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Christine Knabe - One of the best experts on this subject based on the ideXlab platform.

  • effect of rapidly resorbable bone substitute materials on the temporal expression of the osteoblastic phenotype in vitro
    Journal of Biomedical Materials Research Part A, 2008
    Co-Authors: Christine Knabe, Itai Kranz, Renate Gildenhaar, Paul Ducheyne, Alireza Houshmand, G Berger, Michael Stiller
    Abstract:

    Ideally, bioactive ceramics for use in Alveolar Ridge Augmentation should possess the ability to activate bone formation and, thus, cause the differentiation of osteoprogenitor cells into osteoblasts at their surfaces. Therefore, in order to evaluate the osteogenic potential of novel bone substitute materials, it is important to examine their effect on osteoblastic differentiation. This study examines the effect of rapidly resorbable calcium–alkali–orthophosphates on osteoblastic phenotype expression and compares this behavior to that of β-tricalcium phosphate (TCP) and bioactive glass 45S5. Test materials were three materials (denominated GB14, GB9, GB9/25) with a crystalline phase Ca2KNa(PO4)2 and with a small amorphous portion containing either magnesium potassium phosphate (GB14) or silica phosphate (GB9 and GB9/25, which also contains Ca2P2O7); and a material with a novel crystalline phase Ca10[K/Na](PO4)7 (material denominated 352i). SaOS-2 human bone cells were grown on the substrata for 3, 7, 14, and 21 days, counted, and probed for an array of osteogenic markers. GB9 had the greatest stimulatory effect on osteoblastic proliferation and differentiation, suggesting that this material possesses the highest potency to enhance osteogenesis. GB14 and 352i supported osteoblast differentiation to the same or a higher degree than TCP, whereas, similar to bioactive glass 45S5, GB9/25 displayed a greater stimulatory effect on osteoblastic phenotype expression, indicating that GB9/25 is also an excellent material for promoting osteogenesis. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008

  • effect of rapidly resorbable bone substitute materials on the temporal expression of the osteoblastic phenotype in vitro
    Journal of Biomedical Materials Research Part A, 2008
    Co-Authors: Christine Knabe, Itai Kranz, Renate Gildenhaar, Paul Ducheyne, Alireza Houshmand, G Berger, Michael Stiller
    Abstract:

    Ideally, bioactive ceramics for use in Alveolar Ridge Augmentation should possess the ability to activate bone formation and, thus, cause the differentiation of osteoprogenitor cells into osteoblasts at their surfaces. Therefore, in order to evaluate the osteogenic potential of novel bone substitute materials, it is important to examine their effect on osteoblastic differentiation. This study examines the effect of rapidly resorbable calcium-alkali-orthophosphates on osteoblastic phenotype expression and compares this behavior to that of beta-tricalcium phosphate (TCP) and bioactive glass 45S5. Test materials were three materials (denominated GB14, GB9, GB9/25) with a crystalline phase Ca(2)KNa(PO(4))(2) and with a small amorphous portion containing either magnesium potassium phosphate (GB14) or silica phosphate (GB9 and GB9/25, which also contains Ca(2)P(2)O(7)); and a material with a novel crystalline phase Ca(10)[K/Na](PO(4))(7) (material denominated 352i). SaOS-2 human bone cells were grown on the substrata for 3, 7, 14, and 21 days, counted, and probed for an array of osteogenic markers. GB9 had the greatest stimulatory effect on osteoblastic proliferation and differentiation, suggesting that this material possesses the highest potency to enhance osteogenesis. GB14 and 352i supported osteoblast differentiation to the same or a higher degree than TCP, whereas, similar to bioactive glass 45S5, GB9/25 displayed a greater stimulatory effect on osteoblastic phenotype expression, indicating that GB9/25 is also an excellent material for promoting osteogenesis.

  • effect of rapidly resorbable calcium phosphates and a calcium phosphate bone cement on the expression of bone related genes and proteins in vitro
    Journal of Biomedical Materials Research Part A, 2004
    Co-Authors: Renate Gildenhaar, Christine Knabe, G Berger, J Meyer, C R Howlett, Boban Markovic, Hala Zreiqat
    Abstract:

    The use of biodegradable bone substitutes is advantageous for Alveolar Ridge Augmentation because it avoids second-site surgery for autograft harvesting. This study examines the effect of novel, rapidly resorbable calcium phosphates and a calcium phosphate bone cement on the expression of bone-related genes and proteins by human bone-derived cells (HBDCs) and compares this behavior to that of tricalciumphosphate (TCP). Test materials were alpha-TCP, two materials with a crystalline phase Ca(2)KNa(PO(4))(2) and with a small amorphous portion containing either magnesium potassium phosphate (material denominated GB14) or silica phosphate (material denominated GB9), and a calcium phosphate bone cement (material denominated Biocement D). HBDCs were grown on the substrata for 3, 7, 14, and 21 days, counted, and probed for various mRNAs and proteins (type I collagen, osteocalcin, osteopontin, osteonectin, alkaline phosphatase, and bone sialoprotein). All substrates supported continuous cellular growth for 21 days. In the presence of GB14 and Biocement D specimens cell proliferation was reduced and cell differentiation increased. At day 21, the greatest number of cells was found on GB9 expressing significantly higher levels of bone-related proteins than cells grown on all other surfaces. Because all novel materials facilitated the expression of the osteoblastic phenotype at least as much as TCP and the polystyrene control, these biomaterials can be regarded as excellent candidate bone substitute materials. GB9 induced the highest proliferation and cellular differentiation after 21 days of incubation, suggesting that this material may possess a higher potency for enhancing osteogenesis than TCP.

  • the functional expression of human bone derived cells grown on rapidly resorbable calcium phosphate ceramics
    Biomaterials, 2004
    Co-Authors: Renate Gildenhaar, Christine Knabe, G Berger, C R Howlett, Boban Markovic, Hala Zreiqat
    Abstract:

    Abstract The use of biodegradable bone substitutes is advantageous for Alveolar Ridge Augmentation, since it avoids second-site surgery for autograft harvesting. This study examines the effect of novel, rapidly resorbable calcium phosphates on the expression of bone-related genes and proteins by human bone-derived cells (HBDC) and compares this behavior to that of tricalciumphosphate (TCP). Test materials were α-TCP, and four materials which were created from β-Rhenanite and its derivatives: R1-β-Rhenanite (CaNaPO4); R1/M2 composed of CaNaPO4 and MgNaPO4; R1+SiO2 composed of CaNaPO4 and 9% SiO2 (wt%); and R17-Ca2KNa(PO4)2. HBDC were grown on the substrata for 3, 5, 7, 14 and 21 days, counted and probed for various mRNAs and proteins (Type I collagen, osteocalcin, osteopontin, osteonectin, alkaline phosphatase and bone sialoprotein). All substrata supported continuous cellular growth for 21 days. At day 21, surfaces of R1+SiO2 and R17 had the highest number of HBDC. At 14 and 21 days, cells on R1 and on R1+SiO2 displayed significantly enhanced expression of all osteogenic proteins. Since all novel calcium phosphates supported cellular proliferation together with expression of bone-related proteins at least as much as TCP, these ceramics can be regarded as potential bone substitutes. R1 and R1+SiO2 had the most effect on osteoblastic differentiation, thus suggesting that these materials may possess a higher potency to enhance osteogenesis than TCP.

Cristiano Susin - One of the best experts on this subject based on the ideXlab platform.

  • Histological analysis and gene expression profile following Augmentation of the anterior maxilla using rhBMP-2/ACS versus autogenous bone graft
    Journal of Clinical Periodontology, 2016
    Co-Authors: Rubens Moreno Freitas, João Antonio Chaves De Souza, W M Tamashiro, Claudio Marcantonio, Cristiano Susin, Luis Antonio Violin Dias Pereira, Ulf M E Wikesjö, Elcio Marcantonio
    Abstract:

    Aim: The objective of this report was to present histological characteristics and gene expression profile of newly formed bone following horizontal Augmentation of the atrophic anterior maxilla using recombinant human bone morphogenetic protein-2 in an absorbable collagen sponge carrier (rhBMP-2/ACS) versus an autogenous bone graft (ABG). Methods: Bone core biopsies from 24 subjects participating in a randomized clinical trial were obtained at dental implant placement, 6 months following Alveolar Ridge Augmentation using rhBMP-2/ACS (rhBMP-2 at 1.5 mg/ml; total dose 4.2 mg) or a particulate ABG harvested from the mandibular retro-molar region. A titanium mesh was used to provide wound stability and space for bone formation. Analysis included histological/histometric observations and gene expression profile of the newly formed bone. Results: rhBMP-2/ACS yielded bone marrow rich in capillaries, undifferentiated cells and bone lining cells compared with the ABG (p = 0.002). Whereas no significant differences were observed in total bone fraction (p = 0.53), non-vital bone particles trapped in lamellar vital bone were observed in the ABG group (p < 0.001). Real-time PCR showed greater BMP-2 and RUNX2 expression for rhBMP-2/ACS over the ABG (p = 0.001 and 0.0021, respectively), while the ABG exhibited greater expression of RANKL: OPG, BSP and OPN over rhBMP-2/ACS (p = 0.01, 0.005 and 0.0009, respectively). Conclusions: Our observations suggest that formative biological processes explain bone formation following implantation of rhBMP-2/ACS, whereas remodelling, resorptive/formative processes, characterizes sites receiving ABGs.

  • Alveolar Ridge Augmentation using implants coated with recombinant human bone morphogenetic protein 2 histologic observations
    Journal of Clinical Periodontology, 2008
    Co-Authors: Ulf M E Wikesjö, Cristiano Susin, Michael D Rohrer, Mohammed Qahash, Giuseppe Polimeni, Richard H Shanaman, John M Wozney, Jan Hall
    Abstract:

    Background: Studies using ectopic rodent, orthotopic canine, and non-human primate models show that bone morphogenetic proteins (BMPs) coated onto titanium surfaces induce local bone formation. The objective of this study was to examine the ability of recombinant human BMP-2 (rhBMP-2) coated onto a titanium porous oxide implant surface to stimulate local bone formation including osseointegration and vertical Augmentation of the Alveolar Ridge. Material and Methods: Bilateral, critical-size, 5 mm, supra-Alveolar, peri-implant defects were created in 12 young adult Hound Labrador mongrel dogs. Six animals received implants coated with rhBMP-2 at 0.75 or 1.5 mg/ml, and six animals received implants coated with rhBMP-2 at 3.0 mg/ml or uncoated control. Treatments were randomized between jaw quadrants. The mucoperiosteal flaps were advanced, adapted and sutured to submerge the implants for primary intention healing. The animals received fluorescent bone markers at weeks 3, 4, 7 and 8 post-surgery when they were euthanized for histologic evaluation. Results: Jaw quadrants receiving implants coated with rhBMP-2 exhibited gradually regressing swelling that became hard to palpate disguising the contours of the implants. The histologic evaluation showed robust bone formation reaching or exceeding the implant platform. The newly formed bone exhibited characteristics of the adjoining resident Type II bone including cortex formation for sites receiving implants coated with rhBMP-2 at 0.75 or 1.5 mg/ml. Sites receiving implants coated with rhBMP-2 at 3.0 mg/ml exhibited more immature trabecular bone formation, seroma formation and peri-implant bone remodelling resulting in undesirable implant displacement. Control implants exhibited minimal, if any, bone formation. Thus, implants coated with rhBMP-2 at 0.75, 1.5 and 3.0 mg/ml exhibited significant bone formation (height and area) compared with the sham-surgery control averaging (± SD) 4.4 ± 0.4, 4.2 ± 0.7 and 4.2 ± 1.2 versus 0.8 ± 0.3 mm; and 5.0 ± 2.2, 5.6 ± 2.2 and 7.4 ± 3.5 versus 0.7 ± 0.3mm 2 , respectively (p<0.01). All the treatment groups exhibited clinically relevant osseointegration. Conclusions: rhBMP-2 coated onto titanium porous oxide implant surfaces induced clinically relevant local bone formation including vertical Augmentation of the Alveolar Ridge and osseointegration. Higher concentrations/doses were associated with untoward effects.

Elcio Marcantonio - One of the best experts on this subject based on the ideXlab platform.

  • Histological analysis and gene expression profile following Augmentation of the anterior maxilla using rhBMP-2/ACS versus autogenous bone graft
    Journal of Clinical Periodontology, 2016
    Co-Authors: Rubens Moreno Freitas, João Antonio Chaves De Souza, W M Tamashiro, Claudio Marcantonio, Cristiano Susin, Luis Antonio Violin Dias Pereira, Ulf M E Wikesjö, Elcio Marcantonio
    Abstract:

    Aim: The objective of this report was to present histological characteristics and gene expression profile of newly formed bone following horizontal Augmentation of the atrophic anterior maxilla using recombinant human bone morphogenetic protein-2 in an absorbable collagen sponge carrier (rhBMP-2/ACS) versus an autogenous bone graft (ABG). Methods: Bone core biopsies from 24 subjects participating in a randomized clinical trial were obtained at dental implant placement, 6 months following Alveolar Ridge Augmentation using rhBMP-2/ACS (rhBMP-2 at 1.5 mg/ml; total dose 4.2 mg) or a particulate ABG harvested from the mandibular retro-molar region. A titanium mesh was used to provide wound stability and space for bone formation. Analysis included histological/histometric observations and gene expression profile of the newly formed bone. Results: rhBMP-2/ACS yielded bone marrow rich in capillaries, undifferentiated cells and bone lining cells compared with the ABG (p = 0.002). Whereas no significant differences were observed in total bone fraction (p = 0.53), non-vital bone particles trapped in lamellar vital bone were observed in the ABG group (p < 0.001). Real-time PCR showed greater BMP-2 and RUNX2 expression for rhBMP-2/ACS over the ABG (p = 0.001 and 0.0021, respectively), while the ABG exhibited greater expression of RANKL: OPG, BSP and OPN over rhBMP-2/ACS (p = 0.01, 0.005 and 0.0009, respectively). Conclusions: Our observations suggest that formative biological processes explain bone formation following implantation of rhBMP-2/ACS, whereas remodelling, resorptive/formative processes, characterizes sites receiving ABGs.

Ulf M E Wikesjö - One of the best experts on this subject based on the ideXlab platform.

  • Histological analysis and gene expression profile following Augmentation of the anterior maxilla using rhBMP-2/ACS versus autogenous bone graft
    Journal of Clinical Periodontology, 2016
    Co-Authors: Rubens Moreno Freitas, João Antonio Chaves De Souza, W M Tamashiro, Claudio Marcantonio, Cristiano Susin, Luis Antonio Violin Dias Pereira, Ulf M E Wikesjö, Elcio Marcantonio
    Abstract:

    Aim: The objective of this report was to present histological characteristics and gene expression profile of newly formed bone following horizontal Augmentation of the atrophic anterior maxilla using recombinant human bone morphogenetic protein-2 in an absorbable collagen sponge carrier (rhBMP-2/ACS) versus an autogenous bone graft (ABG). Methods: Bone core biopsies from 24 subjects participating in a randomized clinical trial were obtained at dental implant placement, 6 months following Alveolar Ridge Augmentation using rhBMP-2/ACS (rhBMP-2 at 1.5 mg/ml; total dose 4.2 mg) or a particulate ABG harvested from the mandibular retro-molar region. A titanium mesh was used to provide wound stability and space for bone formation. Analysis included histological/histometric observations and gene expression profile of the newly formed bone. Results: rhBMP-2/ACS yielded bone marrow rich in capillaries, undifferentiated cells and bone lining cells compared with the ABG (p = 0.002). Whereas no significant differences were observed in total bone fraction (p = 0.53), non-vital bone particles trapped in lamellar vital bone were observed in the ABG group (p < 0.001). Real-time PCR showed greater BMP-2 and RUNX2 expression for rhBMP-2/ACS over the ABG (p = 0.001 and 0.0021, respectively), while the ABG exhibited greater expression of RANKL: OPG, BSP and OPN over rhBMP-2/ACS (p = 0.01, 0.005 and 0.0009, respectively). Conclusions: Our observations suggest that formative biological processes explain bone formation following implantation of rhBMP-2/ACS, whereas remodelling, resorptive/formative processes, characterizes sites receiving ABGs.

  • Alveolar Ridge Augmentation using implants coated with recombinant human bone morphogenetic protein 2 histologic observations
    Journal of Clinical Periodontology, 2008
    Co-Authors: Ulf M E Wikesjö, Cristiano Susin, Michael D Rohrer, Mohammed Qahash, Giuseppe Polimeni, Richard H Shanaman, John M Wozney, Jan Hall
    Abstract:

    Background: Studies using ectopic rodent, orthotopic canine, and non-human primate models show that bone morphogenetic proteins (BMPs) coated onto titanium surfaces induce local bone formation. The objective of this study was to examine the ability of recombinant human BMP-2 (rhBMP-2) coated onto a titanium porous oxide implant surface to stimulate local bone formation including osseointegration and vertical Augmentation of the Alveolar Ridge. Material and Methods: Bilateral, critical-size, 5 mm, supra-Alveolar, peri-implant defects were created in 12 young adult Hound Labrador mongrel dogs. Six animals received implants coated with rhBMP-2 at 0.75 or 1.5 mg/ml, and six animals received implants coated with rhBMP-2 at 3.0 mg/ml or uncoated control. Treatments were randomized between jaw quadrants. The mucoperiosteal flaps were advanced, adapted and sutured to submerge the implants for primary intention healing. The animals received fluorescent bone markers at weeks 3, 4, 7 and 8 post-surgery when they were euthanized for histologic evaluation. Results: Jaw quadrants receiving implants coated with rhBMP-2 exhibited gradually regressing swelling that became hard to palpate disguising the contours of the implants. The histologic evaluation showed robust bone formation reaching or exceeding the implant platform. The newly formed bone exhibited characteristics of the adjoining resident Type II bone including cortex formation for sites receiving implants coated with rhBMP-2 at 0.75 or 1.5 mg/ml. Sites receiving implants coated with rhBMP-2 at 3.0 mg/ml exhibited more immature trabecular bone formation, seroma formation and peri-implant bone remodelling resulting in undesirable implant displacement. Control implants exhibited minimal, if any, bone formation. Thus, implants coated with rhBMP-2 at 0.75, 1.5 and 3.0 mg/ml exhibited significant bone formation (height and area) compared with the sham-surgery control averaging (± SD) 4.4 ± 0.4, 4.2 ± 0.7 and 4.2 ± 1.2 versus 0.8 ± 0.3 mm; and 5.0 ± 2.2, 5.6 ± 2.2 and 7.4 ± 3.5 versus 0.7 ± 0.3mm 2 , respectively (p<0.01). All the treatment groups exhibited clinically relevant osseointegration. Conclusions: rhBMP-2 coated onto titanium porous oxide implant surfaces induced clinically relevant local bone formation including vertical Augmentation of the Alveolar Ridge and osseointegration. Higher concentrations/doses were associated with untoward effects.

Frank Schwarz - One of the best experts on this subject based on the ideXlab platform.

  • histomorphometrical assessment of vertical Alveolar Ridge Augmentation using extracted tooth roots in the canine
    Clinical Oral Investigations, 2020
    Co-Authors: Puria Parvini, Carla Schliephake, Sarah Almaawi, Katrin Schwarz, Robert Sader, Shahram Ghanaati, Frank Schwarz
    Abstract:

    To histomorphometrically evaluate the influence of autoclavation on the efficacy of extracted tooth roots (TR) used for vertical Alveolar Ridge Augmentation. Upper premolars were randomly assigned to either autoclavation (TR-A) or an untreated control group (TR-C) and used as block grafts for vertical Alveolar Ridge Augmentation in both lower quadrants (n = 4 beagle dogs). Tissue biopsies were obtained after 15 weeks of submerged healing. Histological analyses considered gain in Ridge height (GRH), augmented area (AA), and the proportion of mineralized (MT) and non-mineralized tissue (NMT). TR-C and TR-A grafts were commonly associated with a complete replacement resorption and a marked gain in Ridge height. Significant differences between groups were noted for mean GRH [TR-C: 2.35 ± 0.55 vs. TR-A: 2.46 ± 0.21 mm] and AA [TR-C: 11.88 ± 4.31 vs. TR-A: 8.65 ± 1.59 mm2] values. Within AA, both groups revealed a comparable distribution of mean MT and NMT values. The linear regression analysis pointed to a significant correlation between NMT and AA values. Both TR-C and TR-A grafts supported vertical Alveolar Ridge Augmentation; however, GRH was improved in the TR-A group. TR grafts may serve as a potential alternative for vertical Alveolar Ridge Augmentation.

  • efficacy of autogenous tooth roots for lateral Alveolar Ridge Augmentation and staged implant placement a prospective controlled clinical study
    Journal of Clinical Periodontology, 2018
    Co-Authors: Frank Schwarz, Robert Sader, Didem Hazar, Kathrin Becker, Jurgen C Becker
    Abstract:

    OBJECTIVES To assess and compare the efficacy and safety of autogenous tooth roots (TR) and autogenous bone blocks (AB) for lateral Alveolar Ridge Augmentation and two-stage implant placement. MATERIAL AND METHODS A total of 30 patients in need of implant therapy and lateral Ridge Augmentation were allocated to parallel groups receiving either (a) healthy autogenous tooth roots (e.g. retained wisdom or impacted teeth) (n = 15) or (b) cortical autogenous bone blocks harvested from the retromolar area. After 26 weeks of submerged healing, the primary endpoint was defined as the crestal Ridge width (mm) (CW26) being sufficient to place an adequately dimensioned titanium implant at the respective sites. RESULTS Soft tissue healing was uneventful in both groups. CW26 at V isit 6 allowed for a successful implant placement in all patients of both TR (15/15) and AB groups (15/15). Mean CW26 values amounted to 10.06 ± 1.85 mm (median: 11.0) in the TR and 9.20 ± 2.09 mm (median: 8.50) in the AB group, respectively. The difference between both groups did not reach statistical significance (p = 0.241). CONCLUSIONS TR may serve as an alternative graft to support lateral Alveolar Ridge Augmentation and two-stage implant placement.

  • Radiographic outcomes following lateral Alveolar Ridge Augmentation using autogenous tooth roots
    SpringerOpen, 2018
    Co-Authors: Puria Parvini, Robert Sader, Didem Sahin, Jürgen Becker, Frank Schwarz
    Abstract:

    Abstract Background To assess and compare the radiographic outcomes following lateral Alveolar Ridge Augmentation using autogenous tooth roots (TR) and autogenous bone (AB) blocks. Methods In a total of 30 patients, lateral Ridge Augmentation was conducted in parallel groups using either (1) healthy autogenous tooth roots (e.g., retained wisdom or impacted teeth) (n = 15) or (2) cortical autogenous bone blocks harvested from the retromolar area. Cone-beam computed tomographic (CBCT) scans taken at 26 weeks of submerged healing were analyzed for the basal graft integration (i.e., contact between the graft and the host bone in %) (BI26) and the cross-sectional grafted area (mm2) (SA26). Results Both groups revealed a comparable clinical width of the Alveolar Ridge at baseline (CWb). Mean BI26 and SA26 values amounted to 69.26 ± 26.01% (median 72.44) and 22.07 ± 12.98 mm2 (median 18.83) in the TR group and 79.67 ± 15.66% (median 78.85) and 12.42 ± 10.11 mm2 (median 11.36) in the AB group, respectively. Between-group differences in mean SA26 values were statistically significant (p = 0.031). Linear regression analysis failed to reveal any significant correlations between BI26 and CWb/SA26 values in either group. Conclusions TR grafts may be associated with improved SA26 values following lateral Alveolar Ridge Augmentation. Trial registration DRKS00009586. Registered 10 February 2016