Extraction Sockets and Implantation of Hydroxyapatites With Membrane Barriers A Histologic Study Stuart Froum, DDS, Sang-Choon Cho, DDS, Nicolas Elian, DDS, Edwin Rosenberg, DDS, Michael Rohrer, DDS, Dennis Tarnow, DDS Extraction Sockets and Implantation of Hydroxyapatites With Membrane Barriers A Histologic Study Stuart Froum, DDS," Sang-Choon Cho, DDS.t Nicolas Elian, DDS.t Edwin Rosenberg, DDS,§ Michael Rohrer, DDS,|| Dennis Tarnow, DDSH As a result of (he bone resorpiion and soft tissue shrinkage lhat occurs alter routine atraumatic tooth extraetion. ideal implant placement and implant esthetics are often compromised. Controlled elinieal studies have documented an average of 4.4 mm of horizontal and 1.2 mm of vertical bone resorption 6 months after tooth extraction. ' Other studies have documented significant dimensional changes in the surrounding alveolar bone after extraction procedures.3"5 In ! study, the incidence of anterior ridge deformities in partially edentulous pa- (ients was reported to he 9\r/< .6 Various materials have been used to prevent or minimize ridge collapse after tooth extraction in an attempt to improve implant placement and the subsequent esthetics of the final implant prosthesis. The use of xenografts (hovine bone)7** and alloplasts (including bioactive glass11 "J and calcified copolymer" °) have been shown both clinically and histologically to improve hone quality and quantity of the healed extraction socket before implant placement. Use of membrane 'Clinical Prolessor ana Director 01 Clinical Research Ashman Department of Implant Dentistry, New York University. Knser Dental Center. New Yak NY TOinical Assistant Professor and Research Scientist. Ashman Department of Implant Dentistry, New Yorft University. Kriser Dental Center, New YorK, NY JDirectorof International Program. Assistant Professor. Ashman Department of Implant Dentistry. New York University. Knser Denial Center, New York. Nv §Professor Penodontics and Implant Dentistry University of Pennsylvania, Philadelphia. Pennsylvania UProfessor and Director. Division of Oral and Maxiiiofacal Pathology, University of Minnesota. School o! Dentistry. Minneapolis, Minnesota IProiBSSor and Chair, Ashman Department of Implant Dentistry, New York University. Krise Dental Center. New York. NY ISSN 1056-6163/04/01302-163 implanl Dentistry Volume 13 • Numoer 2 Copyright C 20O4 by Lippmcoll WiHem;, 4 Wilkms DOl: tOi097/0«-ID.0000127524.98819FF The purpose of this pilot study was to investigate tlie effect on extraction socket healing when an absorbabie hydroxyapatitc {AH) mui a nonabsorbiMe anorganic bovine bone mineral (ABB) covered with either an acellular dermal matrix allografl (ADMA) or expanded polytetrajhioroethylene (ePTFE) membrane barrier were left exposed to the oral cavity. Following tooth extraction, a total of 76 sockets in 15 patients with deficient buccal plates of ^5 mm were randomly divided into 4 treatment groups: 1) AH covered with ADMA. 2) AH covered with an ePTFE membrane, 3) ABB covered with ADMA, and 4) ABB covered with an ePTFE membrane. Primary coverage was not attempted or obtained in any of the 16 treated sockets. Six to 8 months postexination at the time of implant placement, histologic cores of the treatment sites were obtained. These cores were processed, stained with Stevenel's blue/ van Gieson 's picro fuchsin, and histomorphometricalh' analyzed. Vital bone, connective tissue and marrow, and residual graft particles were reported at a percentage of the total core. The mean vital bone was 34.59c (AH with ADMA). 41.77c (ABB with ADMA). 27.67c (ePTFE and AH), and 17.8% tePTFE and ABB). The average percentage of vital bone in the 8 sockets covered with ADAM A was 38% compared with an average percentage vital bone cf22% in the 8 sockets covered with ePTFE membrane barriers. Became of the small number of specimens in the 4 groups. statistical analysis was not possible. However, in this pilot study, ADMAcovered sites resulted in more vital bone present 6 to 8 months postsa ket treatment than obtained in the ePTFEcovered sites regardless of bone replacement materials used. Further research is warranted to see if these results show a similar difference in bone-lo-implant contact after implant placement. (Implant Dent 2004; 13:153- 164) Key Words: extraction socket, bonier membrane, histomorphometric analysis, absorbabie hydroxyapatite, acellular dermal matrix allograft barriers with allografts,14 with bone replacement materials (BRM),'Si6 and BRM or bone grafts combined with calcium sulfate1718 have also been udvocated as immediate socket treatment to minimize bone resorption and augment existing hone for implant placement. The use of nonabsorbable and absorbabie membrane barriers at the lime of tooth extraction have also demonstrated the ability to reduce hard tissue resorption.1: However, the concept of socket preservation with grails, bone substitutes, and/or membrane barriers is not without controversy. Two separate studies reported that decalcified free/e-dried bone, with and without barrier membranes. bovine hone, and autogenous bone when implanted in healing extraction sockets interfered with normal healing IMPLANT DENTISTRY / VOLUME 13, NUMBER 2 2004 153 and did not result in any increased bone-to-implant contact.IW0 Recently, an acellular dermal matrix allogralt (ADMA) was introduced as a substitute for autogenous connective tissue grafts for various periodontal, pcri-impiant, and extraction socket treatments. Although the cellular components of the allograft are removed, the ultrastruclural integrity of the extracellular matrix is maintained.21"* Therefore, the use of ADMA to increase the /.one of attached gingiva around teeth and dental implants,-4 21 treat gingival recession defects,28'33 cover submerged implants that have been immediately inserted mio fresh extraction sockets." and in socket preservation treatment to decrease loss of ridge height and width alter tooth extraction111"' has been described. The use of guided bone regeneration with nonabsorbable ePTFE membranes1 and absorhable membranes" immediately alter tooth extraction have demonstrated superior clinical results in 2 separate studies, hoth using a nonfilled extraction socket as the healing control. Both studies attempted primary closure of the wound over the membrane barrier. However, in 3 lest patients using expanded polytetrafluoroethylcne (ePTFE) membranes, exposure ol the membrane produced results with "similar dimensional changes as controls."1 A surgical technique has been described using a high-density PTFK membrane and paniculate bone replacement material without primary closure to enhance socket healing. The author noted that this technique facilitates the preservation of keratinized mucosa and gingival architecture." It is therefore of interest to see if ADMA and/or ePTFH barriers are able to produce an improved healing result in fresh extraction sockets when primary coverage is purposely not attempted. The purpose of this pilot study was to compare, and histologically evaluate, the healing of extraction sockets implanted with either an ahsorbable or nonabsorbable hydmxyapatilc and covered by an ADMA or an ePTFH membrane. MATKKIALS AND METHODS Sixteen16 teeth scheduled for extraction, for periodontal or prosthetic reasons, and replacement with an implant were selected in 15 patients (9 males, n females) with an age range of 26 to 71 years (average, 48.1 years) who presented to the Ashman Department of Implant Dentistry at New York University Kriser Dental Center. The diagnosis of these teeth for extraction was confirmed by 2 separate instructors on faculty who were not part of the study. All patients met the established physical and psychologic criteria for implant treatment in the Department of Implant Dentistry. In addition, patients did not have any medical conditions and were not taking any medications that were associated with a compromised bone healing response fie, diabetes, autoimmune dysfunction, prolonged cortisone therapy, or chemotherapy). Pregnant women, or women intending to become pregnant within 1 year of the start of the study, were excluded from consideration. All patients were oonsmokers or previous smokers who had not smoked for at least 6 months. All patients had no known allergy to tetracycline and had not received any antibiotic over the previous 6 months. Patients were given an explanation of the nature of the study and, alter expressing a wish to participate, they signed a written consent form before their participation. The informed consent and instruction to patient forms as well as the study protocol were approved by the University Committee on Activities Involving Human Subjects. Participating patients were told that if they decided to discontinue their participation in the sludy at any time, they could continue being treated at New York University Dental Center as a regular clinic patient. Measurements The measurement techniques used have been previously described.9 To briefly review, before extraction, radiographs, impressions, and diagnostic casts were taken. A template was then fabricated on the study model, including at least I tooth anterior or posterior to the hopeless tooth. A light-cured resin material was used to fabricate the template. The crown of the hopeless tooth was cut off on the study model and a guide hole was drilled with a 3 X 10-mm drill through the template directly above the outline of the rooi on the model. A metal ring was placed in the hole and resin was added around the ring to stabilize ils position. At the time of implant surgery (6-H months after extraction), the template was again positioned to obtain a histologic core from the identical site. Surgical Protocol After administration of local anesthesia, crestal. intrasulcular. and where necessary, vertical incisions were made to expose the involved roots and alveolar crest. Full-thickness huccal and lingual flaps were raised and split apically with sharp dissection to adequately view the sockets and allow sufficient flap release to obtain closure (primary closure was not attempted or obtained). After extraction of the tooth, the sockets were debrided, measured, and decorticated with a half-round burr under copious irrigation. After tooth extraction, those sockets with buccal plate bone loss >5 mm were included in the study. Thus, each of the sockets treated had a combined 3- to 4-wall configuration. Treatment selection was then made randomly from sealed envelopes prepared by a statistician. Of the 16 sockets treated. S sockets received ahsorbable hydroxyapatite bone substitutes. Four of these sites were covered with ADMA membranes and the 4 others covered with ePTFE membranes. Fight additional sockets received nonabsorbable anorganic bovine bone substitutes. Four of these sites were covered with ADMA membranes and the other 4 covered with ePTFK membranes (Fig. 1-8). Four treatment groups were therefore established as follows: 1. Fill with absorbablc hydroxyapatite (AH) and covered with ADMA; 2. Fill with AH and covered with an ePTFF membrane: 3. Fill with anorganic bovine bone (ABB) and covered with ADMA; and 1. Fill with \BB and covered with an ePTFE membrane. The AH consisted of a lowdensity 1009£ pure synthetic hydroxy- 154 SDCKKTS AND IMPLANTATION OF HYDHOXYAPATITES Fig. 1. After debndement of the extraction socket on tooth no. 9, the acellular dermatic matrix allograft was fitted and reflected to the lingual. The socket was filled with absorbable hydroxy apatite. Fig. 2. The ADMA was then secured buccally under the periosteum. Fig. 3. The flap was sutured with no attempt at primary closure. Fig. 4. Six weeks postsurgery, the ADMA membrane remains in place with surface sloughing observed, Fig. 5. Three months postsurgery, the flap margins have migrated over the ADMA. upalile with a particle size ranging from 250 to 420 /im (OsteoGraf R/LD; Dentsply. Lakewood, CO). The ABB was a natural anorganic hovinederived microporous hydroxyapatite (1009! protein-irec! with a particle size ranging from 250 to 420 ixm (OstcoGraf R/N300; Dentsply). These hone substitute particles were placed into the socket to the level of the interproximal hone and covered with either ADMA or eFTFE membranes. The ADMA was obtained from tissue hank skin and was processed before tree/e-drying to remove the entire epidermal layer superficial to the basement membrane, removing dermal cellular elements (Allodcrm Life Cell Corp.. The Woodlands. TX). The nonahsorbahle membrane was composed of ePTFE (Gorc-Tex Regenerative material, oval 4 or 6; W.L. Gore &. Associates, Inc.. Flagstaff. AZ). In all cases, the ADMA or cPTFE membranes were shaped to completely cover the socket, extend 4 to 5 mm apical to the huecal and lingual walls. and be located 1 to 2 mm from the adjacent teeth. The harriers were then stabilized by "tucking" them under the buecal and lingual periosteum and connective tissue that had been separated from the hone with a small periosleal elevator. The ADMA barriers were placed with the connective tissue side facing the socket and the basement membrane side (smooth side) facing the oral cavity. In the cases in which the barriers were not stable alter shaping and placement, they were sutured with 5-0 absorbable suture (5-0 coated Vicryl sutures; Ethicon, Inc., Somerville, NJ) to the remaining periosteum at the apical part of the flap. The mucoperiosteal Haps were sutured with 4-0 silk (Silk Black braided 4-0; Ethicon, Inc.), ePTFE (Gore-Tex suture CV-5, Gore-Tex; W.L. Gore & Associates. Inc.). or absorbable sutures {4-0 chromic gut: Ethicon. Inc.) using interrupted and vertical mattress sutures. However, no attempt was made to cover the membrane barriers. The temporary prosthesis was relieved before insertion. Patients were placed on 100 mg doxycyclinc beginning at least 1 hour before surgery and continuing for 13 days after surgery. Patients were also prescribed 0.129? ehlorhexidine rinses (Peridcx: Zila Pharmaceuticals, Inc.. Phoenix, AZ) twice a day beginning the day of surgery and continuing until the time of membrane removal. Patients were seen weekly for 4 weeks and then once a month to monitor healing until the barrier was removed. At these visits, the tissue around the membrane was examined for evidence of inflammation, infection (exudate), or exfoliation of the membrane. The membranes and tissue were irrigated with a syringe filled with Betadine followed by 0.12% chlorhexidine and concluding with 0.9% saline. When inflammation was detected, patients were placed on 100 mg doxycycline once a day for 2 to 4 weeks. When infection or exudate was detected, the membrane barriers (ADMA or ePTFE) were removed and the time of removal recorded (Table t)- Six to 8 months after extraction socket surgery, an implant of appropriate size was placed in the healed socket. At time of implant site preparation, the template was again placed and a core of hone 2.0 mm X 7.0 mm long was obtained. The cores were coded and sent to the Hard Tissue Research Laboratory at the University of Minnesota School of Dentistry. The processing and histomorphomctric measurements were performed by an investigator who had no knowledge of the treatment rendered. The cores were stained with Stevenel's blue/van Gieson's picro fuchsin and histomorphometrically analyzed for bone and soft tissue. Processing and analysis of the specimens using a nondecalcified IMPLANT DHNTISTRY / VOLLMK 13. Nt. MHHK 2 2004 155 Fig. 6. The extraction socket of tooth no. 13 after debridement. Fig. 7. The socket is filled with anorganic bovine bone (ABB). Fig. 8. The ePTFE membrane is secured over the ABB and the flap suture with absorbable vertical mattress sutures. technique has heen described.'' v> Values were then reported using a grid overlay for total bone material, percent connective tissue (%CT), and percent residual implant materials RESULTS Histomorphometric results are presented in Table lot' the 16 extraction sockets covered wilh either ADM A or ePTFE barriers and filled with an AH or a nonabsorbablc ABB. Clinically, all sockets exhibited a normal healing response at the time of implant placement and core removal. The ADM A barriers exhibited surface sloughing within 2 to 4 weeks postplacement. All at but one site, the ADM A was not evident by the 12- week follow-up period. No patient reported knowledge of the barrier exfoliating at those time periods (Figs. 4 and 5). However, at 1 site in the ADM A group and at 6 sites in the ePTFF. group, it was necessary to remove the barriers at various times before implant placement because of infection (exudate) present at the surgical site. The ADMA barrier was removed 6 weeks postplacement and the 6 ePTFE barriers were removed from 4 to 16 weeks after placement. In all cases, removal was accomplished by deepithelialization of the inner layer of the overlying Hap and lifting the barrier with a periostea] elevator and a hemostat. In all except 2 cases (ePTFE membranes), suturing of the overlying flap was not required. In these 2 cases, ePTFH sutures were used to suture the flap over the healing tissue. No attempt was made to debride or remove the tissue under the membrane barrier. Histology of the cores from sockets covered wilh ADMA and filled with AH showed an average vital bone of 34.5% (range. 19-57%), an average marrow and connective tissue of 61.8% (range, 40-81%), and an average residual graft material of 4% (range, 0-1 1%). Bone present at these sites was 100% vital and ranged from \97< to 57%. Evidence of AH particles were still present in all sections but in most specimens appeared separate and distant from the vital bone. In other sections, these particles were incorporated into new bone as well as being separate from vital hone (Figs. 9 and 10). Histology of the sockets covered with ADMA and filled with ABB showed an average vital bone of 4].17, (range. 19.5-62.4%). an average marrow and connective tissue of 45.57< (range, 34—63%), and an average residual graft material of 12.2% (range, 1-30.6%). Particles of ABB were surrounded by vital bone incorporating the particles into a wellformed cancellous bone pattern (Figs. 11 and 12). Histology of sockets covered with ePTFE membranes and filled with AH showed an average vital bone of 27.6% (range, 14-40.1%:), an average marrow and connective tissue of 60.59! (range, 43.5-69.6%), and an average residual graft material of 11.98 (range, 6-19%). Bone present at these sites was IOO'7( vital. All sections contained remaining particles of AH, most surrounded by connective tissue and a lew others in close proximity, even fusing with the hone (Figs. 13 and 14). Histology of the cores from sockets covered with ePTFE membranes and filled with ABB showed an average vital bone of 17.8% (range. 10.6-25%), an average marrow and connective tissue of 6().77f (range, 42-75.4%), and an average residual graft material of 21.4% (range, 14-339J ). The bone present at these 4 sites was 46.2%, 88.27r, 100%, and 100% vital, respectively. Active new bone formation was seen around most of the remaining ABB particles with the beginning of bridging of particles by vital bone (Figs. 15 and 16). The average percentage vital bone in the 8 swkets covered wilh ADMA was 387r compared with an average percentage vital bone of 22.7% in the H sockets covered wilh ePTFF membrane barriers (Table 2). Because of the small number of specimens in the 4 groups, statistical analysis was not possible. DISCUSSION Attempts to prevent or minimize poslcxtraction hone resorption problems include: 1. Immediate placement of an implant in the extraction socket. 2. Immediate implant placement and use of a hone graft or bone substitute in the extraction socket. 3. Placement of various materials immediately after tooth extraction to fill and/or cover the socket in an attempt to prevent resorplion. The implant is then placed in a delayed protocol following socket healing. An extensive literature review of human studies reported high survival I5(l FIXTRACTION SOCKHTS AND IMPLANTATION OH HYDROXYAPATITES Table 1. Histomorphometric Results of the 16 Extraction Sockets Barrier Type ADMA ePTFE Graft Type AH ABB AH ABB Initials LM RZ LW WH PT CL YL IR SL LM GH VL SD RK WG GS Age (yrs) 47 56 63 71 45 26 53 5: 36 47 43 31 60 51 50 3o Sites 7 2 3 9 3 18 14 3 1 1 10 19 4 14 a4 13 Early Removal (months) 1.5 2 1 4 2 4 2 Healing Period (months) 8 6 7 6 6 6 6 6 6 8 8 8 7 7 8 7 Vital Bone (%) 25 19 37 57 19.5 62.4 48.7 36 32 14 40.1 24.3 10.6 12.9 25 23 Marrow (%) 64 81 62 40 49.9 34 35 63 62 67 43.5 69.6 75.4 65.4 42 60 Remaining Graft (%) 11 0 2 30 30.6 3.6 16.3 1 6 19 16.4 6.1 14 21.7 33 17 This table lists histomorphorr.etnc results o* 16 extraction sockets. 8 covered with the ADMA barrier with either AH or ABP as trie socket fill material ana 8 covered with the ePTFE Darner with me sane 2 socket fill materials. The table shows the percent vital bone, percent marrow, and percent of remaining graft matenai >n each of the 16 cores taken. rates after immediate implant placement with a variety of implanl types and variable follow-up periods.4 However, these studies did not address the amount of vertical or horizontal poslimplanl resorption of the buceal or lingual plates of bone. Although I human study41 reported on bone implunt contact of immediately placed implants, crestal bone rcsorption was not specifically studied. Another study evaluated the effect of membrane (ePTFE) placement on ridge width in a dog model comparing nomnemhranetrcated implant sites as controls. The authors noted a trend of a greater increase in ridge width in sites treated with memhranes than control sites. However, the authors also noted that "ridge width measurements were not taken from standardized points and consequently there is a high probability of measurement error.""42 Another animal study4' evaluated bone healing around implants placed into simulated extraction defects of varying widths in 10 mongrel dogs. Although clinically. all test and control sites healed with complete bone fill in the defect, hisiologically, as the gap around the implants widened, bone-to-implant contact decreased, and the point of the highest bone-to-implant contact shifted apically. Again, there were no measurements made to determine if and how much bone resorption took place during the healing period. It is evident that although treatment with immediately placed implants with or without additional augmentation material seems a viable method of ridge preservation, there is a paucity of measurement proof to substantiate this 11 Fig. 9. Seven-month low-power section of a core of bone from a socket treated with ABMA and AH. vital bone measured 37%. Particles of AH remain and are seen within bone and surrounded by connective tissue (original magnification x: Stevenel's Blue/van Gieson's picro fuchsin stain). Fig. 10, High-power view of an area in fhe previous figure showing particle of AH not completely resorbed and totally incorporated to the vital bone (original magnification x20: Stevenel's Blue/van Gieson's picro fuchstn stain). Fig. 11. A low-power histologic section of a core of bone obtained 6 months postgrafting with ABMA and ABB. Vital bone measures 48.7%. The bone and ABB form a cancellous bone pattern with vitai bone bridging among the ABB particles (original magnification x4: Stevenel's Blue/van Gieson's picro fuchsin stain). Fig. 12, A high-power histologtc view of an area of Figure 11 showing ABB particles completely surrounded by vital bone. The green-staining material in contact with the particles on the right is osteoid, which is becoming vital bone (original magnification X20; Stevenel's Blue/van Gieson's picro fuchsin stain). IMPLANT DHNTISTKY / VOLUME 13. NUMBHR 2 2004 157 Fig. 13. Low-power histologic section of a core of bone obtained 8 months postgrafting with ePTFE and AH. AH particles remain, most of which are separate from vital bone, although some are fused to bone, Vital bone measured 24.3% (original magnification x4: Stevenel's Blue/van Gieson's picro fuchsin stain). Fig. 14. A high-power histologic view of an area of Figure 13 showing unabsorbed particles of AHH. The particle on the left is separate from the new bone and the one on the right is fusing with vital bone (original magnification :<20: Stevenel's Blue/van Gieson's picro fuchsin stain). Fig. 15. Low-power histologic section of a core of bone obtained 7 momhs postgrafting with ePTFE and ABB. Most of the particles of ABB are surrounded or in contact with osteoid or new vital bone. Vital bone measured 12.9% (original magnification x4: Stevenel's Blue/van Gieson's picro fuchsin stain). Fig. 16. A high-power histologic view of an area of Figure 15 showing particles of ABB surrounded by vital bone, New bone formation (green stain) is also evident (original magnification x20: Stevenel's Blue/van Gieson's picro fuchsin stain). premise. Recently, u study was performed around 15 immediately placed implants into extraction sockets.* After irnplanl placement, measurements were made of the distance from the coronal border of the buccal to the coronal horder of the lingual plate of bone. No membranes or filling materials were used and primary closure was obtained in all cases. At the lime of second-stage surgery, o months postimplantation, these measurement were repeated. The mean buccal to lingual distance decreased from an initial 10.5 mm ± 1.52 (after implant placement) to 6.X mm ± 1,33 (6 months postimplantation). Thus, the average horizontal bone resorption after immediate implant placement was 3.7 mm (range. 2-5 mm). This is slightly less lhat what was reported for the healed extraction sockets in the control group (no membrane, no fill, primary closure) in a previous study.1 Membrane harriers have been successfully used in the treatment oi' p^riodontal defects and in ridge augmentation procedures before implant placement.4"'"- One study on 26 subjects with mandibular class II furcation delects treated with cPTFE barriers concluded (hat "similar improvement in all clinical and surgical parameters" occurred in both the prematurely exposed and the fully submerged groups.4'1 A technique for immediate implant insertion was described that advocated placement of an ePTFE barrier over the implant without primary (lap coverage "because the membrane is. in effect, taking the place of the flap closure."1'' The membrane remained exposed and in place for "approximately I month" hefore removal. However, ePTFE membrane exposure in cases of ridge augmentation occurred in a number of studies requiring early removal of the barriers and resulting in a compromised result in many cases.4'1" Buser, Jovanovic, and Mellonig reported membrane exposure requiring early removal in 6.3% to 51% of cases treated.47-4" In an attempt to prevent membrane exposure vertical and periostcalrcleasing incisions, coronal flap advancement, and tension-free primary closure are recommended. These procedures result in a compromised vestibule and reduce the amount of keratinized tissue which oftentimes requires additional soft tissue surgical correction." In the current study, to avoid the secondary complications listed here, no attempt at primary closure of the tissue covering the extraction socket was attempted. The results of this study show a trend toward greater vital bone present in the ADMA-covcred sites compared with the elTFE-covered sites (381 vs. 22.7%). This trend was consistent whether comparing ADMA covering absorbable hydroxyapatitc versus cPTFH covering the same AH (34.5% vs. 27.o<#) or ADMA covering anorganic bovine bone versus cPTFE covering the same ABB (4l.7<v? vs. 17.8%). It also appears that better results were obtained, regardless of the barrier, when ABB was used as the fill material. This difference in results favoring ADMA harriers could be the result of the fact that exposure of this membrane is less critical to success than exposure of ePTFE membranes. In fact, many authors (Buser et al..' Simion et al.,55 Wachtel et al.," Jovanovic et al..4Si5S Becker et al.,59 Simion et al.,60 Buser el al.,*1 Jovanovic and Ncvins," and Nowzari and Slots'1*) stressed the importance of keeping the ePTFE barriers submerged to obtain optimum results. The latter article (Nowzari and Slots"1) reported colonization of bacteria on the cPTFE membranes lhat became exposed. This too could have compromised results of ePTFE-covcred sockets in the currenl study. However, the strict recall program and the removal of the I ABMA and 6 ePTFE barriers when infection was evident could have allowed positive vital bone formation with the fill materials used in this study despite membrane exposure. However, the population in this study was too small to detect significant differences in results of the membranes retained for longer periods of lime as was reported in an experimental study in dogs.50 It is interesting that in a published 158 EXTRACTION SOCKHTS AND IMPLANTATION OK HYDROXYAPATITKS case report on 2 successful cases of ridge preservation using ADMA in conjunction with decalcified freeze hone allogral't in a fresh extraction socket, the exposed ADMA memhr; incs exfoliated "atraumatically" 3 weeks poslinserlion. In a published case report of ADMA used for ridge augmentation, the author noted the importance of completely covering "the acellular dermal matrix with a pedicle "and keeping it "completely covered during ihc healing period."" Although no attempt was made to do this in this study, except for I harrier, which was removed 6 weeks postplacemcnt. all 7 of the other ADMA barriers showed surface sloughing 2 to 4 weeks postopcratively and then were not evident al 8 weeks, or in some cases by 12 weeks, post surgery. Because the 7 patients with these ADMA barriers did not report being aware of barrier loss, we must assume the harriers were incorporated into the wound healing (covered by epithelium) or exfoliated without paticnl knowledge. This contrasts to the 6 of X ePTFE barriers, which had to be removed prematurely during the study. This could reflect a better resistance of the ADMA barriers to bacterial colonization with the regimen of postsurgical treatment used in this study. A factor that was not measured in this study was the distance that the flaps were separated after suturing or the amount of exposure of the membranes during the healing phase. There could be a "critical distance" beyond which membrane exposure adversely affects socket healing, However, these variables require more cases, additional measurement parameters, and further investigation. Although the combination of ADMA and ABB appears to result in the highest percentage of vital bone in this investigation, additional clinical and histologic studies are necessary before any speculation or conclusions are made. Certainly, the advantages of materials that result in significant bone fill of a healing extraction socket without the compromises caused by obtaining primary soft tissue closure warrant further investigation. It is also evident that this study did not include a negative (no fill) Table 2. Average Percent of Vital Bone in Sockets Covered With Acellular Dermal Matrix Allogratt (ADMA) or Expanded Polytetrafluoroethylene (ePTFE) Membranes and Filled With Absorbable Hydroxyapatite (AH) or Anorganic Bovine Bone (ABB) Barriers ADMA ePTFE Average Percent Vital Bone 38% 22.7% Grafts AH ABB AH ABB Vital Bone Percent (range) 34.5(19-57) 41.7(19.5-62.4) 27.6(14-40.1) 17.8(10-25) tie summarizes Ihe average percent vital bone in sockets treated with ADMA companjd with sockets treated with ePTFE bamers Average vital bone obtained from sockets filled with AH or ABB and covered with either AOMA or ePTFE barriers is also recorded ADMA, acellular dermal malnx allogratt ePTFE, expanded pofyletrafluofoethylene; AH. absorbabte hydroxyapatite; ABB. anorganic bovine bone mineral Table 3. Average Percent of Vital Bone in Healed Single vs. Multirooted Sockets Anterior Tooth No. 8 13 4 4 7 9 11 10 Single Rooted Percent of Vital Bone 12.9 23 24.3 25 25 57 62 67 37.0% Posterior Tooth No. 14 2 3 3 3 19 14 18 {multirooted) Percent Vital Bone 10.6 19 19.5 36 37 40.1 48.7 62.4 34.2% Tn>s taUe presents tfie average percent of vital bone detained m treated ana Healed scckets ol ether single and muliirooted teetn control group. Using the same measurement technique in a previous study, the "no tilled" and "no membrane" controls showed an average vital bone fill of 32.47, 6 to 8 months postsocket treatment.1' One must be cautious with these comparisons because the methodology was different (in the previous study, primary closure was achieved) and ihe type of tooth (incisor, premolar, molar) and jaw location represent factors that could influence healing and vital bone counts because of differences in the type of bone native to that site. When analyzing the data on all 1 ft sites in this study and comparing the results of multirooted (N = 8) with that of single-rooted teeth (N = 8), it is interesting to note that the average vital bone of the former was 34.16^ (range, 10.6-62.47r), whereas that of single-rooted teeth was 37.031/! (range, 12.9-67'^). Although no statistically significant data can be drawn because of the limited sample size, these findings tend to demonstrate the variability of bone fill in human extraction sockets. For example, one might expect to have significantly more dense bone present after extraction socket healing in the anterior area (single-rooted teeth) because the bone is usually denser in nature. However, the healed sockets in this study show similar percentages of vital bone in single- and multirooted healed sockets. This pilot study demonstrates the need for a much larger sample size to more accurately follow the trends in healing responses. Confounding factors, including socket location, use of different graft materials, use of membranes, type of flap closure (or nonclosure), and the presence and thickness of the bony walls of the sockets, prevent clear conclusions from being drawn from human socket studies. Therefore, at this point, based on the results of the present pilot study as well as the referenced literature, the operator must make clinical decisions based on the individual situations presented. Clearly, further research with a much larger sample size is indicated to isolate the previously mentioned variables to determine the best course of treatment after tooth extraction. IMPLANT DENTISTRY / VOI.UMK 13. NUMKS-;R 2 2004 159 CONCLUSIONS Extraction socket treatment with ABMA barriers produced more vital bone 6 to K months postextraction than did cPTFE membranes, whether placed over AH or nonahsorbable ABB mineral. The combination of ABMA covering ABB produced the greatest amount of vital bone at 6 to X months (4].7'7<) followed by ABMA covering AH (34.5%), ePTFE covering AH (27.67r), and cPTFE covering ABB 1 7.X'/f. Without primary ilap coverage over the extraction socket, I of K ABMA harriers and 6 of X ePTFE barriers had to be removed prematurely because of infection before the 6- to 8-month time period when implants were placed. This pilot study demonstrates the need for a much larger sample size to more accurately follow the irends in healing responses. ACKNOWLEDGMENTS The authors acknowledge the contributions of Hari Prasad. BS, MDT. Research Scientist, University of Minnesota Dental School, for his assistance with the hislologic preparation and histomorphonietric analysis. This study was supported by a grant from LifeCell, the Woodlands, TX. Disclosure The authors claim to have no financial interest in any company or any of the products mentioned in this article. REFERENCES 1. 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. 2. Lekovic V, Camargo P. Klokkevold P, et al. Preservation of alveolar bone in extraction sockets using bioabsorbable membranes. J Periodontol. 1998;69: 1044-1049. 3. Nemcovsky CE, Serfaty V Alveolar ridge preservation following tooih extraction of maxillary anterior teeth. Report on 23 consecutive cases. J Penoaontol. 1996:67:390-395. 4. Johnson K. A study of dimensional changes occurring in the maxilla following tooth extraction. Aust Prosthet J. 1969; 14: 241-244. 5. Johnson K. A study of dimensional changes occurring in the maxilla following closed face immediate denture treatment. Aust Prosthet J. 1969:14:371-376. 6. Abrams H, Kopczyk RA, Kaplan A. Incidence of anterior ridge deformities in partially edentulous patients. J Prosthet Dent. 1987:57:191-194. 7. Indovina A Jr, Block MS. Comparison 3 substitutes canine extraction sites. J Oral Maxillofac Surg. 2002:60:53-58. 8. Artzi Z, Tal H, Dayan D. Porous bovine bone mineral in healing of human extraction socket Part I histomorphometric evaluation at 9 month, J Periodontol, 2002:71:1015-1023. 9. Froum S. Cho SC. Rosenberg E. Histological comparison of healing extraction sockets implanted with b>oactive glass or demineralized freeze dried bone allograft: a pilot study. J Periodontol- 2002: 73:94-102. 10. Norton MR, Wilson J, Dental implants placed in extraction sites implanted with bioactive glass: human histology and clinical outcome. Int J Oral Maxillofac Implants, 2002:7:249-257. 11. Glickman RS, Bae R, Karlis V- A model to evaluate bone substitutes for immediate implant placement. Implant Dentistry. 2001:10:209-215. 12. Ashman A, Lopmto J. Placement of implants into ridges grafted with bio-plant HTR synthetic bone: hislological long-term case history reports. J Oral Implantol. 2000:6276-290. 13. Froum S, Orlowski W. Ridge pres ervation utilizing an alloplast prior to implant placement: clinical and histological case reports. Practical Periodontics AesthetDent. 2000:12:393-402. 14. Dies F, Etienne D, Abboud N, et al. Bone regeneration in extraction sites after immediate placement of an ePTFE mem brane with or without a biomaterial. A report on 12 consecutive cases. Clin Oral Imp Res. 1996:7:277-285. 15. Bartee BK. Extraction site reconstruction for alveolar ridge preservation. Part 2: membrane assisted surgical technique. J Oral Implantol. 2001:7:194-197. 16. Sy IP. Alveolar ridge preservation using a bioactive glass paniculate graft in extraction site defects. General Dentistry. 2002:51:66-68. 17. Anson D. Maxillary anterior esthetic extractions with delayed single-stage implant placement. Compendium of Continuing Education in Dentistry. 2002;23: 829-830. 833-836. 18. Camargo PM, Lekovic V, Weinlaender M. et al. Influence of bioactive glass on changes in alveolar process dimensions after exodontia. Oral Surg Oral Med Oral Pathol. 2000:90:581-586, 19. Becker W, Urist M. Becker B, et al. Clinical histological observations of sites implanted with intraoral autologous bone grafts or allografts. 15 human case reports. J Periodontol, 1996;67:1025-1033. 20. Becker W, Clokie C, Sennerby L, et al. Histoiogic findings after implantation and evaluation of different grafting materials and titanium micro screws into extraction sockets: case reports. J Periodontol. 1998:69:414-421. 21. Wainwright D, Madden M, Luterman A, et al. Clinical evaluation of an acellular allograft dermal matrix in full-thickness burns. J Burn Care Rehabil. 1996:17:124- 126. 22. Rhee PH, Friedman CD, Ridge JA, et al. The use of processed allograft dermal matrix for intraoral resurfacing: an alternative to split thickness skin grafts. Arch Otolaryngol Head Neck Surg. 1998:124: 1201-1204. 23. Wainright DJ. Use of an acellular allograft dermal matrix (AlloDerm) in the management of full thickness burn. Sums. 1995:21:243-248. 24. Silverstein LH, Callan DP. An acellular dermal matrix allograft substitute for palatal denor tissue. Postgrad Dent. 1996: 3:14-21. 25. Cailan DP. Silverstein LH. Use of acellular dermal matrix for increasing keratinized tissue around teeth and implants. Pract Periodont Aesthet Dent. 1998; 10: 731-734. 26. Shulman J. Clinical evaluation of an acellular dermal allograft for increasing the zone of attached gingiva. Pract Periodont Aesthet Dent. 1996:8:201-208. 27. Wei PC, Laurell L, Geivelis M, et al. Acellular dermal matrix allograft to achieve increased attached gtngival. Part 1: a clinical study. J Periodontoi 2000; 71:1297- 1305. 28. Tal H, Subgingival acellular dermal matrix allograft for the treatment of gingival recession: a case report. J Periodontol. 1999:70:1118-1124. 29. Henderson RD, Greenwell H, Drisko C. et al. Predictable multiple site root coverage using an acellular dermal matrix allograft. J Periodontoi. 2001:72: 571-582- 30. Aichelmann-Reidy ME, Yukna RA, Evan GH. et al. Clinical evaluation of acellular allograft dermis for the treatment of human gingival recession. J Periodontol. 2001:723:998-1005. 31. Novaes AB Jr, Gnsi DC, Molina GO, et al. Comparative 6-month clinical study of a sub epithelial connective tissue graft and acellular dermal matrix graft for the treatment of gingival recession J Periodontol. 2001:72:1477-1484. 32. Harris RJ. A comparative study of root coverage obtained with an acellular dermal matrix versus connective tissue grafts. Int J Periodontics Restorative Dent. 2000:20:51-59. 33. Tal H, Moses O, Zohar H, et al. Root coverage of advanced gingival l f > 0 l . X l k \< I K I N S i n M l . \ \ | i l \ l i ' [ A M \ ! I O \ i>|- H V D U O X Y A P A T I T K S recession: a comparative study between acellular dermal matrix allograft and sub epithelial connective tissue grafts. J Periodontol. 2002; 73:1405-1411. 34. Tal H. Ridge preservation and gingival augmentation using resorbable membranes, connective tissue grafts and dermal matrix: report of three cases. Independ Dent. 1998:3:96-100. 35. Fowler EB, Breault LG, Rebitski G. Ridge preservation utilizing an acellular dermal allograft and Deminerahzed freezedried bone allograft: part I. A report of 2 cases. J Periodontol, 2000:71:1353- 1359. 36. Fowler EB, Breault LG, Rebitski G. Ridge preservation utilizing an acellular dermal allograft and demmeralized freezedried bone allograft: part II, Immediate endosseous implant placement [erratum appears in J Periodontol 2000:71:1670]. 2000:71:1360-1364. 37. Rohrer MD, Schubert CC. The cutting- grinding technique for histological preparation of undecalcified bone and bone-anchored implants: improvement in instrumentation and procedures. OralSurg Oral Med Oral Pathol. 1972:74:73-78. 38. Donath K, Breuner G. A method tor the study of undecalcified bones and teeth with the attached soft tissues: the sage Schliff (sawing and grinding) technique. J Oral Pathol. 1982;11:318-326. 39. Froum SJ, Tarnow DP, Wallace SS, et al. Sinus floor elevation using anorganic bovine bone matrix {OsteoGraf/N} with and without autogenous bone: a clinical, histologic, radiographic, and histomorphometric analysis — part 2 of an ongoing prospective study. Int J Perio Rest Dent. 1998:18:528-543. 40. Schwartz-Arad D, Chaushu G. The ways and wherefores of immediate placement of implants into fresh extraction sites: a literature review. J Penodontol. 1997:68: 915-923. 41. Wilson TG Jr, Schenk R, Buser D, et al. Implants piaced in immediate extraction sites: a report of histology and histometric analyses of human biopsies. Int J Oral Maxlllofac Implants 1998:13:333- 341. 42. Becker W, Becker BE, Handelsman M, et al. Guided tissue regeneration for implants placed into extraction sockets: a study in dogs. J Periodontol. 1991 ;62: 703-709. 43. Akimoto K, Becker W, Persson R, et al. Evaluation of titanium implants placed into simulated extraction sockets: a study in dogs. Int J Oral Maxillofac Implants. 1999:14:351-360. 44. Covani U, Cornelini R, Barone A. Bucco-lingual bone remodeling around implants placed into immediate extraction sockets. J Periodontol. 2003:74:268-273. 45. Machtei EE, Schathorn RG. Successful regeneration of mandibular class II furcation defects: an evidence-based treatment approach. Int J Periodont Rest Dent. 1995:15:146-167. 46. Machtei EE, Dunford R, Grossi SG, et al. Gingival recession and exposure of barrier membrane: effect on guided tissue regeneration of class II furcation defects. Int J Peridont Rest Dent. 1995:15:591- 599. 47. Buser D, Bragger U, Lang NP, et al. Regeneration and enlargement of jaw bone using guided tissue regeneration. Clin Oral Impl Res. 1992; 1:22-32. 48. Jovanovic SA, Spiedermann H, Richter JE. Bone Regeneration around titanium dental in dehisced defect sites: a ciinicai study. Int J Oral Maxillofac Implants. 1992:7:233-245. 49. Mellonig JT, Triplett GR. Guided tissue regeneration and endosseous dental implants. Int J Periodont Rest Dent. 1993:13:109-119. 50. Lekholm U, Becker W, Dahlin C, et al. The role of early versus late removal of GTAM membranes on bone formation at oral implants placed into immediate extraction sockets. Clin Oral Impl Res. 1993: 4:121-129. 51. Nevms M, Mellonig JT. The advantages of localized ridge augmentation prior to implant placement: a staged event. Int J Periodont Rest Dent. 1994; 14:97-111. 52. Shanaman RH. The use of guided tissue regeneration to facilitate ideal prosthetic placement of implants. Int J Penodont Rest Dent. 1992:12:257-265. 53. Becker W, Becker BE. Guided tissue regeneration for implants placed into extraction sockets and for implant dehiscences: surgical techniques and case reports. Int J Periodont Rest Dent. 1990:5:377-391. 54. Shanaman RH. A retrospective study of 237 sites treated consecutively with guided tissue regeneration. Int J Periodont Rest Dent. 1994:14:293-301. 55. Simion M, Baldoni J, Zaffe D. Rigenerazione guidata dei tessuti in osteointegrazione (II). Siti post-estrattivi Rivista Italiana di Osteointegrazione. 1991: 1:40-45. 56. Lazzara RL. Immediate implant placement into extraction sites: surgical and restorative advantages. Int J Peno Rest Dent. 1989:9:333-343. 57. Wachtel H. Langford A, Bernimoulin JP, et al. Guided bone regeneration next to osseointegrated implants in humans. Int J Oral Maxillo Imp. 1991 ;6:127-135. 58. Jovanovic SA, Spiekermann H, Richter EJ, et al. Guided tissue regeneration around titanium dental implants. In: Laney WR, Tolman DE, eds. 77ssue Integration in Oral, Orthopedic and Maxillofacial Reconstruction. Quintessence; 1992: 208-215. 59. Becker W, Dahlin C, Becker BE, et al. The use of ePTFE barrier membranes for bone promotion around titanium implants placed into extraction sockets: a prospective multicenter study. Int J Oral Maxillo Imp. 1994;9:31-40. 60. Simion M, Baldoni M. Rossi P, el al. A comparative study of the effectiveness of ePTFE membranes with and without early exposure during the healing period. Int J Periodont Rest Dent. 1994:14:167-180. 61. Buser D, Dula K, Belser U, et al. Localized ridge augmentation using guided bone regeneration 9II). Surgical procedure in the mandible. Int J Periodont Rest Dent. 1995:15:11-29, 62. Jovanovic SA, Nevins M. Bone formation utilizing titanium-reinforced barrier membranes. Int J Periodont Rest Dent. 1995:15:57-69. 63. Nowzari H, Slots J. Microbiologic and clinical study of polytetrafluoroethylene membranes for guided bone regeneration around implants. Into J Oral Maxillo Imp. 1995:10:67-73. 64. Harris RJ. Soft tissue ridge augmentation with an acellular dermal matrix. Int J Periodont Rest Dent. 2003:23:87-92. Reprint requests and correspondence to: Stuart J. Froum, DDS 17 West 54th Street Suite 1 C/D New York, NY 10019 Phone: (212)586-4209 Fax:(212)246-7599 E-mail: dr.froum@verizon.net IMPLANT DKNTISTKY / VOLIMH 13, NUMBER 2 2(X)4 161 Abstract Translations [German, Spanish, Portugese, Japanese] AUTOR(EN): Stuart Froum, D.D.S.*, Sang- Choon ("ho, D.D.S.**. Nicolas Elian, D.D.S.***, Edwin Rosenberg D.D.S.#, Michael Rotarer, I).D.S.##. und IX-nnis Tamow. D.D.S.###. * Ktimscher Professor und Diri'kmr der Umischen Farschung, Aslmuai AbteUimg fur implantalgestitizte ZahnheUhmde, Umversisflt New York, Kriser Denlidzcntnon. New York, NY. ** KIUUMher Assiswnzprqfessor und Miif>lieil des wissenschaftUchen Forschungsteams, Ashman Abteihmg fiir imptantatgestiitzSe ZahnhdHande, Uruversitat New York, Kriser Dentalzentrum. New York. NY. *"* U'iler da intemattonalen Forschungsprogramms, Assistenzprqfessor, Ashman Abieihvig fur wiphuuatgestiitzle ZahnheUkunde, Universitai New York. Kriser lienhilzeninwi. New York, NY- # Professor fur Orthodontic und impkmiatgesiuizie '/jihnhet- Ikunde, Universiidt von Pennsylvania, Philadelphia, FA. M Professor uml Letter. Berekh fur Oral wui KieferpathoJogie, Umversiteil i on MiniH'sota. zithimwdizjnisihe Fakidtat, Minneapolis, MN. MM Professor und Vorsitzendcr, Ashman Abteihmg fiir implantatgestiitzte Zafmheilkunde, Vniversitiii New York, Kriser Dentalzenrrum, New York. NY. SchnftrrrkehrSnum .1. Froum. DOS, 17 West >4th Street, Suite I (711 New York, New York imi9. Telefon: 212 • 586 - 4209, Fax: 212 - 246 - 75W eMciil: drfirxim@verizpn.net Extraktwnshiihlen und die Implantation von Ilydruxylapalit mil Membranbarriere: eine histologische Studie ZVSAMMENFASSVNG: Kinluhrung: Zielset/ung dieser Pilotstudie war es, die Auswirkungen auf den Heilungspro/X'ss bei ExtraktionshOhlen zu untersiichen, wenn ein absorbierbares Hydroxylapalil (AH) und cin nichl absorbierbares anorganisches Rinderknoehenmineral (ARK) /ur Reaktion in dcr Mundhiihlc* belassen wcrden. Eine Bedeckunt; dieser Materialien mit entweder einem azelluliircn. hautsimkturicrlen Allnlransplanlal (AHSA) odcr einer erweiterten PolytetranuiiraLhylnicmbranhaiTierc (ePTFA) war vorgesehen. Materialien und Mflhoden: Bui Zahnexlraktionsbchandlungen an 15 Patienten mil mangelhaften Bukkalplalten von 5 mm cnlsiandcn insgesymi 16 ZahnhOhlcn. Nat'h deni Zutallsprin/ip erfolgte eine Aut'tcilung der I'alienten in vier Hehandlungsgruppen. I. AH bedeckl mil AHSA. 2. AH bedeckt mil einer ePTFA-Mc-mbran. 3. ARK bedeckt mil AHSA. und 4 ARK bedeckt mil einer elTFA-Membran. Bin Primariiber/ug wurde in keinum der Falle versucht b/.w. erreifht. Sechs bis achi Monait? naeh Zahnextraktion war die Implantatsetzung vorgesehen. Zu diesem Zeitpunkt wurden histulogische Kerne der behandeken Bereiche entnommen. Diese Kemstucke wurden weiter verarbeitet, mi! Stevenel-Blau / van Giesonschem Picrol'uchsin eingelarbl und millels histomorphokigischen Messungen analysiert. I'ro/entuale Anteile von vilalem Knochen, Gewebe und Mark sowic verbleibenden Transplantatartikeln in den Gesamtkernen wurden ermittell- Ergebnisse: Durchschnilllieh betrug der Anteil an vitalem Knochengewebe 34.5 It (AH mil AHSA). 41.7 % (ARK mil AHSA), 27,6 % (ePTFA und AH) und^l7.K % (ePTFA und ARK). In den mit AHSA bedeeklen acht Extraktionshohlen Canden sich durchschnittlich 38 % an vitalem Knochen, wahrend die weiLercn aeht, mit eFTFA-Membranbarrieren bedecklen Hohlen nur 22 c/r an vilalem Knochengewebe aufwiesen. Schlussfulgerun^cn: Augrund der geringen An/.ahl an Unlersuehungsproben innerhalb der vier Gruppen war keine statistische Analyse mOglich. Als Ergebnisse dieser Pilotstudie kiinnen aber die nach sechs- bis achtmonatiger Nachbehandlung weiiaus hoheren Anteile an vitalem Knochen in den mil AHSA bedeckten Behandlungsbereithen gegenuber den mit ePTFA bedeckten Stellen t'estgehalten werden. Hierbei spieiten die unit'rschiedliehen Knochenwiederherstellungsmatenalien koine Rolle. Es empfiehll sich, weiterluhrende Forschungen anzustellen, urn die innerhalb dieser Pilotstudie ermilielien Ergebnisse aut eine eventuell ahnlieh lautende Differenz bei KiK)ehengewebe-/u-lmplantat-Kon(akt nach erfolgter Irnplantatsetzung /u untersuchen, SCHLOSSELWORTER: Extrakiionshohle, Barrieremembran, histomorphoiogische Analyse, absorbierbares Hydroxylapatit, azellulares, haulsirukturiertes Allolrunsplantat lf.2 EXTRACTION SOCKHTS ASD IMPLANTATION oi" HYDROXYAPATIIKS AUTOR(ES): Stuart Froum. D.D.S.*. Sang Choon Cho. D.D.S.**. Nicolas Elian. D.D.S.***. Edwin Rosenberg. DJD.SJ, Michael Rohrer, D.D.S.##, y Dennis famow. D.D.S.###. *Profesor Clinico v Director de Investigation Ciinica, Departamento Adman de Odontoiogia tie Imphmtes. Universidad de Nueva York, Centra Denial Kriser, Nueva York, NY. ** Profesor Asisteme Clinico e htvestigador Cientifico. Departamenta Aslunan de Odontoiogia de Implantes, Universidad de Nueva York, Centra Dental Kriser, Nueva York, NY. **rDirector del Programa International, Profesor Asisteme, Departamento Ashman de Odontoiogia de Implantes. Universidad de Nueva York. Centra Dental Kriser. Nueva York, NY. # Profesor, Periodontica v Odortlologfa de bnplantes, Universidad de Pennsylvania, Philadelphia. PA. ## Profesor v Director, Division de pQtohgia Oral v Maxilofatial. Universidad de Minnesota. Facultad de Odontoiogia, Minneapolis. MX. ### Profesor v Jefe, Depariamento Ashnan de Odontoiogia de Implantes, Universidad dc Nueva York, Centra Denial Kriser. Nueva York, NY. Correspondedcia a: Sttuirt J. Froum, DDS. 17 West 54ih Street, Suite I C/D. New York. New York 1(1019. TeUfono: 2I2-5X6-42W, Fax: 212-246-7599. Correo electronico: dr. froum@verizon.net Lavidades de extraction e implantation de hidroxiapatitas con barrens de membranas: Un estudio histoldgico ABSTRACTO: Introduction: El proposito de este estudio piloio foe invesiigar el efecto en la curacion dc la cavidad de extraccion. cuando un mineral de hueso bovino anorganico (ABB por sus siglas en ingles) no absorbible y una hidroxiapalita absorhible (AH por sus siylas en ingles) recuhierlas con una barrens de memhrana de politetrafluoroelileno expandido (ePTEE) o aloinjetto de matriz dermica acelular (ADMA por sus siglas en ingles) se dejaion expuestas en la ca\id:id oial. Materinlt's y metudos: I.uego dc la extraccion del dicnte se dividieron aleatoriamente un total de 16 cavidades en I 5 pacientes con placas bucales defieienles de 5 mm en 4 grupos de traiamiento: 1. AH cubierta con ADMA; 2. AH cubierta con una memhrana de ePTFE: 3. ABB cuhierta con ADMA; 4. ABB cubierta con una membrana de ePTEE. l.a cobertura primaria no se intenlo ni se obtuvo en ninguna de las 16 cavidades tratadas. Seis a oeho meses luego de la extraecion en ei momento de la colocacion del implante, se obluvieron nucleos histologicos de los lugares de trataniiento. Estos nucleos fueron procesados, coloreadas con a/ul dc Sievenel/ picrol'ucsina de van Gieson y anali/:ados histomorfome'tricamente. El hucso vivo, lejido conectivo y medula osea, y partfculas residuales del injerto se ealcularon como porcentaje del nucleo total, Resultados: La mediana do hucso vivo fuc de 34,5% (AH con ADMA). 41.795- (ABB con ADMA). 27.6% (ePTFE y AH) y I7.K7, (ePTFE y ABB). El porcenlaje promedio dc hueso vivo en las 8 cavidades cubiertas con ADMA I'uc del 389r comparado con un porcentaje promedio dc hueso vivo del 22% en las 8 cavidades cubiertas con barreras de membrana de eFTFE. Conclusiones: Debido al pequeno ntimero de especinteaes en lo.s 4 grupos. no tue posihle reali/ar un analisis estadfstico. Sin embargo, en esle esludio piloto. los sicios cuhicrtos con ADMA resultaron en una mayor presencia de hueso viso a los 6 a 8 meses luego del tratamiento de la cavidad que los obtenidos en los silio.s cubiertos con ePTFE independientemente de los maleriales de reemplazo del hueso usados. Se neccsiian investigaciones adicionales para determinar si esios resultados muestran una diferencia similar en el contacio enire el hueso y los implantes luego de la colocacion del implante. PAIABRAS CIAVES: Cavidad de extraccion, barrera dc membrana, analisis histomor- I'ometrico. hidroxiapatita absorhible. aloinjerto de matriz dermica acelular. AUTOR(ES): Stuafl Froum. Doulor em Ciencia Dentaria*. Sang-C'hoon Cho, Doulorem Cieneia Dentana**. Nicolas Elian. Doutor cm Cieneia Dent&ia***, Edwin Rosenberg. Doutor em Cieneia Dentari;i#. Michael Rohrer, Doutor em Cieneia Deniaria## e Dennis Tarnow. Doutor cm Cieneia Dentdria###. "Professor Clinico e Diretorde Pesquisa Climca. Depanamento Ashman de ()doniolo\>ia de l>>iphtnw\, Umversidade de Nova York, Centra Odontoldgico Kriser, Nova York, NY. **Professor Assisleute Clinico e (ieniisiu de Pesquisa, Departamento Ashman de Odontoiogia de Implantes. Universidade de Nova York, Centra Odonlalagico Kriser, Nova York, NY. ***Diretor de Programa Inteniacional. Professor Assistente. Departamento Ashman de Odontoiogia de Implantes, Universidade de Nova York, Centra Odontologtco Kriser. Nova York, NY. if Professor de Periodontia e Odontolagia de Implanles, Universidade da Pensilvania, Filadelfur PA. ##Professor e Diretor. Divisao de Patologia Oral e Maxilojhcial. Universidade de Minnesota, Escola de Odontoiogia, Minneapolis, MN. tffitfProfessor e Chefe, Departamento Ashman de Odontoiogia de Implantes, Universidade de Nova York, CentroOdontologico Kriser, Nova York. NY. Correspondenaa para: Smart J. Froum, DDS. 17 View 54th Street. Suite I C/D. New York, New York HH)!9. Teiefone: 212SH6-4209. Fax: 212- 246-75W. E-mail: dr.froum@verizon.net Cavidades de Extra$ao e Implante de Hidroxiapatitas com Membranas Protetoras: urn Estudo Histologico RESVMO: Intrt>duvao: O objetivo deste estudo-griloto era invesiigar o et'eito na cura da cavidade de cxtracao, quando uma hidroxiapatita absorvfvel (AH) e um mineral de osso bovino anorganico nao-absorvivel (ABB) coberto ou com enxerto aloplastico de main/ dcrmica acelular (ADMA) ou com uma membrana protetora de politetraftuoreiileno expandido (cPTFE) eram deixados expostos a cavidade oral. Material's e Metodos: Apos a extra^ao dentaria, um lotal dc 16 al veolos em 15 pacientes com placas bucais deficients de 5 mm era dividido alealoriamente em 4 grupos de tratamento. 1. AH coberto com ADMA. 2. AH coberto com uma membrana ePTFE. 3. ABB coberto com ADMA. 4. ABB coberto com uma membrana cPTEE. A cobertura primaria nao I'oi tentada ou obtida em nenhum dos 16 alveolos iratados. Seis a oilo meses apos a extracao por ocasiao da colocaeao do implanie. niicleos hislologicos dos locais do tratamento foram obtidos. Estes nucleos foram processados, manchados com azul dc Stevenel/picrofucsina de van Gieson e analisado.s histomori'ometricamenie. Osso vital, tecido conjuntivo c medula. bem como parti'culas <Je enxerto residual t'oram relaladas como porcentagem do nucleo lotal. Resultados: O osso vital medio era 34.5% (AH com ADMA). 4117'A- (ABB com ADMA. 27.6'/, (ePTFE e All) L- I 7.*'.; (el'TFH e ABB) A porcenlagem media de osso vital nos 8 alveolos cobertos com ADAMA era de 38%, em comparacao com uma porcenlagem media de osso vital dc 22r/r nos S alveolos cobenos com membranas protetoras cFTFEI. Conclusoes: Devido ao pequeno numero de especimes nos 4 grupos. a analise esiaitstica nao I'oi possi'vel. Coniudo. nesie estudo-piloto. locais cobertos com ADMA resultaram em mais osso vital presente 6 a 8 meses apos o tratamento do alveolo do que o obiido no iocais cobertos com ePTFE, independente dos materiais para troca de osso usadov Justillca-se pesquisa adicional para veridcar se esles resullados mostram diferenca desse tipo no contaio osso/implante apos a colocacSo do implante PA1A VRAS-CHAVE: Extraction socket, memhrana protetora. analise hislomorfometriea. hidroxiapatitas absovfveis, enxerto aloplaslico de main/ dermica acelular IMPLANT DKNTISTRY / VOLUME 13, NUMBER 2 2004 163 tt-Mffitmembrane barriers^ ft'-•? t Fu*3'T'tfi*{ h«H '>-??> h ft ft : X-^i-7'— I- 7aWv. DDS*. +)->--f x - > -f a - , DDS**. - 3 7 ^ ' 1 ' I 7 > DD5~, x K ^O D—tf>M-/. DDS'. T-f ^/U • u - 7 - , DDS". r - X ft—J—% DDS >i- (ADMA) > (ePTFE) l c J : o r a « S i i t t (All) 3: £U:2Effl»iR«Klf anorganic ^Wmineral (ABB) A' m : Buccal pkne^Smm t = F ^ ^ I. ADMA&SWAH, 2. ePTFE1Saf©AH, 3. t «aii*(42tt/16»ffi'fi'^!(J, primary C. ffiI as»il»¥WR(8fS!***^HK ?*tfc. C i t f. (7)R m mSB*a;S!t«?*i, Stevencl . ftm. nif-gJB®g**i-e*i*!, iqs sts4-c £ y>s % ^ *^EMS 5 *it„ W* : 'I.m±t"£j34..:;% (AHtADMA), 41.7% (ABBtADMA), 27.6% (ePTFEtAH). 17.8% i v i " i l i t ABU) eP III-. membrane . WfiftHV ( - 5?- F : ft B » . barrier membrane, ffl«®liSJ-iftl*»J^«f, Ili^'l'iWfl-1 mmmnr 7 f r. -^>^J^^~ ffli ' (ihli'A: : Stuart J. Froum. DDS, 17 West 54ih Street. Suite I ( !>. Nen York. AT Will!) •U,$ . 212-586-4209 -7T/?7. . 212-246-7599 £*—* . drfroum@verizoiuiet 164 EXTRACTION SOCKETS AND IMPLANTATION OF HYDROXYAPATITES