***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 ability of two different toothbrush bristle ends to produce traumatic gingival abrasion was assessed in a double blind study of 15 male and 15 female young adults . Brushing was performed in a circular fashion using a modified Bass Technique . An apparatus allowing continuous visual feedback of the average brushing force permitted a degree of st and ardization of the system . The upper left canine and bicuspid area had to be brushed for 30 seconds with cut toothbrush bristles ( CP ) and with round ended toothbrush bristles ( RP ) respectively . A two week interval separated the two brushing sessions . Traumatic lesions of the attached gingiva were stained with a disclosing solution , photographed and evaluated planimetrically . The " cut bristles " caused gingival abrasions 30 % greater in extent than the round end bristles . The difference was not due to single brushing strokes accidentally greater for the " cut bristles " . The size of the lesions was not sex dependent . To prevent gingival damage it is desirable to either round the bristles in production or to rid the bristle ends at least of sharp edges AIM To evaluate gingival recession changes after six months of brushing with an oscillating-rotating power toothbrush ( PT ) or an ADA reference manual toothbrush ( MT ) . METHODS AND MATERIAL S Healthy subjects with pre-existing recession were assigned to brush with either a PT ( n=55 ) or an ADA reference MT ( n=54 ) according to a prospect i ve r and omized , controlled , single-blind , parallel group design . Participants were asked to brush their teeth twice daily for two minutes each with the same fluoride toothpaste . Clinical attachment loss and probing pocket depths ( PPDs ) were measured at six sites per tooth to the nearest mm by one calibrated examiner at baseline and after six months . Gingival recession was calculated as the differences between clinical attachment loss and PPDs overall and separately at individual sites . RESULTS As compared with baseline , overall recession at six months was reduced from 2.35 + /- 0.35 mm to 1.98 + /- 0.55 mm ( p<0.001 ) in the PT group and from 2.26 + /- 0.31 mm to 1.90 + /- 0.45 mm ( p<0.001 ) in the MT group . The data showed 40 % ( power ) and 38 % ( manual ) of all recession sites improved by at least 0.5 mm while 51 % and 54 % remained unchanged . Eight percent and 7 % recessions increased over time . Differences between groups were not statistically significant at either timepoint . CONCLUSION Both the PT and the MT significantly reduced pre-existing gingival recession after six months of brushing . This may have been due to improved brushing technique ( i.e. , Hawthorne effect ) . CLINICAL SIGNIFICANCE Based on these six-month data , concern that power tooth brushing results in a higher risk for gingival recession is not warranted The aim of the present study was to evaluate the efficacy of manual and electric toothbrushes in plaque control in periodontal patients after proper instructions . Thirty six periodontal patients ( mean age of 49 years , 21 females and 15 males ) were included and completed the study ( 100 % compliance ) . A single-blinded , r and omized , controlled , cross-over clinical design was adopted , with the patients using during 2 periods of 14 days each the manual and /or electric toothbrush .  Four subgroups of 9 individuals were studied : A1 - -used manual toothbrush in both experimental periods ; A2 - -used the manual toothbrush during the first period and the electrical toothbrush during the second period ; B1 - -used electrical toothbrush during both periods ; B2 - -used the electrical toothbrush in the first period and the manual one in the second period . Brushing was performed during 14 days and at day 14 and 28 it was performed in the clinic , and timing of brushing was recorded without patients being aware . The Plaque Index ( Silness , Löe , 1964 ) was used . Intra-group comparisons were performed by paired t-test and inter-group comparisons by independent sample t-test , with an alpha level of 0.05 . The results showed no difference between the tested brushes neither for plaque nor for timing . However , re-instruction was detected as an important factor , since for all groups the second period , after reinstruction , showed lower plaque scores . It is concluded that professional advice and instruction and re-instruction seem more important in order to obtain good plaque control than the choice of toothbrush in subjects with periodontal disease BACKGROUND Reports suggest powered toothbrushing may provide some clinical benefit over manual tooth-brushing , but most studies have been of short duration with subjects trained in toothbrush use . The aim was to determine if the oscillating-rotating powered brush ( PB ) could safely provide clinical benefits over and above a manual brush ( M ) in subjects with no formal instruction or experience in powered brush use . METHODS This 6-month , single-masked , parallel design , r and omized clinical trial compared the PB with an American Dental Association (ADA)-accepted soft-bristle manual brush in a non-flossing gingivitis population ( n = 157 ) . Subjects were given written instructions but no demonstration on toothbrush use at baseline . Efficacy was assessed by changes in gingival inflammation , plaque , calculus , and stain , while changes in clinical attachment levels and recession measurements provided safety data . A prophylaxis was provided after baseline assessment . The 6-month plaque index ( PI ) was recorded immediately post-brushing after covert timing of the subjects , and correlation analyses were run to assess the relationship of brushing time to PI . Paired t tests , analysis of variance ( ANOVA ) , and analysis of covariance ( ANCOVA ) were used to assess within and between treatment group differences for PB ( n = 76 ) versus M groups ( n = 81 ) . RESULTS Measures of inflammation showed a statistically significant drop for both brushes at 3 and 6 months . Mean overnight full-mouth PI scores were significantly lower at 3 months for the PB ( 1.57 ) compared to the M group ( 1.80 ) , P = 0.0013 . Immediate post-brushing PI at 6 months was also significantly lower for the PB ( 1.10 ) versus M ( 1.39 ) ( P= 0.0025 ) . There was an overall negative correlation for PI and brushing time ( r = -0.377 , P= 0.0001 ) . Mean calculus index ( CI ) scores were lower for the PB at 3 ( P= 0.0304 ) and 6 months ( P = 0.0078 ) , while no significant differences in stain were observable . Clinical attachment level and recession measurements showed no significant between-group changes from baseline for either brush on canine teeth or on teeth with recession at baseline . CONCLUSION The oscillating-rotating toothbrush safely provides clinical benefits in plaque and calculus reduction over a manual brush even in subjects with no formal oral hygiene instruction BACKGROUND The objective of this study was to evaluate the effect of an oscillating/rotating/pulsating powered toothbrush on  plaque and gingivitis prevention over a 9-month period . METHODS The study had an examiner-masked , r and omized , three-group parallel design . A total of 122 subjects > or= 18 years of age in good general health and with at least five teeth per quadrant and no pockets > or= 5 mm were included . A 3-week preexperimental period of extensive oral home care , including rinses , was started to improve gingival health . Professional oral hygiene instruction with a manual brush was provided . At baseline , subjects were assigned to one of three regimens : twice daily brushing with a manual toothbrush , a manual toothbrush and the use of floss , or a powered toothbrush . Subjects were professionally instructed in their regimen and given a prophylaxis . Two weeks later , oral hygiene reinforcement was provided . Gingival bleeding , plaque , staining , and gingival abrasion were assessed during the preexperimental period and at baseline , 10 weeks , and 6 and 9 months . RESULTS There was a significant reduction in plaque and gingivitis from the preexperimental period to baseline . At 10 weeks and 6 and 9 months , the level of plaque was statistically significantly lower with the powered toothbrush versus the other two regimens ( P < or= 0.002 ) . At 10 weeks and 6 months , the level of bleeding in the powered toothbrush group was statistically significantly lower versus manual brushing alone ( P < or= 0.024 ) . CONCLUSIONS The powered toothbrush maintained lower plaque levels for 9 months following the 3-week treatment phase better than the manual toothbrush with or without floss . The powered toothbrush showed significant benefits in preventing gingival bleeding versus manual brushing alone . All regimens were safe for oral tissues Power toothbrushes can offer significant advantages over a manual toothbrush both with respect to plaque removal and compliance . Most studies have , however , been carried out with adult toothbrushes in adult population s. Less is known about the efficacy of children 's power toothbrushes  , although it is likely that similar advantages will be demonstrated . This practice based study used the Debris Index ( DI ) component of the Simplified Oral Hygiene Index to compare baseline oral hygiene with results after 2 months of using the Braun Oral-B Kids ' Power Toothbrush ( D10 ) . The study involved 13 dental offices and a total of 154 children aged 4 to 9 years . For all sites ( facial and lingual ) , using the D10 for 2 months result ed in an approximately 40 % reduction in the DI . Question naires completed by the parents or guardians , the children , and the dentists indicated a very favorable response to the power toothbrush . Both parents and children preferred the D10 to a manual toothbrush and most said they would continue to use it . The fact that children found the D10 fun to use may well aid compliance . Dentists thought that the D10 was effective and , at the end of the study , most said that they would now recommend a power toothbrush . It is concluded from the results of this practice based study that the D10 can help to reduce plaque levels in a population of children who previously relied on a manual toothbrush . The fact that the D10 is appealing to children and fun to use should aid compliance with long-term oral hygiene PURPOSE To measure the  dentin substrate wear  associated with  toothbrush use utilizing an in vitro specimen modeled to simulate the prominences of teeth and thus more closely simulate the clinical situation . MATERIAL S AND METHODS Dentin sections were cast within resin to produce a specimen configuration with three half-round ridges : a central ridge containing dentin ( 3 x 10 mm ) and two similar ridges on each side of the central ridge . The specimens were brushed for the equivalent of the amount of time an individual tooth surface would be brushed in a 2-year period using a machine that simulated typical movement of a toothbrush across the specimen under controlled load and fluid conditions . Brushing was done with either a manual toothbrush ( MTB ) , the Braun Oral-B 3D Excel ( PTB1 ) or the Sonicare Elite ( PTB2 ) and various loads . Dentin substrate loss was measured by profilometry . RESULTS Using this ridged specimen configuration , the results showed that the MTB and PTB1 had the highest amount of dentin substrate wear in both average depth and average maximum depth measurements . Increased toothbrush force from 90 g to 150 g increased the dentin substrate wear of both PTBs . PTB1 produced approximately 4 - 5 times greater average wear than PTB2 ( P < 0.05 ) The objective of this three treatment , three period , single blind , cross-over trial was to evaluate the efficacy of three toothbrushes in a cohort of children undergoing fixed appliance orthodontic therapy .  The brushes used were : ( 1 ) Dental Logic HP550 with regular brush head HP5924 ( Philips , U.K. ) ; ( 2 ) Braun Oral B Plaque Remover ( D7 ) with dedicated orthodontic brush head OD5 - 1 ( Braun AG , Germany ) ; and ( 3 ) a manual dedicated orthodontic toothbrush ( P35 , Oral B Laboratories , Calif. ) . Sixty orthodontic patients , aged 10 to 16 years and wearing upper and lower fixed appliances , were screened and recruited with parental consent . After an oral soft tissue examination at baseline , the percentage of plaque-covered tooth surfaces and gingival bleeding sites were recorded using visible plaque and gingival bleeding indexes . Each subject was r and omly allocated to one of three groups ( n = 20 ) with brushing sequences 1 - 2 - 3 , 2 - 1 - 3 , 3 - 2 - 1 . The first brush was given 2 weeks after baseline ( visit 1 ) . The time interval for using each brush was 4 weeks at the end of which visible plaque and gingival bleeding indexes were recorded and a further prophylaxis given . Statistical analysis was undertaken with analysis of variance . Data were analyzed on a site-specific basis ; buccal smooth and interproximal surfaces , lingual smooth and interproximal surfaces . At baseline the mean visible plaque index for all subjects were ; buccal smooth , 52.5 % ( + /- 22.5 % ) ; buccal interproximal , 70.5 % ( + /- 18.5 % ) ; lingual smooth , 68.5 % ( + /- 21 % ) ; lingual interproximal , 76 % ( + /- 16 % ) 
    Output:
    
A large body of published research in the preceding 2 decades has consistently shown oscillating-rotating toothbrushes to be safe compared to manual toothbrushes , demonstrating that these power toothbrushes do not pose a clinical ly relevant concern to hard or soft tissues