice in water slurry , rinsing and drying with a cotton roll , glass ionomer cement containing chlorhexidine ( GI-CHX ) and glass ionomer ( GI ) were applied r and omly with a micro brush and the varnish was covered with occlusal wax . At baseline , the mean defs was 18.18 and DMFS was 0.25 and after one year 18.24 and 0.83 respectively . The salivary ms scores were high or very high ( SM 2 and 3 ) in 85.6 % at baseline . At the one-year follow up , the GI-CHX and GI material s could not be detected in the fissures . Also , a large number of fissure sealants had been placed in the molars outside the study protocol ; thus 4 % of the GI-CHX and GI , and 70 % of the untreated were sealed at year one . Overall , there was no significant difference between the caries-reducing effect of GI-CHX and GI , but a trend towards a higher effect was seen for GI-CHX . Excluding the sealed molars the reduction was 74 % in the GI-CHX-group , and 71 % in the GI-group . CONCLUSION Addition of 2.5 % chlorhexidine to glass ionomer did not seem to increase the caries-reducing effect of the varnish in this high caries incidence population Evidence on the caries-preventive effect of chlorhexidine ( CHX ) among high-risk children is inconclusive , possibly because obscured by fluoride exposure . We investigated the effect of CHX among initially 3-year-old subjects whose baseline d3 ft was = 0 and whose only regular fluoride exposure came from toothpaste . The subjects were assigned to three groups : high-risk test ( HRT , n = 70 ) , high-risk control ( HRC , n = 71 ) , and low-risk control ( LRC , n = 70 ) . Risk classification was based on salivary mutans streptococcal levels ( MS , 5 cfu/ml ) . Basic measures ( oral hygiene , dietary counselling every 4 months ) were given to all groups . HRT also underwent CHX gel applications for 3 consecutive days at 3-month intervals for 15 months . Eighteen months after baseline d3 ft increments and proportions of children with d3 ft increment ≧1 ( % d3 ft increment ≧1 ) among all groups were assessed . Anti-MS effect on high-risk children and caries-preventive effect on all children were statistically analysed by residual change analysis ( MS ) , non-parametric tests and logistic regression analysis ( caries ) . No differences were found between the groups in basic programme compliance . CHX  significantly reduced MS levels . % d3 ft increment ≧1 and mean d3 ft increments were 34.3 % , 0.56 ( HRT ) , 32.4 % , 0.54 ( HRC ) and 11.4 % , 0.11 ( LRC ) , with HRT/HRC values statistically significantly higher than LRC values and no significant difference between HRT and HRC . HRT children were not less likely to show new lesions than HRC children ( OR = 1.09 ; 95 % confidence interval 0.54–2.19 ) , while high-risk children were 4 times more likely to show new lesions than low-risk children ( OR = 3.71 ; 95 % confidence interval 1.53–9.03 ) . CHX gel applications showed moderate anti-MS effect but negligible caries-preventive effect The aim of the investigation was to evaluate the effect of chlorhexidine gel treatment on  caries development of approximal tooth surfaces  and on salivary counts of Streptococcus mutans .  220 12-year-old schoolchildren , divided into three groups , participated : ( 1 ) chlorhexidine gel group ( n = 72 ) , ( 2 ) placebo gel group ( n = 77 ) , and ( 3 ) control group ( n = 71 ) . The study was carried out double blind with respect to the two gel groups . Group 1 was treated 4 times/year with 1 % chlorhexidine gel and group 2 with a placebo gel . Approximately 1 ml of gel was applied interdentally by means of a flat dental floss . The control group did not receive any gel treatment or flossing . Number of S. mutans in the saliva was estimated on five occasions during the study with the spatula method . After 3 years , the mean approximal caries increment , expressed as new DFS , was 2.50 in the chlorhexidine gel group and 4.30 in the placebo gel group ( p less than 0.05 ) . The corresponding figure in the control group was 5.25 ( p less than 0.001 when compared to group 1 ) . 44 % of the children in the chlorhexidine gel group and 32 % in the placebo gel group did not develop any new approximal caries lesion during the 3-year observation period compared to 18 % in the control group ( group 1 - 3 p less than 0.001 ; group 2 - 3 p less than 0.05 ) . The number of new approximal fillings ( FS ) was 0.24 in the chlorhexidine gel group , 0.75 in the placebo gel group and 0.82 in the control group ( group 1 - 3 p less than 0.01 ; group 2 - 3 p less than 0.05 ) . There was no statistically significant difference between the groups with respect to numbers of S. mutans in saliva . However , there were more individuals with low numbers of S. mutans in the chlorhexidine gel group at the final examination compared to the baseline level ( p less than 0.05 ) Evidence regarding the caries-inhibiting effect of chlorhexidine varnish is inconclusive . This study investigated the caries-inhibiting effect of the varnish EC40 on pits and fissures of first permanent molars . A two-year r and omized controlled trial was carried out among 461 six- to seven-year-old children . In a split-mouth design , one group of molars received EC40 at baseline , 6 , 12 , and 18 months , and another group at baseline , 3 , 12 , and 15 months . Control molars did not receive EC40 .  Adherence to the treatment protocol was good . The dropout rate was 17 % . Blinded examiners performed dental examinations . The caries-inhibiting effects of the two EC40 application schemes were comparable . The prevented fraction of caries was 25 % ( 95%CI , 1 % , 49 % , p = 0.04 ) after 2 years and 9 % ( 95%CI , −11 % , 29 % , p = 0.20 ) one year after termination of the trial , suggesting a short-term benefit from the use of EC40 . The efficiency of EC40 is question able in low-caries-incidence child population We have in two earlier studies evaluated the effect of professional flossing with chlorhexidine ( CHX ) gel treatment , in 4- to 7-year-old preschool children and in 12- to 15-year-old teenagers . The mean caries reduction after 3 years was around 40 % compared to placebo gel or no gel treatment . The aim of the present investigation was to follow up these two clinical studies . The preschool children were followed up to the age of 16 years and the teenager group to the age of 19 . Of the total number of original children , 71 and 80 % were available at the age of 16 and 19 years , respectively . At the 9-year follow-up , when the children were 16 years old , the former CHX group had still significantly lower mean DFS than the control group ( p < 0.05 ) . The differences in caries increment occurred between 7 and 12 years of age , whereas the number of new caries lesions during the next 4 years were almost the same in the three groups . At the 4-year follow-up , when the teenagers were 19 years old , DFS was 6.9 in the former CHX group compared to 10.4 in the control group ( p < 0.05 ) . The main conclusion of these two follow-up studies after 9 and 4 years , respectively , is that caries reductions obtained at the end of professional flossing with a 1 % CHX gel were maintained PURPOSE The purpose of this study was to compare twice daily tooth-brushing using 0.304 percent fluoride toothpaste alone with : ( 1 ) twice daily tooth-brushing plus once daily 10 % casein phosphopeptide-amorphous calcium phosphate ( CPP-ACP ) paste ; and ( 2 ) twice daily tooth-brushing plus once daily 0.12 % chlorhexidine gel ( CHX ) for reducing  early childhood caries ( ECC ) and mutans streptococci ( MS ) colonization . METHODS Subjects ( n=622 ) recruited at birth were r and omized to receive either CPP-ACP or CHX or no product ( study control [ SC ] ) . All children were examined at 6 , 12 , and 18 months old in their homes , and at 24 months old in a community dental clinic . RESULTS At 24 months old , the caries incidence was 1 % ( 2/163 ) in CPP-ACP , 2 % ( 4/180 ) in CHX , and 2 % ( 3/188 ) in SC groups . In children who were previously MS colonized at 12 and 18 months old , 0 % ( 0/11 ) and 5 % ( 3/63 ) , respectively , of the CPP-ACP group remained MS-positive versus 22 % ( 2/9 ) and 72 % ( 18/25 ) in CHX and 16 % ( 4/25 ) and 50 % ( 7/14 ) in SC groups ( P<.001 ) . CONCLUSIONS There is insufficient evidence to justify the daily use of casein phosphopeptide-amorphous calcium phosphate or chlorhexidine gel to control early childhood caries OBJECTIVES . This r and omised , controlled trial compared the effectiveness of 0.12 % chlorhexidine ( CHX ) gel and 304 % fluoride toothpaste to prevent  early childhood caries ( ECC ) in a birth cohort by 24 months . METHODS . The participants were r and omised to receive either ( i ) twice daily toothbrushing with toothpaste and once daily 0.12 % CHX gel ( n = 110 ) or ( ii ) twice daily toothbrushing with toothpaste only ( study controls ) ( n = 89 ) . The primary outcome measured was caries incidence and the secondary outcome was percentage of children with mutans streptococci ( MS ) .  All mothers were contacted by telephone at 6 , 12 , and 18 months . At 24 months , all children were examined at a community dental clinic . RESULTS . At 24 months , the caries prevalence was 5 % ( 3/61 ) in the CHX and 7 % ( 4/58 ) in the controls ( P = 0.7 ) . There were no differences in percentages of MS-positive children between the CHX and control groups ( 54%vs 53 % ) . Only 20 % applied the CHX gel once daily and 80 % less than once daily . CONCLUSIONS . Toothbrushing using 304 % fluoride toothpaste with or without the application of chlorhexidine gel ( 0.12 % ) reduces ECC from 23 % found in the general community to 5 - 7 % . The lack of effect with chlorhexidine is likely to be due to low compliance OBJECTIVE The purpose of this study was to determine whether Cervitec -- a chlorhexidine -- containing varnish could reduce the development of pit and fissure caries in children . METHODS One hundred children each in age groups 7 - 8 and 12 - 14 years were selected from schools in Riyadh , Saudi Arabia . To be included in the study , each child had to have at least two sound contra-lateral first or second permanent molars with deep fissures . A split mouth method was used with one test tooth and one control within the same jaw . The left or the right side was selected r and omly for test or control . The plaque sample s from the occlusal surfaces of the test and control and the saliva sample s were collected at baseline examination and after 9 months to estimate the number of Streptococcus mutans by the strip mutans method of Jensen and Bratthall ( Jensen B , Bratthall D. A new method for the estimation of mutans streptococci in human saliva . Journal of Dental Research 1989;68:468 - 471 ) . Cervitec varnish containing 1 % chlorhexidine ( CHx ) and thymol was applied at baseline , at 3 - 4 months and at 6 months to the test tooth after isolation while the control had prophylaxis using cotton pellet in water each time the varnish was applied to the test tooth 
    Output:
    
We found little evidence from the eight trials on varnishes and gels included in this review to either support or refute the assertion that chlorhexidine is more effective than placebo or no treatment in the prevention of caries or the reduction of mutans streptococci levels in children and adolescents .