Porous membranes of quaternized chitosan composited with strontium-based nanobioceramic for periodontal tissue regeneration

This report demonstrates the development of a degradable quaternary ammonium derivative of chitosan (QC) composited with strontium-containing nanoapatite (SA) for bioactivity. The material was made as porous membrane by solution casting and freeze drying, for guided tissue regeneration (GTR) applications. The micromorphology, tensile strength, suture pull-out strength, degradation ( in vitro, in phosphate buffered saline), and cytocompatibility (using human periodontal ligament cells) were tested to investigate the effect of derivatization and SA addition. The porosity of the membranes increased with increasing SA content and so did the tensile strength and the degradation. The suture pull-out strength, however, showed a decrease. The cell culture evaluation endorsed biocompatibility. The composite with 1.5 mg SA per 1 mL QC was found to have optimal qualities for GTR applications.

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Pull-out strength of orthopaedic screws in polymethylmethacrylate filled medullary cavities of foal third metacarpal bones

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.1055/s-0038-1632801 ◽

2004 ◽

Vol 17 (03) ◽

pp. 136-140

Author(s):

G. S. Martin ◽

M. S. Gill ◽

G. A. Sod

Keyword(s):

Fracture Site ◽

Medullary Cavity ◽

Pull Out ◽

Metacarpal Bones ◽

Cavity Filling ◽

The Mean ◽

Stable Internal Fixation ◽

Empty Control ◽

Pull Out Strength

SummaryThe purpose of this study was to determine the in vitro pull-out force and strength of 4.5-mm and 5.5-mm cortical screws inserted in the diaphysis of foal third metacarpal bones with and without polymethylmethacrylate (PMMA) filling the medullary cavity. Filling the medullary cavity with PMMA significantly increased the pull-out force of 4.5-mm screws by 2.0-fold, and 5.5-mm screws by 2.2-fold, compared to controls (p < 0.001). Also the mean pull-out strength per mm of bones filled with PMMA was significantly greater (p < 0.001) than empty control bones. Our results suggest that filling the medullary cavity with PMMA at sites of greater stress, such as the ends of the plate and near the fracture site, may result in a more stable internal fixation.

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Material Characterization of PCL:PLLA Electrospun Fibers Following Six Months Degradation In Vitro

Polymers ◽

10.3390/polym12030700 ◽

2020 ◽

Vol 12 (3) ◽

pp. 700 ◽

Cited By ~ 4

Author(s):

Alyah H. Shamsah ◽

Sarah H. Cartmell ◽

Stephen M. Richardson ◽

Lucy A. Bosworth

Keyword(s):

Tissue Regeneration ◽

Annulus Fibrosus ◽

Hydrolytic Degradation ◽

Electrospun Nanofibers ◽

Polymer Chains ◽

Poly Lactic Acid ◽

Fiber Morphology ◽

Phosphate Buffered Saline

The annulus fibrosus—one of the two tissues comprising the intervertebral disc—is susceptible to injury and disease, leading to chronic pain and rupture. A synthetic, biodegradable material could provide a suitable scaffold that alleviates this pain and supports repair through tissue regeneration. The transfer of properties, particularly biomechanical, from scaffold to new tissue is essential and should occur at the same rate to prevent graft failure post-implantation. This study outlines the effect of hydrolytic degradation on the material properties of a novel blend of polycaprolactone and poly(lactic acid) electrospun nanofibers (50:50) over a six-month period following storage in phosphate buffered saline solution at 37 °C. As expected, the molecular weight distribution for this blend decreased over the 180-day period. This was in line with significant changes to fiber morphology, which appeared swollen and merged following observation using Scanning Electron Microscopy. Similarly, hydrolysis resulted in considerable remodeling of the scaffolds’ polymer chains as demonstrated by sharp increases in percentage crystallinity and tensile properties becoming stiffer, stronger and more brittle over time. These mechanical data remained within the range reported for human annulus fibrosus tissue and their long-term efficacy further supports this novel blend as a potential scaffold to support tissue regeneration.

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Freeze gelated porous membranes for periodontal tissue regeneration

Acta Biomaterialia ◽

10.1016/j.actbio.2015.05.001 ◽

2015 ◽

Vol 23 ◽

pp. 317-328 ◽

Cited By ~ 61

Author(s):

Saad B. Qasim ◽

Robin M. Delaine-Smith ◽

Tobias Fey ◽

Andrew Rawlinson ◽

Ihtesham Ur Rehman

Keyword(s):

Tissue Regeneration ◽

Porous Membranes ◽

Periodontal Tissue ◽

Periodontal Tissue Regeneration

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Effect of surface topography on pull-out strength of cortical screw after ultrasonic bone drilling: an in vitro study

Journal of the Brazilian Society of Mechanical Sciences and Engineering ◽

10.1007/s40430-020-02449-5 ◽

2020 ◽

Vol 42 (7) ◽

Author(s):

Raj Agarwal ◽

Vivek Jain ◽

Vishal Gupta ◽

Sanjai Saxena ◽

Vagish Dwibedi

Keyword(s):

Surface Topography ◽

In Vitro Study ◽

Vitro Study ◽

Bone Drilling ◽

Pull Out ◽

Cortical Screw ◽

Pull Out Strength ◽

Effect Of Surface

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The Stability of Temporary Restorations Fabricated on a Healing Cap for Immediate Loading: An In Vitro Study

Applied Sciences ◽

10.3390/app8112261 ◽

2018 ◽

Vol 8 (11) ◽

pp. 2261

Author(s):

Sangho Jun ◽

Hyonseok Jang ◽

Enji Cheon ◽

MinJu Kim ◽

Sungwon Ju ◽

...

Keyword(s):

Compressive Strength ◽

Load Distribution ◽

In Vitro Study ◽

Bite Force ◽

Immediate Loading ◽

Pull Out ◽

The Stability ◽

Implant Treatment ◽

Pull Out Strength

The aim of this study was to analyze the load distribution of interim restorations using healing cap during immediate loading implant treatment in vitro. A total of 29 models with interim restorations which were fabricated with healing cap were selected. The pull-out strength was measured with a used healing cap and new healing cap. The compressive strength and sinking distance were also measured. The pull-out strength of interim restoration showed lower value (max. 29.8 N) compared to the natural bite force. The sinking amounts were larger than normal tooth sinking. The sinking amounts of interim restorations fabricated on a healing cap were roughly 3 times (0.3–0.5 mm under 450 N) those of normal teeth. The interim restoration on plastic healing cap would be useful for immediate loading implant treatment.

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MSC/ECM Cellular Complexes Induce Periodontal Tissue Regeneration

Journal of Dental Research ◽

10.1177/0022034517708770 ◽

2017 ◽

Vol 96 (9) ◽

pp. 984-991 ◽

Cited By ~ 27

Author(s):

M. Takewaki ◽

M. Kajiya ◽

K. Takeda ◽

S. Sasaki ◽

S. Motoike ◽

...

Keyword(s):

Bone Regeneration ◽

Growth Medium ◽

Tissue Regeneration ◽

Calcium Deposition ◽

Periodontal Tissue ◽

Class Iii ◽

Beagle Dogs ◽

Defect Model ◽

Periodontal Tissue Regeneration

Transplantation of mesenchymal stem cells (MSCs), which possess self-renewing properties and multipotency, into a periodontal defect is thought to be a useful option for periodontal tissue regeneration. However, developing more reliable and predictable implantation techniques is still needed. Recently, we generated clumps of an MSC/extracellular matrix (ECM) complex (C-MSC), which consisted of cells and self-produced ECM. C-MSCs can regulate their cellular functions in vitro and can be grafted into a defect site, without any artificial scaffold, to induce bone regeneration. Accordingly, this study aimed to evaluate the effect of C-MSC transplantation on periodontal tissue regeneration in beagle dogs. Seven beagle dogs were employed to generate a premolar class III furcation defect model. MSCs isolated from dog ilium were seeded at a density of 7.0 × 104 cells/well into 24-well plates and cultured in growth medium supplemented with 50 µg/mL ascorbic acid for 4 d. To obtain C-MSCs, confluent cells were scratched using a micropipette tip and were then torn off as a cellular sheet. The sheet was rolled up to make round clumps of cells. C-MSCs were maintained in growth medium or osteoinductive medium (OIM) for 5 or 10 d. The biological properties of C-MSCs were evaluated in vitro, and their periodontal tissue regenerative activity was tested by using a dog class III furcation defect model. Immunofluorescence analysis revealed that type I collagen fabricated the form of C-MSCs. OIM markedly elevated calcium deposition in C-MSCs at day 10, suggesting its osteogenic differentiation capacity. Both C-MSCs and C-MSCs cultured with OIM transplantation without an artificial scaffold into the dog furcation defect induced periodontal tissue regeneration successfully compared with no graft, whereas osteogenic-differentiated C-MSCs led to rapid alveolar bone regeneration. These findings suggested that the use of C-MSCs refined by self-produced ECM may represent a novel predictable periodontal tissue regenerative therapy.

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In vitro biomechanical study of pedicle screw pull-out strength based on different screw path preparation techniques

Indian Journal of Orthopaedics ◽

10.4103/0019-5413.177572 ◽

2016 ◽

Vol 50 (2) ◽

pp. 177 ◽

Cited By ~ 1

Author(s):

Mark Moldavsky ◽

Kanaan Salloum ◽

Brandon Bucklen ◽

Saif Khalil ◽

JwalantS Mehta

Keyword(s):

Pedicle Screw ◽

Biomechanical Study ◽

Pull Out ◽

Strength Based ◽

Preparation Techniques ◽

Pull Out Strength

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Axial pull-out strength of 3.5 cortical and 4.0 cancellous bone screws placed in canine proximal tibias using manual and power tapping

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.3415/vcot-07-08-0082 ◽

2008 ◽

Vol 21 (04) ◽

pp. 323-328 ◽

Cited By ~ 4

Author(s):

M. E. Soniat ◽

S. Elder ◽

R. McLaughlin ◽

J. L. Demko

Keyword(s):

Cancellous Bone ◽

Testing Machine ◽

Bone Screws ◽

Materials Testing ◽

Pull Out ◽

Cortical Width ◽

Bone Width ◽

Significant Difference ◽

Pull Out Strength

SummaryAn in vitro experimental cadaveric mechanical testing study was performed using 20 radiographically mature dogs, weighing between 18–33 kg. The aim of the study was to compare the axial pull-out strength of 3.5 mm cortical and 4.0 mm cancellous bone screws inserted in the canine proximal tibia using manual and power tapping techniques. 3.5 cortical and 4.0 cancellous bone screws were inserted in canine cadaver proximal tibiae using a manual or power tapping technique. The screws were extracted using a servohydraulic materials testing machine in order to measure axial pullout strength. Axial pull-out strength was recorded relative to the total bone width and total cortical width of each tibia. The mean axial pull-out strength for all constructs was 717.8±56.5 N without any statistically significant difference among groups (p=0.4183). The groups were equal in animal body weight, cortical width and total bone width (p=0.2808). The axial pull-out strength in proportion to cortical and total bone width was not significantly different among groups (p=0.5318). Axial pull-out strengths of 3.5 mm cortical and 4.0 mm cancellous bone screws inserted in the proximal tibial metaphysis were not significantly different. Axial pull-out strength was not affected by the use of power tapping in either screw type.

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