Horizontal Bone Augmentation With Autogenous and Collagenated Xenogeneic Bone Blocks: A Split-Mouth Prospective Clinical, Tomographic, and Histological Pilot Study.

The aim of this study was to compare the clinical, tomographic, and histological performance of collagenated xenogeneic bone blocks (CXBB) in horizontal bone augmentations for implant placement. Five patients with an absence of the 4 upper incisors and an HAC 3 horizontal bone defect, with a remaining of 3 to 5 mm, underwent a bone-grafting procedure with CXBB (test group [TG], n = 5) and autogenous graft (control group [CG], n = 5), with one type of graft used on the right side and other type on the left side. Changes in bone thickness and density (tomographic evaluation), levels of complications (clinically), and distribution pattern between mineralized and nonmineralized tissue (histomorphometrically) were analyzed. Tomographic analysis showed a horizontal bone increase of 4.25 ± 0.78 mm in the TG and 3.08 ± 0.8 mm in the CG between baseline and 8 months postoperatively (P < .05). The horizontal loss between the day of installation of the blocks and 8 months postoperatively was 1.02 ± 0.39 mm for the TG and 1.10 ± 0.71 mm for the CG (P > .05). With regard to bone density, the TG blocks right after installation had 440.2 ± 89.15 HU, and after 8 months, the region reached 730.7 ± 130.98 HU, representing an increase of 29.05%. For the CG blocks, bone density increased from 1052.2 ± 398.35 HU to 1222.5 ± 453.28 HU, representing an increase of 17.03%. The increase in bone density was significantly higher in the TG (P < .05). Clinically, no cases of exposure of the bone blocks and no failure of incorporation were observed. Histomorphometrically, the percentage of mineralized tissue was lower in the TG than in the CG (48.10% ± 2.88% and 53.53% ± 1.05%, respectively), and the opposite was verified for the levels of nonmineralized tissue (52.79% ± 2.88% and 46.47% ± 1.05%, respectively; P < .05). The use of CXBB achieved higher levels of horizontal gain, with lower bone density and lower levels of mineralized tissue when compared with the use of autogenous blocks.

Interdisciplinary treatment of ankylosed upper central incisors with an anterior vertical ridge defect: A case report.

This case report describes the successful 10-years interdisciplinary treatment of ankylosed upper central incisors with an anterior vertical ridge defect. This treatment was challenging as ankylosis was present before the growth spurt. Orthodontic treatment in association with decoronation, a xenogeneic bone graft, an autogenous sub-epithelial connective tissue graft, and implant placement were performed to correct the vertical ridge defect and to re-establish appropriate function, gingival health, and aesthetics. Decoronation performed during the growth spurt was the key to avoiding alveolar ridge deformity.

Influence of Xenogeneic and Alloplastic Carriers for Bone Augmentation on Human Unrestricted Somatic Stem Cells.

Alloplastic and xenogeneic bone grafting materials are frequently used for bone augmentation. The effect of these materials on precursor cells for bone augmentation is yet to be determined. The aim of this study was to ascertain, in vitro, how augmentation materials influence the growth rates and viability of human unrestricted somatic stem cells. The biocompatibility of two xenogeneic and one alloplastic bone graft was tested using human unrestricted somatic stem cells (USSCs). Proliferation, growth, survival and attachment of unrestricted somatic stem cells were monitored after 24 h, 48 h and 7 days. Furthermore, cell shape and morphology were evaluated by SEM. Scaffolds were assessed for their physical properties by Micro-CT imaging. USSCs showed distinct proliferation on the different carriers. Greatest proliferation was observed on the xenogeneic carriers along with improved viability of the cells. Pore sizes of the scaffolds varied significantly, with the xenogeneic materials providing greater pore sizes than the synthetic inorganic material. Unrestricted somatic stem cells in combination with a bovine collagenous bone block seem to be very compatible. A scaffold's surface morphology, pore size and bioactive characteristics influence the proliferation, attachment and viability of USSCs.

Clinical Reference Strategy for the Selection of Treatment Materials for Maxillofacial Bone Transplantation: A Systematic Review and Network Meta-Analysis.

Bone graft materials have mixed effects of bone repair in the field of oral maxillofacial surgery. The qualitative analyses performed by previous studies imply that autogenous odontogenic materials and autogenous bone have similar effects on bone repair in clinical jaw bone transplantation. This retrospective systematic assessment and network meta-analysis aimed to analyze the best effect of clinical application of autogenous odontogenic materials and autogenous, allogeneic, and xenogeneic bone grafts in bone defect repair. A systematic review was performed by searching the PubMed, Cochrane Library, and other journal databases using selected keywords and Medical Subject Headings search terms. 10 Papers (n = 466) that met the inclusion criteria were selected. The assessment of heterogeneity did not reveal any overall statistical difference or heterogeneity (P = 0.051 > 0.05), whereas the comparison between autogenous and allogeneic bone grafts revealed local heterogeneity (P = 0.071 < 0.1). Risk of bias revealed nine unclear studies and one high-risk study. The overall consistency was good (P = 0.065 > 0.05), and the local inconsistency test did not reveal any inconsistency. The publication bias was good. The confidence regarding the ranking of bone graft materials after GRADE classification was moderate. The effects on bone repair in the descending order were as follows: autogenous odontogenic materials, xenogeneic bone, autogenous bone, and allogeneic bone. This result indicates that the autogenous odontogenic materials displayed stronger effects on bone repair compared to other bone graft materials. Autogenous odontogenic materials have broad development prospects in oral maxillofacial surgery.

The optimization of pepsin processing time to balance the mechanical and biological properties of xenogeneic bone.

Xenogeneic bone showed great prospects to treat large bone defects due to its bionic composition and structure, but the immunogenicity limited its wide applications. Previously, we developed a pepsin treating method to eliminate the immunogenicity of xenogeneic bone. In this study, we further investigated the effect of pepsin processing time on the biological and mechanical properties. The results indicated that increased pepsin treating time impaired the mechanical properties of xenogeneic bone. And MC3T3-E1 cells showed enhanced adhesion ability, as well as increased production of alkaline phosphatase and calcium nodulus production on the xenogeneic bone processed by pepsin for 24 hr (P24), as compared with xenogeneic bone processed by pepsin for 30 hr (P30) and 36 hr (P36). In addition, we found no significant inflammatory responses after implanting different xenogeneic bone into the intermuscular site of rats. These results suggested that xenogeneic bone processed by pepsin for 24 hr may be a preferable choice when using the xenogeneic bone as biomaterials for further researches.

[Performance evaluation of two antigen-extracted xenogeneic ostein and experimental study on repairing skull defects in rats].

OBJECTIVE: To evaluate the physical and chemical properties, immunogenicity, and osteogenesis of two antigen-extracted xenogeneic bone scaffolds-decalcified bone matrix (DBM) and calcined bone. METHODS: By removing the inorganic and organic components of adult pig femus, xenogeneic DBM and calcined bone were prepared respectively. The density and pH value of the two materials were measured and calculated, the material morphology and pore diameter were observed by scanning electron microscope, and the surface contact angle was measured by automatic contact angle measuring instrument. The safety, osteogenic activity, and immunogenicity of the two materials were evaluated by cytotoxicity test, osteoblast proliferation test, DNA residue test, and human peripheral blood lymphocyte proliferation test. The two materials were implanted into the 5 mm full-thickness skull defect of 6-week-old male Sprague Dawley rats (the blank control group was not implanted with materials). The materials were taken at 4 and 8 weeks after operation, the repair effect of the materials on the rat skull was observed and evaluated by gross observation, Micro-CT scanning, and HE staining observation. RESULTS: Compared with calcined bone, DBM has lower density and poor hydrophilicity; the pH value of the two materials was 5.5-6.1, and the pore diameter was 160-800 µm. The two materials were non-cytotoxic and could promote the proliferation of osteoblasts. The absorbance ( A) values of osteoblast proliferation at 1, 4, and 7 days in the DBM group were significantly higher than those in the calcined bone group ( P<0.05). The DNA residues of the two materials were much lower than 50 ng/mg dry weight, and neither of them could stimulate the proliferation and differentiation of human peripheral blood lymphocytes. The results of animal experiments in vivo showed that the bone volume/total volume (BV/TV) in DBM group and calcined bone group were significantly higher than that in blank control group at 4 weeks after operation ( P<0.05), and that in calcined bone group was significantly higher than that in DBM group ( P<0.05); at 8 weeks after operation, there was no significant difference in BV/TV between groups ( P>0.05). HE staining showed that at 4 and 8 weeks after operation, the defect in the blank control group was filled with fibrous connective tissue, the defect was obvious, and no bone growth was found; the defect in DBM group and calcined bone group had been repaired to varying degrees, and a large number of new bone formation could be seen. The material degradability of DBM group was better than that of calcined bone group. CONCLUSION: The physical and chemical properties and degradability of the two kinds of xenogeneic bone scaffolds were slightly different, both of them have no immunogenicity and can promote the repair and reconstruction of skull defects in rats.

Bone remodeling around implants placed after socket preservation: a 10-year retrospective radiological study.

BACKGROUND: To evaluate and compare the long-term clinical and radiological outcomes of post-extraction sockets after ridge preservation either with porcine xenograft or collagen alone. Patients underwent single-tooth extraction in the posterior mandible. Fresh extraction sockets were filled with pre-hydrated cortico-cancellous porcine bone or collagen sponge. Two or 3 months later, a ridge expansion technique with immediate implant positioning placement was performed. Primary (alveolar width changes) and secondary outcomes (adverse events and long-term maintenance of buccal plate covering the implant) were evaluated. RESULTS: Thirty-four women and 20 men were selected: 30 implants (group A) placed into healed post-extraction sockets grafted with porcine bone and 24 (group B) into sockets filled with a collagen sponge. There was a significant loss in width in both groups from the first and second surgery (ranging between 2.7 mm and 4.5 mm). The ridge splitting with bone expansion resulted in significant long-term increases in width for both procedures and implant sites. Non-significant differences in alveolar width were registered between the groups at 10-year follow-up even if the analysis of the implant buccal bone coverage suggested that group A had significantly worst results. CONCLUSIONS: Porcine bone group had significantly better short-term outcomes with lower long-term maintenance of the buccal plate.

In Vivo Analysis of the Biocompatibility and Bone Healing Capacity of a Novel Bone Grafting Material Combined with Hyaluronic Acid.

The present in vivo study analyses both the inflammatory tissue reactions and the bone healing capacity of a newly developed bone substitute material (BSM) based on xenogeneic bone substitute granules combined with hyaluronate (HY) as a water-binding molecule. The results of the hyaluronate containing bone substitute material (BSM) were compared to a control xenogeneic BSM of the same chemical composition and a sham operation group up to 16 weeks post implantationem. A major focus of the study was to analyze the residual hyaluronate and its effects on the material-dependent healing behavior and the inflammatory tissue responses. The study included 63 male Wistar rats using the calvaria implantation model for 2, 8, and 16 weeks post implantationem. Established and Good Laboratory Practice (GLP)-conforming histological, histopathological, and histomorphometrical analysis methods were conducted. The results showed that the new hyaluronate containing BSM was gradually integrated within newly formed bone up to the end of the study that ended in a condition of complete bone defect healing. Thereby, no differences to the healing capacity of the control BSM were found. However, the bone formation in both groups was continuously significantly higher compared to the sham operation group. Additionally, no differences in the (inflammatory) tissue response that was analyzed via qualitative and (semi-) quantitative methods were found. Interestingly, no differences were found between the numbers of pro- and anti-inflammatory macrophages between the three study groups over the entire course of the study. No signs of the HY as a water-binding part of the BSM were histologically detectable at any of the study time points, altogether the results of the present study show that HY allows for an optimal material-associated bone tissue healing comparable to the control xenogeneic BSM. The added HY seems to be degraded within a very short time period of less than 2 weeks so that the remaining BSM granules allow for a gradual osteoconductive bone regeneration. Additionally, no differences between the inflammatory tissue reactions in both material groups and the sham operation group were found. Thus, the new hyaluronate containing xenogeneic BSM and also the control BSM have been shown to be fully biocompatible without any differences regarding bone regeneration.

The use of solvent-preserved human and bovine cancellous bone blocks for lateral defect augmentation - an experimental controlled study in vivo.

BACKGROUND: The aim of this study was to compare new bone formation, resorbed bone matrix, and fibrous enclosed residual bone substitute material in laterally augmented alveolar bone defects using allogeneic, pre-treated and cleaned human bone blocks (tested in dogs, therefore considered to be xenogeneic), and pre-treated and cleaned bovine cancellous bone blocks, both with and without a collagen membrane in order to evaluate their augmentative potential. METHODS: Thirty-two critical size horizontal defects were prepared in the mandible of 4 adult foxhound dogs (8 per dog, 4 on each side). After 3 months of healing, the defects were laterally augmented in a split-mouth-design with either human (HXB) or bovine solvent-preserved bone blocks (BXB). Afterwards, defects were randomly covered with a bovine collagenous membrane (HXB + M, BXB + M). After a healing interval of 6 months, percentages of new bone formation, resorbed bone matrix, and fibrous enclosed residual bone substitute material were compared. RESULTS: Results showed little new bone formation of up to 3.7 % in human bone blocks (HXB 3.7 % ± 10.2, HXB + M 0.3 %± 0.4, BXB, 0.1 % ± 0.8, BXB + M 2.6 % ± 3.2, p = > 0.05). Percentages of fibrous encapsulation were higher in human bone blocks than in bovine bone blocks (HXB 71.2 % ± 8.6, HXB + M 73.71 % ± 10.6, BXB, 60.5 % ± 27.4, BXB + M 52.5 % ± 28.4, p = > 0.05). Resorption rates differed from 44.8 % in bovine bone blocks covered with a membrane to 17.4 % in human bone blocks (HXB 17.4 % ± 7.4, HXB + M 25.9 % ± 10.7, BXB, 38.4 % ± 27.2, BXB + M 44.8 % ± 29.6, p = > 0.05). The use of additional membranes did not significantly affect results. CONCLUSIONS: Within its limitations, results of this study suggest that solvent-preserved xenogenic human and bovine bone blocks are not suitable for lateral bone augmentation in dogs. Furthermore, defect coverage with a membrane does not positively affect the outcome.

Split bone block technique: 4-month results of a randomised clinical trial comparing clinical and radiographic outcomes between autogenous and xenogeneic cortical plates.

PURPOSE: To evaluate short-term clinical and radiographic outcomes of bone regeneration procedures using thin cortical porcine xenogeneic bone plates in combination with autogenous bone chips compared with thin autogenous cortical plates and autogenous bone chips. MATERIALS AND METHODS: A total of 19 patients (12 women and 7 men, mean age 58.24 ± 3.09 years) were randomly allocated to two different groups regarding surgical procedure: autogenous cortical plates (ACP group) and xenogeneic cortical plates (XCP group). Preoperative CBCT scans were performed for each patient. Surgical time and postoperative pain were recorded, as well as tissue healing and graft resorption after 4 months, then another surgical procedure was performed to place dental implants. Data were analysed using an analysis of covariance. RESULTS: Twenty-one surgical procedures were performed on 19 patients (10 from the XCP group and 9 from the ACP group). The operative time was significantly lower in the XCP group (25.45 ± 3.88 minutes) than in the ACP group (44.10 ± 3.60 minutes). The XCP group also showed less pain, but not significantly less, than the ACP group. The graft resorption rate in the ACP and XCP groups was 2.03 ± 1.58% and 3.49 ± 2.38% respectively, showing no statistically significant difference. CONCLUSIONS: Despite the limited sample size and non-uniform distribution between the maxilla and mandible as surgical sites, the results suggest that XCP and ACP grafts are similar in terms of bone volume gain and graft resorption rate, with no significant differences in wound healing or complication rate. Nevertheless, the XCP group recorded lower pain levels and required significantly less operative time compared to the ACP group.

Long-term outcomes following lateral alveolar ridge augmentation using a collagenated xenogeneic bone block: a monocenter, prospective single-arm clinical study.

OBJECTIVES: To assess the long-term clinical outcomes following lateral alveolar ridge augmentation using a collagenated xenogeneic bone block (CXBB) and staged implant placement. MATERIAL AND METHODS: A total of n = 9 patients (9 implants) were available for the analysis. Each subject had received lateral ridge augmentation using a size-adapted rigidly fixed CXBB and contour augmentation at single-tooth gaps. Implant placement was performed after 24 weeks of submerged healing. Clinical parameters (e.g., bleeding on probing (BOP), probing pocket depth (PD), mucosal recession (MR)) were recorded at 16 to 20 weeks after the cementation of the crown (baseline) and scheduled for 0.5 (visit 1 (V1)), 1.5 (V2), 2.5 (V3), 3.5 (V4), and 4.5 (V5) years after implant loading. RESULTS: Changes in clinical parameters commonly remained low throughout the entire observation period. Significant changes to baseline were merely noted for mean BOP scores at V4 (19.14 ± 17.75%; n = 7; P = 0.029) and mean PD scores at V2 (0.78 ± 0.98 mm; n = 9; P = 0.044) and V3 (1.33 ± 1.05 mm; n = 9; P = 0.009), respectively. CONCLUSION: CXBB was associated with high clinical implant success and survival rates on the long-term.

Structural and chemical features of xenograft bone substitutes: A systematic review of in vitro studies.

Xenograft bone substitutes are obtained from different species and prepared by various procedures including heat treatment, hydrazine, and chemical and hydrothermal methods. These grafts are utilized widely because of similar structure and properties to human bone, proper bone formation, and biocompatibility. The aim of this systematic review was to evaluate different xenografts from structural and chemical aspects. In vitro studies published in English language, which assessed xenografts' features, met the inclusion criteria. Electronic search of four databases including PubMed, Google Scholar, Scopus, and Web of Science and a hand search until September 2020 were performed. The irrelevant studies were the ones which focused on cell adhesion and effect of growth factors. Finally, 25 studies were included in the review. Nineteen studies used bovine xenografts, and 12 studies applied heat treatment as their preparation method. Particles showed various morphologies, and their largest size was observed at 5 mm. From 18 studies, it is found that the smallest pore size was 1.3 µm and the highest pore size was 1000 µm. There is large heterogeneity of porosity, crystallinity, Ca/P ratio, and osteogenesis based on the preparation method. Proper porosity and the connection between pores affect bone regeneration. Therefore, biomaterial selection and outcomes evaluation should be interpreted separately.

The assessment of xenogeneic bone immunotoxicity and risk management study.

BACKGROUND: Xenogeneic bone has been widely used in a variety of clinical bone-related disease to promote bone healing and restore bone defects. However, the adverse effects of immune system limit its application in the clinic. The aim of this study was to evaluate xenogeneic bone safety of immunotoxicity and explore the methods for immune risk supervision. RESULTS: Xenogeneic bone, which is freeze-dried bovine cancellous bone, was implanted into the muscle of mice. On day 7, 14 and 28, the effects of xenogeneic bone were examined on humoral immunity and cellular immunity, including the levels of IgG, IgM, C3, inflammatory factors (TNF-α, IL-6), alkaline phosphatase (ALP) and the lymphocyte phenotype. The data showed that xenogeneic bone implantation had no potential to induce immune responses not only in humoral immunity but also in cellular immunity. To reveal the risk of immunogenicity, the residual DNA and the clearance of α-gal epitope were analyzed in 2 different bones (bone 1 is deproteinized bone, bone 2 is acellular and defatted bone). It was suggested that DNA of xenogeneic bone can be limited to < 50 ng per mg dry weight for the repair or regeneration with the acceptable immune risk. And α-gal clearance of xenogeneic bone could be an effective risk factor for improving xenograft quality management. CONCLUSIONS: Through the detection of xenogeneic bone immunotoxicity, our findings indicated that the supervisions of risk factors could contribute to reduce the immune risk. And the risk factors under the acceptable limitation could decrease or replace animal experiment. However, it still needs to be studied on the limitation of α-gal epitope to predict rejection of xenogeneic bone more accurately.

Comparison of Material-mediated Bone Regeneration Capacities of Sintered and Non-sintered Xenogeneic Bone Substitutes via 2D and 3D Data.

BACKGROUND/AIM: The aim of this study was the development of a new osteoconductivity index to determine the bone healing capacities of bone substitute materials (BSM) on the basis of 3D microcomputed tomographic (µ-CT) data. MATERIALS AND METHODS: Sinus biopsies were used for the comparative analysis of the integration behavior of two xenogeneic BSM (cerabone® and Bio-Oss®). 3D µ-CT and data sets from histomorphometrical measurements based on 2D histological slices were used to measure the bone-material-contact and the tissue distribution within the biopsies. The tissue reactions to both BSM were microscopically analyzed. RESULTS: The 3D and 2D results of the osteoconductivity measurements showed comparable material-bone contacts for both BSM, but the 2D data were significantly lower. The same results were found when tissue distribution was measured in both groups. The histopathological analysis showed comparative tissue reactions in both BSM. CONCLUSION: Osteoconductivity index is a reliable measurement parameter for determining the healing capacities of BSM. The observed differences between both measurement methods could be assigned to the resolution capacity of µ-CT data that did not allow for a precise interface distinction between both BSM and bone tissue. Histomorphometrical data based on histological slides still allow for a more exact evaluation.

Ectopic osteogenesis effect of antigen-extracted xenogeneic cancellous bone graft with chitosan/rhBMP-2/bFGF sequential sustained-release nanocapsules.

To explore the ectopic osteogenesis effect of sequential sustained release application of recombinant human bone morphogenic protein-2 (rhBMP-2) and basic fibroblast growth factor (bFGF). Antigen-extracted xenogeneic cancellous bone coupled with growth factor-loaded chitosan nanocapsules were implanted in rats in intramuscular site in accordance with the following experimental pattern: group A: simultaneous burst release of rhBMP-2 and bFGF; group B: simultaneous sustained release of rhBMP-2 and bFGF; group C: preferential burst release of rhBMP-2, then sustained release of bFGF; group D: preferential burst release of bFGF, then sustained release of rhBMP-2; group E: sustained release of rhBMP-2 alone; group F: sustained release of bFGF alone, blank control group G: antigen-extracted xenogeneic cancellous bone graft only; negative control group H: not filled with anything. Specimens were obtained after executing the animals at 2 and 4 weeks for general observation and weighing, calcium content detection, micro-CT scanning and bone parameter measurement analysis, H&E staining, ALP staining and CD34 staining. The materials weight of A-2, B-2, C-2, A-4, B-4, C-4, D-4 and E-4 were significantly higher than that of preoperative materials ( P < 0.05). The concentration of calcium of group B-4 was the highest (414.7 ± 12.03 mg/dl). Micro-CT scanning and bone parameter measurement analysis showed that the values of bone mineral density and trabecular thickness of group A, B, D, E at 4 weeks were both higher than the ones at 2 weeks ( P < 0.05), and both the bone mineral density (367.52 ± 11.64 mg/cc) and the trabecular thickness (126.17 ± 11.36 µm) of group B-4 were the highest. H&E staining showed that a large region of calcified cartilage and haemopoietic tissues were newly formed, especially in group B-4. ALP staining and CD34 staining showed the most positive expression region in group B-4. Therefore, we conclude that simultaneous sustained release of rhBMP-2 and bFGF is the ideal way to release drug, and has better inducement of antigen-extracted xenogeneic cancellous bone graft.

Histomorphometric and immunohistochemical evaluation of collagen containing xenogeneic bone blocks used for lateral bone augmentation in staged implant placement.

BACKGROUND: The osteoconductive properties of collagen containing xenogeneic bone blocks (CCXBB) remain unclear. The aim of this prospective single-arm clinical study was to assess the histological outcomes of CCXBB blocks used as bone replacement grafts for lateral bone augmentation procedures. METHODS: In 15 patients with severe horizontal alveolar ridge resorption, lateral augmentation procedures were performed using CCXBB as bone replacement grafts. Twenty-six weeks postoperatively, a re-entry procedure was performed to evaluate the bone width for adequate implant placement and two histological specimens were retrieved from each patient, one being processed for ground sectioning and the other for decalcified paraffin-included sections. In non-decalcified sections, the relative proportions occupied by bone, biomaterials, and connective tissue present in the biopsies were identified. In de-calcified sections, structures and cells positive for osteopontin (OPN), tartrate-resistant acid phosphatase activity (TRAP), osteocalcin (OSC), and alkaline phosphatase (ALP) were assessed. RESULTS: Soft tissue dehiscence occurred during the follow-up in 5 out of 15 patients (33.3%). The mean crest width at baseline was 2.78 mm (SD 0.57) and the mean crest width at re-entry was 6.90 mm (SD 1.22), with a mean ridge width increase of 4.12 mm (SD 1.32). Twenty-six bone biopsies were obtained from 13 patients. Histomorphometric analysis showed a mean of 26.90% (SD 12.21) of mineralized vital bone (MVB), 21.37% (SD 7.36) of residual CCXBB, 47.13% (SD 19.15) of non-mineralized tissue, and 0.92% of DBBM. The immunohistochemical analysis revealed a large number of OPN-positive cells 8.12% (SD 4.73), a lower proportion of TRAP positive multinuclear cells 5.09% (SD 4.91), OSC-positive cells 4.09% (SD 4.34), and a limited amount of ALP positive cells 1.63% (SD 2). CONCLUSIONS: CCXBB achieved significant horizontal crestal width allowing for staged implant placement in most of the patients. In light of the histological outcomes and implant failures, special attention must be placed to prevent soft tissue dehiscence when CCXBB is used in severe atrophic alveolar crests.

Performance and safety of collagenated xenogeneic bone block for lateral alveolar ridge augmentation and staged implant placement. A monocenter, prospective single-arm clinical study.

OBJECTIVES: To assess the clinical safety and performance of collagenated xenogeneic bone block (CXBB) for lateral alveolar ridge augmentation and two-stage implant placement. MATERIAL & METHODS: In ten patients exhibiting a single-tooth gap, the surgical procedure included the preparation of mucoperiosteal flaps, a rigid fixation of CXBB (Geistlich Bio-Graft® ) using an osteosynthesis screw, and contour augmentation. After 24 weeks of submerged healing, the primary endpoint was defined as the final ridge width sufficient to place an adequately dimensioned titanium implant at the respective sites. Secondary outcomes included, for example, the gain in ridge width (mm). Clinical parameters (e.g., bleeding on probing - BOP, probing depth - PD, mucosal recession - MR) were assessed immediately after the cementation of the crown and at the final visit. RESULTS: At 24 weeks, implant placement could be achieved in 8 of 10 patients exhibiting a mean gain in ridge width (mean ± SD) of 3.88 ± 1.75 mm. Histological analysis has pointed to a homogeneous osseous organization of CXBB. The changes of mean BOP, PD, and MR values at the final visit amounted to 16.62 ± 32.02%, 0.04 ± 0.21 mm, and -0.04 ± 0.12 mm, respectively. CONCLUSIONS: CXBB may be successfully used to support lateral alveolar ridge augmentation and two-stage implant placement.

Induction of multinucleated giant cells in response to small sized bovine bone substitute (Bio-Oss™) results in an enhanced early implantation bed vascularization.

PURPOSE: The host tissue reaction to the xenogeneic bone substitute Bio-Oss™ (Geistlich Biomaterials, Wolhousen, Switzerland) was investigated focusing on the participating inflammatory cells and implantation bed vascularization. MATERIALS AND METHODS: Bio-Oss™ was implanted subcutaneously into CD1 mice for up to 60 days and analyzed by means of specialized histological and histomorphometrical techniques after explantation. RESULTS: Bio-Oss™ induced within the first 15 days an early high vascularization combined with a marked presence of multinucleated giant cells. The latter cells were associated mainly with the smaller sized granules within the implantation bed. Toward the end of the study the number of multinucleated giant cells decreased while the tissue reaction to the larger granules was mainly mononuclear. CONCLUSION: The results of the present study showed that smaller xenogeneic bone substitute granules induce multinucleated giant cells, whereas the larger-sized ones became integrated within the implantation bed by means of a mononuclear cell-triggered granulation tissue. Obviously, the presence of multinucleated giant cells within biomaterial implantation beds is not only related to the type of synthetic bone substitute material, but also to the granule size of the natural-based xenogeneic bone substitute material.

Surgical reconstruction of peri-implant bone defects with prehydrated and collagenated porcine bone and collagen barriers: case presentations.

BACKGROUND: Surgical reconstruction of peri-implant defects is challenging and unpredictable due to, for example, the extent of the bone defect or the osteogenic potential of adjunctive materials used. PURPOSE: To study the healing capacity of a new bone xenograft material in the treatment of peri-implant defects. MATERIAL AND METHODS: In three cases with advanced peri-implant defects, flap surgery was performed. After thorough debridement including cleaning of the exposed implant surface, prehydrated and collagenated porcine bone (PCPB) particles were placed into the defect. A bioresorbable collagen barrier was adapted and placed over the defect and the flaps were relocated. After 6 and 12 months of healing, clinical and radiographic examinations were done. In one case, the surgical procedure was repeated 6 months postoperatively. One year after the second surgery, a bone biopsy was harvested and analyzed with histology. RESULTS: All defects healed uneventfully. At 6 months, probing depths were reduced by 3-4 mm with no bleeding on probing or pus formation. At 12 months, healthy peri-implant conditions were found. Intra-oral radiographs showed gain of the marginal bone level by 2-4 mm. In the case where reconstructive surgery was repeated, histology showed osteoconductive properties as bone formation with typical osteoblastic seams was observed directly on the surface of the grafted particles. CONCLUSION: The presented cases show that PCPB have favorable properties enhancing bone regeneration in peri-implant bone defects.

The Effect of New Bone Formation of Onlay Bone Graft Using Various Graft Materials with a Titanium Cap on the Rabbit Calvarium

0.05).SUMMARY: This result suggests that autogenous bone is the best choice for new bone formation, but when autogenous bone graft is in limited availability, alloplastic and xenogenic bone graft also can be an alternative bone graft material to use with a suitably guided membrane.