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  1. Article ; Online: The Sigmoidal Nature of Bone Anchorage.

    Liddell, Robert S / Davies, John E

    The International journal of oral & maxillofacial implants

    2022  Volume 37, Issue 1, Page(s) e1–e11

    Abstract: Purpose: The purpose of this study was to show the full evolution of bone anchorage caused by the growth of secondary stability and to determine which empirical model would provide the best quantitative description of this growth.: Materials and ... ...

    Abstract Purpose: The purpose of this study was to show the full evolution of bone anchorage caused by the growth of secondary stability and to determine which empirical model would provide the best quantitative description of this growth.
    Materials and methods: The retention and anchorage of machined (M), grit-blasted and dual acid etched (BAE), and BAE implants with discrete crystals of calcium phosphate (+DCD) were evaluated with both ex vivo and in vivo methods. Ex vivo evaluation of implant retention was tested by measuring the force required to pull implants out of blood-filled osteotomies formed in bovine bone for up to 1 hour. In vivo measurements of bone anchorage were evaluated by reverse torque testing of implants placed in the proximal metaphysis of rat tibiae up to 28 days after initial placement. Four models were fit to the reverse torque results, and fits were evaluated by Bayesian and Akaike information criteria (BIC and AIC) and analysis of variance (ANOVA).
    Results: AIC and BIC were 655.53 and 684.78, 472.53 and 512.74, 477.40 and 513.96, and 470.60 and 507.16 for the monomolecular, Richards, Gompertz, and logistic curves, respectively. Comparison of the Richards and logistic curves by analysis of variance (ANOVA) resulted in a P value of .78. A comparison of the three implant types using the logistic curve found that M implants had an earlier inflection point compared with BAE implants (P = .038), and the BAE+DCD implants had the greatest peak anchorage and were significantly greater than both M (P < .0001) and BAE implants (P = .005).
    Conclusion: Bone anchorage was found to follow sigmoidal growth, which was best described by the logistic function. Further comparison of the fit values for the logistic curve shows that both overall anchorage and timing of bone anchorage are influenced by implant surface topography.
    MeSH term(s) Animals ; Bayes Theorem ; Cattle ; Dental Implants ; Osseointegration ; Rats ; Surface Properties ; Titanium/chemistry ; Torque
    Chemical Substances Dental Implants ; Titanium (D1JT611TNE)
    Language English
    Publishing date 2022-03-02
    Publishing country United States
    Document type Journal Article
    ZDB-ID 632880-5
    ISSN 1942-4434 ; 0882-2786
    ISSN (online) 1942-4434
    ISSN 0882-2786
    DOI 10.11607/jomi.9042
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 2179: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

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  2. Article: Umbilical Cord Stem Cell Lysate: A New Biologic Injectate for the Putative Treatment of Acute Temporomandibular Joint Inflammation.

    Ward, Christopher K / Gill, Rita G / Liddell, Robert S / Davies, John E

    Journal of inflammation research

    2023  Volume 16, Page(s) 4287–4300

    Abstract: Objective: To compare in vivo, the acute anti-inflammatory effects of a lysate derived from human umbilical perivascular mesenchymal cells with the cells themselves in both an established hind-paw model of carrageenan-induced inflammation and also in ... ...

    Abstract Objective: To compare in vivo, the acute anti-inflammatory effects of a lysate derived from human umbilical perivascular mesenchymal cells with the cells themselves in both an established hind-paw model of carrageenan-induced inflammation and also in the inflamed temporomandibular joint.
    Study design: Human umbilical cord perivascular cells were harvested and cultured in xeno- and serum-free conditions to P3. In addition, P3 cells were used to prepare a proprietary 0.22 micron filtered lysate. First, CD1 immunocompetent mice underwent unilateral hind-paw injections of carrageenan for induction of inflammation, followed immediately by treatment with saline (negative control), 1% cell lysate, or viable cells. The contralateral paw remained un-injected with carrageenan. Paw circumference was measured prior to injections and 48 hr later and myeloperoxidase and TNF-alpha concentrations were measured post-sacrifice in excised tissue. Second, immunocompetent Male Wistar rats underwent unilateral intra-articular temporomandibular (TMJ) injections from the same treatment groups and were sacrificed at 4 and 48 hr post-injection. The contralateral TMJ remained un-injected with carrageenan. Articular tissue and synovial aspirates, from the treated TMJ were obtained for histologic and leukocyte infiltration analyses.
    Results: The lysate and cell-treated hind-paw demonstrated reduced tissue edema, and significantly lower concentrations of myeloperoxidase and TNF-alpha at 48 hr compared to untreated controls. Treated TMJs demonstrated lower concentrations of leukocytes in the synovium compared to controls and histologic evidence, in the peri-articular tissue, of reduced inflammation.
    Conclusion: In this preliminary study, both the human umbilical perivascular cells and a highly diluted lysate produced therefrom were anti-inflammatory.
    Language English
    Publishing date 2023-09-27
    Publishing country New Zealand
    Document type Journal Article
    ZDB-ID 2494878-0
    ISSN 1178-7031
    ISSN 1178-7031
    DOI 10.2147/JIR.S420741
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Relative contributions of implant hydrophilicity and nanotopography to implant anchorage in bone at Early Time Points.

    Liddell, Robert S / Liu, Zhen-Mei / Mendes, Vanessa C / Davies, John E

    Clinical oral implants research

    2019  Volume 31, Issue 1, Page(s) 49–63

    Abstract: Objective: To compare the contributions of implant hydrophilicity and nanotopography on anchorage in bone. The effect of elevated calcium surface chemistry on bone anchorage was also investigated.: Materials and methods: A full factorial study design ...

    Abstract Objective: To compare the contributions of implant hydrophilicity and nanotopography on anchorage in bone. The effect of elevated calcium surface chemistry on bone anchorage was also investigated.
    Materials and methods: A full factorial study design was implemented to evaluate the effects of ultraviolet (UV) light and/or sodium lactate (SL) and discrete crystalline deposition of nanocrystals (DCD) treatments on the osseointegration of dual acid-etched (AE) titanium alloy (Ti6Al4V) and grit blasted and AE (BAE) commercially pure titanium (CpTi) implants. Sodium hydroxide (NaOH)-treated CpTi implants were immersed in simulated body fluid (SBF) to increase calcium surface chemistry. Implants were placed in the femora of Wistar rats and tested using pull-out testing (BAE implants: 5, 9, 14 days) or tensile testing (AE implants: 9 days, NaOH implants: 28 days).
    Results: Ti6Al4V-AE implants with DCD- and UV-treated surfaces significantly increased bone anchorage compared with untreated Ti6Al4V-AE alloy implants. Pull-out testing of BAE-CpTi implants with the DCD treatment showed increased disruption force values compared with surfaces without the DCD treatment at 5, 9 and 14 days by 4.1N, 13.9N and 15.5N, respectively, and UV-treated implants showed an increase at 14 days by 8.4N. No difference was found between NaOH + SBF and NaOH + H
    Conclusions: Bone anchorage of implants was found to be improved by UV-treating implants or nanotopographically complex surfaces. However, implant nanotopography was found to have a greater contribution to the overall bone anchorage and is more consistent compared with the time-dependent nature of the UV treatment.
    MeSH term(s) Animals ; Dental Implants ; Hydrophobic and Hydrophilic Interactions ; Microscopy, Electron, Scanning ; Osseointegration ; Rats ; Rats, Wistar ; Surface Properties ; Titanium
    Chemical Substances Dental Implants ; Titanium (D1JT611TNE)
    Language English
    Publishing date 2019-11-06
    Publishing country Denmark
    Document type Journal Article
    ZDB-ID 1067626-0
    ISSN 1600-0501 ; 0905-7161
    ISSN (online) 1600-0501
    ISSN 0905-7161
    DOI 10.1111/clr.13546
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 3171: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)

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  4. Article ; Online: The influence of implant design on the kinetics of osseointegration and bone anchorage homeostasis.

    Liddell, Robert S / Ajami, Elnaz / Li, Yunqing / Bajenova, Elena / Yang, Yuan / Davies, John E

    Acta biomaterialia

    2020  Volume 121, Page(s) 514–526

    Abstract: Titanium implants have shown considerable success in terms of achieving quick and long-lasting stability in bone through the process of osseointegration. Further work aims to improve implant success rates by modifying implant design on the nano-, micro-, ...

    Abstract Titanium implants have shown considerable success in terms of achieving quick and long-lasting stability in bone through the process of osseointegration. Further work aims to improve implant success rates by modifying implant design on the nano-, micro-, and macro- scales with the goal of achieving higher levels of bone anchorage more quickly. However, the most frequently used methods of analysis do not investigate bone anchorage as a whole but as a series of discrete points, potentially missing relevant insight which could inform the effects of topography on these 3 scale ranges. Herein we utilize an asymptotic curve fitting method to obtain a biologically relevant description of reverse torque data and compare the anchorage of 12 different implant groups. Implant surface topography had a significant effect on the rate and degree of anchorage achieved during the initial bone formation period of osseointegration but was not found to influence the relative change in anchorage during bony remodeling. Threaded implants significantly decreased the time required to reach peak anchorage compared to non-threaded implants and implants with micro-topographically complex surfaces required greater torque to be removed than implants without such features. Nanotopography increased overall anchorage and decreased the time required to reach peak anchorage but to a lesser degree than microtopography or macrogeometry respectively. The curve fitting method utilized in the present study allows for a more integrated analysis of bone anchorage and permits investigation of osseointegration with respect to time, which may lead to a more targeted approach to implant design.
    MeSH term(s) Dental Implants ; Homeostasis ; Kinetics ; Osseointegration ; Surface Properties ; Titanium/pharmacology
    Chemical Substances Dental Implants ; Titanium (D1JT611TNE)
    Language English
    Publishing date 2020-11-30
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2173841-5
    ISSN 1878-7568 ; 1742-7061
    ISSN (online) 1878-7568
    ISSN 1742-7061
    DOI 10.1016/j.actbio.2020.11.043
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Hyperglycemia compromises Rat Cortical Bone by Increasing Osteocyte Lacunar Density and Decreasing Vascular Canal Volume.

    Ay, Birol / Parolia, Kushagra / Liddell, Robert S / Qiu, Yusheng / Grasselli, Giovanni / Cooper, David M L / Davies, John E

    Communications biology

    2020  Volume 3, Issue 1, Page(s) 20

    Abstract: Uncontrolled diabetes is associated with increased risk of bony fractures. However, the mechanisms have yet to be understood. Using high-resolution synchrotron micro-CT, we calculated the changes in the microstructure of femoral cortices of ... ...

    Abstract Uncontrolled diabetes is associated with increased risk of bony fractures. However, the mechanisms have yet to be understood. Using high-resolution synchrotron micro-CT, we calculated the changes in the microstructure of femoral cortices of streptozotocin-induced hyperglycemic (STZ) Wistar Albino rats and tested the mechanical properties of the mineralized matrix by nanoindentation. Total lacunar volume of femoral cortices increased in STZ group due to a 9% increase in lacunar density. However, total vascular canal volume decreased in STZ group due to a remarkable decrease in vascular canal diameter (7 ± 0.3 vs. 8.5 ± 0.4 µm). Osteocytic territorial matrix volume was less in the STZ group (14,908 ± 689 µm
    MeSH term(s) Animals ; Bone Density ; Cortical Bone/blood supply ; Cortical Bone/diagnostic imaging ; Cortical Bone/metabolism ; Cortical Bone/pathology ; Diabetes Mellitus, Experimental ; Hyperglycemia/metabolism ; Hyperglycemia/pathology ; Imaging, Three-Dimensional ; Immunohistochemistry ; Male ; Osteocytes/metabolism ; Rats ; X-Ray Microtomography
    Language English
    Publishing date 2020-01-09
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 2399-3642
    ISSN (online) 2399-3642
    DOI 10.1038/s42003-019-0747-1
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Early bone anchorage to micro- and nano-topographically complex implant surfaces in hyperglycemia.

    Ajami, Elnaz / Bell, Spencer / Liddell, Robert S / Davies, John E

    Acta biomaterialia

    2016  Volume 39, Page(s) 169–179

    Abstract: Unlabelled: The aim of this work was to investigate the effect of implant surface design on early bone anchorage in the presence of hyperglycemia. 108 Wistar rats were separated into euglycemic (EG) controls and STZ-treated hyperglycemic (HG) groups, ... ...

    Abstract Unlabelled: The aim of this work was to investigate the effect of implant surface design on early bone anchorage in the presence of hyperglycemia. 108 Wistar rats were separated into euglycemic (EG) controls and STZ-treated hyperglycemic (HG) groups, and received bilateral femoral custom rectangular implants of two surface topographies: grit blasted (GB) and grit-blast with a superimposed calcium phosphate nanotopography (GB-DCD). The peri-implant bone was subjected to a tensile disruption test 5, 7, and 9days post-operatively (n=28/time point); the force was measured; and the residual peri-implant bone was observed by scanning electron microscopy (SEM). Disruption forces at 5days were not significantly different from zero for the GB implants (p=0.24) in either metabolic group; but were for GB+DCD implants in both metabolic groups (p<0.001). Contact osteogenesis was greater on GB-DCD than the GB surface. The nano-and micro-surfaced implants showed significantly different disruption forces at all time points (e.g. >15N and <5N respectively at 9days). Such differences were not seen within the GB implants, as all values were very low (<5N). Even in hyperglycemia the GB-DCD surface outperformed the GB surfaces in both metabolic groups. Significantly, SEM of peri-implant bone showed compromised intra-fibrillar collagen mineralization in hyperglycemia, while inter-fibrillar and cement line mineralization remained unaffected. Enhanced bone anchorage to the implant surfaces was observed on the nanotopographically complex surface independent of metabolic group. The compromised intra-fibrillar mineralization observed provides a mechanism by which early bone mineralization is affected in hyperglycemia.
    Statement of significance: It is generally accepted that the hyperglycemia associated with diabetes mellitus compromises bone quality, although the mechanism by which this occurs is unknown. Uncontrolled hyperglycemia is therefore a contra-indication for bone implant placement. It is also known that nano-topographically complex implant surfaces accelerate early peri-implant healing. In this report we show that, in our experimental model, nano-topographically complex surfaces can mitigate the compromised bone healing seen in hyperglycemia. Importantly, we also provide a mechanistic explanation for compromised bone quality in hyperglycemia. We show that intra-fibrillar collagen mineralization is compromised in hyperglycemia, but that interfibrillar and cement line mineralization, remain unaffected.
    MeSH term(s) Animals ; Calcification, Physiologic ; Calcium Phosphates ; Coated Materials, Biocompatible ; Femur/metabolism ; Femur/pathology ; Hyperglycemia/metabolism ; Hyperglycemia/pathology ; Male ; Rats ; Rats, Wistar ; Surface Properties ; Suture Anchors
    Chemical Substances Calcium Phosphates ; Coated Materials, Biocompatible ; calcium phosphate (97Z1WI3NDX)
    Language English
    Publishing date 2016--15
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2173841-5
    ISSN 1878-7568 ; 1742-7061
    ISSN (online) 1878-7568
    ISSN 1742-7061
    DOI 10.1016/j.actbio.2016.05.017
    Database MEDical Literature Analysis and Retrieval System OnLINE

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