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 Extraction socket remodeling and ridge preservation strategies have been extensively explored . PURPOSE To evaluate the efficacy of applying a micro-titanium stent as a pressure bearing device on extraction socket remodeling of maxillary anterior tooth . MATERIAL S AND METHODS Twenty-four patients with a extraction socket of maxillary incisor were treated with spontaneous healing ( control group ) or by applying a micro-titanium stent as a facial pressure bearing device over the facial bone wall ( test group ) . Two virtual models obtained from cone beam computed tomography data before extraction and 4 months after healing were 3-dimenionally superimposed . Facial bone wall resorption , extraction socket remodeling features and ridge width preservation rate were determined and compared between the groups . RESULTS Thin facial bone wall result ed in marked resorption in both groups . The greatest palatal shifting distance of facial bone located at the coronal level in the control group , but middle level in the test group . Compared with the original extraction socket , 87.61 ± 5.88 % ridge width was preserved in the test group and 55.09 ± 14.46 % in the control group . CONCLUSIONS Due to the facial pressure bearing property , the rigid micro-titanium stent might preserve the ridge width and alter the resorption features of extraction socket BACKGROUND Tooth extraction typically leads to loss of ridge width and height . The primary aim of this 6-month r and omized , controlled , blinded , clinical study was to determine whether ridge preservation would prevent post- extraction resorptive changes as assessed by clinical and histologic parameters . METHODS Twenty-four patients , 10 males and 14 females , aged 28 to 76 ( mean 51.5 + /- 13.6 ) , requiring a non-molar extraction and delayed implant placement were r and omly selected to receive either extraction alone ( EXT ) or ridge preservation ( RP ) using tetracycline hydrated freeze-dried bone allograft ( FDBA ) and a collagen membrane . A replaced flap , which did not completely cover the sockets , was used . Following extraction , horizontal and vertical ridge dimensions were determined using a modified digital caliper and an acrylic stent , respectively . Prior to implant placement , a 2.7 x 6.0 mm trephine core was obtained and preserved in formalin for histologic analysis . RESULTS The width of the RP group decreased from 9.2 + /- 1.2 mm to 8.0 + /- 1.4 mm ( P<0.05 ) , while the width of the EXT group decreased from 9.1 + /- 1.0 mm to 6.4 + /- 2.2 mm ( P<0.05 ) , a difference of 1.6 mm . Both the EXT and RP groups lost ridge width , although an improved result was obtained in the RP group . Most of the resorption occurred from the buccal ; maxillary sites lost more width than m and ibular sites . The vertical change for the RP group was a gain of 1.3 + /- 2.0 mm versus a loss of 0.9 + /- 1.6 mm for the EXT group ( P<0.05 ) , a height difference of 2.2 mm . Histologic analysis revealed more bone in the RP group : about 65 + /- 10 % versus 54 + /- 12 % in the EXT group . The RP group included both vital bone ( 28 % ) and non-vital ( 37 % ) FDBA fragments . CONCLUSIONS Ridge preservation using FDBA and a collagen membrane improved ridge height and width dimensions when compared to extraction alone . These dimensions may be more suitable for implant placement , especially in areas where loss of ridge height would compromise the esthetic result . The quantity of bone observed on histologic analysis was slightly greater in preservation sites , although these sites included both vital and non-vital bone . The most predictable maintenance of ridge width , height , and position was achieved when a ridge preservation procedure was employed OBJECTIVE This systematic review aims to evaluate the scientific evidence on the efficacy in the surgical protocol s design ed for preserving the alveolar ridge after tooth extraction and to evaluate how these techniques affect the placement of dental implants and the final implant supported restoration . MATERIAL AND METHODS A thorough search in MEDLINE - PubMed , Embase and the Cochrane Central Register of controlled trials ( CENTRAL ) was conducted up to February 2011 . R and omized clinical trials and prospect i ve cohort studies with a follow-up of at least 3 months reporting changes on both the hard and soft tissues ( height and /or width ) of the alveolar process ( mm or % ) after tooth extraction were considered for inclusion . RESULTS The screening of titles and abstract s result ed in 14 publications meeting the eligibility criteria . Data from nine of these 14 studies could be grouped in the meta-analyses . Results from the meta-analyses showed a statistically significant greater ridge reduction in bone height for control groups as compared to test groups ( weighted mean differences , WMD = -1.47 mm ; 95 % CI [ -1.982 , -0.953 ] ; P < 0.001 ; heterogeneity : I(2 ) = 13.1 % ; χ(2 ) P-value = 0.314 ) and a significant greater reduction in bone width for control groups compared to the test groups ( WMD = -1.830 mm ; 95 % CI [ -2.947 , -0.732 ] ; P = 0.001 ; heterogeneity : I(2 ) = 0 % ; χ(2 ) P-value = 0.837 ) . Subgroup analysis was based on the surgical protocol used for the socket preservation ( flapless/flapped , barrier membrane/no membrane , primary intention healing/no primary healing ) and on the measurement method utilized to evaluate morphological changes . Meta-regression analyses demonstrated a statistically significant difference favoring the flapped subgroup in terms of bone width ( meta-regression ; slope = 2.26 ; 95 % IC [ 1.01 ; 3.51 ] ; P = 0.003 ) . CONCLUSIONS The potential benefit of socket preservation therapies was demonstrated result ing in significantly less vertical and horizontal contraction of the alveolar bone crest . The scientific evidence does not provide clear guidelines in regards to the type of bio material , or surgical procedure , although a significant positive effect of the flapped surgery was observed . There are no data available to draw conclusions on the consequences of such benefits on the long-term outcomes of implant therapy OBJECTIVE To evaluate dimensional alterations of the alveolar ridge that occurred following tooth extraction at sites grafted with Bio-Oss ( ® ) Collagen . MATERIAL AND METHODS Twenty-eight subjects with maxillary incisors , canines , and premolars scheduled for extraction were included . The tooth was carefully removed . The patients were r and omly assigned to a test or a control group . In the test group patients , Bio-Oss ( ® ) Collagen was placed in the fresh extraction socket while in the controls no grafting was performed . Radiographic examination ( cone beam computed tomograms , CBCT ) was performed immediately after tooth extraction and socket treatment . Four months later , a new CBCT was obtained . In the radiographs , ( i ) the distance ( mm ) between base of the alveolar process ( apex ) and the buccal and palatal crests was determined , ( ii ) the outer profile of alveolar process of the experimental sites was outlined , and the cross section of the area ( mm(2 ) ) determined . RESULTS After 4 months of healing , the buccal and to a less extent also the palatal bone plate had become markedly reduced in height . The placement of a bio material in the socket failed to prevent resorption of the buccal and palatal bone walls . The cross-sectional area of the control ridge was reduced about 25 % and of the test ridge with 3 % . CONCLUSION The placement of a xenograft in fresh extraction sockets markedly counteracted the reduction in the hard tissue component of the edentulous sites 
    Output:
    
agent
The use of DBB/CF reduced the magnitude of vertical bone resorption , yet the study showed high risk of bias .
Implication s of Key Findings Within the limitations of this systematic review , L-PRF reduced the magnitude of vertical and horizontal bone resorption , which places L-PRF as a potential material of choice for ridge preservation procedures .
Conclusions Within the limitations and weaknesses of both studies , the use of DBB/CF prevented the vertical crestal bone resorption while the L-PRF prevented both the horizontal and vertical crestal bone resorption .
***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 Extraction socket remodeling and ridge preservation strategies have been extensively explored . PURPOSE To evaluate the efficacy of applying a micro-titanium stent as a pressure bearing device on extraction socket remodeling of maxillary anterior tooth . MATERIAL S AND METHODS Twenty-four patients with a extraction socket of maxillary incisor were treated with spontaneous healing ( control group ) or by applying a micro-titanium stent as a facial pressure bearing device over the facial bone wall ( test group ) . Two virtual models obtained from cone beam computed tomography data before extraction and 4 months after healing were 3-dimenionally superimposed . Facial bone wall resorption , extraction socket remodeling features and ridge width preservation rate were determined and compared between the groups . RESULTS Thin facial bone wall result ed in marked resorption in both groups . The greatest palatal shifting distance of facial bone located at the coronal level in the control group , but middle level in the test group . Compared with the original extraction socket , 87.61 ± 5.88 % ridge width was preserved in the test group and 55.09 ± 14.46 % in the control group . CONCLUSIONS Due to the facial pressure bearing property , the rigid micro-titanium stent might preserve the ridge width and alter the resorption features of extraction socket BACKGROUND Tooth extraction typically leads to loss of ridge width and height . The primary aim of this 6-month r and omized , controlled , blinded , clinical study was to determine whether ridge preservation would prevent post- extraction resorptive changes as assessed by clinical and histologic parameters . METHODS Twenty-four patients , 10 males and 14 females , aged 28 to 76 ( mean 51.5 + /- 13.6 ) , requiring a non-molar extraction and delayed implant placement were r and omly selected to receive either extraction alone ( EXT ) or ridge preservation ( RP ) using tetracycline hydrated freeze-dried bone allograft ( FDBA ) and a collagen membrane . A replaced flap , which did not completely cover the sockets , was used . Following extraction , horizontal and vertical ridge dimensions were determined using a modified digital caliper and an acrylic stent , respectively . Prior to implant placement , a 2.7 x 6.0 mm trephine core was obtained and preserved in formalin for histologic analysis . RESULTS The width of the RP group decreased from 9.2 + /- 1.2 mm to 8.0 + /- 1.4 mm ( P<0.05 ) , while the width of the EXT group decreased from 9.1 + /- 1.0 mm to 6.4 + /- 2.2 mm ( P<0.05 ) , a difference of 1.6 mm . Both the EXT and RP groups lost ridge width , although an improved result was obtained in the RP group . Most of the resorption occurred from the buccal ; maxillary sites lost more width than m and ibular sites . The vertical change for the RP group was a gain of 1.3 + /- 2.0 mm versus a loss of 0.9 + /- 1.6 mm for the EXT group ( P<0.05 ) , a height difference of 2.2 mm . Histologic analysis revealed more bone in the RP group : about 65 + /- 10 % versus 54 + /- 12 % in the EXT group . The RP group included both vital bone ( 28 % ) and non-vital ( 37 % ) FDBA fragments . CONCLUSIONS Ridge preservation using FDBA and a collagen membrane improved ridge height and width dimensions when compared to extraction alone . These dimensions may be more suitable for implant placement , especially in areas where loss of ridge height would compromise the esthetic result . The quantity of bone observed on histologic analysis was slightly greater in preservation sites , although these sites included both vital and non-vital bone . The most predictable maintenance of ridge width , height , and position was achieved when a ridge preservation procedure was employed OBJECTIVE This systematic review aims to evaluate the scientific evidence on the efficacy in the surgical protocol s design ed for preserving the alveolar ridge after tooth extraction and to evaluate how these techniques affect the placement of dental implants and the final implant supported restoration . MATERIAL AND METHODS A thorough search in MEDLINE - PubMed , Embase and the Cochrane Central Register of controlled trials ( CENTRAL ) was conducted up to February 2011 . R and omized clinical trials and prospect i ve cohort studies with a follow-up of at least 3 months reporting changes on both the hard and soft tissues ( height and /or width ) of the alveolar process ( mm or % ) after tooth extraction were considered for inclusion . RESULTS The screening of titles and abstract s result ed in 14 publications meeting the eligibility criteria . Data from nine of these 14 studies could be grouped in the meta-analyses . Results from the meta-analyses showed a statistically significant greater ridge reduction in bone height for control groups as compared to test groups ( weighted mean differences , WMD = -1.47 mm ; 95 % CI [ -1.982 , -0.953 ] ; P < 0.001 ; heterogeneity : I(2 ) = 13.1 % ; χ(2 ) P-value = 0.314 ) and a significant greater reduction in bone width for control groups compared to the test groups ( WMD = -1.830 mm ; 95 % CI [ -2.947 , -0.732 ] ; P = 0.001 ; heterogeneity : I(2 ) = 0 % ; χ(2 ) P-value = 0.837 ) . Subgroup analysis was based on the surgical protocol used for the socket preservation ( flapless/flapped , barrier membrane/no membrane , primary intention healing/no primary healing ) and on the measurement method utilized to evaluate morphological changes . Meta-regression analyses demonstrated a statistically significant difference favoring the flapped subgroup in terms of bone width ( meta-regression ; slope = 2.26 ; 95 % IC [ 1.01 ; 3.51 ] ; P = 0.003 ) . CONCLUSIONS The potential benefit of socket preservation therapies was demonstrated result ing in significantly less vertical and horizontal contraction of the alveolar bone crest . The scientific evidence does not provide clear guidelines in regards to the type of bio material , or surgical procedure , although a significant positive effect of the flapped surgery was observed . There are no data available to draw conclusions on the consequences of such benefits on the long-term outcomes of implant therapy OBJECTIVE To evaluate dimensional alterations of the alveolar ridge that occurred following tooth extraction at sites grafted with Bio-Oss ( ® ) Collagen . MATERIAL AND METHODS Twenty-eight subjects with maxillary incisors , canines , and premolars scheduled for extraction were included . The tooth was carefully removed . The patients were r and omly assigned to a test or a control group . In the test group patients , Bio-Oss ( ® ) Collagen was placed in the fresh extraction socket while in the controls no grafting was performed . Radiographic examination ( cone beam computed tomograms , CBCT ) was performed immediately after tooth extraction and socket treatment . Four months later , a new CBCT was obtained . In the radiographs , ( i ) the distance ( mm ) between base of the alveolar process ( apex ) and the buccal and palatal crests was determined , ( ii ) the outer profile of alveolar process of the experimental sites was outlined , and the cross section of the area ( mm(2 ) ) determined . RESULTS After 4 months of healing , the buccal and to a less extent also the palatal bone plate had become markedly reduced in height . The placement of a bio material in the socket failed to prevent resorption of the buccal and palatal bone walls . The cross-sectional area of the control ridge was reduced about 25 % and of the test ridge with 3 % . CONCLUSION The placement of a xenograft in fresh extraction sockets markedly counteracted the reduction in the hard tissue component of the edentulous sites 
    Output:
    