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: Background : The evidence stemming from trials on restorative material s is shaped not only by trial findings , but also trial design and validity . We aim ed to evaluate both aspects in r and omized controlled dental restorative trials published from 2005–2015 . Methods : Using systematic review methodology , we retrieved trials comparing  restorative or adhesive dental material s. Two authors independently assessed design , risk of bias , registration status , and findings of trials . Descriptive and regression analyses were performed . Results : 114 studies on 15,321 restorations placed mainly in permanent teeth of 5232 patients were included . Per trial , the median number of patients was 37 ( 25th/75th percentiles : 30/51 ) . Follow-up was 24 ( 20/48 ) months . Seventeen percent of trials reported on sample size calculations , 2 % had been registered . Most trials ( 90 % ) used US Public Health Service ( USPHS ) criteria , and had a high risk of bias . More recent trials were more likely to have been registered , to have reported on sample size calculations , to be of low risk of bias , and to use other than USPHS- criteria . Twenty-three percent of trials yielded significant differences between groups . The likelihood of such differences was significantly increased in older studies , studies with potential reporting bias , published in journals with high impact factor ( > 2 ) , longer follow-up periods , and not using USPHS- criteria . Conclusions : The majority of dental restorative trials published from 2005–2015 had limited validity . Risk of bias decreased in more recent trials . Future trials should aim for high validity , be registered , and use defined and appropriate sample sizes , follow-up periods , and outcome measures PURPOSE This longitudinal r and omized controlled clinical trial evaluated direct composite restorations for clinical acceptability as posterior restoratives in single- or multi-surface cavities and provides a survey of the 4-year results . MATERIAL S AND METHODS Three dentists placed 46 Quixfil ( Xeno III ) and 50 Tetric Ceram ( Syntac Classic ) composite restorations in stress-bearing Class I and II cavities in first or second molars ( 43 adult patients ) . Clinical evaluation was performed at baseline and after 4 years by 2 other dentists using modified USPHS criteria . At the last recall period , 37 Quixfil and 46 Tetric Ceram restorations  were assessed . RESULTS A total of 89.2 % of Quixfil and 97.8 % of Tetric Ceram posterior composites were assessed to be clinical ly excellent or acceptable with predominating alfa scores . Up to the 4-year recall , four Quixfil restorations failed because of bulk fracture , partial tooth fracture ( 2x ) and postoperative symptoms . One Tetric Ceram restoration was lost due to problems with tooth integrity . No significant differences between the two composites could be detected at 4 years for any of the evaluated clinical criteria ( p > 0.05 ) . The comparison of restoration performance with time within both groups yielded a significant increase in marginal discoloration and decrease in marginal integrity for both material s. After 4 years , small restorations exhibited significantly less marginal discoloration than large restorations . CONCLUSION Clinical assessment of stress-bearing Quixfil and Tetric Ceram posterior composite restorations showed good clinical results with predominantly alfa scores for both material OBJECTIVES To analyze the relationship between the cavity depth and liners with postoperative sensitivity of  resin composite restorations .  METHODS A clinical follow-up was conducted on 319 resin composite restorations made in the final year of an undergraduate program over a 3-year period . Along with the analyses of cavity type , cavity depth , type of pulpal protection and the material s used , the postoperative sensitivity was also examined on each restoration . RESULTS Thirty-nine percent of the restorations had no protective layer ( Group 1 ) . As the depth of the prepared cavities increased , the restorations received one of the three pulpal protection methods ; a calcium hydroxide base ( Group 2 ) , glass ionomer cement ( Group 3 ) , or protection with a calcium hydroxide base in combination with glass ionomer cement ( Group 4 ) . The incidence of postoperative sensitivity showed no significant difference among Groups 1 , 2 and 3 , but was significantly lower in Group 1 than in Group 4 . The restorations made in shallow and medium depth cavities demonstrated significantly less-postoperative sensitivity than those made in deep cavities . The newer generation dentine-bonding agents showed a significantly lower incidence of postoperative sensitivity than the early generation group . CONCLUSIONS Postoperative sensitivity in resin  composite restorations was not related to the absence of protective layers but increased with the depth of cavities restored with the resin composite . The type of dentine-bonding agents could also be responsible for postoperative sensitivity PURPOSE To evaluate the 3-year clinical durability of the flowable bulk-fill resin composite SDR in Class I and Class II restorations . MATERIAL S AND METHODS Thirty-eight pairs of Class I and 62 pairs of Class II restorations were placed in 44 male and 42 female patients ( mean age 52.4 years ) . Each patient received at least two extended Class I or Class II restorations that were as similar as possible . In all cavities , a one-step self-etching adhesive ( XenoV+ ) was applied . One of the cavities of each pair was r and omly assigned to receive the flowable bulk-fill resin composite SDR in increments up to 4 mm as needed to fill the cavity 2 mm short of the occlusal cavosurface . The occlusal part was completed with an ormocer-based nanohybrid resin composite ( Ceram X mono+ ) . In the other cavity , only the resin composite CeramX mono+ was placed in 2 mm increments . The restorations were evaluated using slightly modified USPHS criteria at baseline and then annually for 3 years . Caries risk and bruxing habits of the participants were estimated . RESULTS No post-operative sensitivity was reported . At the 3-year follow-up , 196 restorations - 74 Class I and 122 Class II - were evaluated . Seven restorations failed ( 3.6 % ) , 4 SDR-CeramX mono+ and 3 CeramX mono+ only restorations , all of which were Class II . The main reason for failure was tooth fracture , followed by resin composite fracture . The annual failure rate ( AFR ) for all restorations ( Class I and II ) was 1.2 % for the bulkfilled restorations and 1.0 % for the resin composite-only restorations ( p > 0.05 ) . For the Class II restorations , the AFR was 2.2 % and 1.6 % , respectively . CONCLUSION The 4-mm bulk-fill technique showed good clinical effectiveness during the 3-year follow-up OBJECTIVE The objective of this split-mouth r and omized controlled study was to compare the 2-year clinical performance of two restorative techniques and material s for posterior permanent carious teeth . METHOD AND MATERIAL S After signing informed consent , 30 patients aged between 7 and 16 received two Class 1 restorations on cavities on permanent first or second molar teeth performed with one of two systems : incrementally placed conventional posterior composite resin ( Herculite Ultra , Kerr ) , and sonic-resin placement system ( SonicFill , Kerr ) with single-component self-etch adhesive system ( Kerr ) according to the manufacturers ' directions . Two blinded observers evaluated the restorations at three times ( baseline , and after 1 and 2 years ) according to the US Public Health Service modified criteria . Kruskal-Wallis test and Mann-Whitney U-test were used to compare the clinical performance of the restorative systems . RESULTS The restorative systems showed similar clinical performance at 2 years . At the end of 2 years in both groups , one restoration 's marginal staining Alpha ratings decreased . In the same period , two restorations in the conventional group and one in the SonicFill group received Bravo ratings for color match and surface roughness scorings . CONCLUSION The sonic-resin placement system demonstrated similar results to incrementally placed conventional composite resin in terms of clinical success . Considering the advantages of providing up to 5 mm in a single layer , and the adjustability of the viscosity , bulk-fill composite restorations seem to be a good alternative to posterior Class 1 composite restorations . CLINICAL RELEVANCE This study suggests that a new dental material for bulk-fill technology exhibits similar clinical success to incrementally placed composite resin OBJECTIVE The aim of this study was to evaluate the morphology of the resin-dentin interface formed in vivo with two posterior resin composite placement techniques ( incremental and bulk ) . METHOD AND MATERIAL S After approval from the patients , 12 Class II cavities with margins in enamel ( 2.5 x 2.5 x 4.5 mm ) were prepared in caries-free premolars scheduled to be extracted for orthodontic reasons ( n = 6 ) . The cavities were restored with Single Bond + Filtek P60 as a bulk condensable technique or Single Bond + Filtek Z250 as an oblique incremental technique . After 1 week , the teeth were extracted with minimal trauma to the restored area . After the teeth were sectioned , a polyvinyl siloxane impression was taken from the resin-dentin interface to control for artifacts created during preparation for scanning electron microscopy . The specimens were subsequently processed for and observed under a scanning electron microscope to assess gap formation . RESULTS The mean percentage of gap formation was 6.1 % for teeth restored with the incremental placement technique and 18.7 % for teeth restored with the bulk placement technique . The difference was statistically significant . CONCLUSION The incremental placement of posterior resin composites may still provide better seal than the new bulk condensable technique The objective of this longitudinal clinical r and omized trial was to evaluate the clinical performance of a nanofilled and a nanohybrid resin composite in Class I occlusal restorations of posterior teeth over the course of 54 months . Forty-one adolescents participated in the study . The teeth were restored with Adper Single Bond 2 ( 3 M ESPE ) and nanofilled ( Filtek Z350 , 3 M ESPE ) , nanohybrid ( Esthet-X , Dentsply ) and microhybrid Filtek Z250 ( 3 M ESPE ) used as a control . After 54 months , the restorations were evaluated in accordance with the modified United States Public Health Service criteria . The McNemar and Friedman tests were used for statistical analysis , at a level of significance of 5 % . Five failed restorations were observed during the follow-up . A change to unacceptable restoration occurred for one Esthet-X , two Filtek Z350 , and two Filtek Z250 restorations , which received the clinical ly unacceptable score , Charlie , for both anatomic form and marginal adaptation . Secondary caries and postoperative sensitivity occurred in one Filtek Z250 and one Filtek Z350 restoration . When the five evaluation periods ( baseline and six , 12 , 30 , and 54 months ) were compared , significant differences were found in the marginal adaptation of Filtek Z250 and Filtek Z350 . Significant differences in the roughness criteria ( p=0.005 ) were also observed when the three composites were compared after 54 months ( Filtek Z350 > Filtek Z250 > Esthet-X ) , always within clinical ly acceptable limits . The material s investigated showed acceptable clinical performance for Class I restoration after 54 months . Long-term reevaluations are necessary for a more detailed analysis of these composites Background : Recently , manufacturers have introduced bulk-fill composite resins that reportedly can be placed in increments of 4 mm or greater . Objective : The purpose of this article was to report the results of 12 months prospect i ve r and omized clinical trial that evaluated the clinical performance of one high-viscosity bulk-fill composite resin in Class II cavities of posterior teeth . Material s and Methods : Thirty-four participants had at least two Class II cavities included the study . Class II cavities restored with either a Tetric EvoCeram bulk-fi fill or universal nano-hybrid resin composite ( Tetric EvoCeram ) . A total of 74 restorations ( 37 with each material ) on 34 patients were placed according to the manufacturers ' instructions by one calibrated operator . Results : Seventy restorations were evaluated after 12 months evaluation period . No postoperative sensitivity , anatomic form , retention , and secondary caries were observed after 6 and 12 months . Regarding the items color match , marginal discoloration , and marginal adaptation , the statistical analysis did not detect any statistical significance between two material s ( P > 0.05 ) . Conclusion : After 12 months of clinical service , all restorations evaluated for both material s were classified as ideal , receiving predominantly Alfa scores for all parameters analyzed . Clinical Relevance : This study presents that high-viscosity bulk-fill resin composites ( RCs ) perform just as well as nano-hybrid RCs with the 2 mm RC layering technique , therefore could be alternative to conventional nano-hybrid RCs OBJECTIVE The objective of this 6 year prospect i ve r and omized equivalence trial was to evaluate the long-term clinical performance of a new nano-hybrid resin composite ( RC ) in Class II restorations in an intraindividual comparison with its well-established conventional hybrid RC predecessor . METHODS Each of 52 participants received at least two , as similar as possible , Class II restorations .  The cavities were chosen at r and om to be restored with an experimental nano-hybrid RC ( Exite/Tetric EvoCeram ( TEC ) ; n=61 ) and a conventional hybrid RC ( Exite/Tetric Ceram ( TC ) ; n=61 ) . The restorations were evaluated with slightly modified USPHS criteria at bas 
    Output:
    
agent
Conclusions The present systematic review and meta- analysis indicate similar clinical performances of bulk-fill and conventional resin composites over a follow-up period of 12 to 72 months .
Clinical significance Based on the results of this study , the bulk-fill resin composites could be an alternative for direct restorations in posterior teeth .
***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: Background : The evidence stemming from trials on restorative material s is shaped not only by trial findings , but also trial design and validity . We aim ed to evaluate both aspects in r and omized controlled dental restorative trials published from 2005–2015 . Methods : Using systematic review methodology , we retrieved trials comparing  restorative or adhesive dental material s. Two authors independently assessed design , risk of bias , registration status , and findings of trials . Descriptive and regression analyses were performed . Results : 114 studies on 15,321 restorations placed mainly in permanent teeth of 5232 patients were included . Per trial , the median number of patients was 37 ( 25th/75th percentiles : 30/51 ) . Follow-up was 24 ( 20/48 ) months . Seventeen percent of trials reported on sample size calculations , 2 % had been registered . Most trials ( 90 % ) used US Public Health Service ( USPHS ) criteria , and had a high risk of bias . More recent trials were more likely to have been registered , to have reported on sample size calculations , to be of low risk of bias , and to use other than USPHS- criteria . Twenty-three percent of trials yielded significant differences between groups . The likelihood of such differences was significantly increased in older studies , studies with potential reporting bias , published in journals with high impact factor ( > 2 ) , longer follow-up periods , and not using USPHS- criteria . Conclusions : The majority of dental restorative trials published from 2005–2015 had limited validity . Risk of bias decreased in more recent trials . Future trials should aim for high validity , be registered , and use defined and appropriate sample sizes , follow-up periods , and outcome measures PURPOSE This longitudinal r and omized controlled clinical trial evaluated direct composite restorations for clinical acceptability as posterior restoratives in single- or multi-surface cavities and provides a survey of the 4-year results . MATERIAL S AND METHODS Three dentists placed 46 Quixfil ( Xeno III ) and 50 Tetric Ceram ( Syntac Classic ) composite restorations in stress-bearing Class I and II cavities in first or second molars ( 43 adult patients ) . Clinical evaluation was performed at baseline and after 4 years by 2 other dentists using modified USPHS criteria . At the last recall period , 37 Quixfil and 46 Tetric Ceram restorations  were assessed . RESULTS A total of 89.2 % of Quixfil and 97.8 % of Tetric Ceram posterior composites were assessed to be clinical ly excellent or acceptable with predominating alfa scores . Up to the 4-year recall , four Quixfil restorations failed because of bulk fracture , partial tooth fracture ( 2x ) and postoperative symptoms . One Tetric Ceram restoration was lost due to problems with tooth integrity . No significant differences between the two composites could be detected at 4 years for any of the evaluated clinical criteria ( p > 0.05 ) . The comparison of restoration performance with time within both groups yielded a significant increase in marginal discoloration and decrease in marginal integrity for both material s. After 4 years , small restorations exhibited significantly less marginal discoloration than large restorations . CONCLUSION Clinical assessment of stress-bearing Quixfil and Tetric Ceram posterior composite restorations showed good clinical results with predominantly alfa scores for both material OBJECTIVES To analyze the relationship between the cavity depth and liners with postoperative sensitivity of  resin composite restorations .  METHODS A clinical follow-up was conducted on 319 resin composite restorations made in the final year of an undergraduate program over a 3-year period . Along with the analyses of cavity type , cavity depth , type of pulpal protection and the material s used , the postoperative sensitivity was also examined on each restoration . RESULTS Thirty-nine percent of the restorations had no protective layer ( Group 1 ) . As the depth of the prepared cavities increased , the restorations received one of the three pulpal protection methods ; a calcium hydroxide base ( Group 2 ) , glass ionomer cement ( Group 3 ) , or protection with a calcium hydroxide base in combination with glass ionomer cement ( Group 4 ) . The incidence of postoperative sensitivity showed no significant difference among Groups 1 , 2 and 3 , but was significantly lower in Group 1 than in Group 4 . The restorations made in shallow and medium depth cavities demonstrated significantly less-postoperative sensitivity than those made in deep cavities . The newer generation dentine-bonding agents showed a significantly lower incidence of postoperative sensitivity than the early generation group . CONCLUSIONS Postoperative sensitivity in resin  composite restorations was not related to the absence of protective layers but increased with the depth of cavities restored with the resin composite . The type of dentine-bonding agents could also be responsible for postoperative sensitivity PURPOSE To evaluate the 3-year clinical durability of the flowable bulk-fill resin composite SDR in Class I and Class II restorations . MATERIAL S AND METHODS Thirty-eight pairs of Class I and 62 pairs of Class II restorations were placed in 44 male and 42 female patients ( mean age 52.4 years ) . Each patient received at least two extended Class I or Class II restorations that were as similar as possible . In all cavities , a one-step self-etching adhesive ( XenoV+ ) was applied . One of the cavities of each pair was r and omly assigned to receive the flowable bulk-fill resin composite SDR in increments up to 4 mm as needed to fill the cavity 2 mm short of the occlusal cavosurface . The occlusal part was completed with an ormocer-based nanohybrid resin composite ( Ceram X mono+ ) . In the other cavity , only the resin composite CeramX mono+ was placed in 2 mm increments . The restorations were evaluated using slightly modified USPHS criteria at baseline and then annually for 3 years . Caries risk and bruxing habits of the participants were estimated . RESULTS No post-operative sensitivity was reported . At the 3-year follow-up , 196 restorations - 74 Class I and 122 Class II - were evaluated . Seven restorations failed ( 3.6 % ) , 4 SDR-CeramX mono+ and 3 CeramX mono+ only restorations , all of which were Class II . The main reason for failure was tooth fracture , followed by resin composite fracture . The annual failure rate ( AFR ) for all restorations ( Class I and II ) was 1.2 % for the bulkfilled restorations and 1.0 % for the resin composite-only restorations ( p > 0.05 ) . For the Class II restorations , the AFR was 2.2 % and 1.6 % , respectively . CONCLUSION The 4-mm bulk-fill technique showed good clinical effectiveness during the 3-year follow-up OBJECTIVE The objective of this split-mouth r and omized controlled study was to compare the 2-year clinical performance of two restorative techniques and material s for posterior permanent carious teeth . METHOD AND MATERIAL S After signing informed consent , 30 patients aged between 7 and 16 received two Class 1 restorations on cavities on permanent first or second molar teeth performed with one of two systems : incrementally placed conventional posterior composite resin ( Herculite Ultra , Kerr ) , and sonic-resin placement system ( SonicFill , Kerr ) with single-component self-etch adhesive system ( Kerr ) according to the manufacturers ' directions . Two blinded observers evaluated the restorations at three times ( baseline , and after 1 and 2 years ) according to the US Public Health Service modified criteria . Kruskal-Wallis test and Mann-Whitney U-test were used to compare the clinical performance of the restorative systems . RESULTS The restorative systems showed similar clinical performance at 2 years . At the end of 2 years in both groups , one restoration 's marginal staining Alpha ratings decreased . In the same period , two restorations in the conventional group and one in the SonicFill group received Bravo ratings for color match and surface roughness scorings . CONCLUSION The sonic-resin placement system demonstrated similar results to incrementally placed conventional composite resin in terms of clinical success . Considering the advantages of providing up to 5 mm in a single layer , and the adjustability of the viscosity , bulk-fill composite restorations seem to be a good alternative to posterior Class 1 composite restorations . CLINICAL RELEVANCE This study suggests that a new dental material for bulk-fill technology exhibits similar clinical success to incrementally placed composite resin OBJECTIVE The aim of this study was to evaluate the morphology of the resin-dentin interface formed in vivo with two posterior resin composite placement techniques ( incremental and bulk ) . METHOD AND MATERIAL S After approval from the patients , 12 Class II cavities with margins in enamel ( 2.5 x 2.5 x 4.5 mm ) were prepared in caries-free premolars scheduled to be extracted for orthodontic reasons ( n = 6 ) . The cavities were restored with Single Bond + Filtek P60 as a bulk condensable technique or Single Bond + Filtek Z250 as an oblique incremental technique . After 1 week , the teeth were extracted with minimal trauma to the restored area . After the teeth were sectioned , a polyvinyl siloxane impression was taken from the resin-dentin interface to control for artifacts created during preparation for scanning electron microscopy . The specimens were subsequently processed for and observed under a scanning electron microscope to assess gap formation . RESULTS The mean percentage of gap formation was 6.1 % for teeth restored with the incremental placement technique and 18.7 % for teeth restored with the bulk placement technique . The difference was statistically significant . CONCLUSION The incremental placement of posterior resin composites may still provide better seal than the new bulk condensable technique The objective of this longitudinal clinical r and omized trial was to evaluate the clinical performance of a nanofilled and a nanohybrid resin composite in Class I occlusal restorations of posterior teeth over the course of 54 months . Forty-one adolescents participated in the study . The teeth were restored with Adper Single Bond 2 ( 3 M ESPE ) and nanofilled ( Filtek Z350 , 3 M ESPE ) , nanohybrid ( Esthet-X , Dentsply ) and microhybrid Filtek Z250 ( 3 M ESPE ) used as a control . After 54 months , the restorations were evaluated in accordance with the modified United States Public Health Service criteria . The McNemar and Friedman tests were used for statistical analysis , at a level of significance of 5 % . Five failed restorations were observed during the follow-up . A change to unacceptable restoration occurred for one Esthet-X , two Filtek Z350 , and two Filtek Z250 restorations , which received the clinical ly unacceptable score , Charlie , for both anatomic form and marginal adaptation . Secondary caries and postoperative sensitivity occurred in one Filtek Z250 and one Filtek Z350 restoration . When the five evaluation periods ( baseline and six , 12 , 30 , and 54 months ) were compared , significant differences were found in the marginal adaptation of Filtek Z250 and Filtek Z350 . Significant differences in the roughness criteria ( p=0.005 ) were also observed when the three composites were compared after 54 months ( Filtek Z350 > Filtek Z250 > Esthet-X ) , always within clinical ly acceptable limits . The material s investigated showed acceptable clinical performance for Class I restoration after 54 months . Long-term reevaluations are necessary for a more detailed analysis of these composites Background : Recently , manufacturers have introduced bulk-fill composite resins that reportedly can be placed in increments of 4 mm or greater . Objective : The purpose of this article was to report the results of 12 months prospect i ve r and omized clinical trial that evaluated the clinical performance of one high-viscosity bulk-fill composite resin in Class II cavities of posterior teeth . Material s and Methods : Thirty-four participants had at least two Class II cavities included the study . Class II cavities restored with either a Tetric EvoCeram bulk-fi fill or universal nano-hybrid resin composite ( Tetric EvoCeram ) . A total of 74 restorations ( 37 with each material ) on 34 patients were placed according to the manufacturers ' instructions by one calibrated operator . Results : Seventy restorations were evaluated after 12 months evaluation period . No postoperative sensitivity , anatomic form , retention , and secondary caries were observed after 6 and 12 months . Regarding the items color match , marginal discoloration , and marginal adaptation , the statistical analysis did not detect any statistical significance between two material s ( P > 0.05 ) . Conclusion : After 12 months of clinical service , all restorations evaluated for both material s were classified as ideal , receiving predominantly Alfa scores for all parameters analyzed . Clinical Relevance : This study presents that high-viscosity bulk-fill resin composites ( RCs ) perform just as well as nano-hybrid RCs with the 2 mm RC layering technique , therefore could be alternative to conventional nano-hybrid RCs OBJECTIVE The objective of this 6 year prospect i ve r and omized equivalence trial was to evaluate the long-term clinical performance of a new nano-hybrid resin composite ( RC ) in Class II restorations in an intraindividual comparison with its well-established conventional hybrid RC predecessor . METHODS Each of 52 participants received at least two , as similar as possible , Class II restorations .  The cavities were chosen at r and om to be restored with an experimental nano-hybrid RC ( Exite/Tetric EvoCeram ( TEC ) ; n=61 ) and a conventional hybrid RC ( Exite/Tetric Ceram ( TC ) ; n=61 ) . The restorations were evaluated with slightly modified USPHS criteria at bas 
    Output:
    