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 The aim of the following study was to assess contour changes after socket preservation techniques . MATERIAL AND METHODS In five beagle dogs , the distal root of the third and fourth m and ibular premolars was extracted . The following treatments ( Tx ) were r and omly assigned for the extraction socket . Tx 1 : BioOss Collagen . Tx 2 : BioOss Collagen and a free soft tissue graft . Tx 3 : No treatment . Tx 4 : The internal buccal aspect was covered with an experimental collagen membrane , the extraction socket was filled with BioOss Collagen and the membrane folded on top of the graft . Impressions were obtained at baseline , 2 and 4 months after surgery . Bucco-lingual measurements were performed using digital imaging analysis . RESULTS All groups displayed contour shrinkage at the buccal aspect . Only the differences between the two test groups ( Tx 1 , Tx 2 ) and the control group ( Tx 3 ) were significant at the buccal aspect ( p < or = 0.001 ) . No measurements of the Tx 4 group could be performed . CONCLUSION Socket preservation techniques , used in the present experiment , were not able to entirely compensate for the alterations after tooth extraction . Yet , incorporation of BioOss Collagen seems to have the potential to limit but not avoid the post-operative contour shrinkage BACKGROUND Reduction of alveolar height and width after tooth extraction may present problems for implant placement , especially in the anterior maxilla where bone volume is important for biologic and esthetic reasons . Different graft material s have been proposed to minimize the reduction in ridge volume . The aim of this study was to compare radiographic and histomorphometric results of magnesium-enriched hydroxyapatite ( MHA ) and calcium sulfate ( CS ) grafts in fresh sockets after tooth extraction s. METHODS Forty-five fresh extraction sockets with three bone walls were selected in 15 patients . A split-mouth design was used : 15 sockets on the right side of the jaw received MHA , 15 sockets on the left side received CS , and 15 r and om unfilled sockets were considered the control ( C ) group . Intraoral digital radiographs were taken at baseline and at 3 months after graft material placement . At 3 months , cylinder bone sample s were obtained for histology and histomorphometry analysis . RESULTS The difference in mean radiographic vertical bone level from baseline to 3 months was -2.48 + /- 0.65 mm in the CS group , -0.48 + /- 0.21 mm in the MHA group , and -3.75 + /- 0.63 mm in the unfilled C group . Statistically significant differences ( P < 0.05 ) were found between CS and MHA groups and between MHA and C groups . Histologic examination revealed bone formation in all treated sites ; trabecular bone assessment did not differ among apical , mesial , and coronal portions of the specimens . Mean vital bone measurements for CS , MHA , and C groups were 45.0 % + /- 6.5 % , 40.0 % + /- 2.7 % , and 32.8 % + /- 5.8 % , respectively . Statistically significant differences ( P < 0.05 ) were found among all groups . Connective tissue percentages averaged 41.5 % + /- 6.7 % for the CS group , 41.3 % + /- 1.3 % for the MHA group , and 64.6 % + /- 6.8 % for the C group . Statistically significant differences ( P < 0.05 ) were found between CS and C groups and between MHA and C groups . The CS-grafted sockets showed 13.9 % + /- 3.4 % residual implant material , whereas the MHA-treated sockets showed 20.2 % + /- 3.2 % residual material . The difference between the groups was statistically significant ( P < 0.05 ) . CONCLUSIONS Radiographs revealed a greater reduction of alveolar ridge in the CS group than in the MHA group . Histologic examination showed more bone formation and faster resorption in the CS group and more residual implant material in the MHA group BACKGROUND The placement of different graft material s and /or the use of occlusive membranes to cover the extraction socket entrance are techniques aim ed at preserving/reducing alveolar ridge resorption . The use of grafting material s in fresh extraction sockets has , however , been question ed because particles of the grafted material have been found in alveolar sockets 6 - 9 months following their insertion . AIM The aims of the study were to ( i ) . evaluate whether alveolar ridge resorption following tooth extraction could be prevented or reduced by the application of a bioabsorbable polylactide-polyglycolide sponge used as a space filler , compared to natural healing by clot formation , and ( ii ) . evaluate histologically the amount and quality of bone tissue formed in the sockets , 6 months after the use of the bioabsorbable material . MATERIAL AND METHODS Thirty-six patients , undergoing periodontal therapy , participated in this study . All patients were scheduled for extraction of one or more compromised teeth . Following elevation of full-thickness flaps and extraction of teeth , measurements were taken to evaluate the distance between three l and marks ( mesio-buccal , mid-buccal , disto-buccal ) on individually prefabricated stents , and the alveolar crest . Twenty-six alveolar sockets ( test ) were filled with a bioabsorbable polylactide-polyglycolide acid sponge ( Fisiograft ) , while 13 sockets ( controls ) were allowed to heal without any filling material . The flaps were sutured with no attempt to achieve primary closure of the surgical wound . Re-entry for implant surgery was performed 6 months following the extraction s. Thirteen biopsies ( 10 test and three control sites ) were harvested from the sites scheduled for implant placement . RESULTS The clinical measurements at 6 months revealed , in the mesial-buccal site , a loss of bone height of 0.2 mm ( 1.4 SD ) in the test and 0.6 mm ( 1.1 SD ) in the controls ; in the mid-buccal portion a gain of 1.3 mm ( 1.9 SD ) in the test and a loss of 0.8 mm ( 1.6 SD ) in the controls ; and in the distal portion a loss of 0.1 mm ( 1.1 SD ) in the test and of 0.8 ( 1.5 SD ) mm in the controls . The biopsies harvested from the test sites revealed that the new bone formed at 6 months was mineralized , mature and well structured . Particles of the grafted material could not be identified in any of the 10 test biopsies . The bone formed in the control sites was also mature and well structured . CONCLUSION The results of this study indicate that alveolar bone resorption following tooth extraction may be prevented or reduced by the use of a bioabsorbable synthetic sponge of polylactide-polyglycolide acid . The quality of bone formed seemed to be optimal for dental implant insertion BACKGROUND Different approaches were advocated to preserve or improve the dimension and contour of the ridge following  tooth extraction .  In some of studies , socket ' flapless extraction ' apparently had a successful outcome . AIM The objective of the present experiment was to compare hard tissue healing following tooth extraction with or without the prior elevation of mucosal full-thickness flaps . MATERIAL AND METHODS Five mongrel dogs were used . The two second m and ibular premolars ( (2)P(2 ) ) were hemi-sected . The mesial roots were retained . By r and om selection the distal root in one side was removed after the elevation of full-thickness flaps while on the contralateral side , root extraction was performed in a flapless procedure . The soft tissue wound was closed with interrupted sutures . After 6 months of healing , the dogs were euthanized and biopsies were sample d. From each experimental site , four ground sections - two from the mesial root and two from the healed socket - were prepared , stained and examined in the microscope . RESULTS The data showed that the removal of a single tooth ( root ) during healing caused a marked change in the edentulous ridge . In the apical and middle portions of the socket site minor dimensional alterations occurred while in the coronal portion of the ridge the reduction of the hard tissue volume was substantial . Similar amounts of hard tissue loss occurred during healing irrespective of the procedure used to remove the tooth was , i.e. flapless or following flap elevation . CONCLUSION Tooth loss ( extraction ) result ed in marked alterations of the ridge . The size of the alveolar process was reduced . The procedure used for tooth extraction - flapless or following flap elevation - apparently did not influence the more long-term outcome of healing The purpose of this study was to evaluate the clinical effectiveness of a bioabsorbable membrane made of glycolide and lactide polymers in preserving alveolar ridges following tooth extraction using a surgical technique based on the principles of guided bone regeneration . Sixteen patients requiring extraction s of 2 anterior teeth or bicuspids participated in the study ( split-mouth design ) . Following elevation of buccal and lingual full-thickness flaps and extraction of teeth , experimental sites were covered with bioabsorbable membranes ; control sites did not receive any membrane . Titanium pins served as fixed reference points for measurements . Flaps were advanced in order to achieve primary closure of the surgical wound . No membrane became exposed in the course of healing . Reentry surgeries were performed at 6 months . Results showed that experimental sites presented with significantly less loss of alveolar bone height , more internal socket bone fill , and less horizontal resorption of the alveolar bone ridge . This study suggests that treatment of extraction sockets with membranes made of glycolide and lactide polymers is valuable in preserving alveolar bone in extraction sockets and preventing alveolar ridge defects The CONSORT ( Consoli date d St and ards of Reporting Trials ) statement is used worldwide to improve the reporting of r and omized , controlled trials . Schulz and colleagues describe the latest version , CONSORT 2010 , which up date s the reporting guideline based on new method ological evidence and accumulating experience . The aim of this study was to investigate the healing of human extraction sockets filled with Bio-Oss particles ( Geistlich Pharma AG , Wolhusen , Switzerl and ) . In 21 subjects , providing a total of 31 healing sites , at least one tooth was scheduled for extraction and the extraction sites for implant therapy . The dimensions of the alveolar ridge at the extraction sites were considered insufficient and required augmentation concomitant with tooth extraction . There were three treatment groups . In group A , the extraction sockets were covered with a Bio-Gide membrane ( Geistlich Pharma AG ) and in group B the extraction sockets were filled with Bio-Oss . The extraction sockets in group C were left to heal spontaneously . Biopsies from the extraction sites were collected at the time of implant installation . Sample s from group A showed large amounts of lamellar bone and bone marrow and small proportions of woven bone . Sites grafted with Bio-Oss ( group B ) were comprised of connective tissue and small amounts of newly formed bone surrounding the graft particles . Only 40 % of the circumference of the Bio-Oss particles was in contact with woven bone . Sites from group C were characterized by the presence of mineralized bone and bone marrow BACKGROUND Various material s have been used immediately following tooth extraction to fill and /or cover the socket in an attempt to limit or prevent ridge resorption . The purpose of the present pilot study was to establish a reliable model to investigate the effect of various bone graft and bone replacement material s on extraction socket healing . This study also compared healing extraction sockets 6 to 8 months postimplantation of a bioactive glass ( BG ) or demineralized freeze-dried bone allograft ( DFDBA ) to an unfilled socket control ( C ) . METHODS Following tooth extraction , a total of 30 sockets in 19 patients were r and omly divided into 3 treatment groups : 10 sockets received BG , 10 sockets DFDBA , and 10 sockets served as unfilled controls . Primary coverage was achieved by flap advancement over each socket . Six to 8 months post extraction at time of implant placement , histological cores of the treatment sites were obtained . These cores were processed , undecalcified sections prepared and stained with Stevenel blue/van Gieson 's picric fuchsin , and histomorphometrically analyzed . Vital bone , connective tissue and marrow , and residual graft particles were reported as a percentage of the total core . RESULTS A model system was described in humans and used to evaluate the healing response in the 3 treatment groups . Results concluded that mean vital bone present was 59.5 % for BG- , 34.7 % for DFDBA- , and 32.4 % for C-treated sites . These differences were not statistically significant . However , the residual implant material was significantly higher in DFDBA-treated ( 13.5 % ) versus BG-treated sockets ( 5.5 % ) . CONCLUSIONS Although the differences in percent vital bone were not statistically significant among the 3 treatment groups in this pilot study , BG material was observed to act as an osteoconductive material which had a positive effect on socket healing at 6 to 8 months post extraction . Further research following implant placement in treated and control sockets is warranted to determine if bone implant contact is improved in BG-filled versus unfilled sockets BACKGROUND Barrier membranes have been used to promote bone ingrowth on implants with dehiscences and fenestrations . Membranes also have been used to protect 
    Output:
    
agent
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
***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 The aim of the following study was to assess contour changes after socket preservation techniques . MATERIAL AND METHODS In five beagle dogs , the distal root of the third and fourth m and ibular premolars was extracted . The following treatments ( Tx ) were r and omly assigned for the extraction socket . Tx 1 : BioOss Collagen . Tx 2 : BioOss Collagen and a free soft tissue graft . Tx 3 : No treatment . Tx 4 : The internal buccal aspect was covered with an experimental collagen membrane , the extraction socket was filled with BioOss Collagen and the membrane folded on top of the graft . Impressions were obtained at baseline , 2 and 4 months after surgery . Bucco-lingual measurements were performed using digital imaging analysis . RESULTS All groups displayed contour shrinkage at the buccal aspect . Only the differences between the two test groups ( Tx 1 , Tx 2 ) and the control group ( Tx 3 ) were significant at the buccal aspect ( p < or = 0.001 ) . No measurements of the Tx 4 group could be performed . CONCLUSION Socket preservation techniques , used in the present experiment , were not able to entirely compensate for the alterations after tooth extraction . Yet , incorporation of BioOss Collagen seems to have the potential to limit but not avoid the post-operative contour shrinkage BACKGROUND Reduction of alveolar height and width after tooth extraction may present problems for implant placement , especially in the anterior maxilla where bone volume is important for biologic and esthetic reasons . Different graft material s have been proposed to minimize the reduction in ridge volume . The aim of this study was to compare radiographic and histomorphometric results of magnesium-enriched hydroxyapatite ( MHA ) and calcium sulfate ( CS ) grafts in fresh sockets after tooth extraction s. METHODS Forty-five fresh extraction sockets with three bone walls were selected in 15 patients . A split-mouth design was used : 15 sockets on the right side of the jaw received MHA , 15 sockets on the left side received CS , and 15 r and om unfilled sockets were considered the control ( C ) group . Intraoral digital radiographs were taken at baseline and at 3 months after graft material placement . At 3 months , cylinder bone sample s were obtained for histology and histomorphometry analysis . RESULTS The difference in mean radiographic vertical bone level from baseline to 3 months was -2.48 + /- 0.65 mm in the CS group , -0.48 + /- 0.21 mm in the MHA group , and -3.75 + /- 0.63 mm in the unfilled C group . Statistically significant differences ( P < 0.05 ) were found between CS and MHA groups and between MHA and C groups . Histologic examination revealed bone formation in all treated sites ; trabecular bone assessment did not differ among apical , mesial , and coronal portions of the specimens . Mean vital bone measurements for CS , MHA , and C groups were 45.0 % + /- 6.5 % , 40.0 % + /- 2.7 % , and 32.8 % + /- 5.8 % , respectively . Statistically significant differences ( P < 0.05 ) were found among all groups . Connective tissue percentages averaged 41.5 % + /- 6.7 % for the CS group , 41.3 % + /- 1.3 % for the MHA group , and 64.6 % + /- 6.8 % for the C group . Statistically significant differences ( P < 0.05 ) were found between CS and C groups and between MHA and C groups . The CS-grafted sockets showed 13.9 % + /- 3.4 % residual implant material , whereas the MHA-treated sockets showed 20.2 % + /- 3.2 % residual material . The difference between the groups was statistically significant ( P < 0.05 ) . CONCLUSIONS Radiographs revealed a greater reduction of alveolar ridge in the CS group than in the MHA group . Histologic examination showed more bone formation and faster resorption in the CS group and more residual implant material in the MHA group BACKGROUND The placement of different graft material s and /or the use of occlusive membranes to cover the extraction socket entrance are techniques aim ed at preserving/reducing alveolar ridge resorption . The use of grafting material s in fresh extraction sockets has , however , been question ed because particles of the grafted material have been found in alveolar sockets 6 - 9 months following their insertion . AIM The aims of the study were to ( i ) . evaluate whether alveolar ridge resorption following tooth extraction could be prevented or reduced by the application of a bioabsorbable polylactide-polyglycolide sponge used as a space filler , compared to natural healing by clot formation , and ( ii ) . evaluate histologically the amount and quality of bone tissue formed in the sockets , 6 months after the use of the bioabsorbable material . MATERIAL AND METHODS Thirty-six patients , undergoing periodontal therapy , participated in this study . All patients were scheduled for extraction of one or more compromised teeth . Following elevation of full-thickness flaps and extraction of teeth , measurements were taken to evaluate the distance between three l and marks ( mesio-buccal , mid-buccal , disto-buccal ) on individually prefabricated stents , and the alveolar crest . Twenty-six alveolar sockets ( test ) were filled with a bioabsorbable polylactide-polyglycolide acid sponge ( Fisiograft ) , while 13 sockets ( controls ) were allowed to heal without any filling material . The flaps were sutured with no attempt to achieve primary closure of the surgical wound . Re-entry for implant surgery was performed 6 months following the extraction s. Thirteen biopsies ( 10 test and three control sites ) were harvested from the sites scheduled for implant placement . RESULTS The clinical measurements at 6 months revealed , in the mesial-buccal site , a loss of bone height of 0.2 mm ( 1.4 SD ) in the test and 0.6 mm ( 1.1 SD ) in the controls ; in the mid-buccal portion a gain of 1.3 mm ( 1.9 SD ) in the test and a loss of 0.8 mm ( 1.6 SD ) in the controls ; and in the distal portion a loss of 0.1 mm ( 1.1 SD ) in the test and of 0.8 ( 1.5 SD ) mm in the controls . The biopsies harvested from the test sites revealed that the new bone formed at 6 months was mineralized , mature and well structured . Particles of the grafted material could not be identified in any of the 10 test biopsies . The bone formed in the control sites was also mature and well structured . CONCLUSION The results of this study indicate that alveolar bone resorption following tooth extraction may be prevented or reduced by the use of a bioabsorbable synthetic sponge of polylactide-polyglycolide acid . The quality of bone formed seemed to be optimal for dental implant insertion BACKGROUND Different approaches were advocated to preserve or improve the dimension and contour of the ridge following  tooth extraction .  In some of studies , socket ' flapless extraction ' apparently had a successful outcome . AIM The objective of the present experiment was to compare hard tissue healing following tooth extraction with or without the prior elevation of mucosal full-thickness flaps . MATERIAL AND METHODS Five mongrel dogs were used . The two second m and ibular premolars ( (2)P(2 ) ) were hemi-sected . The mesial roots were retained . By r and om selection the distal root in one side was removed after the elevation of full-thickness flaps while on the contralateral side , root extraction was performed in a flapless procedure . The soft tissue wound was closed with interrupted sutures . After 6 months of healing , the dogs were euthanized and biopsies were sample d. From each experimental site , four ground sections - two from the mesial root and two from the healed socket - were prepared , stained and examined in the microscope . RESULTS The data showed that the removal of a single tooth ( root ) during healing caused a marked change in the edentulous ridge . In the apical and middle portions of the socket site minor dimensional alterations occurred while in the coronal portion of the ridge the reduction of the hard tissue volume was substantial . Similar amounts of hard tissue loss occurred during healing irrespective of the procedure used to remove the tooth was , i.e. flapless or following flap elevation . CONCLUSION Tooth loss ( extraction ) result ed in marked alterations of the ridge . The size of the alveolar process was reduced . The procedure used for tooth extraction - flapless or following flap elevation - apparently did not influence the more long-term outcome of healing The purpose of this study was to evaluate the clinical effectiveness of a bioabsorbable membrane made of glycolide and lactide polymers in preserving alveolar ridges following tooth extraction using a surgical technique based on the principles of guided bone regeneration . Sixteen patients requiring extraction s of 2 anterior teeth or bicuspids participated in the study ( split-mouth design ) . Following elevation of buccal and lingual full-thickness flaps and extraction of teeth , experimental sites were covered with bioabsorbable membranes ; control sites did not receive any membrane . Titanium pins served as fixed reference points for measurements . Flaps were advanced in order to achieve primary closure of the surgical wound . No membrane became exposed in the course of healing . Reentry surgeries were performed at 6 months . Results showed that experimental sites presented with significantly less loss of alveolar bone height , more internal socket bone fill , and less horizontal resorption of the alveolar bone ridge . This study suggests that treatment of extraction sockets with membranes made of glycolide and lactide polymers is valuable in preserving alveolar bone in extraction sockets and preventing alveolar ridge defects The CONSORT ( Consoli date d St and ards of Reporting Trials ) statement is used worldwide to improve the reporting of r and omized , controlled trials . Schulz and colleagues describe the latest version , CONSORT 2010 , which up date s the reporting guideline based on new method ological evidence and accumulating experience . The aim of this study was to investigate the healing of human extraction sockets filled with Bio-Oss particles ( Geistlich Pharma AG , Wolhusen , Switzerl and ) . In 21 subjects , providing a total of 31 healing sites , at least one tooth was scheduled for extraction and the extraction sites for implant therapy . The dimensions of the alveolar ridge at the extraction sites were considered insufficient and required augmentation concomitant with tooth extraction . There were three treatment groups . In group A , the extraction sockets were covered with a Bio-Gide membrane ( Geistlich Pharma AG ) and in group B the extraction sockets were filled with Bio-Oss . The extraction sockets in group C were left to heal spontaneously . Biopsies from the extraction sites were collected at the time of implant installation . Sample s from group A showed large amounts of lamellar bone and bone marrow and small proportions of woven bone . Sites grafted with Bio-Oss ( group B ) were comprised of connective tissue and small amounts of newly formed bone surrounding the graft particles . Only 40 % of the circumference of the Bio-Oss particles was in contact with woven bone . Sites from group C were characterized by the presence of mineralized bone and bone marrow BACKGROUND Various material s have been used immediately following tooth extraction to fill and /or cover the socket in an attempt to limit or prevent ridge resorption . The purpose of the present pilot study was to establish a reliable model to investigate the effect of various bone graft and bone replacement material s on extraction socket healing . This study also compared healing extraction sockets 6 to 8 months postimplantation of a bioactive glass ( BG ) or demineralized freeze-dried bone allograft ( DFDBA ) to an unfilled socket control ( C ) . METHODS Following tooth extraction , a total of 30 sockets in 19 patients were r and omly divided into 3 treatment groups : 10 sockets received BG , 10 sockets DFDBA , and 10 sockets served as unfilled controls . Primary coverage was achieved by flap advancement over each socket . Six to 8 months post extraction at time of implant placement , histological cores of the treatment sites were obtained . These cores were processed , undecalcified sections prepared and stained with Stevenel blue/van Gieson 's picric fuchsin , and histomorphometrically analyzed . Vital bone , connective tissue and marrow , and residual graft particles were reported as a percentage of the total core . RESULTS A model system was described in humans and used to evaluate the healing response in the 3 treatment groups . Results concluded that mean vital bone present was 59.5 % for BG- , 34.7 % for DFDBA- , and 32.4 % for C-treated sites . These differences were not statistically significant . However , the residual implant material was significantly higher in DFDBA-treated ( 13.5 % ) versus BG-treated sockets ( 5.5 % ) . CONCLUSIONS Although the differences in percent vital bone were not statistically significant among the 3 treatment groups in this pilot study , BG material was observed to act as an osteoconductive material which had a positive effect on socket healing at 6 to 8 months post extraction . Further research following implant placement in treated and control sockets is warranted to determine if bone implant contact is improved in BG-filled versus unfilled sockets BACKGROUND Barrier membranes have been used to promote bone ingrowth on implants with dehiscences and fenestrations . Membranes also have been used to protect 
    Output:
    