***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 objective of this double-blind clinical study was to compare the tooth whitening efficacy ( stain removal ) of a new commercially available tooth whitening dentifrice ( Colgate Total Plus Whitening Toothpaste ) containing 0.2 % triclosan and 3.0 % PVM/MA copolymer in a 0.243 % sodium fluoride/high cleaning silica base , with that of two commercially available dentifrices , Crest Multi-Care Advanced Cleaning Toothpaste and Colgate Winterfresh Gel Fluoride Toothpaste . Following a baseline examination to assess extrinsic tooth stain , qualifying adult male and female subjects were r and omized into three treatment groups which were balanced for gender , age and level of extrinsic tooth stain . Subjects were asked to brush their teeth twice ( morning and evening ) for one minute with their assigned dentifrice using a soft-bristled toothbrush . Examinations for extrinsic tooth stain were repeated after six weeks ' use of the study dentifrices . One-hundred and twenty-three ( 123 ) subjects complied with the protocol and completed the study . At the six-week examination , subjects assigned to the Colgate Total Plus Whitening Toothpaste treatment group exhibited statistically significant reductions in extrinsic tooth stain area and extrinsic tooth stain intensity relative to those subjects assigned to the Crest Multi-Care Advanced Cleaning Toothpaste and the Colgate Winterfresh Gel Fluoride Toothpaste The objective of this double-blind clinical study was to investigate the tooth whitening efficacy of a new commercially available calculus-inhibiting dentifrice ( Colgate Tartar Control Plus Whitening Fluoride dentifrice ) containing tetra-sodium pyrophosphate , sodium tripolyphosphate , and PVM/MA copolymer in a 0.243 % sodium fluoride/silica base ( test dentifrice ) , compared to a commercially available , non-tooth whitening dentifrice containing 0.243 % sodium fluoride in a silica base ( control dentifrice ) . Following a baseline examination for , extrinsic tooth stain , qualifying adult male and female subjects from the Manchester , United Kingdom area were r and omized into two treatment groups which were balanced for gender , age and level of extrinsic tooth stain . Subjects were instructed to brush their teeth twice daily ( morning and evening ) for one minute with their assigned dentifrice using a soft-bristled toothbrush . Examinations for extrinsic tooth stain were repeated after six weeks ' use of the study dentifrices . Seventy-nine(79 ) subjects complied with the protocol and completed the entire study . At the six-week examination , subjects assigned to the test dentifrice treatment group exhibited statistically significant reductions of over 40 % with respect to both extrinsic tooth stain area and extrinsic tooth stain intensity relative to those subjects assigned to the control dentifrice treatment group The objective of this double-blind clinical study was to compare the efficacy for extrinsic tooth stain removal of four commercially available dentifrices : Colgate Tartar Control with Baking Soda & Peroxide Fluoride Toothpaste ; Aquafresh Advanced Whitening Toothpaste with Fluoride ; Rembr and t Tartar Control Low Abrasion Fluoride Whitening Toothpaste ; and Crest Regular Fluoride Toothpaste . Following a baseline examination for extrinsic tooth stain on the anterior six m and ibular and maxillary teeth , qualifying adult male and female subjects from the Philadelphia , Pennsylvania area were r and omized into four treatment groups which were balanced for age , gender , tobacco habits , and level of extrinsic tooth stain . Subjects were instructed to brush their teeth twice daily ( morning and evening ) for one minute with their assigned dentifrice using a soft-bristled toothbrush . Examinations for extrinsic tooth stain were repeated after six weeks ' use of the study dentifrices . One hundred eighty ( 180 ) subjects complied with the protocol , and completed the entire study . At the six-week examination , subjects assigned to the Colgate Tartar Control with Baking Soda & Peroxide Fluoride Toothpaste treatment group exhibited statistically lower levels of extrinsic tooth stain area and extrinsic tooth stain intensity than did those subjects assigned to the Crest Regular Fluoride treatment group . Subjects assigned to the Aquafresh Advanced Whitening treatment group exhibited significantly lower levels of extrinsic tooth stain area than did those assigned the Crest Regular Fluoride group . No other significant differences among the four study dentifrices were noted . Thus , the results of this double-blind clinical study support the conclusion that Colgate Tartar Control with Baking Soda & Peroxide Fluoride Toothpaste provides significantly greater control of extrinsic tooth stain than does Crest Regular Fluoride , a sodium fluoride/silica dentifrice OBJECTIVE The objective of this clinical investigation was to evaluate the effectiveness in removing existing extrinsic tooth stains of a sodium bicarbonate ( baking soda ) , dual-phase dentifrice containing calcium and phosphate ( Test Dentifrice ) , when compared to a commercial hydrated silica dentifrice ( Control Dentifrice ) , during a six-week period of normal , unsupervised use . METHODOLOGY This investigation was a double-blind comparison of two equivalent , parallel groups of subjects assigned to use different dentifrices for six weeks . A total of 108 adult male and female subjects qualified for the trial based on the presence of existing extrinsic tooth stains and other inclusion /exclusion criteria . The two groups were balanced for gender , tobacco use , and extrinsic tooth stain scores , and r and omly assigned the Test or Control dentifrices . All subjects were instructed to brush their teeth twice daily using only the dentifrice and toothbrush provided , and to refrain from using any other oral hygiene products for the duration of the study . Although product usage was unsupervised after the baseline visit , subjects maintained a treatment diary , and product consumption was monitored to estimate compliance . Oral soft and hard tissue and extrinsic stain assessment s ( Modified Lobene Stain Index ) for each subject were conducted at baseline and after two , four , and six weeks of product use . RESULTS A total of 107 subjects complied with the protocol and completed the six-week study . Compared to baseline , at the two- , four- , and six-week examinations the Test Dentifrice group had statistically significant reductions in extrinsic tooth stain . In contrast , the Control Dentifrice group did not attain significant reductions from baseline at any of the exams . At both the four-week and six-week examinations , the Test Dentifrice group had significantly lower levels of extrinsic tooth stain than the Control Dentifrice group . CONCLUSION A sodium bicarbonate , dual-phase dentifrice containing calcium and phosphate demonstrated statisically significant efficacy in removing naturally acquired , extrinsic tooth stain , and was significantly more effective for stain removal than a commercially available , hydrated silica dentifrice The effect of twice-daily brushing with one of three different dentifrices ( Arm & Hammer Dental Care , Arm & Hammer Dental Care Extra Whitening , Crest ) on stain removal and tooth whitening was examined in 115 volunteers over a period of 12 weeks . The facial surfaces of 12 anterior teeth were assessed for stain using a published , modified version of a st and ard stain index . Whiteness was measured on teeth 8 and 9 using a single Vita Lumin-Vaccum Shade Guide for consistency . At baseline , the mean facial stain scores were significantly higher ( p < 0.05 - 0.01 ) for both Arm & Hammer dentifrices than for Crest . In addition , the tooth shades , as indicated by the stain guide , specifically the b * values representing yellowness , were quantified using a Minolta spectrophotometer . Arm & Hammer Dental Care Extra Whitening formula was found to be significantly better than Crest at removing naturally occurring extrinsic stain . The difference between Arm & Hammer Dental Care Extra Whitening and Crest became significant ( p < 0.01 ) after two weeks of use , and remained intact during the balance of the study , achieving p values of 0.0002 for at least one of the three assessed parameters ( total stain , proximal , and facial ) at weeks 4 and 12 . The study also found that Arm & Hammer Dental Care produced a significant increase in tooth whiteness by week 12 , whereas Crest showed no such increase at any time during the study . These results suggest that the two Arm & Hammer Baking Soda products are more effective in reducing stain and increasing whiteness than the st and ard silica-based dentifrice . Their effectiveness is not related to abrasivity since they are less abrasive to tooth enamel than the silica-based product tested OBJECTIVES To evaluate a modified tooth stain index and determine the effect of dietary factors on stain formation . METHODS At baseline , 182 adult volunteers were given a full oral prophylaxis followed by stain assessment using a modification of the Lobene index . This involved assigning separate scores to the mesial ( M ) and distal ( D ) sites of each tooth , in addition to the st and ard gingival area ( G ) and tooth body ( B ) . For each site , stain intensity and areas were scored . The sum of ( intensity X area ) scores was calculated for all sites ( GBMD-value ) and for the gingival and body sites only ( GB-value ) . The subjects used a st and ard abrasive dentifrice and a soft toothbrush for 6 weeks . RESULTS Stain was reassessed and the average increase in GBMD-value was 20.9 ( sd=9.9 ) ( buccal aspect ) and 29.9 ( sd=18.0 ) ( lingual aspect ) . The corresponding GB-values were 4.4 ( sd=4.8 ) and 12.5 ( sd=10.2 ) . The coefficients of variation of the GBMD index values were consistently lower than those of the GB values . Smoking and tea-drinking were found to be the only significant ( p<0.001 ) factors investigated for stain formation . CONCLUSIONS It is concluded that the modified index may well be advantageous to its conventional counterpart because sites with most visible stain are assessed separately and because it may also offer higher discriminatory power due to a lower coefficient of variation OBJECTIVE The primary purpose of this r and omized , controlled , six-week clinical trial was to determine the effectiveness and safety of a new whitening dentifrice in removing extrinsic tooth stain and whitening teeth . An additional two-week exploratory study was conducted to determine whether the whitening or stain-prevention activity of the dentifrice would persist following cessation of use . METHODS In the first study ( Phase I ) , one-hundred and forty-six qualifying subjects were r and omly assigned to either a sodium bicarbonate whitening dentifrice group ( Arm & Hammer Advance White Extreme Whitening Baking Soda and Peroxide Toothpaste ) or a silica-based negative control dentifrice group , and brushed twice daily with their assigned dentifrice for six weeks . Tooth shade on the labial surfaces of the eight incisors was assessed using a Vita Classic shade guide , and extrinsic tooth stain was scored using a Modified Lobene Stain Index ( MLSI ) at baseline , week 4 , and week 6 . In Phase II ( after the week 6 examination ) , volunteers from the Arm & Hammer whitening dentifrice group were r and omly assigned to continue using the whitening dentifrice or to use the negative control dentifrice twice daily for two weeks . The six-week shade and stain index scores served as the baseline for this exploratory phase and were rescored after two weeks . RESULTS The whitening dentifrice group had statistically significant ( p < 0.0001 ) mean shade score reductions of 1.82 and 2.57 from baseline to weeks 4 and 6 , respectively . For the same periods , the negative control dentifrice group was virtually unchanged from baseline . For tooth stain , the MLSI total mean scores for the whitening dentifrice group showed statistically significant ( p < 0.0001 ) decreases from baseline of 1.42 ( 41.6 % ) and 2.11 ( 61.6 % ) at weeks 4 and 6 , respectively . In contrast , the negative control dentifrice group had a MLSI reduction of 0.07 at week 4 and a 0.06 increase at week 6 . Between-group analyses using baseline-adjusted ANCOVA showed the whitening dentifrice to be statistically significantly more effective ( p < 0.0001 ) than the negative control for shade and tooth stain reductions for all index comparisons . Compared to the six-week ( baseline ) scores , subjects who continued to use the whitening dentifrice for the additional two weeks experienced statistically significant ( p < 0.0001 ) further mean reductions of 0.88 in shade score and 0.46 in MLSI score , while subjects who switched to the negative control dentifrice experienced smaller , statistically significant ( p < 0.05 ) reductions of 0.34 in shade score and 0.13 in total MLSI score . CONCLUSION The Arm & Hammer whitening dentifrice tested in this study is effective for removing extrinsic tooth stain and whitening teeth . While the results also suggest that this dentifrice may have stain-prevention activity that persists following cessation of product use , such activity would need to be confirmed with further studies The objective of this double-blind clinical study was to investigate the tooth whitening efficacy of a new dentifrice ( Colgate Tartar Control Plus Whitening Fluoride Toothpaste ) for the removal of extrinsic tooth stain , through a comparison with two commercially available dentifrices , Aquafresh Whitening Toothpaste with Fluoride , and Crest Regular Fluoride Toothpaste . Following a baseline examination for extrinsic tooth stain area and intensity , qualifying adult male and female subjects from the Mississauga , Ontario , Canada area were r and omized into three treatment groups which were balanced for age , gender , and level of extrinsic to 
    Output:
    
In this review , nearly all dentifrices that are specifically formulated for tooth whitening were shown to have a beneficial effect in reducing ETD , irrespective of whether or not a chemical discoloration agent was added