Clinical radiographic, and histologic evaluation of maxillary bone reconstruction by using a titanium mesh and autogenous iliac graft: a case report

The current clinical report describes the use of titanium mesh for maxillary alveolar ridge augmentation. Autogenous bone graft was harvested from the iliac crest and was loaded on a titanium mesh that was left in the patient's maxilla for 7 months before it was removed. Twelve months after the bone grafting procedure the patient received 10 implants on the maxilla, and a biopsy was taken from the augmented ridge. CT scan examination was performed before and after the maxillary ridge augmentation. Clinical evaluation revealed successful integration of the graft. The radiographic analysis demonstrated that a 10-mm vertical ridge augmentation had been achieved. Histologic evaluation revealed remnants of the autogenous bone graft still present, whereas the grafted area had a reduced remodeling activity. The clinical report demonstrated the potential of the titanium mesh to achieve extensive alveolar ridge augmentation, whereas the augmented ridge may possess an inferior capability forbone remodeling.

Osteogenesis by guided tissue regeneration and demineralized bone matrix

AIM

To evaluate in a discriminating capsule model whether bone formation by guided tissue regeneration (GTR) may be influenced by concomitant implantation of demineralized bone matrix (DBM).

MATERIALS AND METHODS

Thirty 4-month-old male albino rats of the Wistar strain were used in the study. Following surgical exposure of the mandibular ramus, a hemispherical, Teflon capsule (5.0 mm in diameter), loosely packed with a standardized amount of DBM, was placed with its open part facing the lateral bone surface of the ramus. At the contralateral side, an empty capsule was placed, serving as control. After healing periods of 15, 30, and 120 days, groups of 10 animals were sacrificed and 40-70 microm thick undecalcified sections of the capsules were produced. In the sections, the cross-sectional areas of (1) the space created by the capsule, (2) newly formed bone, (3) DBM particles, (4) loose connective tissue as well as the (5) height of the capsules, and (6) that of the newly formed bone were measured.

RESULTS

Increasing bone fill was observed in both test and control sites from 30 to 120 days. After 30 days of healing, the mean amount of bone was approx. 3% of the cross-sectional area of the capsules at the test sites while it was 8% in the control sites (p<0.05). However, no statistically significant differences were observed between the test (46%) and control (64%) sites after 120 days regarding any of the measured parameters (p>0.05). The newly formed bone in the DBM group at 120 days, on the other hand, appeared more dense than that in the control capsules.

CONCLUSION

DBM used as an adjunct to GTR did not provide any added effect on bone formation but increased the density of the newly formed bone.

Efficacy of allogenic bone implants in a series of consecutive elective foot procedures

To show the efficacy of an allogenic bone graft in elective foot surgery, the authors report on 39 consecutive procedures in which allograft was implanted in 26 patients during a 30-month period. These procedures were performed for a variety of conditions, including arthrodesis, segmental lengthening, and treatment of nonunion. Allograft material consisted of freeze-dried tricortical iliac crest or demineralized bone matrix used either alone or as a composite. Allograft incorporation in all surgical procedures was retrospectively analyzed. Of 39 consecutive implant procedures, there were 38 healed sites (97%) and 1 nonunion (3%). After radiographic and clinical evaluation of allograft incorporation, the authors conclude that allogenic bone graft is a viable option for a multitude of foot conditions.

Localized vertical maxillary ridge augmentation using symphyseal bone cores: a technique and case report

Vertical augmentation of the alveolar ridge is intended to restore resorbed alveolar ridges. This procedure is important for the placement of dental implants in a favorable position and also to enhance restoration esthetics. This article presents an approach for vertical ridge augmentation in the anterior maxilla utilizing symphyseal bone cores. A patient presented with 2 localized bony defects around the maxillary lateral incisors. Following extraction of these teeth, vertical bone defects of 7 mm on the right and 6 mm on the left were observed in relation to the cementoenamel junction of the adjacent teeth. Two bone cores were harvested from the mandibular symphysis using a trephine. These bone cores were tapped into 2 predrilled osteotomy sites with corresponding diameters until stabilization was achieved. The 2 sites were grafted with demineralized freeze-dried bone allograft and a titanium-reinforced expanded polytetrafluoroethylene membrane. After 5 months, the membranes were removed and vertical ridge augmentation of 5 mm on the right and 4 mm on the left was observed. The width of the ridge was increased as well. Two implants were placed in favorable positions, restored after 6 months, and followed successfully for 1 year after loading. This technique represents a viable approach for augmentation of deficient alveolar ridges prior to the placement of dental implants.

Deproteinized cancellous bovine bone (Bio-Oss) as bone substitute for sinus floor elevation. A retrospective, histomorphometrical study of five cases

OBJECTIVES

To study in detail the performance of deproteinized cancellous bovine bone (DPBB, Bio-Osso) granules as a bone substitute, a histomorphometric was performed on five patients treated with DPBB for reconstruction of the severely atrophic maxilla.

MATERIAL AND METHODS

DPBB was used as mixture with autogenous bone particles, in concentrations that increased from 20% to 100% DPBB, with the time of healing increasing accordingly from 5 to 8 months. A total of 20 vertical biopsies was taken at the time of fixture installation and used for histomorphometry as undecalcified Goldner stained sections.

RESULTS

The results show that in all cases, the DPBB granules had been interconnected by bridges of vital newly formed bone. The volume of bone in the grafted area correlated inversely with the concentration of DPBB grafted, and varied between 37% and 23%. However, the total volume of mineralized material (bone plus DPI3B granules) remained within the same range in all five patients (between 53% and 59%). The high values for osteoid and resorption surface, and the presence of tartrate-resistant acid phosphatase-positive multinucleated osteoclasts in resorption lacunae, indicated that bone remodeling was very active in all grafts. Osteoclasts were also observed in shallow resorption pits on DPBB surfaces. The percentage DPBB surface in contact with bone remained stable at about 35% and could not be related to the proportion of DPBB grafted.

CONCLUSION

Although the number of patients examined was limited, the data suggest that deproteinized cancellous bovine bone, preferably combined with autogenous bone particles, is a suitable material for sinus floor elevation in the severely atrophic human maxilla.

Bone grafting

In recent years our understanding of spinal fusion biology has improved. This includes the continued elucidation of the step-by-step cellular and molecular events involved in the prototypic bone induction cascade, as well as the identification and characterization of the various critical growth factors governing the process of bone formation and bone graft incorporation. Based on these fundamental principles, growth factor technology has been exploited in an attempt to improve rates of spinal fusion, and promising results have been realized in preclinical animal studies and initial clinical human studies. In this article the authors review the recent advances in the biology of bone fusion and provide a perspective on the future of spinal fusion, a future that will very likely include increased graft fusion rates and improved patient outcome as a result of the successful translation of fundamental bone fusion principles to the bedside.

Demineralization for inactivation of infectious retrovirus in systemically infected cortical bone: in vitro and in vivo experimental studies

BACKGROUND

Clinical and experimental studies have demonstrated viral transmission through the transplantation of fresh-frozen infected bone. While sterilization methods sufficient to inactivate the human immunodeficiency virus (HIV) have been shown to markedly alter osteoconductive and osteoinductive properties of bone allografts, the ability of a process for creating demineralized bone matrix to abrogate transmission of a retrovirus has not been investigated, to our knowledge. We hypothesized that a clinically accepted demineralization procedure would alter the nucleic acids of the feline leukemia virus (FeLV, a retrovirus with a structure and replication cycle similar to those of HIV), inactivating the virus in infected bone and rendering it noninfectious.

METHODS

Bone infected with FeLV was demineralized with a method employed for creating demineralized bone matrix powder. The effects of demineralization on cellular and (pro)viral nucleic acids were examined with use of gel electrophoresis and quantitative polymerase chain reaction, respectively. To compare the infectivity of the demineralized bone matrix with that of mineralized bone particles in cell cultures and in animals in which they had been implanted, we measured FeLV p27 antigen and (pro)viral nucleic acids as well as antiviral antibodies.

RESULTS

Demineralization of FeLV-infected bone appeared to inactivate the virus by degradation and fragmentation of the DNA, rendering it noninfectious in both in vitro and in vivo test systems. In contrast, untreated mineralized FeLV-infected bone contained intact nucleic acids and readily transmitted the virus in both test systems.

CONCLUSIONS

The demineralization process inactivated infectious retrovirus in infected cortical bone, thereby preventing disease transmission.

Evaluation of periodontal regeneration following grafting intrabony defects with bio-oss collagen: a human histologic report

This study evaluated the clinical, radiographic, and histologic response to Bio-Oss Collagen when used alone or in combination with Bio-Gide bilayer collagen membrane for the treatment of four intrabony defects (5 to 7 mm) around single-rooted teeth. After reflecting a full-thickness flap, thorough degranulation and root planing were accomplished. In all cases, Bio-Oss Collagen was then used to fill the defects, and in two cases, a Bio-Gide membrane was placed over the filled defect. Radiographs, clinical probing depths, and attachment levels were obtained before treatment and immediately preceding en bloc resection of teeth and surrounding tissues 9 months later. Reduction in pocket depth and gain in clinical attachment level were observed for both treatment protocols. The histologic evaluation demonstrated the formation of a complete new attachment apparatus, evidencing periodontal regeneration that varied with defect morphology. This human histologic study demonstrated that Bio-Oss Collagen has the capacity to induce regeneration of the periodontal attachment apparatus when placed in intrabony defects.

Clinical repair of an osseous defect associated with a cemental tear: a case report

Cemental tears have been described as detachment of cementum caused by trauma or aging. They often result in severe periodontal lesions that may necessitate the extraction of the affected tooth. This case report describes the clinical resolution of a periodontal lesion associated with a cemental tear. A maxillary central incisor was subjected to endodontic treatment twice with no resolution of a deep distobuccal pocket and a palatal sinus tract from its apical region. The preoperative differential diagnosis for the condition present on the tooth included a vertical fracture and a combined periodontal-endodontic lesion. Surgical exploration of the area revealed a cemental tear on the apical third of the tooth. The cementum fragments were removed, root-end resection was performed, and the osseous lesion was treated with an osseous graft and guided tissue regeneration. Clinical examination of the area 1 year after surgery revealed resolution of both the prior pocket and sinus tract. Radiographic examination of the area showed increased radiopacity in the area of the original lesion, suggesting bone fill.

Assessment of the value of anorganic bone additives in sinus floor augmentation: a review of clinical reports

In order to objectively assess the value of anorganic bone additives in sinus floor augmentation, a review of the English literature till May 2002 was carried out. The studies or parts of studies had to include at the least two patients, with a follow-up of at least 3 months, whilst histomorphometric data ought to be available of biopsies taken from the core of the graft. Only 12 studies fulfilled these criteria. Firm conclusions could not be drawn because there were substantial differences in histomorphometric techniques, healing periods and ratio autogenous bone anorganic additives, but it seemed that autogenous bone without anorganic additives resulted in the highest amount of bone after a 4-6 months healing period, while hydroxyapatite and bovine bone mineral, used as a bone substitute, gave the lowest amount of bone. No correlation between bone volume and time of graft healing could be found. The consequences, however, for implant placement and survival are at present, not fully understood. A plea is made for systematic prospective clinical and experimental studies to assess the various bone additives and ratios of autogenous bone to bone additives in composite grafts analysed with an adequate histomorphometric technique. Part of this study was presented at the 15th ICOMS, Durban, South Africa, 19-24 May 2001.

Histologic findings in sinus augmentation with autogenous bone chips versus a bovine bone substitute

PURPOSE

The aim of this study was to compare a bovine bone substitute (Bio-Oss) to autogenous bone with respect to its value as a material for sinus augmentation.

MATERIALS AND METHODS

In 10 beagle dogs 12 months of age, the 3 maxillary premolars were extracted on both sides. Six weeks later, 2 cavities of predefined size were produced in the region of the nasal cavity. The antral window was 25 mm long and had a vertical extension of 7 mm. Two Frialit-2 implants (3 x 8 mm) were placed in each bone defect (n = 20). Every implant was primarily stable because of fixation in native bone. In each maxilla, 1 bone defect was filled with autogenous bone harvested from the mandible and 1 was filled with Bio-Oss (material selected at random). The animals were sacrificed at 90 and 180 days, and histologic specimens were examined and the results subjected to statistical analysis by the Wilcoxon test for paired observations.

RESULTS

No healing problems were observed. Histologically, after 90 days the volume of the augmentation showed a reduction of 14.6 +/- 4.4% within the Bio-Oss group and 3.8 +/- 2.5% in the group with autogenous bone. Bone-implant contact of 52.16 +/- 13.15% in the Bio-Oss group and 60.21 +/- 11.46% in the autogenous bone group was observed. At 180 days, the Bio-Oss group showed bony ingrowth of the substitute, whereas in the autogenous group a differentiation from original bone could no longer be made. The volume reduction was 16.5 +/- 8.67% in the Bio-Oss group and 39.8 +/- 16.14% in the autogenous group. Bone-implant contact of 63.43 +/- 19.56% in the Bio-Oss group and 42.22 +/- 12.80% in the autogenous bone group was measured.

DISCUSSION AND CONCLUSION

The results indicated that because of the nonresorptive properties of the bone substitute Bio-Oss, regeneration of the defects is achievable. It was demonstrated that the bone substitute seemed to behave as a permanent implant. The volume of the area augmented by autogenous bone decreased over the observation period.

Clinical and radiographic treatment evaluation of class III furcation defects using GTR with and without inorganic bone matrix

OBJECTIVE

The aim of this study was to evaluate the effect of guided tissue regeneration (GTR) alone and in conjunction with a bovine inorganic bone matrix in furcation defects.

MATERIAL AND METHODS

Twenty class III furcation defects were treated in 18 non-smoker patients, 35-75 years old. Horizontal (CAL-H) and vertical clinical attachment levels (CAL-V), probing depths (PD), gingival margin levels (GML), horizontal (BDL-H) and vertical bone defect levels (BDL-V), and alveolar crest levels (ACL) were performed at baseline and at 6-month re-entry procedures. Subtraction radiography was used to assess gain or loss in optical density (OD) and area of bone fill (A) (baseline/6 months). After flap elevation, the sites were randomly assigned to receive GTR + Bio-Oss (test) or GTR treatment alone (control). Results were evaluated using anova.

RESULTS

Differences were statistically significant between baseline and re-entry for PD, ACL (p < 0.01) and GML (p < 0.05) for the control group, and for BDL-V (p < 0.01) for the test group. There was a gain in ACL for the test group and a reduction in ACL for the control group (p < 0.01). No differences were observed for OD and A.

CONCLUSION

The results of this study indicate that class III furcation defects are not predictably resolved utilizing GTR or GTR in combination with an inorganic bone matrix.

Healing of intrabony defects following treatment with a bovine-derived xenograft and collagen membrane. A controlled clinical study

AIM

: The purpose of the present study was to compare clinically the treatment of deep intrabony defects with a combination of a bovine-derived xenograft (BDX) and a bioresorbable collagen membrane to access flap surgery.

METHODS

: Twenty-eight patients suffering from chronic periodontitis, and each of whom displayed one intrabony defect, were randomly treated with BDX + collagen membrane (test) or with access flap surgery (control). Soft tissue measurements were made at baseline and at 1 year following therapy.

RESULTS

: No differences in any of the investigated parameters were observed at baseline between the two groups. Healing was uneventful in all patients. At 1 year after therapy, the test group showed a reduction in mean probing depth (PD) from 9.2+/-1.3 to 3.9+/-0.7 mm (p<0.001) and a change in mean clinical attachment level (CAL) from 10.2+/-1.5 to 6.2+/-0.5 mm (p<0.0001). In the control group, the mean PD was reduced from 9.0+/-1.2 to 5.2+/-1.8 mm (p<0.001) and the mean CAL changed from 10.5+/-1.5 to 8.4+/-2.1 mm (p<0.01). The test treatment resulted in statistically higher PD reductions (p<or=0.05) and CAL gains (p<0.001) than the control one. In the test group all sites (100%) gained at least 3 mm of CAL. In the control group no CAL gain occurred in four sites (29%), whereas at six sites (43%) the CAL gain was 2 mm. A CAL gain of 3 mm or more was measured in four defects (29%).

CONCLUSIONS

: Within the limits of the present study, it can be concluded that: (i) at 1 year after surgery both therapies resulted in significant PD reductions and CAL gains, and (ii) treatment with BDX+collagen membrane resulted in significantly higher CAL gains than treatment with access flap surgery.

Bone Graft Alternatives for Spinal Fusion

Bone grafting to achieve fusion is frequently performed in spinal surgery. Autograft is the gold standard bone graft material. However, due to limitations of supply and morbidity associated with the harvest of autograft, alternatives are being considered. Osteoconductive matrices, such as allograft, calcium or ceramic preparations are one such class of potential bone graft alternatives, but generally they lack osteoinductive properties. Recent attention has focused on osteoinductive materials such as demineralised bone matrix, recombinant bone morphogenetic proteins and bone marrow aspirates or blood product concentrates. These products may be combined with osteoconductive carriers and are clearly finding a place in the clinical arena.

The effect of demineralized intramembranous bone matrix and basic fibroblast growth factor on the healing of allogeneic intramembranous bone grafts in the rabbit

The aim here was to explore a new graft material that excludes the need to harvest autogenous bone from patients. Forty-two critical-size (10 x 15 mm) defects were created in rabbit mandibles bilaterally. Five groups of six defects each were grafted with autogenous endochondral (EC) bone, autogenous intramembranous (IM) bone, fresh-frozen allogeneic IM bone only, fresh-frozen allogeneic IM bone and demineralized bone matrix powder prepared from intramembranous bone (DBM(IM)) only, and fresh-frozen allogeneic IM bone and basic fibroblast growth factor (bFGF) mixed with DBM(IM) powder. The remaining defects were used as controls. Three weeks after surgery, the defects were retrieved for histological analysis. The amount of new bone formation was quantified by image analysis. No bone formed across the defect in the controls; 224% more new bone formed in defects grafted with composite allogeneic IM bone/DBM(IM) than in those grafted with allogeneic IM bone alone (p < 0.001); 550% more new bone was formed in defects grafted with composite allogeneic IM bone/DBM(IM)/bFGF than in those grafted with allogeneic IM bone alone (p < 0.001). The amount of new bone in the group receiving composite allogeneic IM bone/bFGF/DBM(IM) was more than that in autogenous EC bone group, and very close to that in autogenous IM group. The results show that a composite of fresh-frozen allogeneic IM bone and bFGF in DBM(IM) powder is a good graft material that warrants further clinical investigation.

Combined therapy of mineral trioxide aggregate and guided tissue regeneration in the treatment of external root resorption and an associated osseous defect

BACKGROUND

The treatment of external root resorption and associated periodontal defects can be challenging to the most astute clinician. In this case report, a multidisciplinary approach was performed to treat a maxillary central incisor that presented with a sinus tract. An amalgam restoration had been placed approximately 10 years earlier to repair an area of external root resorption.

METHODS

A full-thickness mucoperiosteal flap was reflected from teeth #8 to #9. Following degranulation of the area, an amalgam restoration was found on the distal root surface of tooth #8. A 2-wall osseous lesion was also associated with the distal surface of #8. The amalgam was removed and the defect was restored with mineral trioxide aggregate (MTA). The root surface was chemically conditioned with tetracycline, and the osseous defect was grafted with decalcified freeze-dried bone allograft (DFDBA) and a calcium sulfate barrier.

RESULTS

An 8 mm gain in clinical attachment, as well as an increase in radiodensity, was noted on the distal surface of tooth #8 at 15 months postsurgery. The patient was also asymptomatic, with no clinical signs of inflammation present.

CONCLUSIONS

A combined approach utilizing MTA for root surface repair, and DFDBA and calcium sulfate to address an associated osseous lesion, appears to be a viable modality in the treatment of chronic endodontic/periodontal lesions.

Histological assessment of augmented jaw bone utilizing a new collagen barrier membrane compared to a standard barrier membrane to protect a granular bone substitute material

Successful bone augmentation requires predictable space maintenance and adequate exclusion of those cells that lack osteogenetic potential from the defect area. Natural bone mineral is considered to be osteoconductive and is used as space maker in combination with membrane barrier techniques. The aim of this study was to compare qualitative histological results achieved by using deproteinized bovine bone mineral (DBBM) as a space maintainer and a new collagen barrier (Ossix, test group) vs. the same bone substitute and the standard e-PTFE membrane (Gore-Tex), control group). Twenty-eight patients were randomly assigned to the test or the control group. Seven months after augmentation procedures, biopsies were obtained at reentry and were analysed histomorphometrically. In all, 14 specimens of group I (test group, Ossix) and 13 specimens of group II (controls, PTFE-membranes) showed close qualitative similarity of their histologies. Histomorphometrically, total mineralized bone area was 42% +/- 18% in group I vs. 39% +/- 15% in group II. The unmineralized tissue area was 44% +/- 15% vs. 46% +/- 12% and the area of DBBM remnants 14% +/- 9% and 15% +/- 12%, respectively. The differences were statistically nonsignificant (Mann-Whitney test). The occurrence of barrier exposure did not interfere with the histological outcome either in the test or in the control group. The new collagen barrier combined with the DBBM provided qualitative bone regeneration comparable to the standard e-PTFE material combined with the same mineral.

Characterization of bone defect repair in young and aged rat femur induced by xenogenic demineralized bone matrix

BACKGROUND

The osteoinductive effect of some biomaterials could be affected by those systemic conditions typical of old age. The aim of the present paper was to assess the effects of age on the healing of bone defects treated with demineralized bone matrix (DBM).

METHODS

The study was conducted in young (3 month old) and aged (18 month old) rats to assess the efficacy of DBM in the treatment of osseous defects in bone with limited repair capacities. A standard bone defect was created in the distal femoral condyles of male Wistar rats: the left condyle was filled with rabbit DBM granules, while the right condyle was left empty (control). Histological and microhardness analyses were performed at 30 and 45 days after implant surgery.

RESULTS

After implantation of xenogenic DBM, bone healing areas of the aged and young groups showed a significant increase in the formation of newly mineralized bone relative to controls. Measurements of trabecular thickness on day 45 revealed no differences between newly formed and preexisting bone in the young group, while control values were lower. Microhardness measurements demonstrated that newly mineralized bone, either induced by DBM or not, and preexisting bone were comparable in terms of trabecular hardness after 45 days.

CONCLUSIONS

In conclusion, xenogenic DBM seems to be effective in bone defect healing, since it increases mineralized tissue volume. In both DBM-filled and empty sites, age seems to have a detrimental effect on the volume of new bone formation but no influence on bone maturation.

Bone regeneration of localized chronic alveolar defects utilizing cell binding peptide associated with anorganic bovine-derived bone mineral: a clinical and histological study

BACKGROUND

Osteoinduction to treat osseous defects has been attempted by several means. Some clinical studies have demonstrated that a synthetic cell binding peptide (P-15) with anorganic bovine derived bone matrix (ABM) has the ability to enhance bone regeneration. These studies suggest that more histological data are necessary to better understand this process. We have developed a Class III chronic alveolar defect animal model to investigate space-maintaining regenerative materials. The objective of this study was to clinically and histologically evaluate the use of P-15/ABM with or without a bioabsorbable membrane (M) to regenerate localized chronic alveolar ridge defects in dogs.

METHODS

Six adult, male mongrel dogs were used in this study. Bilateral, Class III, alveolar defects were surgically produced following extraction of the mandibular second premolar teeth and local reduction of the alveolar ridge. After an 8-week healing interval, mucoperiosteal flaps were elevated. P-15/ABM with or without bioabsorbable membranes were implanted into contralateral defects in 10 sites. Two sites received no biomaterial (controls). Mucoperiosteal flaps were advanced over the P-15/ABM or P-15/ABM/M constructs and sutured. Pre- and postaugmentation clinical evaluation was done utilizing periodontal probes and calipers. The animals were sacrificed 12 weeks postaugmentation and block specimens processed for histologic evaluation.

RESULTS

Clinical results showed no significant statistical augmentation on the control group (0.0 +/- 0.6 mm). In all experimental sites utilizing P-15/ABM or P-15/ABM/M, relevant ridge augmentation was observed (3.6 +/- 2.0 mm and 2.9 +/- 1.9 mm, respectively). Histologically, all experimental sites showed active bone formation with plump osteoblast and osteoid matrix deposition in the treated area. Bone ingrowth filled the area of the defects treated with P-15/ABM/M. Few P-15/ABM particles were seen in the cellular fibrous tissue surrounding the new formed bone trabeculae.

CONCLUSIONS

P-15/ABM with or without membranes can produce a significant clinical ridge augmentation. Bone formation was histologically observed in all test areas. The association of a membrane with P-15/ABM seemed to enhance the process of bone formation.

Soft tissue and hard tissue engineering in oral and maxillofacial surgery

Autologous, allogenic and alloplastic materials for bony reconstruction in the cranio-maxillofacial area have specific drawbacks, thus stimulating the ongoing search for new (bio-) materials. Cultivated skin and mucosa grafts are in routine clinical use in head and neck reconstruction but so far, to the best of our knowledge, no successful clinical application has been described of periosteum-derived tissue-engineered bone for augmentation of the edentulous posterior maxilla. In a pilot clinical study, augmentation of the posterior maxilla was carried out using a bone matrix derived from mandibular periosteum cells on an Ethisorb fleece. In this paper we demonstrate the fabrication of the matrix, its clinical application, and histological results in two patients. Our results suggest that periosteum-derived osteoblasts on a suitable matrix can form lamellar bone within four months after transplantation and provide a reliable basis for implant insertion.

Bone induction in clinical orthodontics: a review

The major limitations of autogenous grafting are inadequate supply and surgical morbidity, including donor site pain, paresthesia, and infection. Graft resorption can also pose a severe problem. Bone induction is therefore needed to assist in fracture healing and to fill osseous defects. This article reviewed the current development of bone induction in relation to clinical orthodontics.

A comparative study of osseointegration of Avana implants in a demineralized freeze-dried bone alone or with platelet-rich plasma

PURPOSE

The purpose of this study was to assess the efficacy of demineralized bone powder (DBP) alone or combined in a mixture with platelet-rich plasma (PRP) used to enhance osseointegration of dental implants in a dog model.

MATERIALS AND METHODS

Tissue integration was assessed using standard histomorphometric methods at 6 and 12 weeks after surgery. A total of 30 Avana dental implants (SooMin Synthesis Dental Materials Co, Busan, Korea) were inserted in the animals. They were self-tapping screw implants, 10 mm in length and 4 mm in diameter, made of commercially pure titanium. A titanium implant was then placed centrally in each defect. In each dog, the defects were treated with 1 of the following 3 treatment modalities:1) no treatment (control), 2) grafting with DBP, or 3) grafting with DBP and PRP.

RESULTS

Histologic analysis showed that all of the bone defects surrounding the implants that were treated with DBP, with and without PRP, were filled with new bone. The defects that were not treated (control) showed new bone formation only in the inferior threaded portion of the implants. Histomorphometric results revealed a higher percentage of bone contact with DBP and PRP compared with control and DBP.

CONCLUSION

These results suggested that bone defects around titanium implants can be treated successfully with DBP and that PRP may improve bone formation.

Cranioplasty using allogeneic perforated demineralized bone matrix with autogenous bone paste

The efficacy of allogeneic perforated demineralized bone matrix with autogenous bone paste in the treatment of full-thickness cranial defects was evaluated in 10 consecutive patients between June 1998 and December 1998. The skull defects resulted from trauma in 9 patients and removal of a cranial tumor in 1 patient. The size of the skull defects ranged from 8 x 6 cm to 11 x 12.5 cm. Follow-up averaged 33 months for all patients. Postimplantation evaluations included serial photographs, repeated physical examination, and three-dimensional computed tomography for all patients. Visual inspection of the implanted biomaterial 6 months later was possible in 1 patient. The contour of the reconstructed skull was acceptable aesthetically without any secondary depression noted during the follow-up period. Three-dimensional computed tomographic scans taken 2 years after implantation indicated that the allogeneic perforated demineralized bone matrix provided a matrix for new bone formation with remarkable osteoinductive potential for new bone formation. The autogenous bone paste was able to caulk the demineralized bone matrix and fill the contour irregularities and gaps of the reconstructed cranium. The results from this clinical study indicated that allogeneic perforated demineralized bone matrix with autogenous bone paste is a promising alternative to an autogenous bone graft and or alloplastic material for cranioplasty.