***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: The aim of the study was to determine the fate of demineralized freeze-dried bone allograft ( DFDBA ) used in conjunction with a barrier membrane in the management of extraction sockets and deficient alveolar ridges , and to compare the amount of bone formed with that found in untreated sites . Ten biopsies were obtained from 8 grafted patients . Five biopsies were harvested from untreated sites during routine implant placement and analyzed for comparison . In the socket management procedure , DFDBA was packed tightly into the socket and covered with an exp and ed polytetrafluoroethylene ( e-PTFE ) membrane . Primary closure was achieved in all cases . In the ridge regeneration procedure , cortical columns were placed in the ridge projecting outward approximately 3 mm to create and maintain space for DFDBA particles packed between them ; the columns were then covered by an e-PTFE membrane .  Healing time ranged from 8 to 23 months . At the time of implant placement , bone cores ( 7 mm x 2 mm ) were harvested , fixed in 10 % formalin solution , and prepared for histologic examination . At the light microscopic level , no inflammation or fibrous encapsulation was observed . New bone formation on and around DFDBA particles was widespread . Histomorphometric analysis of the grafted specimens and untreated sites was carried out using the trabecular bone volume ( TBV ) index . The TBV in the maxillary test specimens was 55.03 % , as compared to 57.33 % of control cores . Unaltered DFDBA made up 8.7 % of the test specimens . In the m and ibular biopsies , the TBV was 56.6 % , while for the controls it was 40.9 % . The volume of DFDBA still present was 2.45 % . The results tended to indicate that treatment with DFDBA in conjunction with cell occlusive membranes will result in new bone formation , predominantly by the process of conduction , which appears to be similar in amount and nature to that found in cores harvested from healed nonfunctional edentulous areas 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 OBJECTIVES To histologically analyze the early angiogenesis-osteogenesis interplay in post- extraction sockets augmented with magnesium-enriched hydroxyapatite ( Mg-enriched HA ) . MATERIAL AND METHODS Ten post- extraction sites underwent post- extraction ridge preservation procedure .  According to r and omization , sites were divided into two balanced groups and bone specimens were collected 2 or 4 months after surgery . Sections were stained with hematoxylin/eosin , Masson-Goldner trichrome , and tartrate-resistant acid phosphatase ( TRAP ) , respectively . Furthermore , indirect immunohistochemistry was performed using alkaline phosphatase , CD34 and caveolin-1 antibodies . Mean values and st and ard deviations were calculated for each outcome variable . Data were then compared using one-way ANOVA test . P < 0.05 was considered statistically significant . RESULTS Histomorphometric analysis presented 15.0 % ( ±3.5 ) regenerated bone after 2 months of healing . After 4 months , regenerated bone increased 5.1-fold up to 77.4 % ( ± 8.6 ) ( P < 0.001 ) . On the contrary , vessels and capillary reduced from 645 ( ±33 ) to 255 ( ± 94 ) ( caveolin-1 expression , P = 0.008 ) . These findings were confirmed by CD34 expression ( 301 ± 95 and 88 ( ±24 ) , respectively , at 2 and 4 months ( P = 0.046 ) . CONCLUSIONS Within the limits of the present r and omized controlled study , it can be concluded that Mg-enriched HA is a suitable material for socket preservation and ensures early angiogenesis and early osteogenesis 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 To solve some of the problems inherent in bone regeneration , various types of graft material s , matrix , putty , and gel delivery systems have been developed . These deliver demineralized bone matrix ( DBM ) to a graft site and maintain it in an appropriate position to achieve favorable results . This prospect i ve study review ed 10 cases of extraction immediate grafting with a putty – DBM delivery system .  Five patients were male and 5 female . At intervals ranging from 4 to 21 months post extraction grafting , bone cores were harvested at the time of surgical insertion of Replace endosteal two-stage implants . All patients were restored with single-tooth self-st and ing prostheses . Bone quality and quantity in 
    Output:
    
When comparing the percentage of newly formed bone using various grafting material s with NH , calcium sulfate , magnesium enriched hydroxyapatite , and porcine-derived bone grafts offered the best outcomes .
However , due to the heterogeneity of the included studies , the search was extended to determine which type of graft result ed in greatest bone formation .