***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: AIM To evaluate , in young adults , the effect of different preventive programmes on oral hygiene and to determine whether the variables investigated are predictors of gingival health . MATERIAL AND METHODS This r and omized , blinded , parallel , controlled clinical study examined the effectiveness of three dental health programmes . Four hundred subjects aged 20 - 27 years , 211 males and 189 females , participated in the study . They were recruited from a Public Dental Service clinic and from a private dental practice in Jönköping , Sweden . The effect of the programmes on plaque and gingivitis was evaluated over a 3-year period . The programmes included activities that were adapted for individuals as well as for groups . The plaque indices ( PLI ) and gingival indices ( GI ) were used to evaluate the programmes . RESULTS All programmes result ed in a decrease in PLI and GI . The greatest decrease was found in the group that was followed-up every 2 months .  Professional tooth cleaning  was non-significant for the clinical result . Gingival health at baseline , participation in any of the test programmes , and knowledge of the dental diseases caries , gingivitis or periodontitis were significant predictors of good gingival health . CONCLUSIONS The study confirms the efficacy of three different preventive programmes in reducing supragingival plaque and gingival inflammation .  Professional tooth cleaning provided no clinical benefit beyond that derived from individual and group-based health education The present report describes the result of a clinical trial in which a group of adults have been maintained on a proper oral hygiene st and ard over a 6-year period . In 1971 - -72 , 375 individuals were recruited to a test group and 180 to a control group . During the 6 years of trial , 65 persons from the test group and 34 controls were lost . The patients were divided into three age groups ; I less than 35 years , II 36 - -50 years , III greater than 50 years . The members of the test and control groups were first subjected to a Baseline examination which included  assessment  s of  oral hygiene , gingivitis , periodontal disease and caries .  Following this examination all caries lesions were treated and ill-fitting dental restorations adjusted . Each patient was also given a detailed case presentation and a dental prophylaxis . The control group patients were not involved in any further dental health programs during the subsequent 6-year period . Once a year , however , they were recalled to a public dental health clinic for examination and received symptomatic dental treatment . The test group participants , on the other h and , were given a preventive treatment , repeated once every 2 - 3 months which included ( 1 ) instruction and practice in oral hygiene techniques and ( 2 ) meticulous prophylaxis . The patients were re-examined 3 and 6 years after the baseline examination . At the Follow-up examinations the parameters studied at the Baseline examination were recorded again . The findings demonstrated that a preventive program which stimulates individuals to adopt proper oral hygiene habits may resolve gingivitis and prevent progression of periodontal disease and caries . Traditional dental care , on the other h and , did not prevent the progression of caries and periodontitis in adults 69 adults ranging in age from 20 to 73 ( mean age : 37 ) were r and omly assigned to a control ( C ) and a  test ( T ) group . Of these , 61 completed the 3-year longitudinal study . All subjects had varying degrees of gingivitis at the start , but no overt periodontitis . Following a base line examination for P1I , GI , probing depth ( PD ) and recession , a differential darkfield microscopic ( DDFM ) count of subgingival bacterial morphotypes was carried out on a pooled sample originating from one tooth surface in each sextant with the greatest probing depth . Examinations were repeated every 6 months for 3 years . The C group received regular prophylaxes every 6 months . The T subjects received prophylaxes according to a previously described schedule , and on the basis of the DDFM test outcome . Recall intervals at the end of the study for the T group ranged from 1 to 24 months ( mean : 15.7 months ) . Of 30 subjects in the T group at the end of the study , one half had not had their teeth cleaned for periods of 18 to 36 months without any detectable deterioration in their periodontal status by comparison with the other T subjects or the patients in the C group . Both C and T subjects exhibited increased mean P1I and GI scores as compared to base line during the first half of the study . However , mean PD measurements remained unchanged . Increases in PD from base line of 3 mm or more were observed only in approximately 1 out of a 1000 individual tooth surface comparisons , a frequency comparable to that expected to occur by chance alone . This observation indicates that in this population , little if any pocket formation occurred during the study period . GI score increases of 2 units or more occurred in relatively few subjects . 2 of 31 C patients accounted for 42 % of the affected dental units , while 5 out of 30 T subjects accounted for 40.8 % of the affected dental units in that group . These observations suggest that despite the relatively high prevalence and incidence of gingivitis , the subjects were relatively resistant to periodontitis . Neither preventive schedule was effective in eliminating gingivitis . The lack of significant destructive disease in this population prevented any meaningful comparison of the relative effectiveness of the two preventive maintenance regimens in preventing recurrences of periodontitis The beneficial effects of comprehensive dental prophylaxis programs are well recognized . In order to study the factors determining the effectiveness of these programs , 28 periodontal recall patients were subjected to monthly professional mechanical tooth cleanings . Experimental and control teeth were r and omly selected according to a splitmouth cross-over method . The Plaque and Gingival indices were recorded 1 month prior to the study , at the start , and at 4 , 8 , and 12 months . One month prior to the study calculus and bacterial plaque were thoroughly removed from all teeth . During the study period only the experimental teeth were cleaned . Efforts were made not to influence the oral hygiene of the participants by any other means . Following the initial tooth cleaning and during the preexperimental period the Plaque and Gingival indices decreased to a low level on both the experimental and control teeth ( mean P1I = 0.4 , mean GI = 0.3 ) . This high st and ard of oral hygiene and gingival health was maintained throughout the study period , and no differences could be observed between experimental and control teeth . This indicates that factors other than the mechanical professional cleaning were responsible for the maintenance of gingival health . It is suggested that participation in the program in itself may have motivated the patients to improve their oral home care The twice yearly application to children 's teeth of acidulated phosphate fluoride ( APF ) gel in dental trays preceded by a professionally rendered ' dental prophylaxis ' has become the st and ard and most commonly used dental chairside procedure for prevention of dental caries . This study was a r and omized , 3-year , community-based clinical trial of professionally applied APF gel involving the use and non-use of a prior dental prophylaxis and annual and biannual APF applications for children in age groups 6 - 7 ( n = 176 ) and 10 - 11 ( n = 153 ) years initially , who are likely at high risk of future dental caries . The 3-year results of this study show no significant effect on dental caries reduction of either a prior prophylaxis or annual versus biannual APF gel applications . A significant reduction in the frequency of provision of these dental services , limited to high caries risk patients only , is recommended 
    Output:
    
A generalisation on dental prophylaxis before PATF can not be applied to adolescents and adults .
Available evidence ( two other studies ) fails to demonstrate any benefit in the prevention of gingivitis from further dental prophylaxis at interval used for recall examinations .
Dental prophylaxis at intervals of four months or more is not justified for the prevention of gingivitis in the general population