Related Experiment Video
Updated: Aug 2, 2026
08:45
Shrinkage of Dental Composite in Simulated Cavity Measured with Digital Image Correlation
Published on: July 21, 2014
Osteoblast behaviour on HA/PE composite surfaces with different HA volumes
L Di Silvio1, M J Dalby, W Bonfield
1Institute of Orthopaedics, IRC in Biomedical Materials, Stanmore, Middlesex, UK.
Biomaterials
|January 5, 2002
Summary
The 40% hydroxyapatite (HA) reinforced polyethylene (PE) composite, HAPEX, significantly enhanced human osteoblast (HOB) proliferation, differentiation, and cytoskeletal organization compared to the 20% HA/PE material.
Area of Science:
- Biomaterials Science
- Tissue Engineering
- Orthopedic Materials
Background:
- Development of advanced bone analogue materials is crucial for orthopedic research.
- Hydroxyapatite (HA) reinforced polyethylene (PE) composites offer promising mechanical and bioactive properties.
- Optimizing material surface composition is key to enhancing cellular interactions for bone regeneration.
Purpose of the Study:
- To evaluate the in vitro biological response of primary human osteoblasts (HOBs) to a hydroxyapatite (HA) reinforced polyethylene (PE) composite (HAPEX).
- To investigate the effect of varying HA concentrations (20% and 40% vol.) on HOB proliferation, differentiation, and cytoskeletal organization.
- To determine the optimal composition of HAPEX for bone analogue applications.
Main Methods:
- Fabrication and machining of HAPEX composite with controlled surface roughness and minimal batch variation.
- In vitro culture of primary human osteoblasts (HOBs) in direct contact with 20% and 40% HA/PE materials.
- Assessment of HOB proliferation, differentiation, and cytoskeletal organization using standard cell culture assays and microscopy.
Main Results:
- The 40% HA/PE composite demonstrated significantly enhanced HOB proliferation and differentiation compared to the 20% HA/PE composite.
- HOBs cultured on 40% HA/PE exhibited flatter morphology and accelerated cytoskeletal organization.
- An increased number of focal contact points was observed in HOBs cultured on the 40% HA/PE material.
Conclusions:
- The 40% HA/PE composite (HAPEX) exhibits superior biocompatibility and osteogenic potential compared to the 20% HA/PE formulation.
- HAPEX, particularly the 40% HA variant, shows promise as an effective bone analogue material for orthopedic applications.
- Surface composition plays a critical role in modulating cellular behavior and promoting osteoblast function.
Related Concept Videos
01:19Expansion and Contraction in Masonry Walls
Masonry walls are subject to slight expansion and contraction due to variations in temperature and moisture. Thermal movement in masonry is relatively straightforward to measure and plan for. On the other hand, moisture movement poses more of a challenge. New clay masonry units typically absorb water and expand over time under normal environmental conditions. Conversely, new concrete masonry units tend to shrink as they lose the excess moisture acquired during their production process.
To...
To...
01:23Behavior of Concrete Under Compressive Load
Concrete exhibits specific behaviors under different compressive loads. Understanding this is crucial for understanding its structural integrity. When concrete undergoes uniaxial compression, it tends to develop cracks that run parallel to the direction of the force. These parallel cracks stem from localized tensile stresses that occur perpendicular to the compression direction. Additionally, angled cracks may appear due to the formation of shear planes.
As the concrete specimen fractures under...
As the concrete specimen fractures under...
01:12Total Voids in Concrete
Total voids in concrete encompass gel water volume, capillary pores, and entrapped air. Gel water (retained within the cement hydration products) and physically entrapped or adsorbed water are significant for the hydration process. For complete hydration, it's estimated that the space needed for the products of a cubic centimeter of cement doubles. Capillary pores constitute the unoccupied space within the hydrated cement paste, with their size largely influenced by the water-to-cement ratio...
01:27Shrinkage in Concrete
Shrinkage in concrete is primarily due to water loss from evaporation, hydration of cement, or carbonation, leading to a reduction in volume. The volumetric contraction results in volumetric strain in concrete. However, in practice, shrinkage is measured as linear strain, which is one-third of the volumetric strain.
When concrete is still in its plastic state, it can undergo a decrease in volume by about 1% of its absolute volume. This decrease is known as plastic shrinkage. It arises either...
When concrete is still in its plastic state, it can undergo a decrease in volume by about 1% of its absolute volume. This decrease is known as plastic shrinkage. It arises either...
01:25Permeability of Concrete
Permeability in the context of concrete refers to how easily liquids or gases can pass through the material. This quality is crucial for assessing the water-tightness and durability of concrete structures and their resistance to chemical attacks. Concrete permeability can be determined through comparative laboratory tests. These tests typically involve sealing a concrete specimen from the sides, applying water pressure to the top surface with pressure, and measuring the amount of water passing...
01:14Design Example: Managing Concrete Workability
This example deals with managing the workability of concrete for a raft foundation project under hot weather conditions. Workability is crucial for ensuring the concrete is easy to place, compact, and finish. In this scenario, a slump test — a common method to measure the workability of fresh concrete — initially indicated low workability. This was attributed to the rapid water loss from the concrete mix, exacerbated by the high temperatures causing the course aggregates to heat up.
To address...
To address...