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- Giannobile, W. V., et al.
(author)
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Biological factors involved in alveolar bone regeneration Consensus report of Working Group 1 of the 15(th) European Workshop on Periodontology on Bone Regeneration
- 2019
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In: Journal of Clinical Periodontology. - : Wiley. - 0303-6979 .- 1600-051X. ; 46, s. 6-11
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Journal article (peer-reviewed)abstract
- Background and Aims To describe the biology of alveolar bone regeneration. Material and Methods Four comprehensive reviews were performed on (a) mesenchymal cells and differentiation factors leading to bone formation; (b) the critical interplay between bone resorbing and formative cells; (c) the role of osteoimmunology in the formation and maintenance of alveolar bone; and (d) the self-regenerative capacity following bone injury or tooth extraction were prepared prior to the workshop. Results and Conclusions This summary information adds to the fuller understanding of the alveolar bone regenerative response with implications to reconstructive procedures for patient oral rehabilitation. The group collectively formulated and addressed critical questions based on each of the reviews in this consensus report to advance the field. The report concludes with identified areas of future research.
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| 3. |
- Lyngstadaas, S. P., et al.
(author)
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Titanium Granules for Augmentation of the Maxillary Sinus - A Multicenter Study
- 2015
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In: Clinical Implant Dentistry and Related Research. - : Wiley. - 1523-0899. ; 17
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Journal article (peer-reviewed)abstract
- BackgroundBiomaterials are commonly used to augment the maxillary sinus floor prior to or in conjunction with dental implant installation. Recently, porous titanium granules (PTGs) have been used in oral implant surgery to stabilize implants and function as an osteoconductive matrix. PurposeTo evaluate if PTGs can be safely used in a larger population of patients, treated by different surgeons, when sinus floor augmentation was required in conjunction with implant installation. The primary endpoint was 12-month survival rate of the dental implants. Biopsies for histology were taken from the augmented area. Materials and MethodsAt five centers, 40 subjects with uni or bilateral posterior edentulism and atrophy of the posterior maxilla (3-6mm) were enrolled. In a single-stage procedure, PTG and one to three dental implants were installed in each quadrant. In total, 70 implants were included in the study. ResultsOne immobile implant was removed. The mean marginal bone loss was 0.5mm and 0.8mm, on the mesial and distal side, respectively. Histologically, all biopsies demonstrated bone ingrowth. ConclusionsThe results suggest that PTG can be safely and effectively used as augmentation material in the sinus floor when used with dental implants in a one-stage procedure.
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| 4. |
- Obregon-Whittle, Maria V, et al.
(author)
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Enamel matrix derivative stimulates expression and secretion of resistin in mesenchymal cells.
- 2011
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In: European journal of oral sciences. - : Wiley. - 1600-0722 .- 0909-8836. ; 119 Suppl 1, s. 366-72
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Journal article (peer-reviewed)abstract
- In this study we wanted to identify the effect of enamel matrix derivative (EMD) on adipocytokines, so-called adipokines. Primary human cells of mesenchymal origin (osteoblasts, periodontal ligament cells, mesenchymal stem cells, and pulp cells) and hematopoietic origin (monocytes) were incubated with EMD. The levels of adipokines in cell culture medium were quantified using the Lincoplex human adipocyte panel (Luminex) and by real-time PCR of mRNA isolated from cell lysates. Rats were injected with 2 mg of EMD or saline intramuscularly every third day for 14 d. Blood samples were taken before and after injections, and the level of resistin in rat plasma was measured by ELISA. We found a dramatic increase in the secretion of resistin from mesenchymal stem cells, and verified this result in all the cells of mesenchymal origin tested. However, we observed no significant changes in the amount of resistin secreted from monocytes exposed to EMD compared with the control. Injections of EMD significantly enhanced the circulating levels of resistin in rats, and EMD also significantly enhanced the activity of the resistin promoter in transfected mesenchymal stem cells, indicating a direct effect on resistin expression. Our results indicate that resistin may play a role in mediating the biological effect of EMD in mesenchymal tissues.
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| 5. |
- Svensson Bonde, Johan, et al.
(author)
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Histidine tag fusion increases expression levels of active recombinant amelogenin in Escherichia coli
- 2006
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In: Protein Expression and Purification. - : Elsevier BV. - 1046-5928. ; 48:1, s. 134-141
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Journal article (peer-reviewed)abstract
- Amelogenin is a dental enamel matrix protein involved in formation of dental enamel. In this study, we have expressed two different recombinant murine amelogenins in Escherichia coli: the untagged rM179, and the histidine tagged rp(H)M180, identical to rM179 except that it carries the additional N-terminal sequence MRGSHHHHHHGS. The effects of the histidine tag on expression levels, and on growth properties of the amelogenin expressing cells were studied. Purification of a crude protein extract containing rp(H)M 180 was also carried out using IMAC and reverse-phase HPLC. The results of this study showed clearly that both growth properties and amelogenin expression levels were improved for E coli cells expressing the histidine tagged amelogenin rp(H)M 180, compared to cells expressing the untagged amelogenin rM179. The positive effect of the histidine tag on amelogenin expression is proposed to be due to the hydrophilic nature of the histidine tag, generating a more hydrophilic amelogenin, which is more compatible with the host cell. Human osteoblasts treated with the purified rp(H)M 180 showed increased levels of secreted osteocalcin, compared to untreated cells. This response was similar to cells treated with enamel matrix derivate, mainly composed by amelogenin, suggesting that the recombinant protein is biologically active. Thus, the histidine tag favors expression and purification of biologically active recombinant amelogenin. (c) 2006 Elsevier Inc. All rights reserved.
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| 6. |
- Verket, A., et al.
(author)
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Maxillary Sinus Augmentation with Porous Titanium Granules: A Microcomputed Tomography and Histologic Evaluation of Human Biopsy Specimens
- 2013
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In: International Journal of Oral & Maxillofacial Implants. - 0882-2786. ; 28:3, s. 721-728
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Journal article (peer-reviewed)abstract
- Purpose: The aim of this study was to assess bone ingrowth into porous titanium granules used for maxillary sinus augmentation. Materials and Methods: Eighteen biopsy specimens from 17 patients participating in a clinical trial on sinus augmentation using porous titanium granules (PTG) were received in the laboratory. The specimens (trephine cores of 4.5 mm) were obtained 6 months after PTG placement. After being embedded in methacrylate, the samples were scanned in a microcomputed tomography (micro-CT) scanner. Specimens were then cut along the long axis and central slices were ground to 70 mu m before staining with hematoxylin and eosin. Results: The micro-CT analysis demonstrated an average bone fill of 19% (standard deviation [SD] 5.8%), whereas the graft material occupied 22.7% (SD 4.7%). The volume of newly formed bone decreased with the distance from the residual bone of the sinus floor. Two-dimensional histomorphometric analysis demonstrated a mean area of new bone of 16.1% (SD 9.4%). The PTG alone occupied 25.9% of the total mean area (SD 6.1%). The newly formed bone consisted mainly of woven bone growing in close contact with the granules and bridging the intergranular space. The remaining area was occupied predominantly by nonmineralized connective tissue. There were no signs of inflammation in any of the biopsy specimens. Conclusions: After 6 months, new bone had formed at a similar rate and quality as has been reported for other well-recognized bone graft substitutes. The new bone formed in close contact with the PTG, suggesting that the material is osteoconductive.
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| 7. |
- Wohlfahrt, Johan C., et al.
(author)
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Microcomputed tomographic and histologic analysis of animal experimental degree II furcation defects treated with porous titanium granules or deproteinized bovine bone
- 2012
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In: Journal of Periodontology. - : Wiley. - 0022-3492 .- 1943-3670. ; 83, s. 211-221
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Journal article (peer-reviewed)abstract
- Background: Titaniumis an interesting material for osseous reconstruction given its thrombogenic properties. The aim of this study is to compare the potential of porous titaniumgranules (PTGs) with sham and deproteinized bovine bone mineral (DBBM) in the reconstructive treatment of surgically created buccal, degree II furcation defects in mini-pigs. Methods: Buccal degree II furcation defects were surgically created in maxillary premolar teeth in adult, female, mini-pigs and filled with PTG or DBBM or were left empty (sham). After 6 weeks of healing, pigs were euthanized. Teeth with defects were excised en bloc and analyzed by microcomputed tomography (microCT) and histology. Results: The histologic analysis showed significantly more vertical bone formation in both PTG and sham groups compared to DBBM-treated defects (P <0.01). The microCT analysis showed significantly more bucco-palatal bone formation in furcations treated with PTG compared to the DBBM and sham (P <0.05). Bucco-palatal cylindrical microCT cores demonstrated a median defect fill of 96.8% for PTG-implanted defects, which was significantly greater than sham (72.2%) and DBBM (62.0%) (P <0.001) treatments. Significantly more regenerated periodontal ligament was seen for sham than DBBM-treated defects (P <0.05). Root resorption lacunae were small and infrequent and did not differ among groups. Conclusions: The results of this study in mini-pigs suggest that PTG may integrate well in alveolar bone and supports osseous regrowth in degree II furcation defects. Moreover, PTG seems safe to use in close proximity to root surfaces. Clinical studies will be necessary to further explore these experimental animal findings.
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