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: This paper reports the 5-year findings of a multi clinical ( n = 11 ) trial of a posterior composite restorative .  The overall findings , based on data collected from 649 ( 68 per cent ) of the 958 restorations originally included in the study , indicate that the material evaluated satisfies established clinical requirements for posterior composites over periods of up to 5 years . Deviations in the reporting of certain elements of the data appear to have been related to local variations in method Three restorative material s used for cervical erosion /abrasion lesions were evaluated clinical ly after 10 years . Thirty adult patients with at least four cervical lesions received one restoration of each of Ketac-Fil , finished immediately , Ketac-Fil , finished after a delay , Chelon-FIl ( all glass-ionomer cements ) , and Cervident ( a resin composite ) . Restorations were placed without any tooth preparations . Eighteen patients returned for their 10-year examinations . Two experienced examiners provided the periodic evaluations . Complete retention at 10 years was 83 % for Ketac-Fil , finished immediately ; 78 % for Ketac-Fil , finished after a delay ; 67 % for Chelon-Fil ; and 17 % for Cervident . All three glass-ionomer restorative material s exhibited statistically significantly greater retention that did Cervident . When a noninvasive procedure is desired , glass-ionomer material s are the restorative material of choice for abrasion/erosion lesions because of their long-term retention values In a cross-sectional survey the age of restorations in situ was recorded in three patient groups . Group A were r and omly examined regular attenders , group B were irregular attenders r and omly chosen from patient treatment records , and in group C the age of posterior gold and composite resin restorations was recorded in selected regular attenders . The study material included 8310 restorations in group A , 1281 in group B , and 500 restorations in group C. The three material s amalgam , composite , and gold accounted for more than 90 % of all restorations . In group A 3.3 % of the restorations were scheduled for replacement . The most prevalent reasons for replacement were secondary caries , bulk fractures of the restoration , and tooth fractures . The median age of the failed restorations was fairly similar to the median age of the acceptable restorations in situ among the regular patients ( group A ) . The data indicate median ages of 20 years for gold restorations , 12 - 14 years for amalgam restorations , and 7 - 8 years for composite resin restorations . The restoration ages were influenced by the type and size of the restoration , the restorative material used , and possibly also the intra-oral location of the restorations The purpose of this clinical study was to evaluate the factor of the setting rate/Eames working time on fracture at the margins of amalgams . One batch of a high-copper amalgam was modified to obtain two setting rates , one fast and one slow setting .  Two dentists originally placed 134 amalgam restorations in 23 patients . Both dentists used a rubber dam throughout the restorative procedure and prepared cavities as conservatively as possible . The amalgams were condensed by h and and carved with sharp instruments . At 1 year 124 restorations and at 2 years 115 restorations were evaluated for fracture at the margins . Results indicated that there was no significant clinical difference between a slow- and fast- setting alloy , nor was there a difference between the operators The purpose of the study was to estimate the influence of different clinical variables on the replacement rate of  class-II amalgam restorations in permanent teeth . The study included 210 patients who had 468 restorations placed by 7 Sc and inavian dentists . The observation periods varied between 7 and 10 years . At the time of the last recording 188 restorations remained intact in 88 patients , whereas 68 restorations in 53 patients had been replaced . Eighty-six patients with 212 restorations had dropped out of the study . The most prevalent criteria for replacement were secondary caries ( n = 30 ) and restoration bulk fractures ( n = 24 ) . Chi-square analyses of the relationship between the prevalence of replacements and the clinical variables indicated effects of the operator and the patients ' age and caries activity ( p less than 0.001 ) . Similar results were observed when the functional time of the restorations was related to the clinical variables and analyzed by ANOVA and MCA analyses and by survival analyses using logrank and Wilcoxon tests ( p less than 0.001 ) . The survival analyses using the Lee-Desu statistic D showed in addition a slight difference between the restorations in the lower premolars and upper and lower molars . There were no differences in the clinical performance between four non-gamma-2 alloys and one conventional alloy . Furthermore , no differences were noted between the survival rates of MC , DO , and MOD restorations . In a Cox regression model the strongest effects on the estimated survival rates were associated with the patients ' age and caries activity covariates ( global chi-square = 23.5 , df = 2 , p less than 0.001 ) , whereas the effects of the operator and the other clinical variables were insignificant OBJECTIVE This clinical trial aim ed at study ing the long-term performance in routine clinical practice of  saucer-shaped Class II resin composite restorations .  METHOD AND MATERIAL S Fifty-one preparations were completed and filled with either of two light-cured posterior composites by seven dentists of the Public Dental Service . The restorations were evaluated annually , using the US Public Health Service criteria , bitewing radiographs , and dies based on replica impressions . At the final evaluation , the recall rate was 100 % . RESULTS After a mean of 7.2 + /- 1.3 years of service ( censored maximum of 9.6 years ) , 70 % of the restorations were acceptable for continued use . Caries and technical deficiencies were the main causes of failure . CONCLUSION The saucer configuration , by respecting and utilizing inherent properties of the resin composites , spares sound dentin and is preferable to the box preparation A group of 71 patients was examined to determine the longevity of restorations placed at the University of North Carolina School of Dentistry . Patients with an overall restorations failure rate of equal to or greater than 40 per 1000 restoration-yr were categorized as having a " high failure rate " and those below that were considered " low failure rate " . An investigation was made to determine statistical differences between these two groups of patients using survival analysis and various statistical indices . Time of exposure and age of patients for both groups were similar . High rate patients had a greater number of anterior restorations and anterior teeth restored . In addition , the number of restorations per tooth was significantly greater in anterior and posterior teeth of the high failure rate group . No single variable was found to account for the differences in the failure rates in the two groups of patients . A prospect i ve study is needed in order to examine possible causes for restoration failures PURPOSE This paper reports the 5-year performance of the restorations of the high-copper content dental amalgam alloys included in the worldwide programme of clinical trials of Occlusin , including unique data on wear . METHODS The methods employed are common to those previously reported for the multi clinical evaluation of Occlusin . Analysis of the data is limited to simple statistical procedures . RESULTS The findings lend support to existing knowledge concerning the favourable performance of restorations of high-copper content dental amalgam alloys  , notably in relation to restorations in moderate- to large-sized Class II preparations in permanent molar teeth . Analysis of the data sheds new light on the influences of variables , including type of tooth restored , size and class of restoration and the presence or absence of occlusal contact(s ) on performance . CONCLUSION Conclusions are drawn regarding ways in which protocol s for future evaluations of the type reported should be exp and ed , and , together with suggestions for further work , it is concluded that this paper is a timely reminder of the value of existing dental amalgam alloys After 14 years , 40 patients from an in vitro/in vivo study of 12 amalgam alloys were evaluated . All these patients had been attending private practitioners over the past 10 years , and the clinical evaluation revealed that 320 restorations were intact and 47 ( 12.8 % ) had been lost . The majority ( 75.0 % ) of the lost restorations were lost to crown placement or the replacement with another amalgam restoration . The six high-copper alloys exhibited better clinical performance , in both loss rate and fracture at the margins , than did traditional low-copper material s. Fracture at the margins was a better predictor of the loss of a restoration than were mechanical properties In this study 96 teeth of 12 patients were restored with either the conventional alloy Premix , the blended non-gamma 2 amalgam Dispersalloy , or one of the spherical alloys Sybraloy and Tytin . To ascertain an objective comparison of the clinical performance of these alloys , two different alloys were used in each of at least two dental arch quadrants in the same patient and consequently were placed in the same oral environment . Clinical performance of the restorations was evaluated by macrophotography and scanning electron microphotography of replicas made after placement and 2 , 3 , and 5 years thereafter . St and ard criteria were used for the evaluation of anatomic form , surface condition , and marginal adaptation of the fillings . In addition , the filling-enamel interface was assessed from the microphotographs . The three high-copper alloys performed better clinical ly than the conventional alloy , and the spherical alloys had the best qualifications . In addition to visual examination and photographic evaluation of restorations , the micrometric assessment of replica photographs from the scanning electron microscope may render clinical trials of amalgam alloys measurable and less subjective A clinical trial comparing the efficacy of an  occlusal amalgam restoration with a minimal composite restoration and fissure sealant in the management of occlusal caries in young patients has been performed . One hundred and fifty pairs of restorations were placed in 103 patients and assessed during the 5-year follow-up period . Nineteen restorations failed during this period : 11 amalgam and 8 minimal composite . There was some deterioration in anatomical form and marginal integrity of the remaining amalgam restorations . Of the remaining minimal composites , seven suffered clinical ly detectable wear and a further five had some marginal staining . Forty-nine of the minimal composites needed to have repairs to the fissure sealant . The amalgam restorations occupied , on average , 25 % of the occlusal surface of the tooth , compared with 5 % for the minimal composite resin . The results after a 5-year follow-up showed no significant difference in median survival times between the amalgam and the minimal composite 
    Output:
    
agent
However , variability was substantial .
Restoration type , material s , the patient , the operator , the practice environment and type of care system appeared to influence longevity .
***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: This paper reports the 5-year findings of a multi clinical ( n = 11 ) trial of a posterior composite restorative .  The overall findings , based on data collected from 649 ( 68 per cent ) of the 958 restorations originally included in the study , indicate that the material evaluated satisfies established clinical requirements for posterior composites over periods of up to 5 years . Deviations in the reporting of certain elements of the data appear to have been related to local variations in method Three restorative material s used for cervical erosion /abrasion lesions were evaluated clinical ly after 10 years . Thirty adult patients with at least four cervical lesions received one restoration of each of Ketac-Fil , finished immediately , Ketac-Fil , finished after a delay , Chelon-FIl ( all glass-ionomer cements ) , and Cervident ( a resin composite ) . Restorations were placed without any tooth preparations . Eighteen patients returned for their 10-year examinations . Two experienced examiners provided the periodic evaluations . Complete retention at 10 years was 83 % for Ketac-Fil , finished immediately ; 78 % for Ketac-Fil , finished after a delay ; 67 % for Chelon-Fil ; and 17 % for Cervident . All three glass-ionomer restorative material s exhibited statistically significantly greater retention that did Cervident . When a noninvasive procedure is desired , glass-ionomer material s are the restorative material of choice for abrasion/erosion lesions because of their long-term retention values In a cross-sectional survey the age of restorations in situ was recorded in three patient groups . Group A were r and omly examined regular attenders , group B were irregular attenders r and omly chosen from patient treatment records , and in group C the age of posterior gold and composite resin restorations was recorded in selected regular attenders . The study material included 8310 restorations in group A , 1281 in group B , and 500 restorations in group C. The three material s amalgam , composite , and gold accounted for more than 90 % of all restorations . In group A 3.3 % of the restorations were scheduled for replacement . The most prevalent reasons for replacement were secondary caries , bulk fractures of the restoration , and tooth fractures . The median age of the failed restorations was fairly similar to the median age of the acceptable restorations in situ among the regular patients ( group A ) . The data indicate median ages of 20 years for gold restorations , 12 - 14 years for amalgam restorations , and 7 - 8 years for composite resin restorations . The restoration ages were influenced by the type and size of the restoration , the restorative material used , and possibly also the intra-oral location of the restorations The purpose of this clinical study was to evaluate the factor of the setting rate/Eames working time on fracture at the margins of amalgams . One batch of a high-copper amalgam was modified to obtain two setting rates , one fast and one slow setting .  Two dentists originally placed 134 amalgam restorations in 23 patients . Both dentists used a rubber dam throughout the restorative procedure and prepared cavities as conservatively as possible . The amalgams were condensed by h and and carved with sharp instruments . At 1 year 124 restorations and at 2 years 115 restorations were evaluated for fracture at the margins . Results indicated that there was no significant clinical difference between a slow- and fast- setting alloy , nor was there a difference between the operators The purpose of the study was to estimate the influence of different clinical variables on the replacement rate of  class-II amalgam restorations in permanent teeth . The study included 210 patients who had 468 restorations placed by 7 Sc and inavian dentists . The observation periods varied between 7 and 10 years . At the time of the last recording 188 restorations remained intact in 88 patients , whereas 68 restorations in 53 patients had been replaced . Eighty-six patients with 212 restorations had dropped out of the study . The most prevalent criteria for replacement were secondary caries ( n = 30 ) and restoration bulk fractures ( n = 24 ) . Chi-square analyses of the relationship between the prevalence of replacements and the clinical variables indicated effects of the operator and the patients ' age and caries activity ( p less than 0.001 ) . Similar results were observed when the functional time of the restorations was related to the clinical variables and analyzed by ANOVA and MCA analyses and by survival analyses using logrank and Wilcoxon tests ( p less than 0.001 ) . The survival analyses using the Lee-Desu statistic D showed in addition a slight difference between the restorations in the lower premolars and upper and lower molars . There were no differences in the clinical performance between four non-gamma-2 alloys and one conventional alloy . Furthermore , no differences were noted between the survival rates of MC , DO , and MOD restorations . In a Cox regression model the strongest effects on the estimated survival rates were associated with the patients ' age and caries activity covariates ( global chi-square = 23.5 , df = 2 , p less than 0.001 ) , whereas the effects of the operator and the other clinical variables were insignificant OBJECTIVE This clinical trial aim ed at study ing the long-term performance in routine clinical practice of  saucer-shaped Class II resin composite restorations .  METHOD AND MATERIAL S Fifty-one preparations were completed and filled with either of two light-cured posterior composites by seven dentists of the Public Dental Service . The restorations were evaluated annually , using the US Public Health Service criteria , bitewing radiographs , and dies based on replica impressions . At the final evaluation , the recall rate was 100 % . RESULTS After a mean of 7.2 + /- 1.3 years of service ( censored maximum of 9.6 years ) , 70 % of the restorations were acceptable for continued use . Caries and technical deficiencies were the main causes of failure . CONCLUSION The saucer configuration , by respecting and utilizing inherent properties of the resin composites , spares sound dentin and is preferable to the box preparation A group of 71 patients was examined to determine the longevity of restorations placed at the University of North Carolina School of Dentistry . Patients with an overall restorations failure rate of equal to or greater than 40 per 1000 restoration-yr were categorized as having a " high failure rate " and those below that were considered " low failure rate " . An investigation was made to determine statistical differences between these two groups of patients using survival analysis and various statistical indices . Time of exposure and age of patients for both groups were similar . High rate patients had a greater number of anterior restorations and anterior teeth restored . In addition , the number of restorations per tooth was significantly greater in anterior and posterior teeth of the high failure rate group . No single variable was found to account for the differences in the failure rates in the two groups of patients . A prospect i ve study is needed in order to examine possible causes for restoration failures PURPOSE This paper reports the 5-year performance of the restorations of the high-copper content dental amalgam alloys included in the worldwide programme of clinical trials of Occlusin , including unique data on wear . METHODS The methods employed are common to those previously reported for the multi clinical evaluation of Occlusin . Analysis of the data is limited to simple statistical procedures . RESULTS The findings lend support to existing knowledge concerning the favourable performance of restorations of high-copper content dental amalgam alloys  , notably in relation to restorations in moderate- to large-sized Class II preparations in permanent molar teeth . Analysis of the data sheds new light on the influences of variables , including type of tooth restored , size and class of restoration and the presence or absence of occlusal contact(s ) on performance . CONCLUSION Conclusions are drawn regarding ways in which protocol s for future evaluations of the type reported should be exp and ed , and , together with suggestions for further work , it is concluded that this paper is a timely reminder of the value of existing dental amalgam alloys After 14 years , 40 patients from an in vitro/in vivo study of 12 amalgam alloys were evaluated . All these patients had been attending private practitioners over the past 10 years , and the clinical evaluation revealed that 320 restorations were intact and 47 ( 12.8 % ) had been lost . The majority ( 75.0 % ) of the lost restorations were lost to crown placement or the replacement with another amalgam restoration . The six high-copper alloys exhibited better clinical performance , in both loss rate and fracture at the margins , than did traditional low-copper material s. Fracture at the margins was a better predictor of the loss of a restoration than were mechanical properties In this study 96 teeth of 12 patients were restored with either the conventional alloy Premix , the blended non-gamma 2 amalgam Dispersalloy , or one of the spherical alloys Sybraloy and Tytin . To ascertain an objective comparison of the clinical performance of these alloys , two different alloys were used in each of at least two dental arch quadrants in the same patient and consequently were placed in the same oral environment . Clinical performance of the restorations was evaluated by macrophotography and scanning electron microphotography of replicas made after placement and 2 , 3 , and 5 years thereafter . St and ard criteria were used for the evaluation of anatomic form , surface condition , and marginal adaptation of the fillings . In addition , the filling-enamel interface was assessed from the microphotographs . The three high-copper alloys performed better clinical ly than the conventional alloy , and the spherical alloys had the best qualifications . In addition to visual examination and photographic evaluation of restorations , the micrometric assessment of replica photographs from the scanning electron microscope may render clinical trials of amalgam alloys measurable and less subjective A clinical trial comparing the efficacy of an  occlusal amalgam restoration with a minimal composite restoration and fissure sealant in the management of occlusal caries in young patients has been performed . One hundred and fifty pairs of restorations were placed in 103 patients and assessed during the 5-year follow-up period . Nineteen restorations failed during this period : 11 amalgam and 8 minimal composite . There was some deterioration in anatomical form and marginal integrity of the remaining amalgam restorations . Of the remaining minimal composites , seven suffered clinical ly detectable wear and a further five had some marginal staining . Forty-nine of the minimal composites needed to have repairs to the fissure sealant . The amalgam restorations occupied , on average , 25 % of the occlusal surface of the tooth , compared with 5 % for the minimal composite resin . The results after a 5-year follow-up showed no significant difference in median survival times between the amalgam and the minimal composite 
    Output:
    