title: Dimensional changes of the alveolar ridge contour after different socket preservation techniques. Magnesium-enriched hydroxyapatite compared to calcium sulfate in the healing of human extraction sockets: radiographic and histomorphometric evaluation at 3 months. Ridge preservation following tooth extraction using a polylactide and polyglycolide sponge as space filler: a clinical and histological study in humans. Ridge alterations following tooth extraction with and without flap elevation: an experimental study in the dog. Preservation of alveolar bone in extraction sockets using bioabsorbable membranes. CONSORT 2010 Statement: Updated Guidelines for Reporting Parallel Group Randomized Trials Healing of human extraction sockets filled with Bio-Oss. Histological comparison of healing extraction sockets implanted with bioactive glass or demineralized freeze-dried bone allograft: a pilot study. Five-year evaluation of implants placed at extraction and with dehiscences and fenestration defects augmented with ePTFE membranes: results from a prospective multicenter study. Ridge preservation with freeze-dried bone allograft and a collagen membrane compared to extraction alone for implant site development: a clinical and histologic study in humans. Evaluation of the effect of immediate grafting of mandibular postextraction sockets with synthetic bone. Immediate implantation in fresh extraction sockets. A controlled clinical and histological study in man. Xenograft versus extraction alone for ridge preservation after tooth removal: a clinical and histomorphometric study. Randomized study evaluating recombinant human bone morphogenetic protein-2 for extraction socket augmentation. A prospective randomized clinical study of changes in soft tissue position following immediate and delayed implant placement. Factors influencing ridge alterations following immediate implant placement into extraction sockets. Influence of bioactive glass on changes in alveolar process dimensions after exodontia. Osseoretention? Comparative assessment of particulate hydroxyapatite inserted beneath immediate dentures. Alveolar ridge reconstruction and/or preservation using root form bioglass cones.
abstract: 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 defects adjacent to implants placed at the time of extraction . The concept of guided bone regeneration relates to preferentially allowing cells from bone to migrate into various defects while excluding fibrous tissue and epithelium . The purpose of these procedures is to enhance bone-to-implant contact at the treated sites and to prevent mucosal complications . PURPOSE The purpose of this article is to report clinical outcomes for  implants placed at the time of extraction and augmented with exp and ed polytetrafluoroethylene ( ePTFE )  and followed for 5 years . The outcomes for implants with dehiscences and fenestrations augmented with ePTFE barriers and followed up to 5 years also are reported . METHODS AND MATERIAL S Four treatment centers participated in this study ( Tucson , Gothenburg , Spokane , and Leuven ) . In the extraction group , teeth were removed for varying reasons , and Brånemark implants were placed and stabilized within the host bone . Defects present at the coronal implant aspect were covered with ePTFE barrier membranes . Flaps were rotated to cover the membrane-treated sites . If exposure of the material occurred prior to second-stage surgery , the membranes were removed . Barriers remaining unexposed were removed at second-stage surgery . The implants were followed up to 5 years . In the fenestration and dehiscence group , implants with exposed threads were augmented with ePTFE barrier membranes . The barriers were removed at appropriate intervals , and the patients were followed up to 5 years . Radiographic measurements were made from nonst and ardized periapical radiographs at abutment connection and 1 , 3 , and 5-year follow-up visits . RESULTS Forty patients participated in the extraction group . They received a total of 49 implants . Three implants failed prior to loading . The 5-year cumulative survival rates for implants placed at the time of extraction were 93.9 % and 93.8 % , respectively , for maxillary and m and ibular implants . The average maxillary mesial and distal marginal bone loss ( 1 - 5 yr ) was 0.3 mm ( st and ard deviation [ SD ] = 1.5 ) and 0.3 mm ( SD = 1.0 ) . In m and ibles , the average mesial and distal bone loss ( 1 - 5 yr ) was -0.2 mm ( SD = 0.5 ) and -0.05 mm ( SD = 0.6 ) , respectively . The dehiscence and fenestration group included 44 patients . Twenty-six were followed for up to 5 years . Eight patients experienced total implant failure . For dehiscences and fenestrations , the cumulative survival rates were 76.8 % and 83.8 % for maxillary and m and ibular implants , respectively . The average maxillary mesial and distal bone loss ( 1 - 5 yr ) was 0.4 mm ( SD = 0.8 ) and 0.2 mm ( SD = 0.9 ) , respectively . In m and ibles , the average mesial and distal marginal bone loss was 0.3 mm ( SD = 0.9 ) and 0.3 mm ( SD = 0.8 ) , respectively . CONCLUSIONS Implants placed at the time of extraction and augmented with ePTFE barrier membranes have favorable long-term predictability . On the other h and , long-term evaluation of implant dehiscences and fenestrations augmented with barrier membranes indicates that they have less favorable 5-year survival rates . Membrane augmentation of these may be question ed 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 Immediate  m and ibular complete dentures were placed in 18 patients . To prevent ridge resorption , bone grafts with hard tissue replacement synthetic bone were placed in sockets on one side of the m and ible . The untreated sockets on the contralateral side served as controls . Bone density as shown in panoramic radiographs was reported at the time of placement , at 5 months to 6 months postsurgery , at 12 months to 14 months postsurgery , and at 20 months to 24 months postsurgery . The sites treated with hard tissue replacement synthetic bone not only prevented ridge resorption but also showed increased optical ( socket ) density of regenerating bone in the initial phase of the study , and maintained that elevated level at 24 months post extraction BACKGROUND Early implantation may preserve the alveolar anatomy , and the placement of a fixture in a fresh extraction socket helps to maintain the bony crest . Although a number of clinical studies exist , no histological reports show the outcome of implantation in fresh extraction sockets without the use of membranes in humans compared to implants placed in mature bone . METHODS Forty-eight healthy patients , receiving at least 4 fixtures in each of 2 symmetrical quadrants , underwent placement of 1 experimental fixture placed in a fresh extraction socket ( TI ) and 1 contralateral fixture in mature bone ( CI ) . TI were placed after atraumatical tooth extraction , with a surgical site at the apex of the socket and a tight contact between the fixture and the socket 's walls , but without the use of filling material s or membranes . The flap was coronally repositioned to obtain primary wound closure . Immediately after surgical intervention , a st and ardized periapical radiograph was taken . Second-stage surgery was done after 6 months . Six months after the second surgery , a second st and ardized periapical radiograph was taken and clinical parameters ( bleeding and plaque index ) recorded . Marginal bone loss ( MBL ) from the time of implant placement to the time of fixture removal was calculated by comparing periapical radiographs . TI and CI were then removed by a hollow drill to obtain histological specimens . Non-demineralized sections were stained by acid fuchsin and toluidine blue , and by von Kossa to evaluate the degree of bone mineralization . The percentage of direct implant-bone contact ( DBC ) was calculated by a computerized microscopic digitizer . RESULTS No significant differences in the clinical and radiographic parameters were observed between the 2 experimental categories . There was no statistically significant difference between TI and CI for DBC either in the maxilla or in the m and ible . No connective or fibrous tissues were present around TI or CI . Bone resorption was not present in any of the histological sections . CONCLUSIONS The present study shows that when a screw-type dental implant is placed without the use of barrier membranes or other regenerative material s into a fresh extraction socket with a bone-to-implant gap of 2 mm or less , the clinical outcome and degree of osteointegration does not differ from implants placed in healed , mature bone BACKGROUND The preservation of bone volume immediately after tooth removal might be necessary to optimize the success of implant placement in terms of esthetics and function . The objectives of this r and omized clinical trial were two-fold : 1 ) to compare the bone dimensional changes following tooth extraction with extraction plus ridge preservation using corticocancellous porcine bone and a collagen membrane ; and 2 ) to analyze and compare histologic and histomorphometric aspects of the extraction -alone sites to the grafted sites . METHODS Forty subjects who required tooth extraction and implant placement were enrolled in this study . Using a computer-generated r and omization list , the subjects were r and omly assigned to the control group ( EXT ; extraction alone ) or to the test group ( RP ; ridge-preservation procedure with corticocancellous porcine bone and collagen membrane ) . The following parameters were assessed immediately after extraction and 7 months prior to implant placement : plaque index , gingival index , bleeding on probing , horizontal ridge width , and vertical ridge changes . A bone biopsy was taken from the control and test sites 7 months after the surgical treatment . Histologic and histomorphometric analyses were also performed . RESULTS A significantly greater horizontal reabsorption was observed at EXT sites ( 4.3+/-0.8 mm ) compared to RP sites ( 2.5+/-1.2 mm ) . The ridge height reduction at the buccal side was 3.6+/-1.5 mm for the extraction -alone group , whereas it was 0.7+/-1.4 mm for the ridge-preservation group . Moreover , the vertical change at the lingual sites was 0.4 mm in the ridge-preservation group and 3 mm in the extraction -alone group . Forty biopsies were harvested from the experimental sites ( test and control sites ) . The biopsies harvested from the grafted sites revealed the presence of trabecular bone , which was highly mineralized and well structured . Particles of the grafted material could be identified in all sample s. The bone formed in the control sites was also well structured with a minor percentage of mineralized bone . The amount of connective tissue was significantly higher in the extraction -alone group than in the ridge-preservation group . CONCLUSIONS The ridge-preservation approach using porcine bone in combination with collagen membrane significantly limited the resorption of hard tissue ridge after tooth extraction compared to extraction alone . Furthermore , the histologic analysis showed a significantly higher percentage of trabecular bone and total mineralized tissue in ridge-preservation sites compared to extraction -alone sites 7 months after tooth removal BACKGROUND Conventional dentoalveolar osseous reconstruction often involves the use of grafting material s with or without barrier membranes . The purpose of this study was to evaluate the efficacy of bone induction for the placement of dental implants by two concentrations of recombinant human bone morphogenetic protein-2 ( rhBMP-2 ) delivered on a bioabsorbable collagen sponge ( ACS ) compared to placebo ( ACS alone ) and no treatment in a human buccal wall defect model following tooth extraction . METHODS Eighty patients requiring local alveolar ridge augmentation for buccal wall defects ( > or = 50 % buccal bone loss of the extraction socket ) of the maxillary teeth ( bicuspids forward ) immediately following tooth extraction were enrolled . Two sequential cohorts of 40 patients each were r and omized in a double-masked manner to receive 0.75 mg/ml or 1.50 mg/ml rhBMP-2/ACS , placebo ( ACS alone ) , or no treatment in a 2:1:1 ratio . Efficacy was assessed by evaluating the amount of bone induction , the adequacy of the alveolar bone volume to support an endosseous dental implant , and the need for a secondary augmentation . RESULTS Assessment of the alveolar bone indicated that patients treated with 1.50 mg/ml rhBMP-2/ACS had significantly greater bone augmentation compared to controls ( P < or = 0.05 ) . The adequacy of bone for the placement of a dental implant was approximately twice as great in the rhBMP-2/ACS groups compared to no treatment or placebo . In addition , bone density and histology revealed no differences between newly induced and native bone . CONCLUSION The data from this r and omized , masked , placebo-controlled multicenter clinical study demonstrated that the novel combination of rhBMP-2 and a commonly utilized collagen sponge had a striking effect on de novo osseous formation for the placement of dental implants PURPOSE The purpose of this investigation was to compare the efficacy of two therapeutic options-immediate implant placement and ridge preservation with delayed implant placement-in maintaining the position of the soft tissue margins following tooth extraction . MATERIAL S AND METHODS This r and omized controlled study evaluated apicocoronal changes in the midbuccal and proximal mucosal positions at implant placement sites from tooth extraction to 3 and 6 months following extraction . Twenty-four patients ( 26 sites ) r and omly received either immediate implant placement or ridge preservation ( grafting with freeze-dried bone allograft and a collagen membrane ) followed by implant placement 3 months later . Immediate placement sites received bone grafting for horizontal defects > 2 mm ( from implant to cortical wall ) . Soft tissue measurements , vertical measurements , and ridge width measurements were performed and compared for immediate versus delayed implants and thin versus thick biotype . RESULTS The midbuccal soft tissue margins showed minimal recession over 6 months from the time of extraction ( mean 0.17 + /- 0.47 mm ) , with no differences between treatment groups . Interproximal tissue height decreased significantly from extraction to 6 months ( mesial , 1.73 + /- 0.71 mm ; distal , 1.48 + /- 0.80 mm ) , with no significant differences between immediate and delayed placement . Immediate implant sites had greater reductions in ridge width 6 months after extraction than delayed placement sites . Tissue biotype failed to show any significant relationship with the changes identified . CONCLUSIONS This r and omized controlled study comparing soft tissue changes following extraction failed to identify differences between patients treated with immediate or delayed approaches for midbuccal or interproximal soft tissue margins , although greater decreases in ridge width were observed in sites lacking bone grafting . Both immediate and delayed treatment approaches appear to be appropriate following tooth extraction , with the preferred treatment based on factors other than result ant soft tissue changes AIM To identify factors that may influence ridge alterations occurring at the buccal aspect of the extraction site following immediate implant placement . MATERIAL AND METHODS In 93 subjects , single-tooth implants were placed immediately into extraction sockets in the maxilla ( tooth locations 15 - 25 ) . A series of measurements describing the extraction site were made immediately after implant installation and at re-entry , 16 weeks later . The implant sites were stratified according to four factors : ( i ) implant location ( anterior/posterior ) , ( ii ) cause of tooth extraction ( periodontitis/non-periodontitis ) , ( iii ) thickness of the buccal bone walls ( < or = 1 or > 1 mm ) and ( iv ) the dimension of the horizontal buccal gap ( < or = 1 or > 1 mm ) . RESULTS ( i ) The location where the implant was placed ( anterior/posterior ) as well as ( ii ) the thickness of the buccal bone crest and ( iii ) the size of the horizontal buccal gap significantly influenced the amount of hard tissue alteration that occurred during a 4-month period of healing . At implant sites in the premolar segment , the fill of the horizontal gap was more pronounced than in the incisor-canine segment , while the vertical crest reduction was significantly smaller . Furthermore , at sites where the buccal bone wall was thick ( > 1 mm ) and where the horizontal gap was large ( > 1 mm ) , the degree of gap fill was substantial . CONCLUSIONS The thickness of the buccal bone wall as well as the dimension of the horizontal gap influenced the hard tissue alterations that occur following immediate implant placement into extraction sockets BACKGROUND Preservation of the alveolar process after tooth extraction is desirable because it facilitates placement of endosseous implants and minimizes adverse esthetic results associated with fixed partial dentures . The purpose of this study was to evaluate the clinical effectiveness of bioactive glass used as a graft material combined with calcium sulfate used in the form of a mechanical barrier in preserving alveolar ridges after tooth extraction . METHODS Sixteen patients who required extraction of 2 anterior teeth or bicuspids participated in the study ( split mouth design ) . After tooth extraction and elevation of a buccal full-thickness flap , experimental sockets were filled with bioactive glass , which in turn was covered with a layer of calcium sulfate . Control sites did not receive any graft or calcium sulfate . Titanium pins served as fixed reference points for measurements . No attempt was made to advance the flap to cover the socket areas on control or experimental sites ( open socket approach ) . Reentry surgeries were performed at 6 months . RESULTS Reentry surgeries showed that experimental sites presented with ( 1 ) significantly more internal socket bone fill ( 6.43 + /- 2.78 mm vs 4.00 + /- 2.33 mm on control sites ) , ( 2 ) less ( although not statistically significantly less ) resorption of alveolar bone height ( 0.38 + /- 3.18 mm vs 1.00 + /- 2 . 25 mm on control sites ) , and ( 3 ) similar degree of horizontal resorption of the alveolar bony ridge as compared with controls ( 3 . 48 + /- 2.68 mm vs 3.06 + /- 2.41 mm on control sites ) . CONCLUSIONS This study suggests that treatment of extraction sockets with a combination of bioactive glass and calcium sulfate is of some benefit in preserving alveolar ridge dimensions after tooth extraction This paper presents the results of a study to observe the effect on bone resorption and residual alveolar ridge form , of placement of dense non-resorbable hydroxyapatite granules into fresh canine sockets , at the time of immediate denture provision . Thirty five subjects were r and omly divided into two groups cross matched for age and sex . All subjects required bilateral extraction of at least a lower canine and an adjacent tooth . Results demonstrate that six months post- extraction the control group had lost four times more bone than the implant group . These results were highly significant ( P=0.000 , LHS and P=0.001 , RHS ) Extraction of a tooth necessitated by factors such as developmental problems , trauma , severe periodontal disease and endodontic problems often causes deformities of the residual alveolar ridge in the maxillary anterior region . These cases are usually difficult to restore prosthetically and they result in poor esthetics and insufficient occlusal function . This study investigated the efficacy of root form bioactive glass cones implanted into ( a ) artificial sockets produced by bone splitting of previous extraction sites ( group BS ) and ( b ) fresh extraction sockets ( group FES ) . We included conventional extraction sockets sutured without implanting the root form bioactive glass cones as a control ( group C ) . A total of 16 patients were treated for whom extraction s had been indicated due to severe periodontitis . 6 patients with 7 implant sites having Class II or III alveolar ridge deformities comprised the BS group . 5 patients with 10 implant sites comprised the FES group . Group C , comprised 5 patients with 10 extraction sites .  Alveolar ridge width and height measurements were obtained using study casts preoperatively , immediately postoperatively , and at 3 and 12 months after operation . In the BS group , while the width of the alveolar ridge increased by 2.8+/-1.18 mm immediately after ridge augmentation procedure and by 2.4+/-0.93 mm at 1 year after operation ( p<0.01 ) , the height of the alveolar ridge increased by 1.8+/-1.99 mm and 1.4+/-1.74 mm respectively ( p<0.05 ) . In the FES group , the differences between preoperative original ridge height and width and postoperative measurements were not statistically significant , which demonstrated the efficiency of this method in preserving the alveolar ridge . In group C , while alveolar ridge width after 12 months had not significantly changed , alveolar ridge height decreased significantly ( 1.35+/-1.05 mm , p<0.01 ) . After 12 months , no dehiscences were detected and the differences in height between the groups remained significant . The results of this study indicate that this procedure is efficient in reconstructing alveolar ridges deformed as a result of extraction , particularly relevant in relation to preparation for subsequent restorative treatment
target: 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
background: 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 .