JADA Continuing Education
Human mineralized bone in extraction sites before implant placement
Preliminary results
MICHAEL S. BLOCK, D.M.D.,
ISRAEL FINGER, D.D.S. and
ROBERT LYTLE, D.D.S.
 |
ABSTRACT
|
|---|
Background. Bone loss after tooth extraction may prevent dental implant placement. Human mineralized bone grafts can be used to restore bone volume and allow for tooth replacement with dental implants.
Methods. The authors grafted 22 sites in 18 patients with human mineralized bone after tooth extraction. They allowed molar sites 16 weeks for graft healing, placed the implants and restored them with a final crown after a four-month integration period. Single-rooted maxillary sites received implants and immediate placement of provisional crowns or underwent a delayed two-stage restoration approach. The authors used radiographs and clinical examinations to evaluate the results.
Results. All of the sites were restored successfully with a single-tooth implant restoration. Periapical radiographs indicated that the crestal bone levels were limited to the first thread of the implants or slightly coronal to the first thread of the implant. Clinical evaluation indicated excellent gingival health around the provisional and final restorations, without obvious gingival migration.
Conclusions. The use of human mineralized bone may have significant potential to reconstruct missing bone resulting from tooth extraction and to preserve bone after tooth extraction. In addition, healed bone graft sites seem to be able to support immediate placement of a provisional crown and implant restorations.
Clinical Implications. Patients who are having teeth extracted may become candidates for implant restorations when the sites are appropriately grafted to preserve and reconstruct bone volume, thus allowing for more options for reconstructing the missing tooth site.
After tooth extraction, labial or facial bone loss may be significant, resulting in less-than-ideal bone being available for implant placement. Horizontal or vertical deficiency with loss of interseptal, mesial or distal bone also may occur, depending on the etiology leading to tooth extraction, such as severe periodontal disease or chronic bone loss from tooth fracture. Even after a "clean" extraction, bone loss may be unpredictable, resulting in limitation of ideal implant placement.
Human mineralized bone can preserve or recreate an extraction site’s bone bulk in preparation for implant placement without adjunctive grafting procedures.
In an effort to preserve and create sufficient bone for implant placement after mandibular molar extraction, we have used human mineralized cancellous bone (Puros, Sulzer Dental, Carlsbad, Calif.) as a graft material. For mandibular molar sites, we have used advancement flaps to achieve primary closure, without the use of membranes or collagen. This technique has allowed for successful placement of implants in molar sites that otherwise may not have had satisfactory amounts of bone for ideal implant placement.
Mineralized bone allografts have been used for a variety of applications. Because bone contains organic and inorganic material, the cellular reaction to the pro cessed mineralized bone is dependent on the specific method of processing. Becker and colleagues1 demonstrated that mineralized bone obtained from a bone bank without removal of the organic matrix may not have an adverse antigenic response when implanted.
To preserve alveolar bone width and height for implant placement or for prosthetic concerns, allografts, xenografts and alloplasts have been used to graft extraction sites. The alloplasts used include synthetic forms of calcium phosphate materials including dense and porous hydroxylapatite2 and similar types of materials.3,4 These materials have proven useful in retaining alveolar bulk; however, they are very slow to resorb because of their chemical characteristics. We searched the literature and could not find clinical trials indicating the efficacy of this class of materials in preserving extraction site bone, resulting in there being bone available for implant integration.
Xenografts are harvested from nonhuman species, typically bovine, and are processed to remove their antigenicity using various chemical and preparation techniques. Xenografts have been used successfully for the preservation of extraction site bone5; however, in our experience, at four months the graft particles are present without signs of resorption or replacement.
To decrease adverse cell reaction to implanted mineralized bone and to have a source more easily obtained than human material, deproteinized bovine bone, or DBB, material was developed for use as a bone graft substitute. DBB is an anorganic, pathogen-free bovine bone that is a carbonate-containing apatite. It has a crystalline architecture and calcium phosphate ratio similar to that of natural human bone. Bovine-derived cortical mineralized material has been shown to have excellent osteoblast adhesion,6,7 to promote bone formation in critically sized calvarial defects,8 and to support bone formation around teeth and endosseous implants and in ridge augmentation.9–11 The absence of proteins has resulted in minimal immune response in vivo.12,13 Use of DBB in bone defects or extraction sites has resulted in bone fill with an appearance similar to that of control sites, with bone filling the extraction site.5,14–20 DBB has been used to graft small defects between the implant and the labial bone, in conjunction with immediate placement of implants in extraction sites.21 Animal studies have indicated that when there is a space or void between the implant and the walls of the extraction site, the space can be grafted successfully, resulting in excellent bone contact to the implant.22–28 The resorption rate of bovine cortical bone is slow, with the bovine cortical bone being present after 18 months in situ.15,16,21
Allografts such as demineralized freeze-dried bone and solvent-dehydrated mineralized bone have been advocated by manufacturers for use in extraction sites because of their osteoconductive nature and the fact that they will resorb and be replaced within a relatively short period, depending on their density and preparation technique. The use of a solvent-dehydrated mineralized bone to preserve bone height and bulk with eventual implant placement is illustrated in the patients in our study.
Soft tissue such as dura mater or fascia lata have been processed with a solvent dehydration technique and are well-tolerated.29,30 Before applying the solvent dehydration method to bone, cancellous bone is harvested from donors who are free of transmissible diseases. The bone is delipidized with acetone, and an osmotic treatment is performed to remove cells and lower the bone’s antigenicity. An oxidative treatment destroys the remaining proteins and minimizes graft rejection by inactivating enzymes. The bone then is dehydrated by solvents, which remove water from the tissue and further disinfect the bone. The process is concluded by limited dose of 
irradiation.31
The cellular reaction to bone processed using the solvent dehydration method has been assayed in animal models. Primary periosteal osteoblast adhesion and measured cell activities were better with the solvent dehydration bone than with controls.32 In an animal model designed to evaluate bone healing, 84 cylindrical bone defects were created in the femoral condyles of rabbits.33 Grafts included cryopreserved cancellous bone, solvent-dehydrated, -irradiated human bone or bovine bone. There were no differences between cryopreserved and solvent-dehydrated irradiated bone. The solvent-dehydrated group showed isolated osteoclast foci starting the remodeling process at four weeks. At eight to 12 weeks, the marrow in the defects had the appearance of secondary mature marrow with fat and hematopoietic cells. At 26 weeks, the human mineralized solvent-dehydrated bone graft was not apparent in all but one animal.
Solvent-dehydrated mineralized bone allografts have been used to repair long bone defects resulting from trauma and for prosthetic revision. 34 The preliminary conclusions were that human dehydrated and chemically extracted bone yielded very positive results. In the maxillofacial region, small clinical series have reported using solvent-dehydrated mineralized bone for the treatment of cyst defects and for ridge augmentation.35 Twenty-eight patients were treated for repair of cystic defects. Successful clinical results were reported, with bone filling the defects. In another study of 18 patients, nine sandwich and nine onlay grafts were performed using solvent-dehydrated mineralized bone alone. 36 Fifteen cases were successful, and three failed with loss of graft.
Because of the excellent bone response to this type of allograft, we believe that human mineralized bone can be used to preserve and reconstruct bone after tooth extraction and before implant placement. We conducted a preliminary study to test this theory. We do not include long-term follow-up results in this preliminary report.
|
MATERIALS AND METHODS
|
|---|
Population studied.
We enrolled patients in this study if they had a tooth in need of extraction, if their remaining dentition was in good repair with no active periodontal disease and if they were not immunocompromised. We followed 22 sites in 18 patients (four male, 14 female) to the completion of implant placement and restoration. There were 15 single-rooted maxillary tooth sites, six mandibular molar sites and one maxillary molar site.
For molar sites or single-rooted tooth sites with thin or missing cortical bone that had minimal bone available for stabilization of an implant, we placed a human mineralized bone graft and then placed the implant 16 weeks later. For single-rooted tooth sites with intact labial bone and apical bone available for initial stabilization of the implant and relatively healthy gingiva around the tooth to be extracted, we placed implants at the time of extraction. If the implant was placed immediately into an extraction site and there was a gap greater than 1 millimeter between the implant and the labial cortical bone, we placed a human mineralized bone graft into the gap. The technique we used is similar to that presented by Sclar.5
Technique.
Mandibular molar sites.
At the time of tooth extraction, we used an inferior alveolar nerve block combined with local infiltration into the mucosa surrounding the mandibular molar to provide anesthesia, hemostasis and hydropic dissection. We made a sulcular incision with anterior and posterior vertical release incisions to mobilize a flap for primary coverage after the graft was placed. With the full-thickness flap raised, we extracted the tooth, thus minimizing bone removal (Figure 1
). We removed soft-tissue remnants with a curette. Before placing the graft material, we made periosteal releasing incisions to release the flap and allow for a tension-free primary closure of the extraction site.
View larger version (99K):
[in this window]
[in a new window]
|
Figure 1. The mandibular right first molar had significant bone loss necessitating extraction. A sulcular incision was combined with vertical release incisions, exposing the lateral aspect of the tooth. Note the extensive bone loss involving the entire labial cortex to the apexes of the molar.
| |
We filled the extraction sockets with the graft material (Figure 2) using approximately 0.5 to 1 cubic centimeter of the 250 to 1,000 micrometer-sized particles. Among the seven molar sites, five required the labial bone height to be re-established secondary to severe periodontal disease. We removed excess fluid from the grafted site with gauze and gentle pressure to stabilize the graft for flap closure. We closed the mucosa flap primarily using 4-0 nonresorbable sutures; we did not use membranes. Patients were placed on antibiotics for one week.
View larger version (100K):
[in this window]
[in a new window]
|
Figure 2. The lingual cortex was intact; however, the labial cortex and meduallary bone were gone. Approximately 1 cubic centimeter of human mineralized bone was compacted firmly into the site.
| |
We took radiographs after 14 weeks to confirm bone consolidation and to help plan implant placement. The grafted sites appeared to have sufficient ridge width for the placement of wide-diameter implants and to have sufficient ridge height for the placement of implants at least 10 mm in length (Figure 3 and Figure 4). In five sites, we placed a provisional crown immediately after implant placement and a final crown after four months (Figure 5).
View larger version (99K):
[in this window]
[in a new window]
|
Figure 4. An abutment prepared on a preoperative model was placed into the implant. A provisional crown was placed and cemented; it was not in occlusal contact with the opposing dentition.
| |
Maxillary single-rooted tooth sites.
We administered local anesthetic in the labial and palatal tissue adjacent to the tooth to be extracted. We used a 15C blade to make a sulcular incision around the tooth and a periotome instrument to separate the bone from the tooth’s labial surface carefully. We atraumatically removed the tooth root being careful to avoid removing the labial cortex; the labial cortex was intact in six of 15 sites (Figure 6). We placed implants with their axes slightly palatal to the incisive edge of the planned restorations. Gaps greater than 1 mm between the implant and the cortices were grafted with mineralized bone particles and provisional restorations were placed.
View larger version (61K):
[in this window]
[in a new window]
|
Figure 6. Sulcular incisions were made and two central incisors were removed. There were 8 to 10 millimeters of labial bone missing after the extractions.
| |
In 12 sites, there were labial cortex defects ranging from 4 mm to the entire labial cortex. We firmly compacted up to 1 cc of mineralized bone in these sites (Figure 6
and Figure 7). We placed a piece of collagen (Collaplug, Sulzer Dental) over the site and approximated the gingival margins to the collagen with a horizontal mattress suture. We placed a temporary restoration to preserve the contour of the papilla and to form a sulcus for the final restoration. After 16 weeks, we used a tissue punch to remove a circular piece of gingiva and placed implants into the consolidated graft (Figure 8, page 1636). We then placed a provisional restoration (Figure 9, page 1636) and took periapical radiographs sequentially to monitor bone and implant healing (Figure 10, page 1637).
View larger version (69K):
[in this window]
[in a new window]
|
Figure 7. The extraction sites in which approximately 0.5 cubic centimeter of human mineralized bone was compacted gently.
| |
View larger version (55K):
[in this window]
[in a new window]
|
Figure 8. After 16 weeks, implants were placed after a 3.5-millimeter–diameter tissue punch removed a circular patch of crestal gingiva.
| |
Immediate provisional crown placement protocol.
Before surgery, the restorative dentist (I.F.) obtained diagnostic casts of the patient’s teeth. The restorative dentist removed the proposed tooth to be extracted from the cast. He waxed a planned restoration on the model and fabricated an acrylic surgical guide stent. Using the stent, he drilled a hole into the cast, placed an implant analog and secured it with cement and stone. The restorative dentist chose an abutment and modified it as necessary. A provisional crown was processed with an occlusal hole to allow for access to the abutment screw and for cement release. The restorative dentist modified the occlusion to prevent loading in any movement of the jaws. For central incisor sites, a bite-opening appliance was fabricated to prevent occlusal loading.
At the time of surgery, the surgeon (M.S.B.) oriented the implant similar to the orientation of the implant analog in the diagnostic model. He placed the implant at the correct depth to avoid excessive countersinking, placed the abutment and tried in the provisional crown. If necessary, he modified the provisional crown out of the mouth until occlusion and fit were passive. He then cemented the provisional crown with temporary cement (zinc oxide, no eugenol), checked occlusion to ensure that there was no loading and placed sutures if necessary.
The patients were seen weekly until the immediate effects of surgical intervention were asymptomatic. The surgeon allowed four months for integration and then exposed the implants if provisional crowns had not been placed immediately after the implants were placed. Final restorations were fabricated using cement retention.
Evaluation.
Clinical evaluation included assessment of the soft tissue and ridge contour, including the establishment of integration and functional occlusion with the final restoration. We took routine panoramic and periapical digital radiographs at the time of extraction and implant placement and after the final restoration. We used the radiographs to qualitatively evaluate bone healing and to quantitate the crestal bone level movement. The radiographic images were printed and evaluated by an independent examiner (R.L.), who was not involved in the treatment of these patients.
We used the distance between the threads of the implants to calibrate the bone levels. A caliper was set to one thread distance (0.64 mm), and we recorded the distance from the top of the shoulder of the implant as negative when coronal to the top of the implant shoulder and positive when apical to the shoulder. We recorded the number of threads to the nearest half-thread. We used these values to calculate the movement of the crestal bone on the mesial and distal surface of the implant, comparing baseline (placement) with final restoration.
|
RESULTS
|
|---|
Clinical evaluation.
Molar sites.
The primary closures of the molar sites healed uneventfully. Immediately after release of the flap and primary closure, the vestibule was partially obliterated. By 16 weeks, however, the vestibules had reestablished their original form. The shapes of the ridges were broad with sufficient vertical height for implant placement. All of the molar sites had implants placed 16 weeks after tooth extraction and graft placement.
Four months after the extraction sites had received grafts, we placed the implants. At the time of implant placement, the ridges were "bone-hard" and resisted needle penetration. At the time of implant placement when flaps were raised, the human mineralized cancellous bone grafts appeared similar to native bone with small remnants of the original grafts visible. The graft was very firm, and the drill encountered substantial resistance indicating dense bone formation within the grafted site.
Five molar sites followed a delayed traditional two-stage implant restoration protocol, with implant exposure taking place at four months for implant integration. We placed final restorations within two months of implant exposure.
Two sites had provisional, nonfunctional crowns placed on abutments that were secured to the implants immediately on implant placement. These two implants integrated, and we placed final restorations after four months of healing. The final restorations were pain-free and able to withstand chewing of normal textured food.
Maxillary single-rooted tooth sites.
All of the graft sites healed, and the original ridge forms were retained without the presence of infection. The root prominence of the anterior maxillary sites was re-established even when there was no labial cortex present at the time of the graft.
Twelve sites had significant labial bone defects. These sites were grafted and were allowed to heal for 16 weeks before implant placement. After three weeks, we found complete epithelialization across the single-rooted sites, which had been covered with a collagen material. At 16 weeks, the grafted sites appeared to be bone-hard and filled with bone; minimal remnants of the graft material were present. Subjectively, the resistance to drilling was similar to that of native, edentulous bone. Of these 12 implants, eight followed a two-stage implant placement protocol because of the restorative dentist’s preference and experience, and four required provisional crowns were to be placed at the time of implant placement surgery.
Three sites had sufficient bone present to allow for implant placement at the time of extraction; however, they each had more than a 1-mm gap between the implant and labial bone. These gaps were grafted with human mineralized cancellous bone. Provisional crowns were placed in two of these sites at the time of implant placement, and one site followed a two-stage protocol.
All of the implants placed in the grafted extraction sites integrated and have been restored with a final cemented restoration. None of the cases required additional grafting at the time of implant placement.
Radiographic evaluation.
Radiographs revealed that immediate implant placement resulted in bone at or coronal to the first thread of the implant. At the time of final restoration (four months after implant placement), all of the implants had bone at the level of the first thread and no crestal bone changes more apical than the first thread. We did not see radiolucency at the crestal or apical bone levels, and we did not find a radiolucent seam on these implants.
The average mesial crestal bone level was –0.66 ± 0.67 mm (range 0 to –1.27 mm) at implant placement and 0.51 ± 0.41 mm (range 0 to –1.91 mm) at final restoration. The average distal crestal bone level was –0.48 ± 0.68 mm (range 0.64 to –1.91 mm) at implant placement and was 0.48 ± 0.53 mm (range 0 to 1.27 mm) at final restoration. A measurement of 1.27 mm from the top of the shoulder of the implants correlated to the level of the first thread of the implant.
|
DISCUSSION
|
|---|
Patients who are scheduled to have a tooth extracted may want to replace the tooth. The traditional method has been a fixed partial denture based on the adjacent teeth. With the success of endosseous implants, a single-tooth implant restoration now is a viable option for the patient. After a tooth is extracted, however, resorption of the labial cortical bone can occur and prevent implant placement. In these situations, adjunctive bone grafting may be necessary, but it may increase expense and patient morbidity.
Unpredictable bone loss after tooth extraction or the presence of extensive bone loss at the time of tooth extraction may prevent successful implant placement or necessitate adjunctive hard- or soft-tissue grafting. Using human mineralized bone to graft osseous defects immediately after tooth extraction results in a site that can receive an implant, without the need for bone grafting using ramus, chin or other donor sites.
We do not present long-term results in this preliminary report. Instead, we provide information on a promising technique that may benefit patients. In our short-term experience, bone height has been maintained throughout early loading. From that time forward, we expect it to follow conventional crestal bone level patterns.
When confronted with a molar extraction site with significant bone loss occurring before the extraction, using a graft material that will preserve or recreate bone in the planned implant site is advantageous. The human mineralized bone we evaluated provided a site that allowed implant and immediate provisional crown placement.
|
CONCLUSIONS
|
|---|
Our short-term results indicate that restoration of extraction sites using human mineralized bone has potential. It can preserve or recreate an extraction site’s bone bulk in preparation for implant placement without adjunctive grafting procedures.
View larger version (117K):
[in this window]
[in a new window]
|
Dr. Block is a professor, the director of residency training and interim head, Department of Oral and Maxillofacial Surgery, Louisiana State University Health Sciences Center School of Dentistry, 1100 Florida Ave., New Orleans, La. 70119. Address reprint requests to Dr. Block.
| |
View larger version (121K):
[in this window]
[in a new window]
|
Dr. Finger is a professor and the director of residency training, Department of Prosthodontics, Louisiana State University Health Sciences Center School of Dentistry, New Orleans.
| |
|
FOOTNOTES
|
|---|
Dr. Lytle is a resident, Department of Oral and Maxillofacial Surgery, Louisiana State University Health Sciences Center School of Dentistry, New Orleans.
Dr. Block received a grant from Centerpulse Dental (formerly Sulzer Dental), Carlsbad, Calif., in support of this study.
|
REFERENCES
|
|---|
- Becker W, Urist M, Becker BE, et al. Clinical and histologic observations of sites implanted with intraoral autologous bone grafts or allografts: 15 human case reports. J Periodontol 1996;67:1025–33.[Medline]
- Kent JN, Jarcho M. Ridge augmentation procedures with hydroxylapatite. In: Fonseca RJ, Davis WH, eds. Reconstruction preprosthetic oral and maxillofacial surgery. Philadelphia: Saunders; 1995:853–936.
- Ashman A, Lopinto J. Placement of implants into ridges grafted with bioplant HTR synthetic bone: histological long-term case history reports. J Oral Implantol 2000;26(4):276–90.[Medline]
- Ashman A. Postextraction ridge preservation using a synthetic alloplast. Implant Dent 2000;9(2):168–76.[Medline]
- Sclar AG. Preserving alveolar ridge anatomy following tooth removal in conjunction with immediate implant placement: the Bio-Col technique. In: Block MS, Sclar AG, eds. Atlas of oral and maxillofacial surgery clinics of North America. Philadelphia: Saunders; 1999;39–60.
- Klinge B, Nilveus R, Kiger RD, Egelberg J. Effect of flap placement and defect size on healing of experimental furcation defects. J Periodontal Res 1981;16:236–48.[Medline]
- Spector M. Anorganic bovine bone and ceramic analogs of bone mineral as implants to facilitate bone regeneration. Clin Plast Surg 1994;21:437–44.[Medline]
- Schmitt JM, Buck D, Bennet S, et al. Assessment of an experimental bone wax polymer plus TGF-beta 1 implants into calvarial defects. J Biomed Mater Res 1998;41:584–92.[Medline]
- Camelo M, Nevine ML, Schenk R, et al. Clinical, radiographic, and histological evaluation of human periodontal defects treated with Bio-Oss and Bio-Guide. Int Periodontics Restorative Dent 1998;18:321–31.
- Haas E, Mailath G, Dortbudak O, Watzek G. Bovine hydroxyapatite for maxillary sinus augmentation analysis of interfacial bond strength of dental implants using pull-out tests. Clin Oral Implants Res 1998;9:117–22.[Medline]
- Valentini P, Abensur D. Maxillary sinus floor elevation for implant placement with demineralized freeze-dried bone and bovine bone (Bio-Oss): a clinical study of 20 patients. Int J Periodontics Restorative Dent 1997;17:233–41.
- Chiapasco M, Gatti C, Rossi E, Haefliger W, Markwalder TH. Implant-retained mandibular overdentures with immediate loading: a retrospective multicenter study on 226 consecutive cases. Clin Oral Implants Res 1997;8:48–57.[Medline]
- Schlickewei W, Paul C. Experimentelle Untersuchung zum Knochenersatz mit bovinen Apatit. In: Huggler AH, Kuner E, eds. Aktueller Stand beim Knochenersatz. Berlin: Springer; 1991:59–69.
- Klinge B, Alberius P, Isaksson S, Jonsson J. Osseous response to implanted natural bone mineral and synthetic hydroxylapatite ceramic in the repair of experimental skull bone defects. J Oral Maxillofac Surg 1992;50:241–9.[Medline]
- Berglungh T, Lindhe J. Healing around implants placed in bone defects treated with Bio-Oss: an experimental study in the dog. Clin Oral Implants Res 1997;8:117–24.[Medline]
- Wetzel AC, Stich H, Caffesse RG. Bone apposition into oral implants in the sinus area filled with different grafting materials: a histological study in beagle dogs. Clin Oral Implants Res 1995;6:155–63.[Medline]
- Hammerle CHF, Olah AJ, Schmid J, et al. The biological effect of natural bone mineral on bone neoformation on the rabbit skull. Clin Oral Implants Res 1997;8:198–207.[Medline]
- Yildirim M, Spiekermann H, Biesterfeld S, Edelhoff D. Maxillary sinus augmentation using xenogenic bone substitute material Bio-Oss in combination with venous blood: a histologic and histomorphometric study in humans. Clin Oral Implants Res 2000;11:217–29.[Medline]
- Indovina A Jr, Block MS. Comparison of 3 bone substitutes in canine extraction sites. J Oral Maxillofac Surg 2002;60:53–8.[Medline]
- Dudziak ME, Block MS. Immediate ridge preservation with anorganic bovine bone following tooth extraction. J Oral Maxillofac Surg 2001;59(8 supplement 1):103–4.
- Van Steenberghe D, Callens A, Geers L, Jacobs R. The clinical use of deproteinized bovine bone mineral on bone regeneration in conjunction with immediate implant installation. Clin Oral Implants Res 2000;11:210–6.[Medline]
- Barzilay I, Graser GN, Iranpour B, Natiella JR. Immediate implantation of a pure titanium implant into an extraction socket: report of a pilot procedure. Int J Oral Maxillofac Implants 1991;6(3):277–84.[Medline]
- Barzilay I, Graser GN, Iranpour B, Proskin HM. Immediate implantation of pure titanium implants into extraction sockets of Macaca fascicularis, I: clinical and radiographic assessment. Int J Oral Maxillofac Implants 1996;11(3):299–310.[Medline]
- Block MS, Kent JN. A comparison of particulate and solid root forms of hydroxylapatite in dog extraction sites. J Oral Maxillofac Surg 1986;44(2):89–93.[Medline]
- Block MS. Placement of implants into extraction sites. In: Block MS, Kent JN, eds. Endosseous implants for maxillofacial reconstruction. Philadelphia: Saunders; 1994.
- Corso M, Sirota C, Fiorellini J, Rasool F, Szmukler-Moncler S, Weber HP. Clinical and radiographic evaluation of early loaded free-standing dental implants with various coatings in beagle dogs. J Prosthet Dent 1999;82(4):428–35.[Medline]
- Henry PJ, Tan AE, Leavy J, Johansson CB, Albrektsson T. Tissue regeneration in bony defects adjacent to immediately loaded titanium implants placed into extraction sockets: a study in dogs. Int J Oral Maxillofac Implants 1997;12:758–66.[Medline]
- Lum LB, Beirne OR, Curtis DA. Histologic evaluation of hydroxylapatite-coated versus uncoated titanium blade implants in delayed and immediately loaded applications. Int J Oral Maxillofac Implants 1991;6(4):456–62.[Medline]
- Groutz A, Chaikin DC, Theusen E, Blaivas JG. Use of cadaveric solvent dehydrated fasia lata for cystocele repair: preliminary results. Urology 2001;58(2):179–83.[Medline]
- Yetiser S, Tosun F, Satar B: Revision myringoplasty with solvent-dehydrated human dura mater (Tutoplast). Otolaryngol Head Neck Surg 2001;124(5):518–21.[Medline]
- Sulzer Dental. Tutoplast method. Carlsbad, Calif.: Sulzer Dental; 2001.
- Hofmann A, Hofmann C, Gotzen L. Effect of various bone disinfection and sterilization methods on osteoblast function: a comparative in vitro study. Unfallchirurg 2000;103(5):380–8.[Medline]
- Gunther KP, Scharf H-P, Pesch H-J, Puhl W. Osteointegration of solvent preserved bone transplants in an animal model. Osteologie 1996;5(1):4–12.
- Olmeda A, Varotto D, Pavan M. Innesti massivi con osso umano disidratato ed estratto chimicamente: Risulti preliminary. Abstract da Congresso CIOMS, Nov. 25–27, 1999, Rome.
- Alexopoulou M, Semergidis T, Sereti M. Allogenic bone grafting of small and medium defects of the jaws. J Craniomaxillofac Surg 1998;26(supplement 1):176.
- Sener BC, Tasar F, Akkocaoglu M, Ozgen S, Kasapoglu O. Use of allogenic bone grafts in onlay and sandwich augmentation techniques. J Cranio-Maxillofacial Surg 1998;26(supplement 1):176–7.
TOP
ABSTRACT
MATERIALS AND METHODS
