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The Microdamage and Expression of Sclerostin in Peri-implant Bone under One-time Shock Force Generated by Impact. Sci Rep 2017; 7:6508. [PMID: 28747741 PMCID: PMC5529451 DOI: 10.1038/s41598-017-06867-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 06/19/2017] [Indexed: 11/21/2022] Open
Abstract
Osseointegration is the key to implant stability and occlusal support. Biomechanical response and remodeling of peri-implant bone occurs under impact loading. Sclerostin participates in bone formation and resorption through Wnt and RANKL pathways. However the mechanism of microdamage and expression of sclerostin in peri-implant bone under impact load is still unclear. In present study, specific impact forces were applied to the implants with favorable osseointegration in rabbits. The microdamage of peri-implant bone and the expression of sclerostin, β-catenin and RANKL during the process of bone damage and remodeling were investigated by micro-CT, histology, immunofluorescence and RT-qPCR analysis. Interface separation and trabecular fracture were found histologically, which were consistent with micro-CT analyses. Throughout remodeling, bone resorption was observed during the first 14 days after impact, and osseointegration and normal trabecular structure were found by 28 d. The expression of sclerostin and RANKL increased after impact and reached a maximum by 14 d, then decreased gradually to normal levels by 28 d. And β-catenin expression was opposite. Results indicated that sclerostin may involve in the peri-implant bone damage caused by impact and remodeling through Wnt/β-catenin and RANKL/RANK pathways. It will provide a new insight in the diagnosis and treatment for patients suffering impact.
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Calcei JG, Berhouet J, Elpers M, Catanzano A, Wright TM, Craig EV, Warren RF, Dines DM, Gulotta LV. Retrieval Analysis of Porous Titanium Glenoid Posts: An Evaluation of Osteointegration. Orthopedics 2017; 40:e703-e707. [PMID: 28558113 DOI: 10.3928/01477447-20170522-04] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Accepted: 04/06/2017] [Indexed: 02/03/2023]
Abstract
Glenoid component loosening is a commonly encountered complication of total shoulder replacements. Therefore, focus has been placed on glenoid fixation. Porous metal implants, which promote biological fixation through osteointegration, have provided an uncemented alternative to the traditional cemented implant. In this explantation study, the authors examined the bone ingrowth and ongrowth of a specific porous titanium glenoid peg. Six explanted polyethylene glenoid components with porous titanium-coated central pegs were identified in the authors' implant retrieval program via retrospective review. The retrieved implants were sectioned into thirds with a precision saw and underwent scanning electron microscopy for analysis of bone ingrowth and ongrowth. Bone ingrowth was calculated as bone volume fraction, or the fraction of available pore space filled with bone, whereas ongrowth was the percentage of the perimeter of the implant covered with bone. The 6 total shoulders included in the study were revised at an average of 16.3 months (range, 5-48 months) for instability secondary to subscapularis rupture, subscapularis rupture plus infection, or other rotator cuff tear. All glenoid components were grossly stable on retrieval and had an average of 23% bone ingrowth and 54% ongrowth. The preliminary results show that osteointegration into a porous titanium ingrowth glenoid component is possible in the short-term, even in the presence of an unfavorable biomechanical environment, such as instability and rotator cuff dysfunction, as well as infection. [Orthopedics. 2017; 40(4):e703-e707.].
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Wang L, Aghvami M, Brunski J, Helms J. Biophysical regulation of osteotomy healing: An animal study. Clin Implant Dent Relat Res 2017; 19:590-599. [PMID: 28608504 DOI: 10.1111/cid.12499] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 05/01/2017] [Accepted: 05/02/2017] [Indexed: 02/05/2023]
Abstract
BACKGROUND Osteotomies have been performed for centuries yet there remains a remarkable lack of consensus on optimal methods for cutting bone. There is universal agreement, however, that preserving cell viability is critical. PURPOSE To identify mechanobiological parameters influencing bone formation after osteotomy site preparation. MATERIALS AND METHODS A murine maxillary osteotomy model was used to evaluate healing. Computational modeling characterized stress and strain distributions in the osteotomy, as well as the magnitude and distribution of heat generated by drilling. The impact of osteocyte death and bone composition were assessed using molecular and cellular assays. RESULTS The phases of osteotomy healing in mice align closely with results in large animals; in addition, molecular analyses extended our understanding of osteoprogenitor cell proliferation, differentiation, and mineralization. Computational analyses provided insights into temperature changes caused by drilling and the mechanobiological state in the healing osteotomies, while concomitant cellular assays correlate drill speed with osteocyte apoptosis and bone resorption. Even when drilling was controlled, trabeculated, spongy (Type III) bone healed faster than densely lamellar (Type I) bone because of the abundance of Wnt responsive osteoprogenitor cells in the former. CONCLUSIONS These data provide a mechanobiological framework for evaluating tools and technologies designed to improve osteotomy site preparation.
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Affiliation(s)
- Liao Wang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.,Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, California, 94305
| | - Maziar Aghvami
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, California, 94305
| | - John Brunski
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, California, 94305
| | - Jill Helms
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, California, 94305
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54
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Pei X, Wang L, Chen C, Yuan X, Wan Q, Helms JA. Contribution of the PDL to Osteotomy Repair and Implant Osseointegration. J Dent Res 2017; 96:909-916. [PMID: 28481696 DOI: 10.1177/0022034517707513] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Our objective was to clarify the fate of the periodontal ligament (PDL) retained in the socket after tooth extraction, then determine if this tissue contributed to the osseointegration of "immediate" implants placed in these fresh extraction sockets. Mice underwent maxillary first molar extraction, the residual PDL was removed by an osteotomy, and titanium implants were placed. The osteotomy was created in such a way that the palatal surface was devoid of PDL remnants while the buccal, mesial, and distal surfaces retained PDL fibers. At multiple time points after surgery, tissues were analyzed using a battery of molecular, cellular, and histomorphometrical assays. We found that PDL remnants mineralized and directly contributed to new bone formation in the extraction site. Compared with regions of an extraction site where the PDL was removed by osteotomy, regions that retained PDL fibers had produced significantly more new bone. Around immediate implants, the retained PDL remnants directly contributed to new bone formation and osseointegration. Thus, we conclude that PDL remnants are inherently osteogenic, and if the tissue is healthy, it is reasonable to conclude that curetting out an extraction socket prior to immediate implant placement should be avoided. This recommendation aligns with contemporary trends toward minimally invasive surgical manipulations of the extraction socket prior to immediate implant placement.
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Affiliation(s)
- X Pei
- 1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA
| | - L Wang
- 1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA
| | - C Chen
- 2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA.,3 Craniofacial Research Center, Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan, ROC
| | - X Yuan
- 2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA
| | - Q Wan
- 1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - J A Helms
- 2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA
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55
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Jariwala SH, Wee H, Roush EP, Whitcomb TL, Murter C, Kozlansky G, Lakhtakia A, Kunselman AR, Donahue HJ, Armstrong AD, Lewis GS. Time course of peri-implant bone regeneration around loaded and unloaded implants in a rat model. J Orthop Res 2017; 35:997-1006. [PMID: 27381807 PMCID: PMC5800527 DOI: 10.1002/jor.23360] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 07/02/2016] [Indexed: 02/04/2023]
Abstract
The time-course of cancellous bone regeneration surrounding mechanically loaded implants affects implant fixation, and is relevant to determining optimal rehabilitation protocols following orthopaedic surgeries. We investigated the influence of controlled mechanical loading of titanium-coated polyether-ether ketone (PEEK) implants on osseointegration using time-lapsed, non-invasive, in vivo micro-computed tomography (micro-CT) scans. Implants were inserted into proximal tibial metaphyses of both limbs of eight female Sprague-Dawley rats. External cyclic loading (60 or 100 μm displacement, 1 Hz, 60 s) was applied every other day for 14 days to one implant in each rat, while implants in contralateral limbs served as the unloaded controls. Hind limbs were imaged with high-resolution micro-CT (12.5 μm voxel size) at 2, 5, 9, and 12 days post-surgery. Trabecular changes over time were detected by 3D image registration allowing for measurements of bone-formation rate (BFR) and bone-resorption rate (BRR). At day 9, mean %BV/TV for loaded and unloaded limbs were 35.5 ± 10.0% and 37.2 ± 10.0%, respectively, and demonstrated significant increases in bone volume compared to day 2. BRR increased significantly after day 9. No significant differences between bone volumes, BFR, and BRR were detected due to implant loading. Although not reaching significance (p = 0.16), an average 119% increase in pull-out strength was measured in the loaded implants. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:997-1006, 2017.
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Affiliation(s)
- Shailly H. Jariwala
- Division of Musculoskeletal Sciences, Department of Orthopedics and Rehabilitation, College of Medicine, Pennsylvania State University, Hershey, PA 17033
| | - Hwabok Wee
- Division of Musculoskeletal Sciences, Department of Orthopedics and Rehabilitation, College of Medicine, Pennsylvania State University, Hershey, PA 17033
| | - Evan P. Roush
- Division of Musculoskeletal Sciences, Department of Orthopedics and Rehabilitation, College of Medicine, Pennsylvania State University, Hershey, PA 17033
| | - Tiffany L. Whitcomb
- Department of Comparative Medicine, Pennsylvania State University College of Medicine, Hershey, PA 17033
| | - Christopher Murter
- Division of Musculoskeletal Sciences, Department of Orthopedics and Rehabilitation, College of Medicine, Pennsylvania State University, Hershey, PA 17033
| | - Gery Kozlansky
- Division of Musculoskeletal Sciences, Department of Orthopedics and Rehabilitation, College of Medicine, Pennsylvania State University, Hershey, PA 17033
| | - Akhlesh Lakhtakia
- Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, PA 16802-6812
| | - Allen R. Kunselman
- Department of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, PA 17033
| | - Henry J. Donahue
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA 23284
| | - April D. Armstrong
- Division of Musculoskeletal Sciences, Department of Orthopedics and Rehabilitation, College of Medicine, Pennsylvania State University, Hershey, PA 17033
| | - Gregory S. Lewis
- Division of Musculoskeletal Sciences, Department of Orthopedics and Rehabilitation, College of Medicine, Pennsylvania State University, Hershey, PA 17033
- Author to whom all correspondence should be addressed: Gregory S. Lewis, Ph.D*, Pennsylvania State University College of Medicine, 500 University Drive, Mailbox – H089, Hershey, PA-17033, Phone: (717) 531-5244, Fax no.: (717) 531-7583,
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56
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Bradaschia-Correa V, Josephson AM, Mehta D, Mizrahi M, Neibart SS, Liu C, Kennedy OD, Castillo AB, Egol KA, Leucht P. The Selective Serotonin Reuptake Inhibitor Fluoxetine Directly Inhibits Osteoblast Differentiation and Mineralization During Fracture Healing in Mice. J Bone Miner Res 2017; 32:821-833. [PMID: 27869327 PMCID: PMC5395314 DOI: 10.1002/jbmr.3045] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 11/14/2016] [Accepted: 11/15/2016] [Indexed: 11/10/2022]
Abstract
Chronic use of selective serotonin reuptake inhibitors (SSRIs) for the treatment of depression has been linked to osteoporosis. In this study, we investigated the effect of chronic SSRI use on fracture healing in two murine models of bone regeneration. First, we performed a comprehensive analysis of endochondral bone healing in a femur fracture model. C57/BL6 mice treated with fluoxetine, the most commonly prescribed SSRI, developed a normal cartilaginous soft-callus at 14 days after fracture and demonstrated a significantly smaller and biomechanically weaker bony hard-callus at 28 days. In order to further dissect the mechanism that resulted in a smaller bony regenerate, we used an intramembranous model of bone healing and revealed that fluoxetine treatment resulted in a significantly smaller bony callus at 7 and 14 days postinjury. In order to test whether the smaller bony regenerate following fluoxetine treatment was caused by an inhibition of osteogenic differentiation and/or mineralization, we employed in vitro experiments, which established that fluoxetine treatment decreases osteogenic differentiation and mineralization and that this effect is serotonin-independent. Finally, in a translational approach, we tested whether cessation of the medication would result in restoration of the regenerative potential. However, histologic and μCT analysis revealed non-union formation in these animals with fibrous tissue interposition within the callus. In conclusion, fluoxetine exerts a direct, inhibitory effect on osteoblast differentiation and mineralization, shown in two disparate murine models of bone repair. Discontinuation of the drug did not result in restoration of the healing potential, but rather led to complete arrest of the repair process. Besides the well-established effect of SSRIs on bone homeostasis, our study provides strong evidence that fluoxetine use negatively impacts fracture healing. © 2017 American Society for Bone and Mineral Research.
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Affiliation(s)
- Vivian Bradaschia-Correa
- Department of Orthopaedic Surgery, Langone Medical Center-Hospital for Joint Diseases, New York University, New York, NY, USA
| | - Anne M Josephson
- Department of Orthopaedic Surgery, Langone Medical Center-Hospital for Joint Diseases, New York University, New York, NY, USA
| | - Devan Mehta
- Department of Orthopaedic Surgery, Langone Medical Center-Hospital for Joint Diseases, New York University, New York, NY, USA
| | - Matthew Mizrahi
- Department of Orthopaedic Surgery, Langone Medical Center-Hospital for Joint Diseases, New York University, New York, NY, USA
| | - Shane S Neibart
- Department of Orthopaedic Surgery, Langone Medical Center-Hospital for Joint Diseases, New York University, New York, NY, USA
| | - Chao Liu
- Department of Orthopaedic Surgery, Langone Medical Center-Hospital for Joint Diseases, New York University, New York, NY, USA.,Department of Mechanical and Aerospace Engineering, Tandon School of Engineering, New York University, New York, NY, USA
| | - Oran D Kennedy
- Department of Orthopaedic Surgery, Langone Medical Center-Hospital for Joint Diseases, New York University, New York, NY, USA.,Department of Mechanical and Aerospace Engineering, Tandon School of Engineering, New York University, New York, NY, USA
| | - Alesha B Castillo
- Department of Orthopaedic Surgery, Langone Medical Center-Hospital for Joint Diseases, New York University, New York, NY, USA.,Department of Mechanical and Aerospace Engineering, Tandon School of Engineering, New York University, New York, NY, USA
| | - Kenneth A Egol
- Department of Orthopaedic Surgery, Langone Medical Center-Hospital for Joint Diseases, New York University, New York, NY, USA
| | - Philipp Leucht
- Department of Orthopaedic Surgery, Langone Medical Center-Hospital for Joint Diseases, New York University, New York, NY, USA.,Department of Cell Biology, School of Medicine, New York University, New York, NY, USA
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57
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Li J, Yin X, Huang L, Mouraret S, Brunski JB, Cordova L, Salmon B, Helms JA. Relationships among Bone Quality, Implant Osseointegration, and Wnt Signaling. J Dent Res 2017; 96:822-831. [PMID: 28571512 DOI: 10.1177/0022034517700131] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
A variety of clinical classification schemes have been proposed as a means to identify sites in the oral cavity where implant osseointegration is likely to be successful. Most schemes are based on structural characteristics of the bone, for example, the relative proportion of densely compact, homogenous (type I) bone versus more trabeculated, cancellous (type III) bone. None of these schemes, however, consider potential biological characteristics of the bone. Here, we employed multiscale analyses to identify and characterize type I and type III bones in murine jaws. We then combined these analytical tools with in vivo models of osteotomy healing and implant osseointegration to determine if one type of bone healed faster and supported osseointegration better than another. Collectively, these studies revealed a strong positive correlation between bone remodeling rates, mitotic activity, and osteotomy site healing in type III bone and high endogenous Wnt signaling. This positive correlation was strengthened by observations showing that the osteoid matrix that is responsible for implant osseointegration originates from Wnt-responsive cells and their progeny. The potential application of this knowledge to clinical practice is discussed, along with a theory unifying the role that biology and mechanics play in implant osseointegration.
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Affiliation(s)
- J Li
- 1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - X Yin
- 1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - L Huang
- 2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA.,3 Department of Orthodontics, Stomatological Hospital of Chongqing Medical University, Chongqing, China
| | - S Mouraret
- 2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - J B Brunski
- 2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - L Cordova
- 2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA.,4 Department of Oral and Maxillofacial Surgery, School of Dentistry, University of Chile, Santiago, Chile
| | - B Salmon
- 5 EA 2496, Orofacial Pathologies, Imaging and Biothérapies Laboratoire, L'Université Paris Descartes, Sorbonne Paris Cité, Montrouge, France.,6 Le Service d'Odontologie de Bretonneau, Hôpitaux Universitaires Paris Nord Val de Seine, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - J A Helms
- 2 Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, CA, USA
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58
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Staruch R, Griffin MF, Butler P. Nanoscale Surface Modifications of Orthopaedic Implants: State of the Art and Perspectives. Open Orthop J 2016; 10:920-938. [PMID: 28217214 PMCID: PMC5299555 DOI: 10.2174/1874325001610010920] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Revised: 11/10/2015] [Accepted: 05/31/2016] [Indexed: 01/18/2023] Open
Abstract
Background: Orthopaedic implants such as the total hip or total knee replacement are examples of surgical interventions with postoperative success rates of over 90% at 10 years. Implant failure is associated with wear particles and pain that requires surgical revision. Improving the implant - bone surface interface is a key area for biomaterial research for future clinical applications. Current implants utilise mechanical, chemical or physical methods for surface modification. Methods: A review of all literature concerning the nanoscale surface modification of orthopaedic implant technology was conducted. Results: The techniques and fabrication methods of nanoscale surface modifications are discussed in detail, including benefits and potential pitfalls. Future directions for nanoscale surface technology are explored. Conclusion: Future understanding of the role of mechanical cues and protein adsorption will enable greater flexibility in surface control. The aim of this review is to investigate and summarise the current concepts and future directions for controlling the implant nanosurface to improve interactions.
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Affiliation(s)
- Rmt Staruch
- Department of Surgery & Interventional Science, University College London, London, England
| | - M F Griffin
- Department of Surgery & Interventional Science, University College London, London, England
| | - Pem Butler
- Department of Surgery & Interventional Science, University College London, London, England; University College London & The Royal Free Hospital, Pond Street, London, England
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59
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Milillo L, Fiandaca C, Giannoulis F, Ottria L, Lucchese A, Silvestre F, Petruzzi M. Immediate vs non-immediate loading post-extractive implants: a comparative study of implant stability quotient (ISQ). ORAL & IMPLANTOLOGY 2016; 9:123-131. [PMID: 28042440 DOI: 10.11138/orl/2016.9.3.123] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE This study aims to evaluate differences in implant stability between post-extractive implants vs immediately placed post-extractive implants by resonance frequency analysis (RFA). MATERIALS AND METHODS Patients were grouped into two different categories. In Group A 10 patients had an immediate post-extractive implant, then a provisional, acrylic resin crown was placed (immediate loading). In Group B (control group) 10 patients only had an immediate post-extractive implant. Both upper and lower premolars were chosen as post-extractive sites. Implant Stability Quotient (ISQ) was measured thanks to RFA measurements (Osstell®). Five intervals were considered: immediately after surgery (T0) and every four weeks, until five months after implant placement (T1, T2, T3, T4,T5). A statistical analysis by means of Student's T-test (significance set at p<0.05) for independent sample was carried out in order to compare Groups A and B. RESULTS The ISQ value between the two groups showed a statistically significant difference (p<0.02) at T1. No statistically significant difference in ISQ was assessed at T0, T2, T3, T4 and T5. CONCLUSIONS After clinical assessment it is possible to confirm that provisional and immediate prosthetic surgery in post-extraction sites with cone-shaped implants, platform-switching abutment and bioactive surface can facilitate osseointegration, reducing healing time.
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Affiliation(s)
| | | | | | - L Ottria
- Department of Clinical Science and Translational Medicine, University of Rome "Tor Vergata", Rome, Italy
| | - A Lucchese
- Dental Clinic of Second University of Naples (SUN), Naples, Italy
| | - F Silvestre
- Departimento de Estomatologia, University of Valencia, Valencia, Spain
| | - M Petruzzi
- Interdisciplinary Department of Medicine (DIM) - Section of Dentistry, University "Aldo Moro" of Bari, Bari, Italy
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60
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Piccinini M, Cugnoni J, Botsis J, Ammann P, Wiskott A. Peri-implant bone adaptations to overloading in rat tibiae: experimental investigations and numerical predictions. Clin Oral Implants Res 2016; 27:1444-1453. [DOI: 10.1111/clr.12760] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Marco Piccinini
- Laboratory of applied mechanics and reliability analysis; École Polytechnique Fédérale de Lausanne; Lausanne Switzerland
| | - Joel Cugnoni
- Laboratory of applied mechanics and reliability analysis; École Polytechnique Fédérale de Lausanne; Lausanne Switzerland
| | - John Botsis
- Laboratory of applied mechanics and reliability analysis; École Polytechnique Fédérale de Lausanne; Lausanne Switzerland
| | - Patrick Ammann
- Division of bone diseases; Department of internal medicine specialities; Geneva University Hospitals and Faculty of Medicine; Geneva Switzerland
| | - Anselm Wiskott
- Division of fixed prosthodontics and biomaterials; University Clinics of Dental Medicine; University of Geneva; Geneva Switzerland
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61
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What Is the Clinical Relevance of Radiographic Nonunion After Single-Level Lumbar Interbody Arthrodesis in Degenerative Disc Disease?: A Meta-Analysis of the YODA Project Database. Spine (Phila Pa 1976) 2016; 41:9-17. [PMID: 26274529 DOI: 10.1097/brs.0000000000001113] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Meta-analysis of 4 randomized controlled clinical trials (RCTs). OBJECTIVE The aim of the study was to determine if patients with degenerative disc disease who achieve radiographic fusion after single-level lumbar interbody arthrodesis have better clinical outcomes than patients with radiographic pseudarthrosis at 12 and 24 months postoperative. SUMMARY OF BACKGROUND DATA The clinical relevance of successful fusion after lumbar arthrodesis with recombinant human bone morphogenetic protein-2 or iliac crest bone autograft has recently been questioned in the literature. METHODS Individual patient-level data of 4 RCTs were obtained from the Yale University Open Data Access Project project and analyzed. Clinical outcomes (Oswestry Disability Index [ODI]; Numeric Rating Scales [NRSs] for back and leg pain) were compared between patients with radiographically confirmed fusion and those with radiographic nonunion 1 and 2 years postoperative. The results of each study were first analyzed separately, and then were pooled by meta-analysis. The GRADE approach was applied to evaluate the level of evidence. RESULTS A total of 496 patients with clinical and radiographic data at 1- and 2-year follow-ups were identified. Of these, 5.5% (95% confidence interval: 3.7; 8.3) had radiographic nonunion which did not require reoperation. Patients with fusion had better improvements in ODI (P < 0.001) and NRS back pain scores (P < 0.001). The overall percentage of fused patients with ODI and NRS back pain scores that exceeded the criteria for minimal clinically important differences was also significantly higher than that of patients with nonunion (ODI, odds ratio [OR] = 2.7, P = 0.019; NRS back pain, OR = 3.5, P = 0.033). The predictive values of fusion for clinical outcomes, however, were poor, with low specificity and low negative predictive values. CONCLUSION The presence of radiographic fusion is clinically significant, as patients with fusion had better clinical outcomes at 1 and 2 years postoperative than those with nonunion; however, patient-centered clinical outcomes should also be taken into consideration as independent, complimentary variables when assessing treatment success.
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62
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Meischel M, Eichler J, Martinelli E, Karr U, Weigel J, Schmöller G, Tschegg E, Fischerauer S, Weinberg A, Stanzl-Tschegg S. Adhesive strength of bone-implant interfaces and in-vivo degradation of PHB composites for load-bearing applications. J Mech Behav Biomed Mater 2016; 53:104-118. [DOI: 10.1016/j.jmbbm.2015.08.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 07/28/2015] [Accepted: 08/04/2015] [Indexed: 11/26/2022]
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63
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Li Z, Kuhn G, von Salis-Soglio M, Cooke SJ, Schirmer M, Müller R, Ruffoni D. In vivo monitoring of bone architecture and remodeling after implant insertion: The different responses of cortical and trabecular bone. Bone 2015; 81:468-477. [PMID: 26303288 DOI: 10.1016/j.bone.2015.08.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 08/17/2015] [Accepted: 08/19/2015] [Indexed: 12/01/2022]
Abstract
The mechanical integrity of the bone-implant system is maintained by the process of bone remodeling. Specifically, the interplay between bone resorption and bone formation is of paramount importance to fully understand the net changes in bone structure occurring in the peri-implant bone, which are eventually responsible for the mechanical stability of the bone-implant system. Using time-lapsed in vivo micro-computed tomography combined with new composite material implants, we were able to characterize the spatio-temporal changes of bone architecture and bone remodeling following implantation in living mice. After insertion, implant stability was attained by a quick and substantial thickening of the cortical shell which counteracted the observed loss of trabecular bone, probably due to the disruption of the trabecular network. Within the trabecular compartment, the rate of bone formation close to the implant was transiently higher than far from the implant mainly due to an increased mineral apposition rate which indicated a higher osteoblastic activity. Conversely, in cortical bone, the higher rate of bone formation close to the implant compared to far away was mostly related to the recruitment of new osteoblasts as indicated by a prevailing mineralizing surface. The behavior of bone resorption also showed dissimilarities between trabecular and cortical bone. In the former, the rate of bone resorption was higher in the peri-implant region and remained elevated during the entire monitoring period. In the latter, bone resorption rate had a bigger value away from the implant and decreased with time. Our approach may help to tune the development of smart implants that can attain a better long-term stability by a local and targeted manipulation of the remodeling process within the cortical and the trabecular compartments and, particularly, in bone of poor health.
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Affiliation(s)
- Zihui Li
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Gisela Kuhn
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | | | | | | | - Ralph Müller
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Davide Ruffoni
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland; Department of Aerospace and Mechanical Engineering, University of Liege, Liege, Belgium.
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64
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Digital volume correlation and micro-CT: An in-vitro technique for measuring full-field interface micromotion around polyethylene implants. J Biomech 2015; 48:3447-54. [PMID: 26113290 DOI: 10.1016/j.jbiomech.2015.05.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 04/21/2015] [Accepted: 05/26/2015] [Indexed: 11/20/2022]
Abstract
Micromotion around implants is commonly measured using displacement-sensor techniques. Due to the limitations of these techniques, an alternative approach (DVC-μCT) using digital volume correlation (DVC) and micro-CT (μCT) was developed in this study. The validation consisted of evaluating DVC-μCT based micromotion against known micromotions (40, 100 and 150 μm) in a simplified experiment. Subsequently, a more clinically realistic experiment in which a glenoid component was implanted into a porcine scapula was carried out and the DVC-μCT measurements during a single load cycle (duration 20 min due to scanning time) was correlated with the manual tracking of micromotion at 12 discrete points across the implant interface. In this same experiment the full-field DVC-μCT micromotion was compared to the full-field micromotion predicted by a parallel finite element analysis (FEA). It was found that DVC-μCT micromotion matched the known micromotion of the simplified experiment (average/peak error=1.4/1.7 μm, regression line slope=0.999) and correlated with the micromotion at the 12 points tracked manually during the realistic experiment (R(2)=0.96). The DVC-μCT full-field micromotion matched the pattern of the full-field FEA predicted micromotion. This study showed that the DVC-μCT technique provides sensible estimates of micromotion. The main advantages of this technique are that it does not damage important parts of the specimen to gain access to the bone-implant interface, and it provides a full-field evaluation of micromotion as opposed to the micromotion at just a few discrete points. In conclusion the DVC-μCT technique provides a useful tool for investigations of micromotion around plastic implants.
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65
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Heinemann F, Hasan I, Bourauel C, Biffar R, Mundt T. Bone stability around dental implants: Treatment related factors. Ann Anat 2015; 199:3-8. [PMID: 25770887 DOI: 10.1016/j.aanat.2015.02.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 11/15/2022]
Abstract
The bone bed around dental implants is influenced by implant and augmentation materials, as well as the insertion technique used. The primary influencing factors include the dental implant design, augmentation technique, treatment protocol, and surgical procedure. In addition to these treatment-related factors, in the literature, local and systemic factors have been found to be related to the bone stability around implants. Bone is a dynamic organ that optimises itself depending on the loading condition above it. Bone achieves this optimisation through the remodelling process. Several studies have confirmed the importance of the implant design and direction of the applied force on the implant system. Equally dispersed strains and stresses in the physiological range should be achieved to ensure the success of an implant treatment. If a patient wishes to accelerate the treatment time, different protocols can be chosen. However, each one must consider the amount and quality of the available local bone. Immediate implantation is only successful if the primary stability of the implant can be provided from residual bone in the socket after tooth extraction. Immediate loading demands high primary stability and, sometimes, the distribution of mastication forces by splinting or even by inserting additional implants to ensure their success. Augmentation materials with various properties have been developed in recent years. In particular, resorption time and stableness affect the usefulness in different situations. Hence, treatment protocols can optimise the time for simultaneous implant placements or optimise the follow-up time for implant placement.
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Affiliation(s)
- Friedhelm Heinemann
- Department of Prosthodontics, Gerodontology and Biomaterials, University of Greifswald, Rotgerberstr. 8, 17489 Greifswald, Germany.
| | - Istabrak Hasan
- Endowed Chair of Oral Technology, Department of Prosthodontics, Preclinical Education and Dental Materials Science, University of Bonn, Welschnonnenstr. 17, 53111 Bonn, Germany; Department of Prosthodontics, Preclinical Education and Dental Materials Science, University of Bonn, Welschnonnenstr. 17, 53111 Bonn, Germany
| | - Christoph Bourauel
- Endowed Chair of Oral Technology, Department of Prosthodontics, Preclinical Education and Dental Materials Science, University of Bonn, Welschnonnenstr. 17, 53111 Bonn, Germany
| | - Reiner Biffar
- Department of Prosthodontics, Gerodontology and Biomaterials, University of Greifswald, Rotgerberstr. 8, 17489 Greifswald, Germany
| | - Torsten Mundt
- Department of Prosthodontics, Gerodontology and Biomaterials, University of Greifswald, Rotgerberstr. 8, 17489 Greifswald, Germany
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66
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Cha JY, Pereira MD, Smith AA, Houschyar KS, Yin X, Mouraret S, Brunski JB, Helms JA. Multiscale analyses of the bone-implant interface. J Dent Res 2015; 94:482-90. [PMID: 25628271 DOI: 10.1177/0022034514566029] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Implants placed with high insertion torque (IT) typically exhibit primary stability, which enables early loading. Whether high IT has a negative impact on peri-implant bone health, however, remains to be determined. The purpose of this study was to ascertain how peri-implant bone responds to strains and stresses created when implants are placed with low and high IT. Titanium micro-implants were inserted into murine femurs with low and high IT using torque values that were scaled to approximate those used to place clinically sized implants. Torque created in peri-implant tissues a distribution and magnitude of strains, which were calculated through finite element modeling. Stiffness tests quantified primary and secondary implant stability. At multiple time points, molecular, cellular, and histomorphometric analyses were performed to quantitatively determine the effect of high and low strains on apoptosis, mineralization, resorption, and collagen matrix deposition in peri-implant bone. Preparation of an osteotomy results in a narrow zone of dead and dying osteocytes in peri-implant bone that is not significantly enlarged in response to implants placed with low IT. Placing implants with high IT more than doubles this zone of dead and dying osteocytes. As a result, peri-implant bone develops micro-fractures, bone resorption is increased, and bone formation is decreased. Using high IT to place an implant creates high interfacial stress and strain that are associated with damage to peri-implant bone and therefore should be avoided to best preserve the viability of this tissue.
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Affiliation(s)
- J Y Cha
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA Orthodontic Department, College of Dentistry, Yonsei University, Seoul, South Korea
| | - M D Pereira
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA
| | - A A Smith
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA
| | - K S Houschyar
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA
| | - X Yin
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA State Key Laboratory of Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - S Mouraret
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA
| | - J B Brunski
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA
| | - J A Helms
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA
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67
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Rao PJ, Pelletier MH, Walsh WR, Mobbs RJ. Spine interbody implants: material selection and modification, functionalization and bioactivation of surfaces to improve osseointegration. Orthop Surg 2015; 6:81-9. [PMID: 24890288 DOI: 10.1111/os.12098] [Citation(s) in RCA: 152] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 02/18/2014] [Indexed: 01/09/2023] Open
Abstract
The clinical outcome of lumbar spinal fusion is correlated with achievement of bony fusion. Improving interbody implant bone on-growth and in-growth may enhance fusion, limiting pseudoarthrosis, stress shielding, subsidence and implant failure. Polyetheretherketone (PEEK) and titanium (Ti) are commonly selected for interbody spacer construction. Although these materials have desirable biocompatibility and mechanical properties, they require further modification to support osseointegration. Reports of extensive research on this topic are available in biomaterial-centric published reports; however, there are few clinical studies concerning surface modification of interbody spinal implants. The current article focuses on surface modifications aimed at fostering osseointegration from a clinician's point of view. Surface modification of Ti by creating rougher surfaces, modifying its surface topography (macro and nano), physical and chemical treatment and creating a porous material with high interconnectivity can improve its osseointegrative potential and bioactivity. Coating the surface with osteoconductive materials like hydroxyapatite (HA) can improve osseointegration. Because PEEK spacers are relatively inert, creating a composite by adding Ti or osteoconductive materials like HA can improve osseointegration. In addition, PEEK may be coated with Ti, effectively bio-activating the coating.
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Affiliation(s)
- Prashanth J Rao
- Neurospine Clinic, Prince of Wales Hospital, Sydney, NSW, Australia; University of New South Wales, Sydney, NSW, Australia; Surgical and Orthopaedics Research Laboratory, Sydney, NSW, Australia
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68
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Mouraret S, Von Kaeppler E, Bardet C, Hunter DJ, Chaussain C, Bouchard P, Helms JA. The potential for vertical bone regeneration via maxillary periosteal elevation. J Clin Periodontol 2014; 41:1170-7. [PMID: 25229322 DOI: 10.1111/jcpe.12310] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2014] [Indexed: 11/30/2022]
Abstract
BACKGROUND While many studies have been performed on the characteristics and regenerative capacity of long bone periosteum, the craniofacial periosteum remains poorly understood. AIM The aim of this study was to investigate the potential for a maxillary periosteum tunnelling procedure to induce vertical alveolar bone regeneration. MATERIALS AND METHODS We employed a murine injury model that activates skeletal stem cells in the periosteum without overtly damaging the underlying cortical bone, preserving the integrity of the long bone and maxilla, and avoiding the introduction of pathological motion at the injury site. Further, we introduced a collagen sponge to serve as a scaffold, providing the necessary space for vertical bone regeneration. RESULTS Periosteal elevation alone resulted in bone formation in the tibia and delayed bone resorption in the maxilla. With the presence of the collagen sponge, new bone formation occurred in the maxilla. CONCLUSIONS Periosteal response to injury varies with anatomical location, so conclusions from long bone studies should not be extrapolated for craniofacial applications. Murine maxillary periosteum has the osteogenic potential to induce vertical alveolar bone regeneration.
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Affiliation(s)
- Sylvain Mouraret
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA; Department of Periodontology, Service of Odontology, Rothschild Hospital, AP-HP, Paris 7 - Denis, Diderot University, U.F.R. of Odontology, Paris, France
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69
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Immediate loading: from biology to biomechanics. Report of the Committee on Research in fixed Prosthodontics of the American Academy of fixed Prosthodontics. J Prosthet Dent 2014; 113:96-107. [PMID: 25444287 DOI: 10.1016/j.prosdent.2014.08.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 08/15/2014] [Accepted: 08/18/2014] [Indexed: 11/22/2022]
Abstract
One of the key issues of modern implant rehabilitation is the overall shortening of treatment time. High survival rates for immediately loaded implants have been reported in many but not all treatment modalities. In recent years, considerable evidence for the successful immediate loading outcome has been documented in both animal and human studies. The mechanical force generated by immediate loading may explain the favorable biologic response of bone and surrounding tissue when the design is biomechanically sound. However, in certain treatment modalities, including but not limited to immediately placed maxillary anterior single implants, immediately placed single molar implants, unsplinted implants in overdentures, and implants in maxillary anterior partial fixed dental prostheses, loading dental implants indiscriminately and immediately is not safe because of potentially unfavorable stress distribution and a negative cellular response under such high stress during early healing.
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70
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Ogawa T, Vandamme K, Zhang X, Naert I, Possemiers T, Chaudhari A, Sasaki K, Duyck J. Stimulation of titanium implant osseointegration through high-frequency vibration loading is enhanced when applied at high acceleration. Calcif Tissue Int 2014; 95:467-75. [PMID: 25209971 DOI: 10.1007/s00223-014-9896-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 06/28/2013] [Indexed: 11/28/2022]
Abstract
Low-magnitude high-frequency loading, applied by means of whole body vibration (WBV), affects the bone. Deconstructing a WBV loading stimulus into its constituent elements and investigating the effects of frequency and acceleration individually on bone tissue kinetics around titanium implants were aimed for in this study. A titanium implant was inserted in the tibia of 120 rats. The rats were divided into 1 control group (no loading) and 5 test groups with low (L), medium (M) or high (H) frequency ranges and accelerations [12-30 Hz at 0.3×g (F(L)A(H)); 70-90 Hz at 0.075×g (F(M)A(M)); 70-90 Hz at 0.3×g (F(M)A(H)); 130-150 Hz at 0.043×g (F(H)A(L)); 130-150 Hz at 0.3×g (F H A H)]. WBV was applied for 1 or 4 weeks. Implant osseointegration was evaluated by quantitative histology (bone-to-implant contact (BIC) and peri-implant bone formation (BV/TV)). A 2-way ANOVA (duration of experimental period; loading mode) with α = 0.05 was performed. BIC significantly increased over time and under load (p < 0.0001). The highest BICs were found for loading regimes at high acceleration with medium or high frequency (F(M)A(H) and F(H)A(H)), and significantly differing from F(L)A(H) and F(M)A(M) (p < 0.02 and p < 0.005 respectively). BV/TV significantly decreased over time (p < 0.0001). Loading led to a site-specific BV/TV increase (p < 0.001). The highest BV/TV responses were found for F(M)A(H) and F(H)A(H), significantly differing from F(M)A(M) (p < 0.005). The findings reveal the potential of high-frequency vibration loading to accelerate and enhance implant osseointegration, in particular when applied at high acceleration. Such mechanical signals hold great, though untapped, potential to be used as non-pharmacologic treatment for improving implant osseointegration in compromised bone.
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Affiliation(s)
- Toru Ogawa
- BIOMAT KU Leuven, Department of Oral Health Sciences & Dental Clinic, KU Leuven & University Hospitals Leuven, Kapucijnenvoer 7, P.O. Box 7001, 3000, Leuven, Belgium
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71
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Abstract
Bones adapt to accommodate the physical forces they experience through changes in architecture and mass. Stem cells differentiate into bone-forming osteoblasts, and mechanical stimulation is involved in this process. Various studies have applied controlled mechanical stimulation to stem cells and investigated the effects on osteogenic lineage commitment. These studies demonstrate that physical stimuli can induce osteogenic lineage commitment. Tension, fluid shear stress, substrate material properties, and cell shape are all factors that influence osteogenic differentiation. In particular, the level of tension is important. Also, rigid substrates with stiffness similar to collagenous bone induce osteogenic differentiation, while softer substrates induce other lineages. Finally, cells allowed to adhere over a larger area are able to differentiate towards the osteogenic lineage while cells adhering to a smaller area are restricted to the adipogenic lineage. Stem cells are able to sense their mechanical environments through various mechanosensors, including the cytoskeleton, focal adhesions, and primary cilia. The cytoskeleton provides a structural frame for the cell, and myosin interacts with actin to generate cytoskeletal tension, which is important for mechanically induced osteogenesis of stem cells. Adapter proteins link the cytoskeleton to integrins, which attach the cell to the substrate, forming a focal adhesion. A variety of signaling proteins are also associated with focal adhesions. Forces are transmitted to the substrate at these sites, and an intact focal adhesion is important for mechanically induced osteogenesis. The primary cilium is a single, immotile, antenna-like structure that extends from the cell into the extracellular space. It has emerged as an important signaling center, acting as a microdomain to facilitate biochemical signaling. Mechanotransduction is the process by which physical stimuli are converted into biochemical responses. When potential mechanosensors are disrupted, the activities of components of mechanotransduction pathways are also inhibited, preventing mechanically induced osteogenesis. Calcium, mitogen-activated protein kinase/extracellular signal-regulated kinase, Wnt, Yes-associated protein/transcriptional coactivator with PDZ-binding motif and RhoA/Rho kinase signaling are some of the mechanotransduction pathways proposed to be important. In this review, types of mechanical stimuli, mechanosensors, and key pathways involved in mechanically induced osteogenesis of stem cells are discussed.
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72
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Hoffmann W, Bormann T, Rossi A, Müller B, Schumacher R, Martin I, de Wild M, Wendt D. Rapid prototyped porous nickel-titanium scaffolds as bone substitutes. J Tissue Eng 2014; 5:2041731414540674. [PMID: 25383165 PMCID: PMC4221926 DOI: 10.1177/2041731414540674] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 05/22/2014] [Indexed: 01/19/2023] Open
Abstract
While calcium phosphate–based ceramics are currently the most widely used materials in bone repair, they generally lack tensile strength for initial load bearing. Bulk titanium is the gold standard of metallic implant materials, but does not match the mechanical properties of the surrounding bone, potentially leading to problems of fixation and bone resorption. As an alternative, nickel–titanium alloys possess a unique combination of mechanical properties including a relatively low elastic modulus, pseudoelasticity, and high damping capacity, matching the properties of bone better than any other metallic material. With the ultimate goal of fabricating porous implants for spinal, orthopedic and dental applications, nickel–titanium substrates were fabricated by means of selective laser melting. The response of human mesenchymal stromal cells to the nickel–titanium substrates was compared to mesenchymal stromal cells cultured on clinically used titanium. Selective laser melted titanium as well as surface-treated nickel–titanium and titanium served as controls. Mesenchymal stromal cells had similar proliferation rates when cultured on selective laser melted nickel–titanium, clinically used titanium, or controls. Osteogenic differentiation was similar for mesenchymal stromal cells cultured on the selected materials, as indicated by similar gene expression levels of bone sialoprotein and osteocalcin. Mesenchymal stromal cells seeded and cultured on porous three-dimensional selective laser melted nickel–titanium scaffolds homogeneously colonized the scaffold, and following osteogenic induction, filled the scaffold’s pore volume with extracellular matrix. The combination of bone-related mechanical properties of selective laser melted nickel–titanium with its cytocompatibility and support of osteogenic differentiation of mesenchymal stromal cells highlights its potential as a superior bone substitute as compared to clinically used titanium.
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Affiliation(s)
- Waldemar Hoffmann
- Departments of Biomedicine and Surgery, University Hospital Basel, Basel, Switzerland ; University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Institute for Medical and Analytical Technologies, Gründenstrasse 40, 4132 Muttenz, Switzerland
| | - Therese Bormann
- University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Institute for Medical and Analytical Technologies, Gründenstrasse 40, 4132 Muttenz, Switzerland ; Biomaterials Science Center, University of Basel, Basel, Switzerland
| | - Antonella Rossi
- Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, Zurich, Switzerland ; Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, Cagliari, Italy
| | - Bert Müller
- Biomaterials Science Center, University of Basel, Basel, Switzerland
| | - Ralf Schumacher
- University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Institute for Medical and Analytical Technologies, Gründenstrasse 40, 4132 Muttenz, Switzerland
| | - Ivan Martin
- Departments of Biomedicine and Surgery, University Hospital Basel, Basel, Switzerland
| | - Michael de Wild
- University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Institute for Medical and Analytical Technologies, Gründenstrasse 40, 4132 Muttenz, Switzerland
| | - David Wendt
- Departments of Biomedicine and Surgery, University Hospital Basel, Basel, Switzerland
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73
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Duyck J, Vandamme K. The effect of loading on peri-implant bone: a critical review of the literature. J Oral Rehabil 2014; 41:783-94. [DOI: 10.1111/joor.12195] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2014] [Indexed: 12/22/2022]
Affiliation(s)
- J. Duyck
- BIOMAT Research Group; Department of Oral Health Sciences; KU Leuven; Leuven Belgium
| | - K. Vandamme
- BIOMAT Research Group; Department of Oral Health Sciences; KU Leuven; Leuven Belgium
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74
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Mishra P, Hill M, Glynne-Jones P. Deformation of red blood cells using acoustic radiation forces. BIOMICROFLUIDICS 2014; 8:034109. [PMID: 25379070 PMCID: PMC4162412 DOI: 10.1063/1.4882777] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 05/29/2014] [Indexed: 05/08/2023]
Abstract
Acoustic radiation forces have been used to manipulate cells and bacteria in a number of recent microfluidic applications. The net force on a cell has been subject to careful investigation over a number of decades. We demonstrate that the radiation forces also act to deformcells. An ultrasonic standing wave field is created in a 0.1 mm glass capillary at a frequency of 7.9 MHz. Using osmotically swollen red-blood cells, we show observable deformations up to an aspect ratio of 1.35, comparable to deformations created by optical tweezing. In contrast to optical technologies, ultrasonic devices are potentially capable of deforming thousands of cells simultaneously. We create a finite element model that includes both the acoustic environment of the cell, and a model of the cell membrane subject to forces resulting from the non-linear aspects of the acoustic field. The model is found to give reasonable agreement with the experimental results, and shows that the deformation is the result of variation in an acoustic force that is directed outwards at all points on the cell membrane. We foresee applications in diagnostic devices, and in the possibility of mechanically stimulating cells to promote differentiation and physiological effects.
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Affiliation(s)
- Puja Mishra
- Engineering Sciences, University of Southampton , Southampton SO17 1BJ, United Kingdom
| | - Martyn Hill
- Engineering Sciences, University of Southampton , Southampton SO17 1BJ, United Kingdom
| | - Peter Glynne-Jones
- Engineering Sciences, University of Southampton , Southampton SO17 1BJ, United Kingdom
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75
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Zhang X, Duyck J, Vandamme K, Naert I, Carmeliet G. Ultrastructural characterization of the implant interface response to loading. J Dent Res 2014; 93:313-8. [PMID: 24389808 DOI: 10.1177/0022034513518345] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Dynamic loading can affect the bone surrounding implants. For ultrastructural exploration of the peri-implant tissue response to dynamic loading, titanium implants were installed in rat tibiae, in which one implant was loaded while the contralateral served as the unloaded control. The loaded implants received stimulation either within 24 hrs after implantation (immediate loading) or after a 28-day healing period (delayed loading) for 4, 7, 14, 21, or 28 days. The samples were processed for histology and gene expression quantification. Compared with the unloaded control, bone-to-implant contact increased significantly by immediate loading for 28 days (p < .05), but not in case of delayed loading. No effect of loading was observed on the bone formation in the implant thread areas, on the blood vessel area, and on endosteal callus formation. Loading during healing (immediate) for 7 days induced, relative to the unloaded control, a 2.3-fold increase of Runx2 in peri-implant cortical bone (p < .01) without a change in the RANKL/Opg ratio. Loading after healing (delayed) for 7 days up-regulated Runx2 (4.3-fold, p < .01) as well as Opg (22.3-fold, p < .05) compared with the unloaded control, resulting in a significantly decreased RANKL/Opg ratio. These results indicate a stimulating effect of dynamic loading on implant osseointegration when applied during the healing phase. In addition, gene expression analyses revealed molecular adaptations favoring bone formation and, at the same time, affecting bone remodeling.
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Affiliation(s)
- X Zhang
- Department of Oral Health Sciences, BIOMAT Research Cluster & Prosthetic Dentistry, KU Leuven & University Hospitals Leuven, Leuven, Belgium
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76
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Mouraret S, Hunter D, Bardet C, Brunski J, Bouchard P, Helms J. A pre-clinical murine model of oral implant osseointegration. Bone 2014; 58:177-84. [PMID: 23886841 PMCID: PMC4962868 DOI: 10.1016/j.bone.2013.07.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 05/31/2013] [Accepted: 07/10/2013] [Indexed: 10/26/2022]
Abstract
Many of our assumptions concerning oral implant osseointegration are extrapolated from experimental models studying skeletal tissue repair in long bones. This disconnect between clinical practice and experimental research hampers our understanding of bone formation around oral implants and how this process can be improved. We postulated that oral implant osseointegration would be fundamentally equivalent to implant osseointegration elsewhere in the body. Mice underwent implant placement in the edentulous ridge anterior to the first molar and peri-implant tissues were evaluated at various timepoints after surgery. Our hypothesis was disproven; oral implant osseointegration is substantially different from osseointegration in long bones. For example, in the maxilla peri-implant pre-osteoblasts are derived from cranial neural crest whereas in the tibia peri-implant osteoblasts are derived from mesoderm. In the maxilla, new osteoid arises from periostea of the maxillary bone but in the tibia the new osteoid arises from the marrow space. Cellular and molecular analyses indicate that osteoblast activity and mineralization proceeds from the surfaces of the native bone and osteoclastic activity is responsible for extensive remodeling of the new peri-implant bone. In addition to histologic features of implant osseointegration, molecular and cellular assays conducted in a murine model provide new insights into the sequelae of implant placement and the process by which bone is generated around implants.
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Affiliation(s)
- S. Mouraret
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA 94305, USA
- Department of Periodontology, Service of Odontology, Rothschild Hospital, AP-HP, Paris 7 Denis, Diderot University, U.F.R. of Odontology, Paris, France
| | - D.J. Hunter
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA 94305, USA
| | - C. Bardet
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA 94305, USA
- Dental School University Paris Descartes PRES Sorbonne Paris Cité, EA 2496 Montrouge, France
| | - J.B. Brunski
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA 94305, USA
| | - P. Bouchard
- Department of Periodontology, Service of Odontology, Rothschild Hospital, AP-HP, Paris 7 Denis, Diderot University, U.F.R. of Odontology, Paris, France
| | - J.A. Helms
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA 94305, USA
- Corresponding author. Fax: +1 650 736 4374. (J.A. Helms)
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Abstract
AIM The aim of this search was to assess the biological consequences that overload might have on already osseointegrated oral implants through a systematic screening of the scientific literature. METHOD Detailed searches through PUBMED, OVID, EMBASE and LILACS databases were made. Articles published up to December 2011 and those reported on the clinical, radiographic and/or histological outcome of oral implants subjected to so-called overload were considered eligible for inclusion. Identified studies were assessed by one non-blinded reviewer according to well-defined inclusion and exclusion criteria. When doubt arose, the co-authors were counselled until final agreement was obtained. The PICO questions formulated was:"what is the effect of overload vs. no overload on bone/implant loss in clinically stable implants?" RESULTS The database searches as well as additional hand searching, resulted in 726 potentially relevant titles. Eventually, 16 clinical and 25 animal studies were considered relevant to the topic. After inclusion/exclusion criteria assessment, all clinical studies and all but three animal studies and one systematic review were considered at high risk of bias and excluded. The included animal studies did not reveal an association between overload and peri-implant bone loss in the absence of peri-implant inflammation, whereas in its presence, overload seemed to aggravate the peri-implant tissue breakdown. CONCLUSIONS The effect of implant overload on bone/implant loss in clinically well-integrated implants is poorly reported and provides little unbiased evidence to support a cause-and-effect relationship. The PICO question remained unanswered. At the animal level, "overload", mimicked by supra-occlusal contacts acting in an uninflamed peri-implant environment, did not negatively affect osseointegration and even was anabolic. In contrast, supra-occlusal contacts in the presence of inflammation significantly increased the plaque-induced bone resorption.
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Affiliation(s)
- Ignace Naert
- KU Leuven, Clinical Unit for Prosthetic Dentistry, BIOMAT KU Leuven, Department of Oral Health Sciences & Dental Clinics University Hospitals, KU Leuven (Catholic University of Leuven), Kapucijnenvoer 7 blok a bus 7001, BE, 3000, Leuven, Belgium.
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78
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Mouraret S, Hunter DJ, Bardet C, Popelut A, Brunski JB, Chaussain C, Bouchard P, Helms JA. Improving oral implant osseointegration in a murine model via Wnt signal amplification. J Clin Periodontol 2013; 41:172-80. [PMID: 24164629 DOI: 10.1111/jcpe.12187] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2013] [Indexed: 11/28/2022]
Abstract
AIM To determine the key biological events occurring during implant failure and then we use this knowledge to develop new biology-based strategies that improve osseointegration. MATERIALS AND METHODS Wild-type and Axin2(LacZ/LacZ) adult male mice underwent oral implant placement, with and without primary stability. Peri-implant tissues were evaluated using histology, alkaline phosphatase (ALP) activity, tartrate resistant acid phosphatase (TRAP) activity and TUNEL staining. In addition, mineralization sites, collagenous matrix organization and the expression of bone markers in the peri-implant tissues were assessed. RESULTS Maxillary implants lacking primary stability show histological evidence of persistent fibrous encapsulation and mobility, which recapitulates the clinical problems of implant failure. Despite histological and molecular evidence of fibrous encapsulation, osteoblasts in the gap interface exhibit robust ALP activity. This mineralization activity is counteracted by osteoclast activity that resorbs any new bony matrix and consequently, the fibrous encapsulation remains. Using a genetic mouse model, we show that implants lacking primary stability undergo osseointegration, provided that Wnt signalling is amplified. CONCLUSIONS In a mouse model of oral implant failure caused by a lack of primary stability, we find evidence of active mineralization. This mineralization, however, is outpaced by robust bone resorption, which culminates in persistent fibrous encapsulation of the implant. Fibrous encapsulation can be prevented and osseointegration assured if Wnt signalling is elevated at the time of implant placement.
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Affiliation(s)
- Sylvain Mouraret
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Stanford School of Medicine, Stanford, CA, USA; Department of Periodontology, Service of Odontology, Rothschild Hospital, AP-HP, Paris 7 - Denis, Diderot University, U.F.R. of Odontology, Paris, France
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79
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Troib A, Landau D, Kachko L, Rabkin R, Segev Y. Epiphyseal growth plate growth hormone receptor signaling is decreased in chronic kidney disease–related growth retardation. Kidney Int 2013; 84:940-9. [DOI: 10.1038/ki.2013.196] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 03/20/2013] [Accepted: 03/21/2013] [Indexed: 12/15/2022]
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80
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de Ávila Kfouri F, Duailibi MT, Bretos JLG, Carvalho AB, Pallos D, Duailibi SE. Piezoelectric osteotomy for the placement of titanium implants in rabbits: histomorphometry study. Clin Oral Implants Res 2013; 25:1182-8. [DOI: 10.1111/clr.12229] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Flávio de Ávila Kfouri
- Pos-Graduate Program; Division of Plastic Surgery; Universidade Federal de São Paulo (UNIFESP); São Paulo SP Brazil
| | - Monica Talarico Duailibi
- Division of Plastic Surgery; Department of Surgery; Universidade Federal de São Paulo (UNIFESP); São Paulo SP Brazil
| | - José Luis Gonçalves Bretos
- Division of Plastic Surgery; Department of Surgery; Universidade Federal de São Paulo (UNIFESP); São Paulo SP Brazil
| | - Aluizio Barbosa Carvalho
- Division of Nephrology; Department of Medicine; Universidade Federal de São Paulo (UNIFESP); São Paulo SP Brazil
| | - Debora Pallos
- Department of Periodontics and Implantology; School of Dentistry; University of Santo Amaro; São Paulo SP Brazil
| | - Silvio Eduardo Duailibi
- Division of Plastic Surgery, Department of Surgery and Institute of Science and Technology; Universidade Federal de São Paulo (UNIFESP); São José dos Campos SP Brazil
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81
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Micromotion-induced strain fields influence early stages of repair at bone-implant interfaces. Acta Biomater 2013; 9:6663-74. [PMID: 23337705 DOI: 10.1016/j.actbio.2013.01.014] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 12/06/2012] [Accepted: 01/14/2013] [Indexed: 11/24/2022]
Abstract
Implant loading can create micromotion at the bone-implant interface. The interfacial strain associated with implant micromotion could contribute to regulating the tissue healing response. Excessive micromotion can lead to fibrous encapsulation and implant loosening. Our objective was to characterize the influence of interfacial strain on bone regeneration around implants in mouse tibiae. A micromotion system was used to create strain under conditions of (1) no initial contact between implant and bone and (2) direct bone-implant contact. Pin- and screw-shaped implants were subjected to displacements of 150 or 300 μm for 60 cycles per day for 7 days. Pin-shaped implants placed in five animals were subjected to three sessions of 150 μm displacement per day, with 60 cycles per session. Control implants in both types of interfaces were stabilized throughout the healing period. Experimental strain analyses, microtomography, image-based displacement mapping, and finite element simulations were used to characterize interfacial strain fields. Calcified tissue sections were prepared and Goldner trichrome stained to evaluate the tissue reactions in higher and lower strain regions. In stable implants bone formation occurred consistently around the implants. In implants subjected to micromotion bone regeneration was disrupted in areas of high strain concentrations (e.g. >30%), whereas lower strain values were permissive of bone formation. Increasing implant displacement or number of cycles per day also changed the strain distribution and disturbed bone healing. These results indicate that not only implant micromotion but also the associated interfacial strain field contributes to regulating the interfacial mechanobiology at healing bone-implant interfaces.
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82
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Sun X, Kang Y, Bao J, Zhang Y, Yang Y, Zhou X. Modeling vascularized bone regeneration within a porous biodegradable CaP scaffold loaded with growth factors. Biomaterials 2013; 34:4971-81. [PMID: 23566802 DOI: 10.1016/j.biomaterials.2013.03.015] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 03/06/2013] [Indexed: 01/08/2023]
Abstract
Osteogenetic microenvironment is a complex constitution in which extracellular matrix (ECM) molecules, stem cells and growth factors each interact to direct the coordinate regulation of bone tissue development. Importantly, angiogenesis improvement and revascularization are critical for osteogenesis during bone tissue regeneration processes. In this study, we developed a three-dimensional (3D) multi-scale system model to study cell response to growth factors released from a 3D biodegradable porous calcium phosphate (CaP) scaffold. Our model reconstructed the 3D bone regeneration system and examined the effects of pore size and porosity on bone formation and angiogenesis. The results suggested that scaffold porosity played a more dominant role in affecting bone formation and angiogenesis compared with pore size, while the pore size could be controlled to tailor the growth factor release rate and release fraction. Furthermore, a combination of gradient VEGF with BMP2 and Wnt released from the multi-layer scaffold promoted angiogenesis and bone formation more readily than single growth factors. These results demonstrated that the developed model can be potentially applied to predict vascularized bone regeneration with specific scaffold and growth factors.
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Affiliation(s)
- Xiaoqiang Sun
- School of Mathematical Science, Beijing Normal University, Beijing 100875, PR China.
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83
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Chou HY, Müftü S. Simulation of peri-implant bone healing due to immediate loading in dental implant treatments. J Biomech 2013; 46:871-8. [DOI: 10.1016/j.jbiomech.2012.12.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 12/19/2012] [Accepted: 12/21/2012] [Indexed: 10/27/2022]
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84
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Winter W, Klein D, Karl M. Effect of Model Parameters on Finite Element Analysis of Micromotions in Implant Dentistry. J ORAL IMPLANTOL 2013; 39:23-9. [DOI: 10.1563/aaid-joi-d-11-00221] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Micromotion between dental implant and bony socket may occur in immediate-loading scenarios. Excessive micromotion surpassing an estimated threshold of approximately 150 μm may result in fibrous encapsulation instead of osseointegration of the implant. As finite element analysis (FEA) has been applied in this field, it was the aim of this study to evaluate the effect of implant-related variables and modeling parameters on simulating micromotion phenomena. Three-dimensional FEA models representing a dental implant within a bony socket were constructed and used for evaluating micromotion (global displacement) and stress transfer (von Mises equivalent stress) at the implant-bone interface when static loads were applied. A parametric study was conducted altering implant geometry (cylinder, screw), direction of loading (axial, horizontal), healing status (immediate implant, osseointegrated implant), and contact type between implant and bone (friction free, friction, rigid). Adding threads to a cylindrically shaped implant as well as changing the contact type between implant and bone from friction free to rigid led to a reduction of implant displacement. On the other hand, reducing the elastic modulus of bone for simulating an immediate implant caused a substantial increase in displacement of the implant. Altering the direction of loading from axial to horizontal caused a change in loading patterns from uniform loading surrounding the whole implant to localized loading in the cervical area. Implant-related and bone-related factors determine the degree of micromotion of a dental implant during the healing phase, which should be considered when choosing a loading protocol.
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Affiliation(s)
- Werner Winter
- Department of Mechanical Engineering, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Daniel Klein
- Department of Mechanical Engineering, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Matthias Karl
- Department of Prosthodontics, School of Dental Medicine, University of Erlangen-Nuremberg, Erlangen, Germany
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85
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Coelho PG, Marin C, Teixeira HS, Campos FE, Gomes JB, Guastaldi F, Anchieta RB, Silveira L, Bonfante EA. Biomechanical Evaluation of Undersized Drilling on Implant Biomechanical Stability at Early Implantation Times. J Oral Maxillofac Surg 2013; 71:e69-75. [DOI: 10.1016/j.joms.2012.10.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 10/05/2012] [Accepted: 10/06/2012] [Indexed: 11/16/2022]
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86
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Arciniegas M, Peña J, Gil FJ, Manero JM. In vitroresponse of preosteoblastic MG63 cells on Ni-free Ti shape memory substrates. J Biomed Mater Res B Appl Biomater 2013; 101:709-20. [DOI: 10.1002/jbm.b.32873] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 11/19/2012] [Accepted: 11/25/2012] [Indexed: 11/06/2022]
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87
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Long JP, Hollister SJ, Goldstein SA. A paradigm for the development and evaluation of novel implant topologies for bone fixation: in vivo evaluation. J Biomech 2012; 45:2651-7. [PMID: 22951278 PMCID: PMC3462280 DOI: 10.1016/j.jbiomech.2012.08.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 07/17/2012] [Accepted: 08/09/2012] [Indexed: 11/21/2022]
Abstract
While contemporary prosthetic devices restore some function to individuals who have lost a limb, there are efforts to develop bio-integrated prostheses to improve functionality. A critical step in advancing this technology will be to securely attach the device to remnant bone. To investigate mechanisms for establishing robust implant fixation in bone while undergoing loading, we previously used a topology optimization scheme to develop optimized orthopedic implants and then fabricated selected designs from titanium (Ti)-alloy with selective laser sintering (SLS) technology. In the present study, we examined how implant architecture and mechanical stimulation influence osseointegration within an in vivo environment. To do this, we evaluated three implant designs (two optimized and one non-optimized) using a unique in vivo model that applied cyclic, tension/compression loads to the implants. Eighteen (six per implant design) adult male canines had implants surgically placed in their proximal, tibial metaphyses. Experimental duration was 12 weeks; daily loading (peak load of ±22 N for 1000 cycles) was applied to one of each animal's bilateral implants for the latter six weeks. Following harvest, osseointegration was assessed by non-destructive mechanical testing, micro-computed tomography (microCT) and back-scatter scanning electron microscopy (SEM). Data revealed that implant loading enhanced osseointegration by significantly increasing construct stiffness, peri-implant trabecular morphology, and percentages of interface connectivity and bone ingrowth. While this experiment did not demonstrate a clear advantage associated with the optimized implant designs, osseointegration was found to be significantly influenced by aspects of implant architecture.
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Affiliation(s)
- Jason P Long
- Department of Orthopaedic Surgery, the University of Michigan, United States.
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88
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Park D, Spencer JA, Koh BI, Kobayashi T, Fujisaki J, Clemens TL, Lin CP, Kronenberg HM, Scadden DT. Endogenous bone marrow MSCs are dynamic, fate-restricted participants in bone maintenance and regeneration. Cell Stem Cell 2012; 10:259-72. [PMID: 22385654 DOI: 10.1016/j.stem.2012.02.003] [Citation(s) in RCA: 489] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 12/06/2011] [Accepted: 02/02/2012] [Indexed: 12/18/2022]
Abstract
Mesenchymal stem cells (MSCs) commonly defined by in vitro functions have entered clinical application despite little definition of their function in residence. Here, we report genetic pulse-chase experiments that define osteoblastic cells as short-lived and nonreplicative, requiring replenishment from bone-marrow-derived, Mx1(+) stromal cells with "MSC" features. These cells respond to tissue stress and migrate to sites of injury, supplying new osteoblasts during fracture healing. Single cell transplantation yielded progeny that both preserve progenitor function and differentiate into osteoblasts, producing new bone. They are capable of local and systemic translocation and serial transplantation. While these cells meet current definitions of MSCs in vitro, they are osteolineage restricted in vivo in growing and adult animals. Therefore, bone-marrow-derived MSCs may be a heterogeneous population with the Mx1(+) population, representing a highly dynamic and stress responsive stem/progenitor cell population of fate-restricted potential that feeds the high cell replacement demands of the adult skeleton.
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Affiliation(s)
- Dongsu Park
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
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89
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Leucht P, Monica SD, Temiyasathit S, Lenton K, Manu A, Longaker MT, Jacobs CR, Spilker RL, Guo H, Brunski JB, Helms JA. Primary cilia act as mechanosensors during bone healing around an implant. Med Eng Phys 2012; 35:392-402. [PMID: 22784673 DOI: 10.1016/j.medengphy.2012.06.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 05/26/2012] [Accepted: 06/03/2012] [Indexed: 01/05/2023]
Abstract
The primary cilium is an organelle that senses cues in a cell's local environment. Some of these cues constitute molecular signals; here, we investigate the extent to which primary cilia can also sense mechanical stimuli. We used a conditional approach to delete Kif3a in pre-osteoblasts and then employed a motion device that generated a spatial distribution of strain around an intra-osseous implant positioned in the mouse tibia. We correlated interfacial strain fields with cell behaviors ranging from proliferation through all stages of osteogenic differentiation. We found that peri-implant cells in the Col1Cre;Kif3a(fl/fl) mice were unable to proliferate in response to a mechanical stimulus, failed to deposit and then orient collagen fibers to the strain fields caused by implant displacement, and failed to differentiate into bone-forming osteoblasts. Collectively, these data demonstrate that the lack of a functioning primary cilium blunts the normal response of a cell to a defined mechanical stimulus. The ability to manipulate the genetic background of peri-implant cells within the context of a whole, living tissue provides a rare opportunity to explore mechanotransduction from a multi-scale perspective.
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Affiliation(s)
- P Leucht
- Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA.
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90
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A new piezoelectric actuator induces bone formation in vivo: a preliminary study. J Biomed Biotechnol 2012; 2012:613403. [PMID: 22701304 PMCID: PMC3369535 DOI: 10.1155/2012/613403] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 03/21/2012] [Accepted: 04/09/2012] [Indexed: 01/17/2023] Open
Abstract
This in vivo study presents the preliminary results of the use of a novel piezoelectric actuator for orthopedic application. The innovative use of the converse piezoelectric effect to mechanically stimulate bone was achieved with polyvinylidene fluoride actuators implanted in osteotomy cuts in sheep femur and tibia. The biological response around the osteotomies was assessed through histology and histomorphometry in nondecalcified sections and histochemistry and immunohistochemistry in decalcified sections, namely, through Masson's trichrome, and labeling of osteopontin, proliferating cell nuclear antigen, and tartrate-resistant acid phosphatase. After one-month implantation, total bone area and new bone area were significantly higher around actuators when compared to static controls. Bone deposition rate was also significantly higher in the mechanically stimulated areas. In these areas, osteopontin increased expression was observed. The present in vivo study suggests that piezoelectric materials and the converse piezoelectric effect may be used to effectively stimulate bone growth.
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91
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Mathieu V, Vayron R, Soffer E, Anagnostou F, Haïat G. Influence of healing time on the ultrasonic response of the bone-implant interface. ULTRASOUND IN MEDICINE & BIOLOGY 2012; 38:611-618. [PMID: 22341053 DOI: 10.1016/j.ultrasmedbio.2011.12.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 12/13/2011] [Accepted: 12/16/2011] [Indexed: 05/31/2023]
Abstract
The aim of the present study is to investigate the effect of bone healing on the ultrasonic response of coin-shaped titanium implants inserted in rabbit tibiae. The ultrasound response of the interface was measured in vitro at 15 MHz after 7 and 13 weeks of healing time. The average value of the ratio r between the amplitudes of the echo of the bone-implant interface and of the water-implant interface was determined. The bone-implant contact (BIC) was measured by histomorphometry and the degree of mineralisation of bone was estimated qualitatively by histologic staining. The significant decrease of the ultrasonic quantitative indicator r (p = 2.10⁻⁴) vs. healing time (from r = 0.53 to r = 0.49) is explained by (1) the increase of the BIC (from 27% to 69%) and (2) the increase of mineralization of newly formed bone tissue, both phenomena inducing a decrease of the gap of acoustical impedance.
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Affiliation(s)
- Vincent Mathieu
- CNRS, Université Paris 7, Laboratoire de Biomécanique Biomatériaux Ostéo-Articulaires, UMR CNRS 7052, Paris, France.
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92
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Zhang X, Vandamme K, Torcasio A, Ogawa T, van Lenthe GH, Naert I, Duyck J. In vivo assessment of the effect of controlled high- and low-frequency mechanical loading on peri-implant bone healing. J R Soc Interface 2012; 9:1697-704. [PMID: 22279157 DOI: 10.1098/rsif.2011.0820] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The aim of this study was to investigate the effect of controlled high- (HF) and low-frequency (LF) mechanical loading on peri-implant bone healing. Custom-made titanium implants were inserted in both tibiae of 69 adult Wistar rats. For every animal, one implant was loaded by compression through the axis of tibia (test), whereas the other one was unloaded (control). The test implants were randomly distributed among four groups receiving different loading regimes, which were determined by ex vivo calibration. Within the HF (40 Hz) or LF (2 Hz) loading category, the magnitudes were chosen as low- (LM) and high-magnitude (HM), respectively, leading to constant strain rate amplitudes for the two frequency groups. This resulted in the four loading regimes: (i) HF-LM (40 Hz-0.5 N); (ii) HF-HM (40 Hz-1 N); (iii) LF-LM (2 Hz-10 N); and (iv) LF-HM (2 Hz-20 N) loading. Loading was performed five times per week and lasted for one or four weeks. Tissue samples were processed for histology and histomorphometry (bone-to-implant contact, BIC; and peri-implant bone fraction, BF) at the cortical and medullar level. Data were analysed statistically with ANOVA and paired t-tests with the significance level set at 0.05. For the one-week experiments, an increased BF adjacent to the implant surface at the cortical level was exclusively induced by the LF-HM loading regime (2 Hz-20 N). Four weeks of loading resulted in a significant effect on BIC (and not on BF) in case of HF-LM loading (40 Hz-0.5 N) and LF-HM loading (2 Hz-20 N): BIC at the cortical level significantly increased under both loading regimes, whereas BIC at the medullar level was positively influenced only in case of HF-LM loading. Mechanical loading at both HF and LF affects osseointegration and peri-implant BF. Higher loading magnitudes (and accompanying elevated tissue strains) are required under LF loading to provoke a positive peri-implant bone response, compared with HF loading. A sustained period of loading at HF is needed to result in an overall enhanced osseointegration.
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Affiliation(s)
- Xiaolei Zhang
- Department of Prosthetic Dentistry, BIOMAT Research Cluster, Biomechanics Section, KU Leuven, Leuven, Belgium
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93
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Wiskott HWA, Bonhote P, Cugnoni J, Durual S, Zacchetti G, Botsis J, Scherrer SS, Ammann P. Implementation of the “loaded implant” model in the rat using a miniaturized setup - description of the method and first results. Clin Oral Implants Res 2011; 23:1352-9. [DOI: 10.1111/j.1600-0501.2011.02349.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/18/2011] [Indexed: 11/30/2022]
Affiliation(s)
| | - Philippe Bonhote
- Department of Mechanical Engineering; School of Business and Engineering; Yverdon; Switzerland
| | - Joel Cugnoni
- Laboratory of Applied Mechanics and Reliability Analysis; Ecole Polytechnique Fédérale de Lausanne; Lausanne; Switzerland
| | - Stéphane Durual
- Laboratory of Biomaterials; University of Geneva; Geneva; Switzerland
| | - Giovanna Zacchetti
- Division of Bone Diseases; Department of Rehabilitation and Geriatrics; Geneva University Hospital; Geneva; Switzerland
| | - John Botsis
- Laboratory of Applied Mechanics and Reliability Analysis; Ecole Polytechnique Fédérale de Lausanne; Lausanne; Switzerland
| | | | - Patrick Ammann
- Division of Bone Diseases; Department of Rehabilitation and Geriatrics; Geneva University Hospital; Geneva; Switzerland
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94
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Bonsignore LA, Colbrunn RW, Tatro JM, Messerschmitt PJ, Hernandez CJ, Goldberg VM, Stewart MC, Greenfield EM. Surface contaminants inhibit osseointegration in a novel murine model. Bone 2011; 49:923-30. [PMID: 21801863 PMCID: PMC3200470 DOI: 10.1016/j.bone.2011.07.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 07/08/2011] [Accepted: 07/11/2011] [Indexed: 12/18/2022]
Abstract
Surface contaminants, such as bacterial debris and manufacturing residues, may remain on orthopedic implants after sterilization procedures and affect osseointegration. The goals of this study were to develop a murine model of osseointegration in order to determine whether removing surface contaminants enhances osseointegration. To develop the murine model, titanium alloy implants were implanted into a unicortical pilot hole in the mid-diaphysis of the femur and osseointegration was measured over a five week time course. Histology, backscatter scanning electron microscopy and X-ray energy dispersive spectroscopy showed areas of bone in intimate physical contact with the implant, confirming osseointegration. Histomorphometric quantification of bone-to-implant contact and peri-implant bone and biomechanical pullout quantification of ultimate force, stiffness and work to failure increased significantly over time, also demonstrating successful osseointegration. We also found that a rigorous cleaning procedure significantly enhances bone-to-implant contact and biomechanical pullout measures by two-fold compared with implants that were autoclaved, as recommended by the manufacturer. The most likely interpretation of these results is that surface contaminants inhibit osseointegration. The results of this study justify the need for the development of better detection and removal techniques for contaminants on orthopedic implants and other medical devices.
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Affiliation(s)
- Lindsay A Bonsignore
- Department of Orthopaedics, Case Western Reserve University, Cleveland, Ohio, USA
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95
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Zeng X, He H, Zhang L, Wu Y, Wang Y, Gong P. A potential therapeutic approach to overload-induced bone loss around implant: Parathyroid hormone (PTH). Med Hypotheses 2011; 77:701-4. [DOI: 10.1016/j.mehy.2011.06.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 04/04/2011] [Accepted: 06/03/2011] [Indexed: 01/01/2023]
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96
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Immediate semi-static loading using compression healing abutments: a stability study in dogs. Res Vet Sci 2011; 93:484-7. [PMID: 21911236 DOI: 10.1016/j.rvsc.2011.07.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 07/30/2011] [Indexed: 11/22/2022]
Abstract
Loading in implant dentistry to accelerate prosthodontic treatment has been receiving increasing interest. The aim of this study was to investigate the effect of an early controlled lateral loading (after 7 days) on the establishment of osseointegration by means of resonance frequency analysis. Two groups of six beagle dogs each were used. Group I had implants without loading. Group II had implants loaded with a new prototype compression abutment that created controlled semi-static loading. Loaded implants showed slightly better stability after 5 weeks of healing, but the difference was not significant. We concluded that controlled loading is beneficial to maintain, and even improve, stability during the early critical healing period.
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97
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Use of micro-CT-based finite element analysis to accurately quantify peri-implant bone strains: a validation in rat tibiae. Biomech Model Mechanobiol 2011; 11:743-50. [DOI: 10.1007/s10237-011-0347-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Accepted: 08/22/2011] [Indexed: 10/17/2022]
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98
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Involvement of Wnt activation in the micromechanical vibration-enhanced osteogenic response of osteoblasts. J Orthop Sci 2011; 16:598-605. [PMID: 21833614 DOI: 10.1007/s00776-011-0124-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Accepted: 06/13/2011] [Indexed: 02/05/2023]
Abstract
BACKGROUND Low-magnitude vibration has been widely used as a tool for rehabilitation, enhancing physical performance, and stimulating bone development. Although mechanical stimulation generated by vibrations is regarded as important factor in bone remodeling, the underlying cellular and molecular regulatory mechanisms of this response, which may be important in the development of new mechanobiological strategies, currently remain unclear. METHODS In this study, to investigate the mechanobiological mechanisms of vibration-enhanced osteogenic responses in osteoblasts, MC3T3-E1 cells were subjected to vibrations of different amplitude (0.06, 0.14, 0.32, 0.49, 0.66, and 0.8 × g) at 40 Hz for 30 min/day over 3 days. The osteogenesis-related transcription factors Wnt10B, Sclerostin, OPG, and RANKL were analyzed for mRNA and protein expression. RESULTS The results revealed that protein expression of Wnt10B and OPG was increased in a magnitude-dependent manner by mechanical vibrations at amplitudes of 0.06, 0.14, 0.32, and 0.49 × g; the maximum increases were 2.4-fold (p < 0.001) and 7.9-fold (p < 0.001), respectively, at 0.49 × g. Sclerostin and RANKL levels were reduced at all amplitudes. On the basis of mRNA levels, the reduced expression of RANKL was further downregulated (p < 0.05) whereas OPG expression was further increased (p < 0.01) when the MC3T3-E1 cells were treated with LiCl compared with the effects of vibration alone. CONCLUSIONS The findings may indicate that Wnt signaling is involved in mechanotransduction at low-magnitude vibration; this may provide a cellular basis, and impetus for further development of, biomechanically based intervention for enhancing bone strength and accelerating implant osseointegration.
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99
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Stacchi C, Vercellotti T, Torelli L, Furlan F, Di Lenarda R. Changes in Implant Stability Using Different Site Preparation Techniques: Twist Drills versus Piezosurgery. A Single-Blinded, Randomized, Controlled Clinical Trial. Clin Implant Dent Relat Res 2011; 15:188-97. [DOI: 10.1111/j.1708-8208.2011.00341.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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100
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Sato R, Matsuzaka K, Kokubu E, Inoue T. Immediate loading after implant placement following tooth extraction up-regulates cellular activity in the dog mandible. Clin Oral Implants Res 2011; 22:1372-8. [DOI: 10.1111/j.1600-0501.2010.02118.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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