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: OBJECTIVES To evaluate the push-out bond strength and the sealing ability of five adhesive cements routinely used for fiber-post bonding . METHODS Fifty extracted single-rooted teeth were r and omly divided in five groups and restored using Parapost FiberLux and the following luting agents : Panavia 21 ( PAN ) , Clearfil Esthetic Cement ( CLF ) , Variolink II ( VAR ) , RelyX Unicem ( UNI ) and experimental GC self-adhesive cement ( EGC ) . After 1 week of water storage at 37 degrees C , three sections ( coronal , middle and apical ) of 2 mm thickness were prepared from each specimen . Sealing ability was quantified with a fluid-filtration system ( Flodec ) during 10 min , after which the push-out bond strength was immediately measured . Data were analyzed with ANOVA ( push-out ) and Kruskal-Wallis ( sealing ability ) . RESULTS The push-out bond strength and sealing ability were not significantly different among the coronal , middle and apical sections for each luting agent . The highest push-out bond strength was measured for CLF ( 14.60+/-3.63 MPa ) , which was not significantly different from PAN ( 12.57+/-2.45 MPa ) , but significantly higher than VAR ( 11.09+/-4.09 MPa ) , UNI ( 11.29+/-4.31 MPa ) and EGC ( 7.65+/-4.79 MPa ) . When evaluating the sealing ability , significant differences were not found among PAN , CLF and VAR , and between UNI and EGC . The latter luting agents scored significantly lower than the former ones . The push-out bond strength was correlated to the sealing ability ( p<0.001 ) . SIGNIFICANCE The self-etching MDP-based cements presented the highest push-out bond strength . Although the bonding effectiveness of self-adhesive cements appears promising , their interaction with root dentin might be too weak to minimize microleakage at the post-cement-dentin interface OBJECTIVES This retrospective study investigated the clinical effectiveness over up to 8 years of parallel-sided and of tapered glass-fiber posts , in combination with either hybrid composite or dual-cure composite resin core material , in endodontically treated , maxillary anterior teeth covered with full-ceramic crowns . METHODS The study population comprised 192 patients and 526 endodontically treated teeth , with various degrees of hard-tissue loss , restored by the post- and -core technique .  Four groups were defined based on post shape and core build-up material s , and within each group post- and -core restorations were assigned r and omly with respect to root morphology . Inclusion criteria were symptom-free endodontic therapy , root-canal treatment with a minimum apical seal of 4 mm , application of rubber dam , need for post- and -core complex because of coronal tooth loss , and tooth with at least one residual coronal wall . Survival rate of the post- and -core restorations was determined using Kaplan-Meier statistical analysis . RESULTS The restorations were examined clinical ly and radiologically ; mean observation period was 5.3 years . The overall survival rate of glass-fiber post- and -core restorations was 98.5 % . The survival rate for parallel-sided posts was 98.6 % and for tapered posts was 96.8 % . Survival rates for core build-up material s were 100 % for dual-cure composite and 96.8 % for hybrid light-cure composite . CONCLUSIONS For both glass-fiber post design s and for both core build-up material s , clinical performance was satisfactory . Survival was higher for teeth retaining four and three coronal walls This study examined the contribution of testing time on the interfacial strengths of  fiber posts to radicular dentin . Twenty-five fiber posts were luted to root segments  with resin cements and a zinc phosphate cement . Immediately upon setting of the material s , the roots were sectioned into slices and r and omly divided into two subgroups , depending on testing time ( immediate vs. 24-hours ) , for push-out test . The results showed an improvement on the interfacial strength after 24 hours of storage . When data were pooled for each cement , the interfacial strengths ( MPa ) were : Optibond Solo Plus/Nexus : 10.3+/-3.8a ; zinc phosphate cement : 10.1+/-2.7a ; Multilink : 9.6+/-3.8ab ; RelyX Unicem : 7.1+/-4.9bc ; AllBond 2/Duolink : 6.7+/-3.5c ( groups with same superscript letter were not statistically significant ) . It is concluded that bond strength can increase during the first 24 hours and that the interfacial strength is predominantly contributed by frictional retention PURPOSE This controlled clinical trial aim ed to compare the 3-year outcomes of glass fiber posts and composite cores with gold alloy-based posts and cores for the restoration of endodontically treated teeth . MATERIAL S AND METHODS One hundred forty-four patients in need of 205 restorations on endodontically treated teeth were selected and followed for 7 to 37 months ( mean : 21 ± 9 months ) . The teeth were primarily stratified based on the remaining tissue available to restore the tooth core with or without a post . Then , r and omization allocated the teeth to either test group 1 ( prefabricated glass fiber posts ) , test group 2 ( custom-made glass fiber posts ) , or test group 3 ( composite cores without posts ) . The control group consisted of gold alloy-based posts and cores . All posts/cores were covered with all-ceramic single crowns .  Failures were either absolute , such as root fractures or irreparable fractures of the post/core , or relative , such as loss of post retention or reparable fractures of the core . Success and survival probability lifetime curves , corrected for clustering , were drawn for the entire data set . RESULTS The recall rate at 3 years was 97.1 % . Absolute failures consisted of two root fractures and one endodontic failure , while relative failures included three instances of retention loss of the post/core and one post fracture . Because of the low number of events , no statistical tests were performed . The success and survival probabilities over all groups together at 3 years amounted to 91.7 % and 97.2 % , respectively . CONCLUSIONS After being followed for up to 3 years , both cast gold and composite post and core systems performed well clinical ly . Longer follow-up times are needed to detect possible significant differences . Int J Prosthodont 2011;24:363 - 372 OBJECTIVES The aim of this study is to provide prospect i ve clinical data for the survival of postendodontic reconstructions of teeth with varying degrees of hard tissue loss using tapered or parallel-sided post shapes . METHODS Eighty-three patients got 105 glass fibre reinforced posts of tapered ( Luscent Anchors , Dentatus , Sweden ) and parallel-sided , serrated ( FibreKor , Jeneric Pentron , USA ) post shape . A dual curing hybrid composite Compolute ( 3 M ESPE , Germany ) was used as luting material , EBS-Multi ( 3 M ESPE ) as adhesive system and Clearfil Core ( Kuraray , Japan ) for core built-up . The restorations were followed for a minimum of 24 months . The statistical analysis was performed on a r and om sub- sample of one restoration per subject . The Fisher exact test was used to compare frequencies of failures after 12 and 24 month . A Kaplan-Meier- analysis was used to analyse time-to-failure in both groups . Differences of survival time between post types were tested with the log-rank test . RESULTS 3.8 % of the restorations failed after 12 month , 12.8 % after 24 month , respectively . The main failure type observed was post fractures . All but one failed teeth could be restored . There was no difference in failure frequency between post types after 12 or 24 months . The log-rank test showed no differences in survival between the two types of post ( p=0.37 ) . CONCLUSION Parallel-sided and tapered glass fibre posts result after 2 years of clinical service in an equal rate of survival AIM To compare regional bond strength in different thirds of the root canal , among glass fiber-reinforced ( FRC ) endodontic posts luted with different cements , using the push-out test . MATERIAL AND METHODS Sixty extracted human anterior teeth were endodontically treated with gutta-percha and AH Plus sealer . The crown portion was removed , and a dowel space was prepared . Prepared teeth were r and omly assigned to one of six groups ( n = 10 ) for luting glass FRC Postec posts , with one of the six cement systems ( Ketac Cem Aplicap , Relyx Unicem Aplicap , Variolink II/Excite DCS , Panavia F/ED Primer , C&B cement/All-Bond 2 , and Multilink/Multilink Primer A/B ) , using an alignment technique . Specimens were embedded in resin , and each root was sectioned into six 1-mm thick serial slices . A push-out test was performed to measure regional bond strengths and to identify the type of failure . RESULTS The highest bond strength values were found in the cervical third and the lowest in the apical third . Highest values were obtained using Variolink II , Panavia F , and Multilink resin cements followed by C&B resin cement and Relyx Unicem ionomer resin cement ; Ketac-cem ionomer cement showed the lowest value . CONCLUSION Highest bond strength values were obtained in the cervical third and with resin cements INTRODUCTION This is the first clinical long-term pilot study that tested the biomimetic concept of using more flexible , dentine-like ( low Young modulus ) glass fiber-reinforced epoxy resin posts ( GFREPs ) compared with rather rigid , stiff ( higher Young modulus ) titanium posts ( TPs ) in order to improve the survival rate of severely damaged endodontically treated teeth . METHODS Ninety-one subjects in need of postendodontic restorations in teeth with 2 or less remaining cavity walls were r and omly assigned to receive either a tapered TP ( n = 46 ) or a tapered GFREP ( n = 45 ) . The posts were adhesively luted using self-adhesive resin cement . The composite core build-ups were prepared ensuring a circumferential 2-mm ferrule . The primary endpoint was a loss of restoration for any reason . To study group differences , the log-rank test was calculated ( P < .05 ) . Hazard plots were constructed . RESULTS After 84 months of observation ( mean = 71.2 months ) , 7 restorations failed ( ie , 4 GFREPs and 3 TPs ) . The failure modes were as follows : GFREP : root fracture ( n = 3 ) , core fracture ( n = 1 ) and TP : endodontic failure ( n = 3 ) . No statistical difference was found between the survival rates ( GFREPs = 90.2 % , TPs = 93.5 % , P = .642 ) . The probability of no failure was comparable for both post material s ( risk ratio ; 95 % confidence interval , 0.965 - 0.851/1.095 ) . CONCLUSIONS When using self-adhesive luted prefabricated posts in severely destroyed abutment teeth with 2 or less cavity walls and a 2-mm ferrule , postendodontic restorations achieved high long-term survival rates irrespective of the post material used ( ie , glass fiber vs titanium ) 
    Output:
    
agent
The results showed heterogeneity in all comparisons , and higher bond strength to dentin was identified for self-adhesive cements .
Although the articles included in this meta- analysis showed high heterogeneity and high risk of bias , the in vitro literature seems to suggest that use of self-adhesive resin cement could improve the retention of GFPs into root canals
***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: OBJECTIVES To evaluate the push-out bond strength and the sealing ability of five adhesive cements routinely used for fiber-post bonding . METHODS Fifty extracted single-rooted teeth were r and omly divided in five groups and restored using Parapost FiberLux and the following luting agents : Panavia 21 ( PAN ) , Clearfil Esthetic Cement ( CLF ) , Variolink II ( VAR ) , RelyX Unicem ( UNI ) and experimental GC self-adhesive cement ( EGC ) . After 1 week of water storage at 37 degrees C , three sections ( coronal , middle and apical ) of 2 mm thickness were prepared from each specimen . Sealing ability was quantified with a fluid-filtration system ( Flodec ) during 10 min , after which the push-out bond strength was immediately measured . Data were analyzed with ANOVA ( push-out ) and Kruskal-Wallis ( sealing ability ) . RESULTS The push-out bond strength and sealing ability were not significantly different among the coronal , middle and apical sections for each luting agent . The highest push-out bond strength was measured for CLF ( 14.60+/-3.63 MPa ) , which was not significantly different from PAN ( 12.57+/-2.45 MPa ) , but significantly higher than VAR ( 11.09+/-4.09 MPa ) , UNI ( 11.29+/-4.31 MPa ) and EGC ( 7.65+/-4.79 MPa ) . When evaluating the sealing ability , significant differences were not found among PAN , CLF and VAR , and between UNI and EGC . The latter luting agents scored significantly lower than the former ones . The push-out bond strength was correlated to the sealing ability ( p<0.001 ) . SIGNIFICANCE The self-etching MDP-based cements presented the highest push-out bond strength . Although the bonding effectiveness of self-adhesive cements appears promising , their interaction with root dentin might be too weak to minimize microleakage at the post-cement-dentin interface OBJECTIVES This retrospective study investigated the clinical effectiveness over up to 8 years of parallel-sided and of tapered glass-fiber posts , in combination with either hybrid composite or dual-cure composite resin core material , in endodontically treated , maxillary anterior teeth covered with full-ceramic crowns . METHODS The study population comprised 192 patients and 526 endodontically treated teeth , with various degrees of hard-tissue loss , restored by the post- and -core technique .  Four groups were defined based on post shape and core build-up material s , and within each group post- and -core restorations were assigned r and omly with respect to root morphology . Inclusion criteria were symptom-free endodontic therapy , root-canal treatment with a minimum apical seal of 4 mm , application of rubber dam , need for post- and -core complex because of coronal tooth loss , and tooth with at least one residual coronal wall . Survival rate of the post- and -core restorations was determined using Kaplan-Meier statistical analysis . RESULTS The restorations were examined clinical ly and radiologically ; mean observation period was 5.3 years . The overall survival rate of glass-fiber post- and -core restorations was 98.5 % . The survival rate for parallel-sided posts was 98.6 % and for tapered posts was 96.8 % . Survival rates for core build-up material s were 100 % for dual-cure composite and 96.8 % for hybrid light-cure composite . CONCLUSIONS For both glass-fiber post design s and for both core build-up material s , clinical performance was satisfactory . Survival was higher for teeth retaining four and three coronal walls This study examined the contribution of testing time on the interfacial strengths of  fiber posts to radicular dentin . Twenty-five fiber posts were luted to root segments  with resin cements and a zinc phosphate cement . Immediately upon setting of the material s , the roots were sectioned into slices and r and omly divided into two subgroups , depending on testing time ( immediate vs. 24-hours ) , for push-out test . The results showed an improvement on the interfacial strength after 24 hours of storage . When data were pooled for each cement , the interfacial strengths ( MPa ) were : Optibond Solo Plus/Nexus : 10.3+/-3.8a ; zinc phosphate cement : 10.1+/-2.7a ; Multilink : 9.6+/-3.8ab ; RelyX Unicem : 7.1+/-4.9bc ; AllBond 2/Duolink : 6.7+/-3.5c ( groups with same superscript letter were not statistically significant ) . It is concluded that bond strength can increase during the first 24 hours and that the interfacial strength is predominantly contributed by frictional retention PURPOSE This controlled clinical trial aim ed to compare the 3-year outcomes of glass fiber posts and composite cores with gold alloy-based posts and cores for the restoration of endodontically treated teeth . MATERIAL S AND METHODS One hundred forty-four patients in need of 205 restorations on endodontically treated teeth were selected and followed for 7 to 37 months ( mean : 21 ± 9 months ) . The teeth were primarily stratified based on the remaining tissue available to restore the tooth core with or without a post . Then , r and omization allocated the teeth to either test group 1 ( prefabricated glass fiber posts ) , test group 2 ( custom-made glass fiber posts ) , or test group 3 ( composite cores without posts ) . The control group consisted of gold alloy-based posts and cores . All posts/cores were covered with all-ceramic single crowns .  Failures were either absolute , such as root fractures or irreparable fractures of the post/core , or relative , such as loss of post retention or reparable fractures of the core . Success and survival probability lifetime curves , corrected for clustering , were drawn for the entire data set . RESULTS The recall rate at 3 years was 97.1 % . Absolute failures consisted of two root fractures and one endodontic failure , while relative failures included three instances of retention loss of the post/core and one post fracture . Because of the low number of events , no statistical tests were performed . The success and survival probabilities over all groups together at 3 years amounted to 91.7 % and 97.2 % , respectively . CONCLUSIONS After being followed for up to 3 years , both cast gold and composite post and core systems performed well clinical ly . Longer follow-up times are needed to detect possible significant differences . Int J Prosthodont 2011;24:363 - 372 OBJECTIVES The aim of this study is to provide prospect i ve clinical data for the survival of postendodontic reconstructions of teeth with varying degrees of hard tissue loss using tapered or parallel-sided post shapes . METHODS Eighty-three patients got 105 glass fibre reinforced posts of tapered ( Luscent Anchors , Dentatus , Sweden ) and parallel-sided , serrated ( FibreKor , Jeneric Pentron , USA ) post shape . A dual curing hybrid composite Compolute ( 3 M ESPE , Germany ) was used as luting material , EBS-Multi ( 3 M ESPE ) as adhesive system and Clearfil Core ( Kuraray , Japan ) for core built-up . The restorations were followed for a minimum of 24 months . The statistical analysis was performed on a r and om sub- sample of one restoration per subject . The Fisher exact test was used to compare frequencies of failures after 12 and 24 month . A Kaplan-Meier- analysis was used to analyse time-to-failure in both groups . Differences of survival time between post types were tested with the log-rank test . RESULTS 3.8 % of the restorations failed after 12 month , 12.8 % after 24 month , respectively . The main failure type observed was post fractures . All but one failed teeth could be restored . There was no difference in failure frequency between post types after 12 or 24 months . The log-rank test showed no differences in survival between the two types of post ( p=0.37 ) . CONCLUSION Parallel-sided and tapered glass fibre posts result after 2 years of clinical service in an equal rate of survival AIM To compare regional bond strength in different thirds of the root canal , among glass fiber-reinforced ( FRC ) endodontic posts luted with different cements , using the push-out test . MATERIAL AND METHODS Sixty extracted human anterior teeth were endodontically treated with gutta-percha and AH Plus sealer . The crown portion was removed , and a dowel space was prepared . Prepared teeth were r and omly assigned to one of six groups ( n = 10 ) for luting glass FRC Postec posts , with one of the six cement systems ( Ketac Cem Aplicap , Relyx Unicem Aplicap , Variolink II/Excite DCS , Panavia F/ED Primer , C&B cement/All-Bond 2 , and Multilink/Multilink Primer A/B ) , using an alignment technique . Specimens were embedded in resin , and each root was sectioned into six 1-mm thick serial slices . A push-out test was performed to measure regional bond strengths and to identify the type of failure . RESULTS The highest bond strength values were found in the cervical third and the lowest in the apical third . Highest values were obtained using Variolink II , Panavia F , and Multilink resin cements followed by C&B resin cement and Relyx Unicem ionomer resin cement ; Ketac-cem ionomer cement showed the lowest value . CONCLUSION Highest bond strength values were obtained in the cervical third and with resin cements INTRODUCTION This is the first clinical long-term pilot study that tested the biomimetic concept of using more flexible , dentine-like ( low Young modulus ) glass fiber-reinforced epoxy resin posts ( GFREPs ) compared with rather rigid , stiff ( higher Young modulus ) titanium posts ( TPs ) in order to improve the survival rate of severely damaged endodontically treated teeth . METHODS Ninety-one subjects in need of postendodontic restorations in teeth with 2 or less remaining cavity walls were r and omly assigned to receive either a tapered TP ( n = 46 ) or a tapered GFREP ( n = 45 ) . The posts were adhesively luted using self-adhesive resin cement . The composite core build-ups were prepared ensuring a circumferential 2-mm ferrule . The primary endpoint was a loss of restoration for any reason . To study group differences , the log-rank test was calculated ( P < .05 ) . Hazard plots were constructed . RESULTS After 84 months of observation ( mean = 71.2 months ) , 7 restorations failed ( ie , 4 GFREPs and 3 TPs ) . The failure modes were as follows : GFREP : root fracture ( n = 3 ) , core fracture ( n = 1 ) and TP : endodontic failure ( n = 3 ) . No statistical difference was found between the survival rates ( GFREPs = 90.2 % , TPs = 93.5 % , P = .642 ) . The probability of no failure was comparable for both post material s ( risk ratio ; 95 % confidence interval , 0.965 - 0.851/1.095 ) . CONCLUSIONS When using self-adhesive luted prefabricated posts in severely destroyed abutment teeth with 2 or less cavity walls and a 2-mm ferrule , postendodontic restorations achieved high long-term survival rates irrespective of the post material used ( ie , glass fiber vs titanium ) 
    Output:
    