human
***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: STATEMENT OF PROBLEM Composite resins are still outperformed by amalgams in the clinical practice with secondary caries and fractures being their most common failures . A material that suffers less polymerization shrinkage might improve the clinical performance of composite resins . PURPOSE To evaluate the clinical performance of a low-shrink silorane-based composite resin ( Filtek LS Low Shrink Posterior Restorative , 3 M ESPE , St. Paul , MN , USA ) in comparison with a methacrylate-based composite resin ( Tetric EvoCeram , Ivoclar Vivadent , Schaan , Principality of Liechtenstein ) over time . MATERIAL S AND METHODS C and i date s in need of Class II composite resin restorations participated in this r and omized controlled clinical trial . Those were 25 female and six male subjects with average age of 44.3 ± 12.7 years . Participants received 82 restorations , being 54 in premolars and 28 in molars . Procedures , which included the restoration of primary caries lesions or replacement of failing restorations , were done using modified preparations with no bevels or additional retention . Restorations were placed using Filtek LS ( and dedicated self-etch adhesive ) or Tetric EvoCeram ( with AdheSE , Ivoclar Vivadent ) , following manufacturers ' instructions . Incremental placement technique was applied and the restorations were immediately finished . Follow-up evaluations occurred at six , 12 , 24 , and 36 months and were done using the Fédération Dentaire Internationale criteria . Statistical analysis was performed using generalized estimating equations . RESULTS The recall rate at 36 months was 89 % . All interaction terms were not significant . CONCLUSIONS Filtek LS performs as well  as Tetric EvoCeram performs in the clinical setting at 36 months . CLINICAL SIGNIFICANCE The silorane-based composite resin Filtek LS and the conventional methacrylate-based composite resin Tetric EvoCeram performed similarly well in posterior restorations over at least 36 months of clinical service STUDY QUESTION Are there differences in the method ological quality of Cochrane systematic review s ( CRs ) and non-Cochrane systematic review s ( NCRs ) of assisted reproductive technologies ? SUMMARY ANSWER CRs on assisted reproduction are of higher method ological quality than similar review s published in other journals . WHAT IS KNOWN ALREADY The quality of systematic review s varies . STUDY DESIGN , SIZE AND DURATION This was a cross-sectional study of 30 CR and 30 NCR systematic review s that were r and omly selected from the eligible review s identified from a literature search for the years 2007 - 2011 . MATERIAL S , SETTING AND METHODS We extracted data on the reporting and method ological characteristics of the included systematic review s. We assessed the method ological quality of the review s using the 11-domain Measurement Tool to Assess the Method ological Quality of Systematic Review s ( AMSTAR ) tool and subsequently compared CR and NCR systematic review s. MAIN RESULTS AND THE ROLE OF CHANCE The AMSTAR quality assessment found that CRs were superior to NCRs . For 10 of 11 AMSTAR domains , the requirements were met in > 50 % of CRs , but only 4 of 11 domains showed requirements being met in > 50 % of NCRs . The strengths of CRs are the a priori study design , comprehensive literature search , explicit lists of included and excluded studies and assessment s of internal validity . Significant failings in the CRs were found in duplicate study selection and data extraction ( 67 % meeting requirements ) , assessment for publication bias ( 53 % meeting requirements ) and reporting of conflicts of interest ( 47 % meeting requirements ) . NCRs were more likely to contain method ological weaknesses as the majority of the domains showed < 40 % of review s meeting requirements , e.g. a priori study design ( 17 % ) , duplicate study selection and data extraction ( 17 % ) , assessment of study quality ( 27 % ) , study quality in the formulation of conclusions ( 23 % ) and reporting of conflict of interests ( 10 % ) . LIMITATIONS , REASONS FOR CAUTION The AMSTAR assessment can only judge what is reported by authors . Although two of the five authors are involved in the production of CRs , the risk of bias was reduced by not involving these authors in the assessment of the systematic review quality . WIDER IMPLICATION S OF THE FINDINGS Not all systematic review s are equal . The reader needs to consider the quality of the systematic review when they consider the results and the conclusions of a systematic review . STUDY FUNDING /COMPETING INTEREST(S ) There are no conflicts with any commercial organization . Funding was provided for the students by the summer studentship programme of the Faculty of Medical and Health Sciences of the University of Auckl and OBJECTIVE The aim of this prospect i ve r and omized-controlled clinical trial is to assess the long-term performance of two direct composite resins in posterior teeth . This study provides a survey of the one-year results . MATERIAL S AND METHODS A total of 1805 restorations were placed by students in stress-bearing Class I/II cavities ( including cuspal-coverage ) in molars and premolars in 456 patients . Clinical evaluation was performed at baseline and after one year using modified USPHS criteria . The restorations in each patient were performed either with Ceram X/Prime&Bond NT or Tetric Ceram/Optibond Solo Plus . RESULTS After one year 528 fillings with Ceram X and 580 with Tetric Ceram were available for evaluation of substance loss , contact point , color match , marginal staining , marginal adaptation , secondary caries and radiographic examination ( if necessary ) . This represents a recall rate of 61.18 % ( 279 patients ) . The failure rate per material was 5.3 % in the Ceram X group and 6.1 % in the Tetric Ceram group . Most of the failures were associated with marginal adaptation/integrity of the filling . A significant influence on the occurrence of a failure was observed for the number of treated teeth per patient , the age of the patient , the mesio-distal extension of the restoration and the tooth position . Gender , material , a previous root canal treatment , the bucco-lingual extension of the filling or cuspal-coverage did not significantly influence the failure rate . Patients attending the first recall were significantly older and had more fillings than patients not attending . CONCLUSIONS In a group of Class I/II restorations ( including cuspal-coverage ) , there was no significant difference in failure rates between ormocer-based and bis-GMA-based restorative systems after one year . A previous root canal treatment had no negative influence on the failure rate . A longer observation period is indicated to get clear evidence of the long-term performance of these composite resin systems PURPOSE To compare the 2-year clinical performance of a silorane-based resin composite with that of an established nanoceramic resin composite for class 1 posterior restorations . METHODS In this r and omized controlled study , 100 class 1 molar cavities were prepared in 50 subjects . Each subject received a restoration with Filtek Silorane and Ceram . X Duo in different quadrants . The restorations were evaluated using the modified USPHS criteria at baseline and 6 , 12 , and 24 months . Parametric changes over the 2-year period were assessed with the Friedman test . The baseline and recall scores were compared by using the Wilcoxon signed-rank test ( P < 0.05 ) . RESULTS No subject developed secondary caries or postoperative sensitivity . Further , the resin composites showed no significant differences in all the evaluated parameters over 2 years ( P > 0.05 ) . At 2 years , four Filtek Silorane and seven Ceram . X Duo restorations had Bravo scores for anatomic form , marginal adaptation , and surface texture ( P < 0.05 ) ; however , these changes were mainly the effect of scoring shifts from Alfa to Bravo . Overall , both material s showed good clinical results with predominantly Alfa scores OBJECTIVES To determine the marginal adaptation of bulk-fill composites in class II MO cavities . METHODS St and ardized class II MO cavities with bevelled enamel margins were prepared in 40 extracted human molars . The teeth were r and omly assigned to one of the five experimental groups ( n=8 ) . The teeth were restored with two horizontal increments of composite ( 4 mm and 2 mm thickness ) . The experimental groups were ( 1st/2nd increment ) : Gr . A - Venus Bulk-Fill/Venus Diamond ; Gr . B - Tetric EvoCeram BulkFill/Tetric EvoCeram ; Gr . C - Surefil SDR/Ceram-X ; Gr . D - SonicFill ; Gr . E - Ceram-X/Ceram-X ( control ) . After finishing procedures , impressions were made using a polyvinyl siloxane and epoxy resin replicas were obtained . Thermo-mechanical stressing was carried out 24h after the restorative procedure . All specimens were su bmi tted to 240,000 occlusal loading and simultaneous 600 thermal cycles in water at 5 ° C and 50 ° C . After loading , a new set of epoxy resin replicas was obtained . Scanning electron microscopy was carried out at 200 × magnification . Results for the marginal adaptation were expressed as percentages of continuity relative to the exposed interface and analyzed by ANOVA and Duncan post hoc test ( p<0.05 ) . RESULTS In enamel , no significant differences were detected before and after thermo-mechanical loading between groups . In dentine , the worst results were observed in Gr . A CONCLUSION By applying simple layering techniques , bulk-fill material s do not allow better marginal adaptation than a st and ard composite . CLINICAL SIGNIFICANCE A new class of resin-base composite ( bulk-fill ) was recently launched on the market . The bulk-fill composites exhibited adequate marginal adaptation and similar to the results of the st and ard composite OBJECTIVE The objective of this r and omized controlled prospect i ve clinical trial was to evaluate the efficacy of a flowable resin composite ( SDR ) bulk fill technique in posterior restorations and to compare it intraindividually with a conventional 2 mm resin composite curing technique in a 3-year follow up . MATERIAL S AND METHODS Thirty-eight pairs Class II and 15 pairs Class I restorations were placed in 38 patients with a mean age of 55.3 years ( range 32 - 87 ) . Each patient received at r and om at least two , as similar as possible , Class II or Class I restorations of two restorative techniques . In all cavities a single step self-etch adhesive ( Xeno V ) was applied . In one of the cavities of each pair , a flowable resin composite ( SDR ) was placed , in bulk increments up to 4 mm as needed to fill the cavity 2 mm short of the occlusal cavosurface . The occlusal part was completed with a nano-hybrid resin composite ( Ceram X mono ) layer . In the second cavity , the hybrid resin composite was placed in 2 mm increments . The restorations were evaluated using slightly modified USPHS criteria at baseline and then yearly during 3 years . Caries risk and parafunctional habits of the participants were estimated . RESULTS After three years , 76 Class II and 28 Class I restorations could be observed . One molar resin composite-only tooth showed post-operative sensitivity during 3 weeks for temperature changes and occlusal forces . Two failed Class II molar restorations in the resin composite-only group were observed during the first year , one cusp fracture and one resin composite fracture . An annual failure rate of 1.3 % was found for the resin composite only restorations and of 0 % in the bulk-filled restorations ( n.s . ) . Ten participants were estimated as having high caries risk and eleven showed active bruxing habits . SIGNIFICANCE The 4 mm bulk-fill technique with the flowable resin composite SDR showed highly clinical effectiveness , which was comparable during the 3-year follow-up with the 2 mm resin composite layering technique OBJECTIVES The aim of this study was to quantify the polymerization volumetric shrinkage of one regular and two low shrinkage bulk fill composites in class I cavities with or without an adhesive layer , using three-dimensional ( 3D ) micro-computed tomography ( μCT ) . METHODS Class I cavity preparations ( 2.5 mm depth × 4 mm length × 4 mm wide ) were st and ardized in 36 extracted human third molars , which were r and omly divided in six groups ( n = 6 each ) as follows : Group VIT ( regular composite without bonding agent ) ; Group SDR ( low shrinkage flowable composite without bonding agent ) ; Group TET ( low shrinkage composite without bonding agent ) ; Group VIT/P ( regular composite with bonding agent ) ; Group SDR/X ( low shrinkage flowable composite with bonding agent ) ; TET/T ( low shrinkage composite with bonding agent ) . Each tooth was scanned via µCT at cavity preparation , immediately after cavity filling , and after light-curing . Acquired μCT data were imported into Amira software for analysis and volume values evaluated between steps from cavity preparation until light-curing . RESULTS Both low shrinkage composites showed a significantly less volumetric shrinkage than VIT . The use of dental adhesive significantly decreased the average volumetric contraction similarly for the three composites , by about 20 % . CONCLUSION Both low shrinkage composites showed less volumetric polymerization contraction than the regular composite . The use of dental adhesive decreased the total volumetric shrinkage for all evaluated composites PURPOSE To compare the clinical performance of a silorane-based 
    Output:
    
agent
The meta- analysis of the data in the included studies demonstrated that only one variable ( marginal adaptation after 12 months ) showed statistically significant outcomes , in which methacrylates-based composites presented significantly better results than resin composites containing modified monomers .
The good level of the scientific evidence as well as the overall low risk of bias of the included studies indicate that composites with silorane , ormocer or bulk-fill type modified monomers have a clinical performance similar to conventional resin composites
***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: STATEMENT OF PROBLEM Composite resins are still outperformed by amalgams in the clinical practice with secondary caries and fractures being their most common failures . A material that suffers less polymerization shrinkage might improve the clinical performance of composite resins . PURPOSE To evaluate the clinical performance of a low-shrink silorane-based composite resin ( Filtek LS Low Shrink Posterior Restorative , 3 M ESPE , St. Paul , MN , USA ) in comparison with a methacrylate-based composite resin ( Tetric EvoCeram , Ivoclar Vivadent , Schaan , Principality of Liechtenstein ) over time . MATERIAL S AND METHODS C and i date s in need of Class II composite resin restorations participated in this r and omized controlled clinical trial . Those were 25 female and six male subjects with average age of 44.3 ± 12.7 years . Participants received 82 restorations , being 54 in premolars and 28 in molars . Procedures , which included the restoration of primary caries lesions or replacement of failing restorations , were done using modified preparations with no bevels or additional retention . Restorations were placed using Filtek LS ( and dedicated self-etch adhesive ) or Tetric EvoCeram ( with AdheSE , Ivoclar Vivadent ) , following manufacturers ' instructions . Incremental placement technique was applied and the restorations were immediately finished . Follow-up evaluations occurred at six , 12 , 24 , and 36 months and were done using the Fédération Dentaire Internationale criteria . Statistical analysis was performed using generalized estimating equations . RESULTS The recall rate at 36 months was 89 % . All interaction terms were not significant . CONCLUSIONS Filtek LS performs as well  as Tetric EvoCeram performs in the clinical setting at 36 months . CLINICAL SIGNIFICANCE The silorane-based composite resin Filtek LS and the conventional methacrylate-based composite resin Tetric EvoCeram performed similarly well in posterior restorations over at least 36 months of clinical service STUDY QUESTION Are there differences in the method ological quality of Cochrane systematic review s ( CRs ) and non-Cochrane systematic review s ( NCRs ) of assisted reproductive technologies ? SUMMARY ANSWER CRs on assisted reproduction are of higher method ological quality than similar review s published in other journals . WHAT IS KNOWN ALREADY The quality of systematic review s varies . STUDY DESIGN , SIZE AND DURATION This was a cross-sectional study of 30 CR and 30 NCR systematic review s that were r and omly selected from the eligible review s identified from a literature search for the years 2007 - 2011 . MATERIAL S , SETTING AND METHODS We extracted data on the reporting and method ological characteristics of the included systematic review s. We assessed the method ological quality of the review s using the 11-domain Measurement Tool to Assess the Method ological Quality of Systematic Review s ( AMSTAR ) tool and subsequently compared CR and NCR systematic review s. MAIN RESULTS AND THE ROLE OF CHANCE The AMSTAR quality assessment found that CRs were superior to NCRs . For 10 of 11 AMSTAR domains , the requirements were met in > 50 % of CRs , but only 4 of 11 domains showed requirements being met in > 50 % of NCRs . The strengths of CRs are the a priori study design , comprehensive literature search , explicit lists of included and excluded studies and assessment s of internal validity . Significant failings in the CRs were found in duplicate study selection and data extraction ( 67 % meeting requirements ) , assessment for publication bias ( 53 % meeting requirements ) and reporting of conflicts of interest ( 47 % meeting requirements ) . NCRs were more likely to contain method ological weaknesses as the majority of the domains showed < 40 % of review s meeting requirements , e.g. a priori study design ( 17 % ) , duplicate study selection and data extraction ( 17 % ) , assessment of study quality ( 27 % ) , study quality in the formulation of conclusions ( 23 % ) and reporting of conflict of interests ( 10 % ) . LIMITATIONS , REASONS FOR CAUTION The AMSTAR assessment can only judge what is reported by authors . Although two of the five authors are involved in the production of CRs , the risk of bias was reduced by not involving these authors in the assessment of the systematic review quality . WIDER IMPLICATION S OF THE FINDINGS Not all systematic review s are equal . The reader needs to consider the quality of the systematic review when they consider the results and the conclusions of a systematic review . STUDY FUNDING /COMPETING INTEREST(S ) There are no conflicts with any commercial organization . Funding was provided for the students by the summer studentship programme of the Faculty of Medical and Health Sciences of the University of Auckl and OBJECTIVE The aim of this prospect i ve r and omized-controlled clinical trial is to assess the long-term performance of two direct composite resins in posterior teeth . This study provides a survey of the one-year results . MATERIAL S AND METHODS A total of 1805 restorations were placed by students in stress-bearing Class I/II cavities ( including cuspal-coverage ) in molars and premolars in 456 patients . Clinical evaluation was performed at baseline and after one year using modified USPHS criteria . The restorations in each patient were performed either with Ceram X/Prime&Bond NT or Tetric Ceram/Optibond Solo Plus . RESULTS After one year 528 fillings with Ceram X and 580 with Tetric Ceram were available for evaluation of substance loss , contact point , color match , marginal staining , marginal adaptation , secondary caries and radiographic examination ( if necessary ) . This represents a recall rate of 61.18 % ( 279 patients ) . The failure rate per material was 5.3 % in the Ceram X group and 6.1 % in the Tetric Ceram group . Most of the failures were associated with marginal adaptation/integrity of the filling . A significant influence on the occurrence of a failure was observed for the number of treated teeth per patient , the age of the patient , the mesio-distal extension of the restoration and the tooth position . Gender , material , a previous root canal treatment , the bucco-lingual extension of the filling or cuspal-coverage did not significantly influence the failure rate . Patients attending the first recall were significantly older and had more fillings than patients not attending . CONCLUSIONS In a group of Class I/II restorations ( including cuspal-coverage ) , there was no significant difference in failure rates between ormocer-based and bis-GMA-based restorative systems after one year . A previous root canal treatment had no negative influence on the failure rate . A longer observation period is indicated to get clear evidence of the long-term performance of these composite resin systems PURPOSE To compare the 2-year clinical performance of a silorane-based resin composite with that of an established nanoceramic resin composite for class 1 posterior restorations . METHODS In this r and omized controlled study , 100 class 1 molar cavities were prepared in 50 subjects . Each subject received a restoration with Filtek Silorane and Ceram . X Duo in different quadrants . The restorations were evaluated using the modified USPHS criteria at baseline and 6 , 12 , and 24 months . Parametric changes over the 2-year period were assessed with the Friedman test . The baseline and recall scores were compared by using the Wilcoxon signed-rank test ( P < 0.05 ) . RESULTS No subject developed secondary caries or postoperative sensitivity . Further , the resin composites showed no significant differences in all the evaluated parameters over 2 years ( P > 0.05 ) . At 2 years , four Filtek Silorane and seven Ceram . X Duo restorations had Bravo scores for anatomic form , marginal adaptation , and surface texture ( P < 0.05 ) ; however , these changes were mainly the effect of scoring shifts from Alfa to Bravo . Overall , both material s showed good clinical results with predominantly Alfa scores OBJECTIVES To determine the marginal adaptation of bulk-fill composites in class II MO cavities . METHODS St and ardized class II MO cavities with bevelled enamel margins were prepared in 40 extracted human molars . The teeth were r and omly assigned to one of the five experimental groups ( n=8 ) . The teeth were restored with two horizontal increments of composite ( 4 mm and 2 mm thickness ) . The experimental groups were ( 1st/2nd increment ) : Gr . A - Venus Bulk-Fill/Venus Diamond ; Gr . B - Tetric EvoCeram BulkFill/Tetric EvoCeram ; Gr . C - Surefil SDR/Ceram-X ; Gr . D - SonicFill ; Gr . E - Ceram-X/Ceram-X ( control ) . After finishing procedures , impressions were made using a polyvinyl siloxane and epoxy resin replicas were obtained . Thermo-mechanical stressing was carried out 24h after the restorative procedure . All specimens were su bmi tted to 240,000 occlusal loading and simultaneous 600 thermal cycles in water at 5 ° C and 50 ° C . After loading , a new set of epoxy resin replicas was obtained . Scanning electron microscopy was carried out at 200 × magnification . Results for the marginal adaptation were expressed as percentages of continuity relative to the exposed interface and analyzed by ANOVA and Duncan post hoc test ( p<0.05 ) . RESULTS In enamel , no significant differences were detected before and after thermo-mechanical loading between groups . In dentine , the worst results were observed in Gr . A CONCLUSION By applying simple layering techniques , bulk-fill material s do not allow better marginal adaptation than a st and ard composite . CLINICAL SIGNIFICANCE A new class of resin-base composite ( bulk-fill ) was recently launched on the market . The bulk-fill composites exhibited adequate marginal adaptation and similar to the results of the st and ard composite OBJECTIVE The objective of this r and omized controlled prospect i ve clinical trial was to evaluate the efficacy of a flowable resin composite ( SDR ) bulk fill technique in posterior restorations and to compare it intraindividually with a conventional 2 mm resin composite curing technique in a 3-year follow up . MATERIAL S AND METHODS Thirty-eight pairs Class II and 15 pairs Class I restorations were placed in 38 patients with a mean age of 55.3 years ( range 32 - 87 ) . Each patient received at r and om at least two , as similar as possible , Class II or Class I restorations of two restorative techniques . In all cavities a single step self-etch adhesive ( Xeno V ) was applied . In one of the cavities of each pair , a flowable resin composite ( SDR ) was placed , in bulk increments up to 4 mm as needed to fill the cavity 2 mm short of the occlusal cavosurface . The occlusal part was completed with a nano-hybrid resin composite ( Ceram X mono ) layer . In the second cavity , the hybrid resin composite was placed in 2 mm increments . The restorations were evaluated using slightly modified USPHS criteria at baseline and then yearly during 3 years . Caries risk and parafunctional habits of the participants were estimated . RESULTS After three years , 76 Class II and 28 Class I restorations could be observed . One molar resin composite-only tooth showed post-operative sensitivity during 3 weeks for temperature changes and occlusal forces . Two failed Class II molar restorations in the resin composite-only group were observed during the first year , one cusp fracture and one resin composite fracture . An annual failure rate of 1.3 % was found for the resin composite only restorations and of 0 % in the bulk-filled restorations ( n.s . ) . Ten participants were estimated as having high caries risk and eleven showed active bruxing habits . SIGNIFICANCE The 4 mm bulk-fill technique with the flowable resin composite SDR showed highly clinical effectiveness , which was comparable during the 3-year follow-up with the 2 mm resin composite layering technique OBJECTIVES The aim of this study was to quantify the polymerization volumetric shrinkage of one regular and two low shrinkage bulk fill composites in class I cavities with or without an adhesive layer , using three-dimensional ( 3D ) micro-computed tomography ( μCT ) . METHODS Class I cavity preparations ( 2.5 mm depth × 4 mm length × 4 mm wide ) were st and ardized in 36 extracted human third molars , which were r and omly divided in six groups ( n = 6 each ) as follows : Group VIT ( regular composite without bonding agent ) ; Group SDR ( low shrinkage flowable composite without bonding agent ) ; Group TET ( low shrinkage composite without bonding agent ) ; Group VIT/P ( regular composite with bonding agent ) ; Group SDR/X ( low shrinkage flowable composite with bonding agent ) ; TET/T ( low shrinkage composite with bonding agent ) . Each tooth was scanned via µCT at cavity preparation , immediately after cavity filling , and after light-curing . Acquired μCT data were imported into Amira software for analysis and volume values evaluated between steps from cavity preparation until light-curing . RESULTS Both low shrinkage composites showed a significantly less volumetric shrinkage than VIT . The use of dental adhesive significantly decreased the average volumetric contraction similarly for the three composites , by about 20 % . CONCLUSION Both low shrinkage composites showed less volumetric polymerization contraction than the regular composite . The use of dental adhesive decreased the total volumetric shrinkage for all evaluated composites PURPOSE To compare the clinical performance of a silorane-based 
    Output:
    