Journal of Alpha Omega International Dental Fraternity Volume 98, Number 2, July 2005 \ ' Alpha Omegan, Volume 98, Number 2, July 200f SCIENTIFIC ARTICLE Immediate Placement of Implants into Extraction Sockets: Rationale, Outcomes, Technique Stuart J. Froum, D.D.S. Dental implants have become a predicable treatment modality for prosthetic restoration of fully and partially edentulous patients.l~* Albrektsson et al. reported 5- to 8-year implant success rates of 99.1% in the mandible and 84.9% in the maxilla.5 These rates were predicated on a traditional implant approach by Branemark et al. and Adell et al. recommending a 6- to 12-month healing period after tooth extraction and prior to implant placement.*' This time frame and the additional 3 to 6 months required for osseointegration of the implants, along with the time necessary for loading and fabrication of the restoration, often resulted in a treatment time of 1 to 2 years before the patient received the final implant supported restoration. In an attempt to reduce this treatment time, implant companies produced textured implants, which allowed earlier loading.89 One-stage implants Stuart Froum, D.D.S. Stuart Froum received his D.D.S. degree in 1970 from New York University Dental Center. He completed a general denlistry residency program at the Fort Hamilton Veterans Administration Hospital, Brooklyn, New York. He received his periodontal specialty training at the Veterans Administration Hospital in New York City. He is a diplomatc of ihe American Board of Periodontics. Currently, he holds the position of clinical professor at New York University Dental Center in both the Department of Periodontics and the Department of implant Dentistry. He is the director of research in the Department of Implant Dentistry at New York University Dental Center. Dr. Froum is currently on the Research Committee of the Academy of Osseointegration. He is also a member of the Continuing Education Oversight Committee of the American Academy of Periodontology. He was the recipient of the Isidore Hirschfeld Award from the Northeast Academy of Periodonlics and received the Clinicai Research Award from the American Academy of Periodontology. Hi- has lectured internationally and published over 70 articles in peerreviewed journals. He has contributed chapters in two textbooks. requiring no second surgery for abutment placement were also introduced.l0~12 In selected cases, implants were loaded with provisional restorations on the day of implant placement13"18 Finally, reports by Schulte et al. in Germany, Lazzara in the United States and others established immediate implant placement (IIP) as a routine clinical procedure.ll>"26 The purpose of this article is to review the rationale, indications, techniques and contraindications for IIP in extraction sockets. Rationale for IIP Literature reviews by Schwartz-A rad and Chaushu, Chen et al. and Mayfield delineated the advantages of immediate versus delayed implant placement as follows27 29: t. Treatment time is reduced. 2. Amount of surgery is reduced. 3. Width and height of the alveolar bone are preserved. 4. Ideal implant location can be achieved provided that the extracted tooth has a desirable alignment and there is maximum soft tissue support. As an adjunct to these advantages, several others accrue, which include less surgical morbidity, a reduction in treatment expense, if additional regenerative techniques (bone grafts and membrane use) are not applied and better patient acceptance of the treatment plan. The biologic advantage often mentioned in the immediate implant literature is the contention that the implant will prevent postsurgical bone resorption seen following tooth extraction as a normal part of the socket healing. This resorption has been documented in several studies and has been reported to result in a 45% Alpha Omegan, Volume 98, Number 2, July 2005 IMMEDIATE PLACEMENT OF IMPLANTS INTO EXTRACTION SOCKETS: RATIONALE, OUTCOMES, TECHNIQUE reduction in the alveolar crest. The majority of this bone loss occurs over the Brst 6 months following extraction and the wearing of a denture.30'" In the posterior maxilla, horizontal bone resorption amounting to 3 to 7 mm after 6 months has been shown to nearly correspond to the vertical bone resorption.52 Two studies by Lekovic et at. and another by Iasella et al. demonstrated significant occlusoapical and buccolingual resorption following tooth extraction in sockets allowed to heal for 4 to 6 months in the absence of any treatment.3*'}b Changes in the horizontal dimension of these sockets showed an average loss of 4.5 mm in buccolingual width and an average 1.5 mm vertical resorption of the buccal plate of bone.H Other articles proposed that the placement of an implant immediately after tooth extraction may help preserve the alveolar bone dimension, allowing placement of longer and wider implants.36"'" However, Covani et al. measured the buccal to lingual bone at the time of HP {15 implants in 15 patients) and again at second-stage surgery 6 months later.39 In spite of the implant being immediately placed, the mean distance in the buccolingual direction decreased from an average of 10.5 mm (± 1.54) to 6.8 mm (± 1.33). A more recent article by Covani compared buccolingual bone resorption in cases of immediate versus delayed (6-8 weeks) implant placement, the results demonstrated that less resorption occurred in sockets receiving the immediate implants (1.9 mm) than in sockets allowed to heal naturally (3.06 mm).*1 Although reduced by IIP, this degree of horizontal resorption may present problems, especially in the esthetic zone, and will be discussed later in this article. Evaluating Outcomes of IIP Ideally, randomized controlled human trials reporting on implant success would present the highest level of scientific rigor to evaluate the efficacy of IIP. However, a recent literature review reported that no studies of this type have been published to date.28 Therefore, controlled clinical trials, documenting implant survival, prospective and retrospective case series and case reports, as well as the few available histologic reports, are used to assess the results of IIP. This article will also rely heavily on the literature reviews and associated consensus statements.27"29 A number of studies reported demonstrate high levels of survival for implants placed immediately after tooth extraction (Table 1). However, differences in technique, use of graft or bone replacement graft and the nonuse or use of nonabsorbable or absorbable membrane barriers, soft tissue closure over the implant, use of implants with different surface textures and sizes and different locations of placement make it difficult to compare and evaluate which variables are crucial for implant success. In reviewing these studies, it will therefore be helpful to describe the materials used and whether soft tissue coverage of the implant was achieved. Wagenberg and Ginsberg retrospectively analyzed 1,081 implants placed into extraction sockets."" Of these, 35% were followed for I year, 46% followed for 2 to 5 years and 19% for 5 to II years postloading. No mention was made of the type of implant surface used. Mineralized freeze-dried bone was packed around the implants, and a polyglactin 910 (Vicryl) membrane was placed extending over the implant 2 to 3 mm beyond the borders of the alveolar defect. No attempt was made to obtain complete flap closure over the membrane. The overall implant survival rate was 95%. Implant failure was twice as high for maxillary molars as for mandibular molars. Becker et al., in a prospective clinical trial, evaluated 134 implants in 81 patients placed in fresh extraction sockets that were not augmented with barrier membranes or graft materials.42 All implants had machined (turned) surfaces. Pedicle flaps were rotated, covering the implant sites. The authors noted that all implants were placed into good jaw bone anatomy and quality. The 7-year cumulative success rate (CSR) was 93.3%. Schwartz-Arad et al. evaluated 56 immediately placed implants in 43 patients, all molars, from 1989 to 1996.+3 They recorded the influence of the following parameters on implant failure: gender, arch, smoking, pre extraction vertical bone loss and implant length. The 5-year CSR was 89%; for men, it was 84%, and for women, it was 93.5%. The 5-year CSR was 82% in the maxilla and 92% in the mandible. Nonsmokers had a CSR of 90%, whereas smokers had 22 Alpha Omegan, Volume 98, Number 2, luly 2005 IMMEDIATE PLACEMENT OF IMPLANTS INTO EXTRACTION SOCKETS: RATIONALE, OUTCOMES, TECHNIQUE Table 1 tmplanl Survival Rates in Studies Using Various Author Krump&Barnettl99152 Gelb 199326 Mendsdorff-Pouilly et al 1994s0 Rosenquist & Grenliie 1996" Becker etal199812 Grunderetal 199951 Schwartz Arad et al 2000JB Schwariz-Arad et al 200043 Gomez-Romon etal 200146 Wagenberg & Ginsberg 200 V Prosper et a! 2003^ Covani et al 200447 Biancho & Son Filippo 20O4i3 tolpts 35 51 81 107 NA 43 '04 591 83 95 116 # of implants 41 50 93 109 134 146 117 56 124 1,081 111 163 116 Immediate Placement Protocols Surface Morphology 5 RS RS S ss THA S = 47 HA coated = 9 GBAE S SB SB AC PLS Aogmenf ND DFDBA e-PTFE 53 HA 55 AM NG, 5nRM NG, NM NGNM AB AB/6 AM 2NAM AB/nzq B5N=4 NAMN=17 FDBA+AM HA, AB 58 NG, NM 105 AB + AM NG, NM Time 3 12.4 rro 30.5 mo (range l-67mo) 7 yrs 3 5 5 yrs 1-5.65 yrs 1-11 yrs 4 A l-9yrs Survival Rate (%) 92.7 98 92.5 9366 93.3 92.4 max 94.7 mand 96 89 97 95 97.3 97 100 AB = autogenous bone; AC = acid etched; AM = absorbable membrane; GT = grit bhsted; HA = hydroxyapatife coated, NAM = non obsorbable membrane; NG = no graft. NM = no membrane; RS = rough surface; SB = sandblasted a CSR of 83%. The authors stated that small autogenous bone chips (from bone adjacent to the implant site or bur debris) were used "when needed" as a graft between the socket walls and implant. Six collagen bioabsorbable and two expanded polytetrafluoroethylene (e-PTFE) nonabsorbabk membranes were used "according to the clinical judgment of the operator." Primary flap closure was obtained according to the authors "in all cases with bone grafting and membranes." Neither mean implant length and diameter nor pre-extraction vertical bone loss had any effect on implant survival. The authors concluded that although immediate implantation was a predictable procedure, implant prognosis was better in the posterior mandible than in the posterior maxilla. Rosenquist and Grenthe evaluated 109 machinesurface immediately placed implants following extraction in 51 patients.14 The mean follow-up period was 30.5 months (range 1-67 months) and "no effort was made to fill the gap between the implant and the surrounding socket gap with a graft." Closure over the implant varied from using pedicles or free mucosal grafts to using e-PTFE membranes in five patients. The implant survival rate was 93.66%. The survival rates differed depending on whether the teeth were extracted for periodontal reasons (survival rate = 92.0%) versus nonperiodontal reasons (survival rate = 95.8%).44 Kan et al., in a prospective study, placed 35 threaded hydroxyapatite (HA)- coated implants in 35 patients with immediate provisionalization. 43 All implants at 12 months remained osseointegrated. However, implants were placed only in sockets with intact labial plates. Midfacial gingival, mesial and distal papilla shrinkage was recorded to be -0.55 ± 0.53 mm, -0.53 ± 0.39 mm and -0.39 ± 0.40 mm, respectively. Gomez-Roman et al. placed 124 stepped-screw implants (grit-blasted and acid-etched surface) in 104 patients immediately following extraction or implant explanation in a retrospective study.46 Grafts included autogenous bone (n = 9) or bone substitutes {n = 24). Membranes were used "if the periosteum was not intact." Implant survival rates remained at 97% from 1 to 5.65 years after implant placement. The average observation period following prosthesis placement was 2.6 years, with the longest observation period, post-implant placement, being Alpha Omegan, Volume 98, Number 2, July 2005 23 IMMEDIATE PLACEMENT OF IMPLANTS INTO EXTRACTION SOCKETS: RATIONALE, OUTCOMES, TECHNIQUE 6.3 years. The technique of implant placement was performed without incisions, and "an attempt was made to cover the implant with flap closure."4*' Gelb retrospectively reported on 50 consecutively placed immediate implants in 35 partially edentulous patients over a 3-year period.26 All implants had turned surfaces. Treatment protocol varied depending on the defect type surrounding the implant. In threewall defects and circumferential defects, decalcified freeze-dried bone allograft (DFDBA) was packed into the defect and covered with an e-PTFK membrane contoured to cover the defect margins by 2 mm. In no-wall defects in which ridge expansion was necessary, DFDBA was used, together with e-PTFE membranes. Treatment and use of DFDBA alone or with a membrane were not part of a controlled protocol but were selected according to bone morphology and then arbitrarily "for comparison." Primary closure was obtained in 36 cases, secondary closure, including connective tissue grafts, in 3 cases, free gingival graft in 1 case, exposed e-PTFE membrane in 6 cases and exposed DFDBA in 4 cases. The patients were followed from August 1989 to April 1993, with a reported implant survival rate of 98%. No mention was made as to whether primary closure had any effect on implant survival. The author concluded that in three-wall and circumferential defects, "e-PTFE membranes provide predictable regeneration of bone and thread coverage." The variability in technique in the abovementioned reviews of immediate implant studies with no control groups emphasizes the need for compari son studies to attempt to assess the most efficacious method of IIP. Covani et al. evaluated IIP in fresh extraction sockets with and without guided bone regeneration (GBR).47 All implants had acid-etched, sandblasted surfaces. One hundred sixty-three implants were placed, 95 in the maxilla and 68 in the mandible. The longest and widest possible implants were used, and all were placed at the level of the bone crest. No grafting materials were used for 58 implants, which presented with no fenestrations or dehiscences and in which the gap distance did not exceed 2 mm. The remaining 105 implants with bone fenestrations or dehiscences or in which the gap between implant surface and surrounding bone exceeded 2 mm were grafted with small autogenous bone chips and covered with bioabsorbable membranes. Flaps were repositioned to obtain primary wound closure. The 4-year CSR (calculated from time of implant placement) was 97%. All implants supported single ceramometal restorations with no splinting. There were no statistically significant differences in clinical attachment level or survival of implants treated with GBR and those treated without GBR. Schwartz Arad et al. placed a total of 380 implants: 316 machine screw-type, 51 HA-coated screw-type and 13 cylinder HA-coated submerged implants.''8 Of the implants placed, 117 were immediate (31%) and 263 were nonimmediate. The authors used small autogenous bone chips (from bone adjacent to the implant or bur debris) between the implant and socket walls "when needed." No mention was made regarding flap closure. The 5-year CSR of all implants was 92%, which included 96% in the mandible and 90% in the maxilla. Immediate implants had a higher 5-year CSR compared to nonimmediate implants (96% vs. 89%, respectively). The main difference was in the maxilla, where the CSR for IIP was 95% versus 88% for nonimmediate placement. Prosper et al., in a randomized study, placed 111 implants, 56 in combination with resorbable HA (HA group) and 55 with a resorbable polyglycolic and polylactic membranes (MR group),49 All implants were sandblasted, selfthreading, pure titanium cylinders with a diameter of 5.9 mm and a length of 11 or 13 mm. All of the fresh extraction sockets had four walls, and < 2 mm discrepancy existed between the implant head and cementoename] junction of the adjacent teeth. The surgeon "tried to appose the two flaps by first intention." The overall incidence of implant success 4 years after placement was 97.3% and did not differ significantly between the HA group (98.2%) and the MR group (96.4%). Mensdorff-Poully et al. retrospectively studied 190 implants, 93 placed immediately postextraction (64 rough surface, 29 machined-surface) and 97 placed delayed (6 to 8 weeks postextraction), which included 57 with a rough surface and 40 with a machined surface.'" In 76 implant placements, a non24 Alpha Omegan. Volume 98, Number 2, July 200J IMMEDIATE PLACEMENT OF IMPLANTS INTO EXTRACTION SOCKETS: RATIONALE, OUTCOMES, TECHNIQUE absorbable e-PTFE membrane was used. For 13 implants, HA or autologous bone grafts were used to fill the gap alone or in combination with GBR. For 114 implants, no membrane was used. After an average of 12.4 months, 85 of 93 IIP implants were available for follow-up. For the delayed group, 88 of 97 were available for evaluation. Survival rates were 92.5% for IIP and 94.9% for delayed implants, showing no statistically significant difference in these values. Grunder et al., in a prospective multicentered study, evaluated 264 machined-surface implants in 143 patients/1 One year postloading, a follow-up was done on 125 patients. One hundred seven patients were followed for 3 years postloading. Over this period of 3 years, the implant survival rate was 92.4% in the maxilla and 94.7% in the mandible. Five methods of placement were used as follows: Group 1: 146 implants had IIP. Group 2: 34 implants were placed after 3 to 5 weeks of healing (no membranes were used). Group 3: 64 implants were placed with membranes over the extraction socket. Group 4: 8 implants were placed, and freezedried bone bone grafts or collagen was used. Group 5: 12 implants were placed with a combination of the above. There was no clinical difference in the survival rate between the immediately placed implants (group 1) and implants placed with a 3- to 5-week delayed protocol (group 2). Krump and Barnctt compared 41 implants placed immediately after extraction to a control group of 154 implants placed into the anterior mandible without extraction.52 All implants had turned surfaces, and no data were given on the use of any regenerative material in the IIP group. The implant survival rate for the IIP group was 92.7%. Implant survival in the control group was 98.1%. The differences in survival rates were not statistically significant. Bianchi and San Filippo evaluated 116 single solid-screw immediately placed implants from 1 to 9 years post-implant placement.51 A subepithelial connective tissue graft was performed at the same time as implant placement to achieve wound closure over 96 implants. No bone graft or membrane was used. Implant survival rates were 100% for implants with and without wound closure. The authors noted that better peri-implant results in terms of stability of probing depths and esthetics were seen around the implants receiving the connective tissue grafts. Although the survival rates of immediately placed implants appear to be similar to those of implants placed with a delayed protocol in healed bone, the question of the bone-to-implant contact (BIC) that occurs in the gap between the implant surface and socket wall should be addressed. Carfsson et al. evaluated titanium implants with initial gap widths of 0.00, 0.35 and 0.85 mm.5"' At 6 weeks, the control (no-gap group) had bone contact approaching 90%, whereas the 0.35 and 0.85 mm sites had residual gaps of 0.22 and 0.54 mm, respectively. Knox et al., in a histologic study, placed eight 3.25 x 10 mm implants in each of six dogs.55 Two sites, one on each side, remained as a control, whereas 0.5, 1.0 and 2.0 mm defects were created circumferentially around the test implants. One side received HA-coated implants, and the other side received grit-blasted titanium (GBT) implants of similar dimension. All dogs were sacrificed at 8 weeks. The HA and GBT implants had levels of osseointegration similar to those of the control group and around implants with the 0.5 mm gap defects. For all other defects, the HA group showed more coronal levels of osseointegration and smaller residual defects than did the GBT group. However, in the larger defects (2.0 mm gap), HA and GBT implants showed larger residual defects and more apical levels of osseointegration than the controts. The authors concluded that "combination therapy using guided tissue regeneration, bone grafts, or both may be indicated in sites with larger bone gaps." Barzilay et al. histologically compared levels of bone integration of immediate implants with implants placed in healed (control) sites in four monkeys 7 months postloading (13 months postimplantation). 56 Histologic Findings from 30 immediate and 9 control turned-surface implants were compared. The percentage of bone integration was similar in both groups. However, the authors noted that "bone patterns peripheral to the interface region differed, Alpha Omegan, Volume 98, Number 2, July 2005 2" IMMEDIATE PLACEMENT OF IMPLANTS INTO EXTRACTION SOCKETS: RATIONALE, OUTCOMES, TECHNIQUE suggesting that special consideration be given to implants placed in the posterior regions of the maxilla and mandible." They suggested using wider implants or implants in narrow posterior ridges to allow the immediate implants to engage cortical bone. This has implications in the discussion of immediate implant indications and techniques later in this article. Akimoto et al. evaluated the effect of gap width on bone healing around commercially pure titanium machined-surface implants placed into simulated extraction sockets of varying widths in 10 mongrel dogs.17 All implants were 10 mm long by 3.3 mm in diameter. Gap sizes of 0.5, 1.0 and 1.4 mm, all 6 mm deep, were created for implant placement. Controls had no gaps. All dogs were sacrificed at 12 weeks, and the percentage of BIC was measured histologically. As the gaps widened, the amount of BIC decreased and the point of the highest BIC shifted apically. These changes were statistically significant for the gap areas and not statistically significant in the 4 mm of apical native bone that surrounded test and control implants. Clinically, the simulated extraction socket defects healed with complete bone fill regardless of flap size. However, the width of the gap at the time of implant placement had a significant impact on the histologic percentage and height of BIC. Similar results in one human were reported by Wilson et al., who placed five titanium plasma-sprayed implants.•"* One served as the control in native bone, and four were placed in immediate extraction sockets. The results showed that all implants integrated with varying percentages of direct BIC. All implants were removed in block sections 6 months postplacement. The BIC of the control implant was 72.14%. The mean BIC of the two immediate implants with small peri-implant bone defects at the time of placement (horizontal defect dimension [HDD] = 1.5 mm) was approximately 50%. Two immediate implants on which the HDD measured more than 4 mm and in which e-PTFE membrane barriers were used and stabilized by the cover screws showed a mean BIC of 17%. The authors concluded that "the horizontal component of the defects was most critical in dictating the final amount of bone-implant contact during a 6 months healing period." They further concluded that in spite of this small sample size, membranes were not necessary in sites in which the HDD does not exceed 1.5 mm.58 Another histologic study in a dog model by Novaes Jr et al. looked at the effect that periapical pathology of the extracted tooth had on the success of the immediately placed implant.3'' Nine months after the induction of periapical lesions, experimental and control (no lesions) teeth were extracted, and sockets were debrided and rinsed with 50 mg/mL solution of tetracycline hydroxide. Twentyeight IntraMobile Cylinder (IMZ) implants were placed, 15 experimental and 13 controls. These implants were slightly larger than the extracted roots. Flaps were sutured over all implants to obtain complete coverage. AH dogs were sacrificed after 12 weeks. The mean percentage of BIC around the experimental implants was 28.6 ± 24.8%, with a range of 25 to 100%. The mean percentage of BIC around the 12 control implants was 38.7 ± 25.5%, with a range of 3.9 to 91.2%. The difference was not statistically significant. The conclusion of this study supported the results of clinical Findings in humans: that chronically infected sites, those showing periapical pathology, may not be contraindicated for IIP if meticulous cleansing and debridement are performed and appropriate antibiotics are administered pre- and postoperatively.60 Indications and Techniques of IIP A review of various implant site classifications and indications for IIP was presented by Saadoun and Landsberg.61 The classification system suggested by Garber and Belser proposed IIP in class I sites (dehiscence of less than 5 mm with no loss of hard or soft tissue) and class II sites (dchiscence equal io 5 mm demonstrating hard and soft tissue collapse in a buccolingual direction only with no alteration in vertical height).62 In both cases, the authors recommended avoiding flap elevation, the use of a barrier membrane and a bone graft where necessary (to support the membrane), and sealing the socket orifice with an epithelial connective tissue graft." The essential requirement mentioned was the attainment of primary implant stability by drilling the osteotomy site 4 to 5 mm apical to the alveolar socket. For class III sites Alpha OmL'finn, Volume 9S, Number 2, July 2005 IMMEDIATE PLACEMENT OF IMPLANTS INTO EXTRACTION SOCKETS: RATIONALE, OUTCOMES, TECHNIQUE (dehisccnces of greater than 5 mm, characterized by a notable collapse of hard and soft tissue with no significant loss of vertical dimension) a delayed approach was recommended with rebuilding the ridge and placing implants 6 to 9 months postsurgery, or IIP using a bone graft, membrane and connective tissue graft. The decision to use delayed placement or IIP would be dependant on the ability to achieve primary implant stability and how critical the esthetic result. In class IV sites, representing severely compromised sockets with insufficient buccolingual bone and no vertical bone loss, the authors suggested a staged approach using autogenous bone grafts and GBR. The delayed implant placement would be performed 6 to 9 months postsurgery using a connective tissue graft. Although these approaches are clearly delineated, the more a clinician combines and compresses the various regeneration procedures in efforts to expedite treatment, the greater the risk and severity of surgical healing and complications.**4 A recent consensus report based on available literature obtained from a thorough MEDI.INE review of studies published between 1990 and June 2003, combined with the clinical experience of the consensus group, classified and defined four different types of implant placement, stating the advantages and disadvantages of each.28 Type 1 was defined as 'implant placement immediately following tooth extraction as part of the same surgical procedure." Type 2 was defined as placement of the implant following complete soft tissue coverage of the socket (typically 4 to 8 weeks postsurgery). Type 3 was defined as implant placement "following substantial clinical and/or radiographic fill of the socket (typically 12-16 weeks)." Type 4 was defined as implant placement in the healed site (typically more than 16 weeks). The indications for a type 1 placement (IIP) were based on the ability to attain primary implant stability with an "appropriately sized implant in an ideal restorative position." Although the majority of comparative data, albeit limited, show that the survival rate for implants placed immediately following extraction of teeth with local pathology is similar to that of implants placed in healed ridges, factors such as soft tissue and bone quantity and quality, as well as the presence of pathology and the condition of the adjacent teeth, enter into the decision of timing of implant placement. For example, in a patient with a thin Biotype (thin scalloped gingiva) in whom the buccal plate is lost or anticipated to resorb, esthetics becomes a primary consideration as to implant timing. If IIP is performed, a barrier membrane and supporting graft are recommended. This presents more risk for complications, leading to an unacceptable esthetic result. In these cases, delayed placement (types 2-4) may be indicated to allow placement in greater bone quantity with improved soft tissue coverage. A thick Biotype (thicker, less scalloped gingival architecture) causes less of a risk of buccal plate resorption, especially where the plate is intact following extraction. These cases present a better indication for IIP. The above guidelines may serve as a foundation for more closely analyzing factors that may contribute to the success of the IIP procedure from both functional (implant survival) and esthetic (implant success in the esthetic zone) aspects. Reviews of the literature on IIP have concluded that there is no consensus on whether the use of bone grafts, bone replacement grafts and/or membranes in combination with implants placed in extraction sockets yields better results than those obtained with unaugmented immediately placed implants.2'"2'' Schropp et al. noted that following placement of 46 acid-etched Osseotite implants, 23 with an immediate (10 days postextraction) and 23 with a delayed (3 months after extraction) protocol in both groups, a higher degree of bone healing was achieved in the infrabony defects surrounding the implant (> 60% of depth) than in dehiscence-type defects (approximately 25% h6' These results were reported using only autogenous bone chips grafted to the exposed implant threads in cases of dehiscences that were present in the delayed implant group. The potential for spontaneous bone healing in three-wall infrabony defects with 1 to 3 mm gaps was approximately 70%. This inability of dehiscence-type defects to heal with bone grafts alone would indicate the need for barrier membranes in these cases. When using barrier membranes, reports of membrane exposure leading to complications such as bone loss, infection and even implant loss ranging between 8 and 100% have been published.6*1-67 However, Lekholm et al., in a canine Alpha Omegan, Volume 98, Number 2, July 2005 IMMEDIATE PLACEMENT OF IMPLANTS INTO EXTRACTION SOCKETS: RATIONALE, OUTCOMES, TECHNIQUE study, reported greater amounts of bone with membrane- treated implants, with late removal of the membranes resulting in maximal bone formation.68 Considering the above results, the clinician should base the decision to perform IIP on the anatomy of the extraction socket, the availability of bone apical to the socket and the quality of soft tissue surrounding the socket. The possible esthetic compromise of the final restoration should be weighed against the advantage of a decrease in the number of surgeries, cost and delivery time of the final restoration. A successful result with IIP is most predictable when an atraumatic extraction of the hopeless tooth can be accomplished in a flapless surgery, preserving the hard and soft tissue morphology of the extraction socket. In the esthetic zone, it is essential to maintain the interproximal papillae and interproximal bone on the adjacent teeth. Predictability for favorable esthetic outcomes is also increased in patients with a flatter and thicker gingival architecture (thick Biotype) (Table 2 and Figures 1 to 7). Thorough socket debridcment is also essential, and although success has been reported with IIP in infected sockets,59'60 in terms of biologic principles and predictability, a delayed implant approach in these cases may be preferable.- 73 Osteotomies should extend 4 to 5 mm apical to the apex of the socket. In the maxillary anterior area, these osteotomies should be guided with a surgical stent, be made on the lingual incline of the extraction socket and be aimed toward the ideal cingulum area of the replaced tooth. The implant should be placed in such a way that it does not place pressure on the buccal plate and cause rcsorption. In cases in which the gingiva is highly scalloped and the buccal plate is thin, maintaining a small gap < 1.5 mm between the buccal surface of the implant and buccal plate is advisable. In the mandibular anterior and premolar areas, the implant should be slightly larger than the socket to eliminate any gap between the implant and the socket walls (Figures 8 to 14). In the posterior areas, the implant should be placed in the intcrseptal bone or, if this bone is missing, in the socket with the greatest number of surrounding walls in a position to engage cortical bone. A wider implant or two implants may be indicated depending on posterior socket morphology. All implants must exhibit primary stability after placement. Limiting the gap between the immediately placed implant and the socket wall to < 2.0 mm allows implant placement without the use of filling materials and barrier membranes. This decreases the potential complications of the immediate implant procedure.47'58'69 This was demonstrated in a study by Paolantonio et al. in 2001 with 96 experimental titanium plasma-sprayed mini-impfants placed, 48 in extraction sockets with horizontal defects < 2 mm and 48 into mature bone to serve as controls without the use of grafts or membranes and with primary closure.69 Reentry at 6 months showed complete fill of all defects. Histologic examination showed no statistically significant differences between test and control sites in the percentage of 13IC and the initial level of BIC. Thus, with Table 2 Risk Factors and Prognosis for Factors Socket morphology Biolype Ability to disinfect socket Smoker > 1 pock/d Buccal dehiscence ± 2 mm Buccal dehiscence > 2 mm Gap between implant and socket < 2 mm Gop between implant and socket z 2 mm Immediate Implant Placement Good 4 walls Thick or thin scalloped Good Good NEZ EZ mem NEZ Mem/BG/CT EZ RA Delayed implant Good NEZ mem/BG EZ RA/deloyed implanf Fair 3 walls Thin scalloped Fair Fair Mem/BG Mem/BG Mem Mem, mem/BG + CT High Risk 2, l,0walis Thin Poor Poor Mem/BG RA-deloyed implant Mem/BG/CT graft RA-delayed implant BG = bone graft or bone replacement graft; CT = subepilhelial connective tissue graft; EZ = esthetic zone; Mem • barrier membrane; NEZ = nonesthetic zone; RA = ridge augmentation. 28 Alpha Omcgan, Volume 98, Number 2, July 2005 IMMEDIATE PLACEMENT OF IMPLANTS INTO EXTRACTION SOCKETS: RATIONALE, OUTCOMES, TECHNIQUE a gap of < 2 mm, especially in circumference defects, also be accomplished using larger-diamctcr complete bone fill can be obtained without the implants.47 However, recent research has shown that adjunctive use of bone and membranes.6^ This may a 2 to 3 mm distance between natural teeth and Figure 1 Clinical view of o maxillary deciduous molar prior to extraction (site 1 3) (case by Dominick Galasso). Figure 2 Periapical radiograph of a hopeless tooth prior to extraction. Figure 3 Occlusal view of the fractured tooth in Figure 1. Figure 4 Clinical view following extraction, immediate implant placement and temporizaHon. Figure 5 Occlusal view of a healing implant. Figure 6 Radiograph of a Final implant supported restoration. Alpha Omegan, Volume 98, Number 2, July 2005 29 IMMEDIATE PLACEMENT OF IMPLANTS INTO EXTRACTION SOCKETS: RATIONALE, OUTCOMES, TECHNIQUE Figure 7 Clinical view of an implant-supported restoration with intact interproximal papillae. Figure 8 Clinical view of four hopeless mandibular incisors prior to extraction (case by Dennis Tarnow). Figure 9 Radiograph of teeth in Figure 8. implants and a minimum 3 mm distance between idjacent implants is necessary to preserve the interdental (intertmplant) papillae.70-71 In light of these findings, smaller-diameter implants may be indicated in the esthetic zone to maintain the necessary 2 to 3 mm implant-to-tooth relationship. In cases in which the gap between implant surface and socket wails exceeds 1.5 to 2.0 mm, bone graft or bone replacement graft materials, together with barrier membranes, may be indi- Figure 10 Atraumatk flapless extraction is performed to preserve the socket walls. cated. However, in a 7-year follow-up study on immediately placed implants, Schwartz-Arad and Chaushu used autogenous bone chips to fill peri-implant defects without using barrier membranes and showed a high survival rate, with very few complications.7- When immediate implants can be placed within the alveolar confines, high survival rates were reported without using grafting materials or barrier membranes. 42 The small circumferential defects between implants and surrounding bone walls were filled with blood and then covered by a pedicle flap. The defects filled with bone, and a 93.3% implant survival rate after 4 years was reported. The use of barrier membranes appears to be advantageous when attempting to regenerate a dehiscence or buccal fenestration with exposed implant threads. Absorbable membranes are Alpha Omegan, Volume 98, Number 2, July 2005 IMMEDIATE PLACEMENT OF IMPLANTS INTO EXTRACTION SOCKETS: RATIONALE, OUTCOMES, TECHNIQUE Figure 1 1 Three immediate implants are placed in the mandibular left lateral incisor and right central and lateral Figure 12 Final restoration prior to insertion. mcisors. Figure 13 Radiograph of the final supported restoration. less prone to bacterial contamination, especially when exposures occur, and are therefore better suited for these purposes. They also exhibit a lower incidence of premature membrane exposure (Figures 15 to 20).7i'74 A recent study by Corneiini et al. compared 6-month hard and soft tissue healing around immediately placed implants using two different groups.7' The test group received Bio-Oss and Bio-Gide mem- Figure 14 Clinical view of tfie restoration 1 year posiioading. branes to treat the gap (defect around the implant), whereas the control group received a Bio-Gide membrane alone. Treatment outcomes showed no differences between test and control implants in radiographic bone levels. Both showed no change from baseline levels and no difference in probing attachment level. However, at the proximal site, the soft tissue margin was located 2.6 mm more coronally than the implant shoulder in the test group compared with 1.3 mm in the control group. The corresponding buccal figures were 2.1 and 0.9 mm in the test and control groups, respectively. Thus, the use of anorganic bovine bone matrix to support the barrier membranes resulted in better soft tissue support for the final restoration. This, again, is critical in the esthetic zone. A recent prospective study of 62 single IIP in 62 patients used five randomly selected groups, one with a nonabsorbable membrane only, two with Alpha Omegan, Volume 98, Number 2, July 2005 IMMEDIATE PLACEMENT OF IMPLANTS INTO EXTRACTION SOCKETS: RATIONALE, OUTCOMES, TECHNIQUE Figure 15 Radiographic view of the hopeless maxillary left Figure 16 Socket with deficient buccal plate following central incisor (case by Borry Wagenberg). extraction. Figure 17 Use of mineralized bone and an absorboble membrane to treat the dehiscence defect associated with IIP. Figure 1 8 Six months post IIP, prior to abutment placement. Figure 20 Clinical view of the restoration 5 year postioading. Figure 19 Final implant prosthesis 5 years postloading. Alpha Onwgcw, Volume 98, Number 2, July 2005 IMMEDIATE PLACEMENT OF IMPLANTS INTO EXTRACTION SOCKETS: RATIONALE, OUTCOMES, TECHNIQUE an absorbable membrane only, group 3 with an absorbable membrane and autogenous bone, group 4 with autogenous bone alone and group 5 with no membrane or bone. The best outcomes in terms of complete bone fill of the defects around the HP was obtained in the group treated with an absorbable membrane and autogenous bone.76 The immediately placed implant should be positioned 0 to 3 mm apical to the crestal bone. If a dehiscence exists, the implant may be placed 3 mm apical to the cementoenamel junction of the adjacent teeth margins. Primary flap closure may be obtained by periosteal releasing and vertical incisions to allow flap advancement. Other methods, including rotational flaps, splint flaps or connective tissue grafts, have also been recommended.77'81 However, high levels of implant survival have been reported without primary flap closure, providing that an absorbable membrane was used to cover the implant." In the esthetic zone, a soft tissue graft placed over the implant and membrane barrier (where used) may avoid any additional mucogingival surgical procedures necessary to reestablish a lost vestibule and repair the soft tissue-implant morphology. In cases in which implant placement is required in a highly esthetic zone, in a patient with a high smile line, IIP may be contraindicated. This is especially true when a thin, highly scalloped gingiva (thin Biotype) is present. Based on studies demonstrating horizontal^ and midfacial"15 buccal plate and gingival resorption 6 to 12 months post-IIP, the risks of a compromised esthetic result would, in my opinion, contraindicate this approach. A delayed approach, type 2 or 3, would allow better tissue control. More over, if soft or hard tissue augmentation were necessary, it may be performed more predictably prior to implant placement. Other contraindications for IIP would include the inability to place the implant in an ideal restorative position because of a compromised socket architecture following tooth extraction. Antibiotic coverage pre- and postsurgery appears to be an important part of most IIP protocols. The use of amoxicillin (1 to 2 g) 1 hour preoperatively and 500 mg three times daily for 7 to 10 days postsurgery is recommended by most authors. Postsurgical use of chlorhexidine rinses twice daily for at least 3 weeks is also recommended. Many authors recommend taking one ibuprofen tablet 800 mg four times a day for 7 to 10 days postsurgery to decrease pain, inflammation and swelling.27 In conclusion, high implant survival rates have been reported for implants placed in fresh extraction sockets (comparable to implants placed in healed ridges).27"29 Moreover, the advantages afforded by IIP make it a valuable modality in implant therapy for both the clinician and the patient. However, as emphasized in a recent literature review, the many variations in treatment protocol for immediately placed implants, together with the paucity of longterm studies of implant success, indicate the necessity for controlled clinical trials to establish predictable and reproducible techniques and results.28 References 1. Adell R, Eriksson B, Lekholm U, et al. A !ong term follow up study of osseointegrated implants in the treatment of the totally edentulous jaw. Int J Oral Maxillofac Implants 1990; 5:347-359. 2. Jemt T, Lekholm U, Ragnar A. Osseointegrated implants in the treatment of partially edentulous patients: a preliminary study on 876 consecutive placed fixtures. Int F Oral Maxillofac Implants 1989; 4:211-218. 3. Jemt T, Lekholm U. Oral implant treatment in posterior partially edentulous jaws: a 5-ycar follow-up report. Int I Oral Maxillofac Implants 1993; 8:635-640. 4. McGlumphy KA, Peterson LJ, Larsen PE, Jeffcoat MK. Prospective study of 429 hydroxyapatite-coated cylindrical Omniioc implants placed in 121 patients. Int ] Oral Maxillofac Implants 2003; 18:82-92. 5. Albrektsson T, Dahl E, Enbom L, et al. Osseointegration oral implants: Swedish multicenter study of 8139 consecutively inserted Nobelpharma implant?, J Periodontol 1988; 59:287-296. 6. Branemark PI, Zarb G, Albrektsson T. Tissue-integrated prosthesis: osseointegration in clinical dentistry. Chicago: Quintessence, 1985. 7. Adell R, Lekholm U, Rockier B, et al. A 15 year study of osseointegrated implants in the treatment of the edentulous iow. Int J Oral Surg !981; 10:387^116. 8. Bornstein MM, Lussi A, Schmid B, et al. Early loading of nonsubmerged titanium implants with a sandblasted and acid-etched (SLA) surface: 3 year results of a prospective study in partially edentulous patients. Int J Oral Maxillofac Implants 2003; 18:659-666. Alpha Omegan, Volume 98. Number 2, July 2005 33 IMMEDIATE PLACEMENT OF IMPLANTS INTO EXTRACTION SOCKETS: RATIONALE, OUTCOMES, TECHNIQUE 9. Weng D, Jacobson Z, Tarnow D, et al. A prospective multicenter clinical trial of 3i machined-surface implants: results after 6 years of follow-up. Int I Oral Maxillofac Implants 2003; 18:417-423. 10. Buser D, Mericskc Stein R, Bernard JP, et al. Long term evaluation of non-submerged ITI implants. Par! I: 8 year life table analysis of a prospective mutlicenter study with 2359 implants. Clin Oral Implants Res 1997; 8:161-172. 11. Vassos DM. Single stage surgery for implant placement: a retrospective study.) Oral Implanto! 1997; 23:181-185. 12. Becker VV, Becker BE, Isidclson H, et al. One step surgical placement of Branemark implants: a prospective multicenter clinical study. Int I Oral Maxillofac Implants 1997; 12:454-^62. 13. Jaffin RA, Kumar A, Bemoan CL. Immediate loading of implants in partially and fully edentulous jaws: a series of 27 case reports. J Periodontol 2000; 71:833-838. 14. Randow K, Ericsson I, Nilner K, et al. Immediate functional loading of Branemark dental implants. An 18 month clinical follow-up study. Clin Oral Implants Res 1999; 10:8-15. 15. Chiapasco M, Gatti C, Rossi E, et al. Implant-retained mandibular overdentures with immediate loading. A retrospective multicenter study on 226 consecutive cases. Clin Oral Implants Res 1997; 8:48-57. 16. Schnitman PA, Wohrle PS, Rubenstein JE, et al. Ten-year results for BrSnemark implants immediately loaded with fixed prostheses at implanl placement. Int J Oral Maxillofac Implants 1997; 12:495-503. 17. Tarnow DP, Emtiaz S, Classi A. Immediate loading of threaded implants at slage I surgery in edentulous arches: ten consecutive case reports with 1—5 year data. Int J Oral Maxillofac Implants !997; 12:319-324. 18. Drago CJ, Lazzara RJ. Immediate provisional restoration of Osseotite implants; a clinical report of 18 month results. Int J Oral Maxiltofac Implants 2004; 19:534-541. 19. Schulte W, Kleineikenscheidt H, Linder K, Schareyka R. The Tubingen immediate implant in clinical studies. Dtsch ZahnarztlZ 1978; 5:348-359. 20. Lazzara RJ. Immediate implant placement into extraction sites. Surgical and restorative advantages. Int [ Periodontics Restorative Dent 1989; 9:333-339. 21. Nyman S, Lang NP, Buser D, Braggc U. Bone regeneration adjacent to titanium dental implants using guided tissue regeneration: a report of two cases. Int f Oral Maxillofac Implants 1990; 5:9-14. 22. Becker W, Becker BE. Guided tissue regeneration for implants placed into extraction sockets and for implant dehiscences. Surgical techniques and case reports. Int J Periodontics Restorative Dent 1990; 10:377-391. 23. Balshi TJ, Hernandez RE, Culler RH, Hertzog CF. Treatment of osseous defects using Vicryl mesh (polyglactin 910) and the Branemark implant. Int J Oral Maxillofac Implant.s 1991:6:87-91. 24. Novaes AB Jr, Novaes AB. IMZ implants placed into extraction sockets in association with membrane therapy (Gengiflex) and porous hydroxyapatite. A case report. Int J Oral Maxillofac Implants 1992; 7:536-540. 25. Novaes AB Jr, Novaes AB. Bone formation over an IMZ implant placed into an extraction socket in association with membrane therapy (Gengiflex). Clin Oral Implants Res 1993:4:106-110. 26. Gelb DA. Immediate implant surgery: three year retrospective evaluation of 50 consecutive cases. Int J Oral Maxillofac Implants 1993; 8:388-399. 27. Schwartz-Arad D, Chaushu G. The ways and wherefores of immediate placement of implant placement of implants into fresh extraction sites: a literature review. J Periodontol 1997; 68:915-923. 28. Chen ST, Wilson TG Jr, Hammerle CF. Immediate or early placement of implants following tooth extraction: review of biologic basis, clinical procedures, and outcomes. Consensus statement. Int J Oral Maxillofac Implants 2004; 19(Suppl):12-28. 29. Mayfield L, Immediate delayed and late submerged and transmucosal implants. In: Lang NP, Karring T, Lindhe J, eds. Proceeding of the Third European Workshop on Periodontology Implant Dentistry. Berlin: Quintessence, 1999:520-534. 30. Carlsson GE, Persson G. Morphologic changes of the mandible after extraction and wearing of the denture. Odontol Rev 1967; 18:27-54. 31. Atwood D. Post extraction changes in the adult mandible as illustrated by microradiographs of midsagittal section and serial cephalometric roentgenograms. | Prosthet Dent 1963; 13:810-816. 32. Johnson K. A study of the dimensional changes occurring in the maxilla after tooth extraction. Part I: normal healing. Aust Dent J 1963; 8:428-434. 33. Lekovic V, Kenney EB, Weinlaender M, et al. A bone regenerative approach to alveolar ridge maintenance following tooth extraction, Report of 10 cases. J Periodontol 1997; 68:563-570. 34. Lekovic V, Camargo PM, Klokkevold PR, et al. ('reservation of alveolar bone in extraction sockets using bioabsorbable membranes. J Periodontol 1998; 69:1044-1049. 35. lasella )M, Greenwell H, Miller RL, et al. 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. J Periodontol 2003; 74:990-999. 36. Fallschussel G. Anatomie des Zahnlosen Oberkiefers. XZ Zahnarztl Implantol 1986; 2:64-72. 37. Dennisen HW, Kalk W, Velhuis HAH, Wan Waas MAF. Anatomic consideration for preventive implantation. Int J Oral Maxillofac Implants 1993; 8:191-196. Aipha Orrtegan, Volume 98, Number 2, July 2005 IMMEDIATE PLACEMENT OF IMPLANTS INTO EXTRACTION SOCKETS: RATIONALE, OUTCOMES, TECHNIQUE 38. Werbitt MI, Goldberg PV. The immediate implant: bone preservation and bone regeneration. Int J Periodonlics Restorative Dent 1992; 12:207-217. 39. Covani U, Cornelini R, Barone A. Bucco-lingual bone remodeling around implants placed into immediate extraction sockets: a case series.) Periodontol 2003; 74:268-273. 40. Covani U, I3ortolaia C, Barone A, Shordone L. Buccolingua! crestal bone changes after immediate and delayed implant placement.) Periodontal 2004; 75:1605-1612. 41. Wagenberg BD, Ginsberg TR. Immediate implant placement on removal of the natural tooth: retrospective analysis of 1,081 implants. Compendium 2001; 22:399-410. 42. Becker BE, Becker W, Ricci A. Geurs N. A prospective clinical trial of endosseous screw-shaped implants placed at the time of tooth extraction without augmentation. J Periodontol 1998; 69:920-926. 43. Schwartz-Arad D, Grossman Y, Chaushu G. The clinical effectiveness ol implants placed immediately into fresh extraction sites of molar teeth. J Periodontol 2000; 71:839-844. 44. Rosenquist B, Grenthe B. Immediate placement of implants into extraction sockets: implanl survival. Int I Oral Maxillofac Implants 1996; 11:205-209. 45. Kan I, Rungcharassaeng K, Lozanda J. Immediate placement and provisionalization of maxillary anterior single implants: 1-year prospective study. Int I Oral Maxillofac Implants 2003; 18:31-39. 46. Gomez-Roman G, Kruppenbacker M, Weber H, Schulte W. Immediate post extraction implant placement with Rootanalog stepped implants: surgical procedure and statistical outcome after 6 years. Int J Oral Maxillofac Implants 2001; 16:503-513. 47. Covani U, Crespi R, Cornelini R, Barone A. Immediate implants supporting single crown restoration: a 4-year prospective study. J Periodontol 2004; 75:982-988. 48. Schwartz-Arad D, Gulaycn N, Chaushu G. Immediate versus non-immediate implantation for full arch fixed reconstruction following extraction of all residual teeth: a retrospective comparative study. I Periodontol 2000; 71:923-928. 49. Prosper I., Gherlome EF, Redalle S, Quaranta M. Four-year follow-up of large diameter implants placed in fresh extraction sockets using a resorbabte membrane or A resorbable alloplastic material. Int I Oral Maxillofac Implants 2003; 18:856-864. 50. Mensdorff-Pouilly N, Haas R, Mailath G, Watzek G. The immediate implant: a retrospective study comparing the different types of immediate implantation. Int | Oral Maxillofac Implants 1994; 9:571-578. 51. Grunder U, Polizzi F, Coene R, et al. A 3-year prospective multicenter follow-up report on the immediate and delayed immediate placement of implants. Int J Oral Maxillofac Implants 1999; 14:210-216. 52. Krump JL, Bamett BG. The immediate implant: a treatment alternative. Int I Oral Maxillofac Implants 1991; 6:19-23. 53. Biancho AE, San Filippo F. Single tooth replacement by immediate implant and connective tissue graft: a 1-9 year clinical evaluation. Clin Oral Implants Res 2004; 15:269-277. 54. Carlsson L, Rostlundt, Albrektsson B, et al. Implant fixation improved by close fit. Cylindrical implant/bone interface studied in rabbits. Acta Orthop Scand 1988; 59:272. 55. Knox R, Caudill R, Meffert R. Histologic evaluation of denta endosseous implants placed in surgically created extractior defects. Int J I'eriodomics Restorative Dent 1991; 11:365-375. 56. Barzilay I, Graser GN, Iranpour B, et al. Immediate implan tation of pure titanium implants into extraction sockets o Macaca fasciculans. Part II: histologic observations. Int Oral Maxillofac Implants 1996; 11:489-497. 57. Akimoto K, Becker W, Persson R, et al. Evaluation of titaniun implants placed into simulated extraction sockets: a study ii dogs. Int J Owl Maxillofac Implants 1999; 14:351-360. 58. Wilson TG, Schenk R, Buser D, Cochran D. Implants placec in immediate extraction sites: a report of histologic and his tometric analysis of human biopsies. Int J Oral MaxiUofa Implants 1998; £3:333-341. 59. Novaes AB Jr, Vidigal GM, Novaes AB, et al. Immediat implants placed into infected sites: a histomorphometric stud in dogs. Int J Oral Maxillofac Implants 1998; 13:422-427. 60. Novaes AB Ir, Novaes AB. Immediate implants placed int infected sites: a clinical report. Int J Oral Maxillofa Implants 1995; 10:609-613. 61. Saadoun AP, Landsberg CJ. Treatment classifications an sequencing for post extraction implant therapy. Pract Per odontics Aesthet Dent 1997; 9:933-941. 62. Garber DA, Belser UC. Restoration driven implant plao ment with restoration generated site development. Con pendContin EducDent 1995; 16:796-304. 63. landsberg Q. Socket seal surgery combined with immedia implant placement: a novel approach for single tooth replac ment. Int I Periodontics Restorative Dent 1997; 17:140-149. 64. Meltzer A. Non-resorbable membrane-assisted bone regei eration: stabilization and the avoidance of micromovemer Dent Implants Update 1995; 6:645-648. 65. Schropp L, Kostopoulos L, Wenzel A. Bone healing folloi ing immediate versus delayed placement of titaniu implants into extraction sockets: a prospective clinic study. Int ] Oral Maxillofac Implants 2003; 18:189-199. 66. Celletti R, Davarpanah M, Etienne D, et al. Guided tiss regeneration around denta! implants in immediate extra tion sockets: a comparison of e/PTFE and a new titaniu membrane, [nt ] Periodontics Restorative Dent 1994; I 243-253. 67. Augthun M, Yildirim M, Spiekermann H, Biesterfeld Healing of bone defects in combination with immedi; implants using the membrane technique. Int J Oral Maxil fac Implants 1995; 10:421-428. 68. Lekholm U, Becker W, Dhlin C, et al. The role of early v sus late removal of GTAM membrane on bone formation Alpha Oinegun, Volume 98, Number 2, July 2005 35 IMMEDIATE PLACEMENT OF IMPLANTS INTO EXTRACTION SOCKETS: RATIONALE, OUTCOMES, TECHNIQUE oral implants placed in immediate extraction sockets: an experimental study in dogs. Gin Oral Implants Res 1993; 4:121-129. 69. Paohiiitonio M, Dolci M, Scarano A, et al. Immediate implantation in fresh attraction sockets. A controlled clinical and histological study in man. J Periodontol 2001; 72:1560-1571. 70. Esposito M, Worthington HV, Coulthard P, JokstaJ A. Interventions for replacing missing teeth: maintaining and re-establishing healthy tissue around dental implants. Cochrane Database Syst Rev 2002; {3):CD003069. 71. Tarnow DP, Cho CS, Wallace SS. The effect of inter-implant distance on the height of the inter-implant bone crest. ] Periodontol 2000; 71:546-549. 72. Schwartz-Arad D, Chaushu G. Placement of implants into fresh extraction sites for 2-7 years retrospective evaluation of 95 immediate implants. J Periodontol 1997; 68:1110-1116. 73. Zitzmann NL', Naef R, Scharer P. Resorbable versus nonresorbable membranes in combination with Bio-Oss for guided bone regeneration. Int J Oral Maxillofac Implants 1997; 12:844-852. 74. Nemcovsky CE, Artzi Z, Moses O, Gclertner I. Healing of marginal defects at implants placed in fresh extraction sockets or after 4-6 weeks of healing. A comparative study. Clin Oral Implants Res 2002; 13:410-419. 75. Chen ST, Darby IB, Adams GG, Reynolds EC. A prospective clinical study of bone augmentation techniques at immediate implants. Clin Oral Implants Res 2005; 16:176-184. 76. Cornelini R, Cangini F, Martuscelli G, Wennstrom J. Deproteinized bovine bone and biodegradable barrier membranes to support healing following immediate placement of transmucosal implants: a short-term controlled clinical trial. Int J Periodontics Restorative Dent 2004; 24:555-563. 77. Evian CI, Cutler S. Autogenous gingival grafts as epithelial barriers for immediate implants: case reports. J Periodontol 1994; 65:201-210. 78. Hurzeler MB, Weng D. Functional and esthetic outcome enhancement of periodontal surgery by application of plastic surgery principles. Int J Periodontics Restorative Dent 1999; 191:36-43. 79. Nemcovsky CE, Artzi Z. Split palatal flap. I. A surgical approach for primary soft tissue healing in ridge augmentation procedures: technique and clinical results. Int J Periodontics Restorative Dent 1999; 192:175-181. 80. Nemcovsky CE, Artzi 2, Moses O. Rotated paiatal flap in immediate implant procedures. Clinical evaluation of 26 consecutive cases. Clin Oral Implants Res 2000; 11:83-90. 81. Nemcovsky CE, Artri Z, Moses O. Rotated split palatal flap tor soft tissue primary coverage over extraction sites with immediate implant placement. Description of the surgical procedure and clinical results. I Periodontol 1999; 70:926. PLEASE SUPPORT HE ALPHA OMEGA FOUNDATION Send Tribute Cards Alpha Omega Foundation Tribute Cards may be purchased for any occasion from your local Tribufe Fund chairperson or Glen Meyer, D.D.S. 7725 Shadowhill Way Cincinnati, OH 45242 513-984-2345 orMeyer5233@aol.com Alpha Omega Foundation of Canada 128 Willowdale Avenue Willowdale, ON M2N 4Y2 Canada 416-250-7417 Regular Tribute Cards are available in packages of six for $30.00. Golden Tribute Cards are $25.00 each and Platinum Tribute Cards are $50.00 or more. Golden and Platinum Cards are recognized in the Alpha Otnegan. Checks should be made payable to the Alpha Omega Foundation or the Alpha Omega Foundation of Canada or payment may be made by credit card.