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 AND AIM This paper review s three published papers and adds results from a fourth study which aim ed to determine which restorative material would be the best alternative(s ) to amalgam ( AM )  in primary teeth . DESIGN All studies had a practice -based design and were part of the routine treatment of children and adolescents . The clinicians were assigned which material s to use in a r and omised matter in the first three studies which lasted for 7 - 8 years . In the fourth study conducted 4 years after the initial studies , the clinicians were free to select the restorative material s. RESULTS AND CONCLUSIONS Resin modified glass ionomer ( RMGI ) and compomer ( COM ) restorations showed similar longevity compared with AM , whereas conventional GI restorations showed significantly shorter longevity . The studies indicated that the ' new and improved ' material s based on in vitro tests did not always show enhanced clinical properties . In the last study , where clinicians freely selected the restorative material s they used in their practice s , seven used COM , one used conventional GI material s and one used a combination of the two types of material BACKGROUND The authors clinical ly examined two restorative material s to evaluate their effectiveness in Class II restorations in primary molars and their ability to inhibit recurrent caries . METHODS Forty subjects , each in need of two Class II restorations in primary molars , took part in this study . Each patient received one  Class II restoration of resin-modified glass ionomer cement and one of amalgam . The authors evaluated the restorations at six-month , one-year , two-year and three-year recall appointments . On exfoliation , teeth with experimental restorations were retrieved and microscopically examined for inhibition of demineralization at restoration margins . RESULTS The results of the clinical evaluation demonstrated no significant differences between the resin-modified glass ionomer cement restorations and the amalgam restorations ( P < .05 ) . Polarized light microscopic examination of the returned teeth that were restored as a part of this study indicated that the resin-modified glass ionomer cement had significantly less enamel demineralization at restoration margins than did amalgam ( P < .0001 ) . CONCLUSIONS The resin-modified glass ionomer cement functioned clinical ly as well as amalgam for Class II restorations in primary molars . However , the resin-modified glass ionomer exhibited significantly less enamel demineralization at restoration margins than did amalgam . CLINICAL IMPLICATION S Resin-modified glass ionomer cement restorative material functions well for Class II restorations in primary molars and exhibits less recurrent caries at restoration margins than does amalgam OBJECTIVES To assess and compare the cumulative survival rate of amalgam and atraumatic restorative treatment ( ART ) restorations in primary molars over 3 years . METHODS 280 children aged 6 - 7 years old were enrolled in a cluster r and omized controlled clinical trial using a parallel group design covering two treatment groups : conventional restorative treatment with amalgam ( CRT ) and atraumatic restorative treatment ( ART ) using a high-viscosity glass-ionomer ( HVGIC ) Ketac Molar Easymix . Three pedodontists placed 750 restorations ( 364 amalgam and 386 ART in 126 and 154 children , respectively ) which were evaluated at 0.5 , 1 , 2 and 3 years . The proportional hazard rate regression model with frailty correction , ANOVA and Wald tests , and the Jackknife procedure were applied in analysing the data . RESULTS The cumulative survival rates over 3 years for all , single- and multiple-surface CRT/amalgam restorations ( 72.6 % , 93.4 % , 64.7 % , respectively ) were no different from those of comparable ART/HVGIC restorations ( 66.8 % ; 90.1 % and 56.4 % , respectively ) ( p=0.10 ) . Single-surface restorations had higher survival rates than multiple-surface restorations for the both treatment procedures ( p<0.0001 ) . A higher proportion of restorations failed because of mechanical reasons ( 94.8 % ) than of secondary caries ( 5.2 % ) . No difference in reasons for restoration failures between all types of amalgam and ART/HVGIC restorations were observed ( p=0.24 ) . SIGNIFICANCE The high-viscosity glass-ionomer used in this study in conjunction with the ART is a viable option for restoring carious dentin lesions in single surfaces in vital primary molars This in vitro study evaluated the bond strength of adhesive restorative material s to sound and eroded dentin . Thirty-six bovine incisors were embedded in acrylic resin and ground to obtain flat buccal dentin surfaces . Specimens were r and omly allocated in 2 groups : sound dentin ( immersion in artificial saliva ) and eroded dentin ( pH cycling model - 3 × / cola drink for 7 days ) . Specimens were then reassigned according to restorative material : glass ionomer cement ( KetacTM Molar Easy Mix ) , resin-modified glass ionomer cement ( VitremerTM ) or adhesive system with resin composite ( Adper Single Bond 2 + Filtek Z250 ) . Polyethylene tubes with an internal diameter of 0.76 mm were placed over the dentin and filled with the material . The microshear bond test was performed after 24 h of water storage at 37ºC. The failure mode was evaluated using a stereomicroscope ( 400 × ) . Bond strength data were analyzed with two-way ANOVA and Tukey 's post hoc tests ( α = 0.05 ) . Eroded dentin showed bond strength values similar to those for sound dentin for all material s. The adhesive system showed the highest bond strength values , regardless of the substrate ( p < 0.0001 ) . For all groups , the adhesive/mixed failure prevailed . In conclusion , adhesive material s may be used in eroded dentin without jeopardizing the bonding quality . It is preferable to use an etch- and -rinse adhesive system because it shows the highest bond strength values compared with the glass ionomer cements tested BACKGROUND Secondary caries or caries adjacent to restorations is the most frequent reason for replacement of dental restorations . Though , limited data is available on variables influencing the development of secondary caries in primary teeth . AIM To investigate risk factors for the development of secondary caries adjacent to direct composite restorations in primary teeth . DESIGN For this retrospective study , data of 2417 composite restorations , which were placed due to primary carious lesions , were considered . A total of 212 restorations failed due to secondary caries within a maximum observation period of 8 years . A control group was r and omly selected . Mann-Whitney U-test , binomial logistic regression with backward elimination and Cox regression with frailty model were performed ( P < 0.05 ) . RESULTS The overall caries experience amounted to 6.3 dmft and 13.3 dmfs . 72.5 % of restorations failed within the first 2 years . Older children and children from families with a higher socio-economic status showed a lower risk for secondary caries . Further , the dentist and the adhesive had a significant influence on the longevity . Posterior restorations had a higher risk to fail in comparison with anterior restorations . CONCLUSIONS Within the limitation of this study , it is concluded that the development of secondary caries is influenced by several factors . Nevertheless , the secondary caries rate was found to be relatively low in this high-risk population BACKGROUND Limited information is available from r and omized clinical trials comparing the longevity of  amalgam and resin-based compomer/composite restorations . The authors compared replacement rates of these types of restorations in posterior teeth during the five-year follow-up of the New Engl and Children 's Amalgam Trial . METHODS The authors r and omized children aged 6 to 10 years who had two or more posterior occlusal carious lesions into groups that received amalgam ( n=267 ) or compomer ( primary teeth)/composite ( permanent teeth ) ( n=267 ) restorations  and followed them up semiannually . They compared the longevity of restorations placed on all posterior surfaces using r and om effects survival analysis . RESULTS The average+/-st and ard deviation follow-up was 2.8+/-1.4 years for primary tooth restorations and 3.4+/-1.9 years for permanent tooth restorations . In primary teeth , the replacement rate was 5.8 percent of compomers versus 4.0 percent of amalgams ( P=.10 ) , with 3.0 percent versus 0.5 percent ( P=.002 ) , respectively , due to recurrent caries . In permanent teeth , the replacement rate was 14.9 percent of composites versus 10.8 percent of amalgams ( P=.45 ) , and the repair rate was 2.8 percent of composites versus 0.4 percent of amalgams ( P=.02 ) . CONCLUSION Although the overall difference in longevity was not statistically significant , compomer was replaced significantly more frequently owing to recurrent caries , and composite restorations required seven times as many repairs as did amalgam restorations . CLINICAL IMPLICATION S Compomer/composite restorations on posterior tooth surfaces in children may require replacement or repair at higher rates than amalgam restorations , even within five years of placement OBJECTIVE The aim of this in vitro study was to evaluate the interaction between two sources of fluoride ( restorative systems and dentifrices ) in inhibiting artificial root caries development . METHODS One hundred and eighty tooth segments were embedded in polyester resin , and s and ed flat . Cylindrical cavities 1.0mm-deep and 1.5mm-diameter were prepared in root dentin and r and omly restored by fluoride-containing restorative systems : Ketac-fil/Espe ( Ke ) , Fuji II LC/GC Corp ( Fj ) , F2000/3 M ( F2 ) , Surefil/Dentsply ( Su ) or a control : Filtek Z250/3 M ( Z2 ) . Ten experimental groups were made to test the association among the five restorative systems and two dentifrices : with F(- ) ( Sensodyne Baking Soda ) or without F(- ) ( Sensodyne Original ) ( n=18 ) . After surface polishing , a 1mm-wide margin around the restorations was demarcated and initial dentin surface Knoop microhardness values ( KHN(i ) ) were obtained . The specimens were su bmi tted to a pH-cycling model , and to applications of slurries of dentifrice . Afterwards the final dentin surface Knoop microhardness values ( KHN(f ) ) were measured . RESULTS The differences between KHN(i ) and KHN(f ) , and the covariate KHN(i ) were considered by the ANCOVA and Tukey 's test ( alpha=0.05 ) . The interaction between restorative system and dentifrice was statistically significant ( p=0.0026 ) . All restorative systems provided some protection against artificial caries challenge when associated with the fluoride-containing dentifrice treatment . The means ( st and ard deviation ) of reductions in Knoop hardness values for systems associated with the fluoride-containing dentifrice were : Ke : 40.0(1.02)(a ) , Fj : 41.9(1.02)(b ) , F2 : 43.3(1.04)(c ) , Su : 43.5(1.00)(c ) , Z2 : 44.0(1.02)(c ) ; and with the non-fluoride-containing dentifrice were : Ke : 42.9(1.02)(a ) , Fj : 44.7(1.01)(b ) , F2 : 45.2(1.09)(bc ) , Su : 46.0(0.99)(c ) , Z2 : 46.6(0.99)(c ) ( statistical differences were expressed by different letters ) . CONCLUSION The cariostatic effect shown by the fluoride-containing dentifrice could enhance that shown by Ketac-fil and Fuji II LC , and could mask that shown by F2000 PURPOSE The authors conducted a r and omized clinical trial to evaluate the survival rate of esthetic restorations in Class I and Class II beveled preparations in primary molars 24 months after placement . The null hypothesis was that there is no difference among survival rates of the restorative material s used . METHODS Forty-eight children ( mean age , 5 years 9 months ) received 141 restorations in beveled cavosurface margins in primary molars r and omly assigned by lottery method : 46 received treatment with Vitremer Tri-Cure Glass Ionomer System ( 3 M ESPE Dental Products , St. Paul , Minn. ) ( 33 Class I and 13 Class II restorations ) , 51 received treatment with Freedom ( SDI , Bayswater , Victoria , Australia ) ( 36 Class I and 15 Class II restorations ) ; 44 received treatment with TPH Spectrum ( Dentsply , Petropolis , Rio de Janeiro , Brazil ) ( 30 Class I and 14 Class II restorations ) . Two examiners whose technique had been calibrated ( weight kappa > 0.85 ) evaluated the restorations using modified U.S. Public Health Service criteria and Visible Plaque Index score at baseline and at 12 , 18 and 24 months . RESULTS After two years , the authors censored data for 17 restorations , considered 101 restorations to be clinical ly successful and deemed 23 restorations failed because of loss of marginal integrity , anatomical form discrepancies and secondary caries . For Class I and Class II restorations , the cum 
    Output:
    
agent
AND PRACTICAL IMPLICATION S Because new caries lesions in the margins of restorations are the main reason for failure and replacement of restorations in primary teeth , it is important to know whether there is a benefit in using GICs in both occlusal and occlusoproximal cavities
***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 AND AIM This paper review s three published papers and adds results from a fourth study which aim ed to determine which restorative material would be the best alternative(s ) to amalgam ( AM )  in primary teeth . DESIGN All studies had a practice -based design and were part of the routine treatment of children and adolescents . The clinicians were assigned which material s to use in a r and omised matter in the first three studies which lasted for 7 - 8 years . In the fourth study conducted 4 years after the initial studies , the clinicians were free to select the restorative material s. RESULTS AND CONCLUSIONS Resin modified glass ionomer ( RMGI ) and compomer ( COM ) restorations showed similar longevity compared with AM , whereas conventional GI restorations showed significantly shorter longevity . The studies indicated that the ' new and improved ' material s based on in vitro tests did not always show enhanced clinical properties . In the last study , where clinicians freely selected the restorative material s they used in their practice s , seven used COM , one used conventional GI material s and one used a combination of the two types of material BACKGROUND The authors clinical ly examined two restorative material s to evaluate their effectiveness in Class II restorations in primary molars and their ability to inhibit recurrent caries . METHODS Forty subjects , each in need of two Class II restorations in primary molars , took part in this study . Each patient received one  Class II restoration of resin-modified glass ionomer cement and one of amalgam . The authors evaluated the restorations at six-month , one-year , two-year and three-year recall appointments . On exfoliation , teeth with experimental restorations were retrieved and microscopically examined for inhibition of demineralization at restoration margins . RESULTS The results of the clinical evaluation demonstrated no significant differences between the resin-modified glass ionomer cement restorations and the amalgam restorations ( P < .05 ) . Polarized light microscopic examination of the returned teeth that were restored as a part of this study indicated that the resin-modified glass ionomer cement had significantly less enamel demineralization at restoration margins than did amalgam ( P < .0001 ) . CONCLUSIONS The resin-modified glass ionomer cement functioned clinical ly as well as amalgam for Class II restorations in primary molars . However , the resin-modified glass ionomer exhibited significantly less enamel demineralization at restoration margins than did amalgam . CLINICAL IMPLICATION S Resin-modified glass ionomer cement restorative material functions well for Class II restorations in primary molars and exhibits less recurrent caries at restoration margins than does amalgam OBJECTIVES To assess and compare the cumulative survival rate of amalgam and atraumatic restorative treatment ( ART ) restorations in primary molars over 3 years . METHODS 280 children aged 6 - 7 years old were enrolled in a cluster r and omized controlled clinical trial using a parallel group design covering two treatment groups : conventional restorative treatment with amalgam ( CRT ) and atraumatic restorative treatment ( ART ) using a high-viscosity glass-ionomer ( HVGIC ) Ketac Molar Easymix . Three pedodontists placed 750 restorations ( 364 amalgam and 386 ART in 126 and 154 children , respectively ) which were evaluated at 0.5 , 1 , 2 and 3 years . The proportional hazard rate regression model with frailty correction , ANOVA and Wald tests , and the Jackknife procedure were applied in analysing the data . RESULTS The cumulative survival rates over 3 years for all , single- and multiple-surface CRT/amalgam restorations ( 72.6 % , 93.4 % , 64.7 % , respectively ) were no different from those of comparable ART/HVGIC restorations ( 66.8 % ; 90.1 % and 56.4 % , respectively ) ( p=0.10 ) . Single-surface restorations had higher survival rates than multiple-surface restorations for the both treatment procedures ( p<0.0001 ) . A higher proportion of restorations failed because of mechanical reasons ( 94.8 % ) than of secondary caries ( 5.2 % ) . No difference in reasons for restoration failures between all types of amalgam and ART/HVGIC restorations were observed ( p=0.24 ) . SIGNIFICANCE The high-viscosity glass-ionomer used in this study in conjunction with the ART is a viable option for restoring carious dentin lesions in single surfaces in vital primary molars This in vitro study evaluated the bond strength of adhesive restorative material s to sound and eroded dentin . Thirty-six bovine incisors were embedded in acrylic resin and ground to obtain flat buccal dentin surfaces . Specimens were r and omly allocated in 2 groups : sound dentin ( immersion in artificial saliva ) and eroded dentin ( pH cycling model - 3 × / cola drink for 7 days ) . Specimens were then reassigned according to restorative material : glass ionomer cement ( KetacTM Molar Easy Mix ) , resin-modified glass ionomer cement ( VitremerTM ) or adhesive system with resin composite ( Adper Single Bond 2 + Filtek Z250 ) . Polyethylene tubes with an internal diameter of 0.76 mm were placed over the dentin and filled with the material . The microshear bond test was performed after 24 h of water storage at 37ºC. The failure mode was evaluated using a stereomicroscope ( 400 × ) . Bond strength data were analyzed with two-way ANOVA and Tukey 's post hoc tests ( α = 0.05 ) . Eroded dentin showed bond strength values similar to those for sound dentin for all material s. The adhesive system showed the highest bond strength values , regardless of the substrate ( p < 0.0001 ) . For all groups , the adhesive/mixed failure prevailed . In conclusion , adhesive material s may be used in eroded dentin without jeopardizing the bonding quality . It is preferable to use an etch- and -rinse adhesive system because it shows the highest bond strength values compared with the glass ionomer cements tested BACKGROUND Secondary caries or caries adjacent to restorations is the most frequent reason for replacement of dental restorations . Though , limited data is available on variables influencing the development of secondary caries in primary teeth . AIM To investigate risk factors for the development of secondary caries adjacent to direct composite restorations in primary teeth . DESIGN For this retrospective study , data of 2417 composite restorations , which were placed due to primary carious lesions , were considered . A total of 212 restorations failed due to secondary caries within a maximum observation period of 8 years . A control group was r and omly selected . Mann-Whitney U-test , binomial logistic regression with backward elimination and Cox regression with frailty model were performed ( P < 0.05 ) . RESULTS The overall caries experience amounted to 6.3 dmft and 13.3 dmfs . 72.5 % of restorations failed within the first 2 years . Older children and children from families with a higher socio-economic status showed a lower risk for secondary caries . Further , the dentist and the adhesive had a significant influence on the longevity . Posterior restorations had a higher risk to fail in comparison with anterior restorations . CONCLUSIONS Within the limitation of this study , it is concluded that the development of secondary caries is influenced by several factors . Nevertheless , the secondary caries rate was found to be relatively low in this high-risk population BACKGROUND Limited information is available from r and omized clinical trials comparing the longevity of  amalgam and resin-based compomer/composite restorations . The authors compared replacement rates of these types of restorations in posterior teeth during the five-year follow-up of the New Engl and Children 's Amalgam Trial . METHODS The authors r and omized children aged 6 to 10 years who had two or more posterior occlusal carious lesions into groups that received amalgam ( n=267 ) or compomer ( primary teeth)/composite ( permanent teeth ) ( n=267 ) restorations  and followed them up semiannually . They compared the longevity of restorations placed on all posterior surfaces using r and om effects survival analysis . RESULTS The average+/-st and ard deviation follow-up was 2.8+/-1.4 years for primary tooth restorations and 3.4+/-1.9 years for permanent tooth restorations . In primary teeth , the replacement rate was 5.8 percent of compomers versus 4.0 percent of amalgams ( P=.10 ) , with 3.0 percent versus 0.5 percent ( P=.002 ) , respectively , due to recurrent caries . In permanent teeth , the replacement rate was 14.9 percent of composites versus 10.8 percent of amalgams ( P=.45 ) , and the repair rate was 2.8 percent of composites versus 0.4 percent of amalgams ( P=.02 ) . CONCLUSION Although the overall difference in longevity was not statistically significant , compomer was replaced significantly more frequently owing to recurrent caries , and composite restorations required seven times as many repairs as did amalgam restorations . CLINICAL IMPLICATION S Compomer/composite restorations on posterior tooth surfaces in children may require replacement or repair at higher rates than amalgam restorations , even within five years of placement OBJECTIVE The aim of this in vitro study was to evaluate the interaction between two sources of fluoride ( restorative systems and dentifrices ) in inhibiting artificial root caries development . METHODS One hundred and eighty tooth segments were embedded in polyester resin , and s and ed flat . Cylindrical cavities 1.0mm-deep and 1.5mm-diameter were prepared in root dentin and r and omly restored by fluoride-containing restorative systems : Ketac-fil/Espe ( Ke ) , Fuji II LC/GC Corp ( Fj ) , F2000/3 M ( F2 ) , Surefil/Dentsply ( Su ) or a control : Filtek Z250/3 M ( Z2 ) . Ten experimental groups were made to test the association among the five restorative systems and two dentifrices : with F(- ) ( Sensodyne Baking Soda ) or without F(- ) ( Sensodyne Original ) ( n=18 ) . After surface polishing , a 1mm-wide margin around the restorations was demarcated and initial dentin surface Knoop microhardness values ( KHN(i ) ) were obtained . The specimens were su bmi tted to a pH-cycling model , and to applications of slurries of dentifrice . Afterwards the final dentin surface Knoop microhardness values ( KHN(f ) ) were measured . RESULTS The differences between KHN(i ) and KHN(f ) , and the covariate KHN(i ) were considered by the ANCOVA and Tukey 's test ( alpha=0.05 ) . The interaction between restorative system and dentifrice was statistically significant ( p=0.0026 ) . All restorative systems provided some protection against artificial caries challenge when associated with the fluoride-containing dentifrice treatment . The means ( st and ard deviation ) of reductions in Knoop hardness values for systems associated with the fluoride-containing dentifrice were : Ke : 40.0(1.02)(a ) , Fj : 41.9(1.02)(b ) , F2 : 43.3(1.04)(c ) , Su : 43.5(1.00)(c ) , Z2 : 44.0(1.02)(c ) ; and with the non-fluoride-containing dentifrice were : Ke : 42.9(1.02)(a ) , Fj : 44.7(1.01)(b ) , F2 : 45.2(1.09)(bc ) , Su : 46.0(0.99)(c ) , Z2 : 46.6(0.99)(c ) ( statistical differences were expressed by different letters ) . CONCLUSION The cariostatic effect shown by the fluoride-containing dentifrice could enhance that shown by Ketac-fil and Fuji II LC , and could mask that shown by F2000 PURPOSE The authors conducted a r and omized clinical trial to evaluate the survival rate of esthetic restorations in Class I and Class II beveled preparations in primary molars 24 months after placement . The null hypothesis was that there is no difference among survival rates of the restorative material s used . METHODS Forty-eight children ( mean age , 5 years 9 months ) received 141 restorations in beveled cavosurface margins in primary molars r and omly assigned by lottery method : 46 received treatment with Vitremer Tri-Cure Glass Ionomer System ( 3 M ESPE Dental Products , St. Paul , Minn. ) ( 33 Class I and 13 Class II restorations ) , 51 received treatment with Freedom ( SDI , Bayswater , Victoria , Australia ) ( 36 Class I and 15 Class II restorations ) ; 44 received treatment with TPH Spectrum ( Dentsply , Petropolis , Rio de Janeiro , Brazil ) ( 30 Class I and 14 Class II restorations ) . Two examiners whose technique had been calibrated ( weight kappa > 0.85 ) evaluated the restorations using modified U.S. Public Health Service criteria and Visible Plaque Index score at baseline and at 12 , 18 and 24 months . RESULTS After two years , the authors censored data for 17 restorations , considered 101 restorations to be clinical ly successful and deemed 23 restorations failed because of loss of marginal integrity , anatomical form discrepancies and secondary caries . For Class I and Class II restorations , the cum 
    Output:
    