You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
with their advantages and defects , self - ligating orthodontic brackets have presented an 
 increased diffusion in orthodontic practice in the last 10 years .  
various aspects of self - ligating brackets have been studied in order to evaluate their 
 properties and characteristics .
frictional forces , torque expression , rotation capacity , bond strength , and reconditioning 
 procedures have been tested . 

moreover , clinical researches have also been carried out to evaluate bonding and the periodontal parameters .  
obtaining adequate force during orthodontic treatment will certainly result in an optimal 
 tissue response and satisfactory tooth movement 
 4 .
higher treatment speed claimed using self - ligating brackets can be 
 reduced from many factors , such as early accidental de - bonding , bracket breakage or damage 
 to the bracket wicket . in order to avoid bracket damages or detachments , forces that 
 have to be applied to open and close the wicket that engage the wire inside the bracket 

in fact , 
 insufficient opening and closure forces do not allow wicket sliding movements , whereas 
 excessive pressure on the wicket can detach or damage the bracket . to our knowledge there are no studies in the literature that measured the opening and 
 closure forces of the self - ligating brackets sliding mechanism .  
accordingly , the aim of the present investigation was to measure and compare the opening 
 and closure forces of three different self - ligating brackets .
the null hypothesis of the 
 study was that there are no significant difference force values among the various groups . 

three different stainless steel pre - adjusted self - ligating brackets were tested : carriere 
 lx ( ortho organizers , carlsbad , california , usa ) , f1000 ( leone , sesto fiorentino , italy ) , 
 and damon q ( ormco , glendora , california , usa ) . for each different bracket ,
20 maxillary 
 right central incisors and 20 mandibular right central incisors were used .  
each specimen was bonded to a plastic support that was then fixed in the lower jaw of an 
 instron universal testing machine ( model 3365 , instron industrial products , grove city , pa 
 usa ) . to evaluate the opening forces of the wickets , a specifically designed bar with a 
 terminal hook
the edge of the hook was inserted in the hole of the wicket of 
 a closed bracket .
the hook was then moved upward in a vertical direction at a crosshead 
 speed of 1 mm per minute until the bracket was completely opened .
maximum 
 opening force value ( n ) was recorded for each specimen .   testing apparatus for opening force measurement ( a : position before test ; b : position 
 after test ) to evaluate the closure forces of the wickets , a specifically designed bar with a terminal 
 flat plane was fixed to the upper part of the testing machine ( figure 2 ) .
the flat plane of the bar was leaned to the upper edge of the 
 wicket of an opened bracket .
the bar was then moved downward in a vertical direction at a 
 crosshead speed of 1 mm per minute until the bracket was completely closed . 

testing apparatus for closure force measurement ( a : position before test ; b : position 
 after test ) a statistical analysis was performed .
descriptive statistics for the opening and closure forces ( n ) of the different brackets are 
 illustrated in table 1 .
the analysis of variance showed the presence of significant 
 differences among the various groups ( p<0.0001 ) . when analyzing the 
 carriere lx brackets
, a post - hoc test showed that the opening force is 
 significantly lower than the closure force ( p<0.001 ) , both for the upper 
 and lower central incisor prescriptions . on the contrary , the f1000 brackets demonstrated an 
 opening force significantly higher than the closure force ( p<0.001 ) , 
 both for the upper and lower central incisor prescriptions .
finally , the damon q brackets 
 showed no significant differences between the opening and closure force when testing the 
 upper central incisor prescription ( p>0.05 ) . on the contrary , for the 
 lower central incisor , the damon q opening forces
means with the same letters are not significantly different moreover , for all the three different devices tested , the upper central incisor bracket 
 showed significantly higher forces than the lower central incisor bracket , both for the 
 opening and closure movements ( p<0.0001 ) .
the different self - ligating brackets 
 showed opening forces between 3.2 n and 5.6 n for the right central upper incisor 
 prescription and between 1.1 n and 3.9 n for the right central lower incisor prescription . 

the f1000 showed significantly higher opening forces than the other brackets for both 
 prescriptions tested .
the lowest forces were recorded with the carriere lx brackets both for 
 the upper and lower right central incisor prescriptions .  
closure forces were recorded between 3.32 n and 4.87 n for the right central upper incisor 
 prescription and between 1.57 n and 2.85 n for the right central lower incisor .
when testing 
 the maxillary right central incisor , the damon q showed significantly higher closure forces 
 than the other brackets ; the lowest forces were recorded with the f1000 . for the mandibular 
 right central incisor , the carriere lx and damon q showed no significant differences between 
 them and both exhibited significantly higher closure forces than the f1000 .  
the great technological advancements that have occurred in the last years have brought 
 research - based findings that have constantly led to the development of new materials and 
 techniques .
these improvements are 
 claimed to simplify the clinical procedures , but many commercially available orthodontic 
 materials have been experimentally evaluated in laboratories but not all aspects were tested to confirm their efficiency 
 and effectiveness . despite the various characteristics of self - ligating brackets that have 
 been evaluated , to date in the 
 literature
there are no studies that evaluated the opening and closure forces of different 
 self - ligating brackets . when analyzing single brackets , in the present study , the carriere 
 lx opening force was significantly lower than the closure force , both for the upper and 
 lower central incisor prescriptions .
on the contrary , the f1000 brackets demonstrated an 
 opening force significantly higher than the closure force , both for the upper and lower 
 central incisor prescriptions .
finally , the damon q brackets showed no significant 
 differences between the opening and closure force when testing the upper central incisor 
 prescription , whereas when testing the lower central incisor , the damon q opening forces 
 were significantly higher than the closure forces .  
moreover , in the present investigation the upper central incisor brackets showed 
 significantly higher forces than the lower central incisor brackets , both for the opening 
 and closure movements for all the three different devices tested .  
this variability of values means that the force applied to open or close a bracket is 
 different , tooth by tooth , also when using the same appliance type .
in fact , the evaluation of the opening and closure forces necessary 
 to allow the slide of the mechanism is necessary because discomfort is a potential side 
 effect during fixed appliance orthodontic therapy .
this can negatively 
 influence the desire to undergo treatment , compliance , and 
 treatment outcome .
for this reason 
 opening and closure forces should not be excessive in order to reduce discomfort when 
 changing the archwire or reactivating the appliance .
on the other side , after closure , the 
 wicket should remain locked until the following orthodontic visit , leaving the wire secured 
 to the bracket and allowing the appliance to express tooth movement .  
first of all this investigation 
 has been conducted under ideal laboratory conditions , whereas in the oral cavity the 
 presence of saliva , plaque , corrosion and other variables can influence the wicket sliding 
 movement . moreover
, clinical 
 experience suggests that a mechanistic view of orthodontics is misleading and so 
 self - ligating brackets and their peculiar characteristics are only a component of 
 orthodontics . among other things , orthodontics deals with science , evidence , psychosocial 
 issues , record taking , diagnoses , treatment , treatment outcomes , artistry , enhancements , and 
 quality - of - life issues .
the findings of 
 the present study , within their extents , suggest further researches in order to analyze all 
 variables and quantify and appraise the real influence of opening and closure forces on the 
 clinical use of self - ligating brackets .
the different self - ligating brackets showed opening forces between 3.2 n and 5.6 n for 
 the right central upper incisor prescription and between 1.1 n and 3.9 n for the right 
 central lower incisor prescription with significant differences among them .  
closure forces were recorded between 3.32 n and 4.87 n for the right central upper 
 incisor prescription and between 1.57 n and 2.85 n for the right central lower incisor 
 prescription with significant differences among the different brackets tested .
upper central incisor brackets showed significantly higher forces than the lower central 
 incisor bracket , both for the opening and closure movements
the different self - ligating brackets showed opening forces between 3.2 n and 5.6 n for 
 the right central upper incisor prescription and between 1.1 n and 3.9 n for the right 
 central lower incisor prescription with significant differences among them .  
closure forces were recorded between 3.32 n and 4.87 n for the right central upper 
 incisor prescription and between 1.57 n and 2.85 n for the right central lower incisor 
 prescription with significant differences among the different brackets tested .
upper central incisor brackets showed significantly higher forces than the lower central 
 incisor bracket , both for the opening and closure movements
the authors wish to thank leone , the ormco and ortho organizers for providing the 
 materials tested in this study .
self - ligating brackets engage the wire by means of a slide mechanism . 
 forces that have to 
 be applied to open and close the sliding mechanism of brackets are still unknown.objective:the aim of this study was to measure and compare the opening and closure forces of 
 different self - ligating brackets . material and methods : three different stainless steel self - ligating brackets ( carriere lx , ortho organizers ; 
 
 f1000 , leone ; damon q , ormco ) were tested . for each different bracket , 
 20 maxillary 
 right central incisors and 20 mandibular right central incisors were used . 
 opening and 
 closure forces were measured using an instron universal testing machine . statistical 
 analysis was performed and anova and tukey tests were carried out . 
 results : opening forces were registered between 1.1 n and 5.6 n , whereas closure forces were 
 recorded between 1.57 n and 4.87 n. significant differences were detected among the 
 different brackets and between the two prescriptions tested . 
 conclusion : the knowledge of different opening and closure forces of self - ligating brackets can 
 help the orthodontist in the clinical management of these devices .