PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 7738269

A new temporary soft lining material.

N J Jepson·J F McCabe·R M Basker
View original source ↗Export metadata ↓

Abstract

The viscoelastic properties of a new light-activated temporary denture soft lining material have been monitored in vitro using a force/distance probe. Its baseline behaviour was characteristic of an elastic material and its compliance considerably less than that of both a short-term and a long-term soft lining material which were used as controls. Sample thickness had no appreciable effect on this compliance. These results suggest that the new product is likely to be perceived as being significantly harder by a patient. Twenty-four weeks' immersion in distilled water had no significant effect on either the compliance or elasticity of the test material and would suggest an improved durability when compared to other conventional short-term resilient denture lining materials, albeit at the expense of compliance.

Explore related subjects

ComplianceDental Stress AnalysisDenture LinersDrug StabilityElasticityMaterials TestingMethacrylatesMethylmethacrylateMethylmethacrylatesModels, StructuralPolyurethanesViscosityJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

N J Jepson, J F McCabe, R M Basker. 1995. A new temporary soft lining material.. https://doi.org/10.1016/0300-5712(95)98979-d

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1994

A computational study of a thin-walled three-dimensional left ventricle during early systole.

A numerical study was conducted to solve the three-dimensional Navier-Stokes equations for time-dependent flow in a compliant thin-walled, anatomically correct left ventricle during early systole. Model parameters were selected so that the simulation results could be compared to clinical data. The results produced endocardial wall motion which was consistent with human heart data, and velocity fields consistent with those occurring in a normally-contracting left ventricle. During isovolumetric contraction the posterior wall moved basally and posteriorly, while the septal wall moved apically and anteriorly. During ejection, the short axis of the ventricle decreased 1.1 mm and the long axis increased 4.2 mm. At the end of the isovolumetric contraction, most of the flow field was moving form the apex toward the base with recirculation regions at the small pocket formed by the concave anterior leaflet, adjacent to the septal wall and near the left ventricular posterior wall. Fluid velocities in the outflow tract matched NMR data to within 10 percent. The results were also consistent with clinical measurements of mitral valve-papillary muscle apparatus displacement, and changes in the mitral valve annular area. The results of the present study show that the thin-walled, three-dimensional left ventricular model simulates observed normal heart phenomena. Validation of this model permits further studies to be performed which involve altered ventricular function due to a variety of cardiac diseases.

Compliance↗
PubMed1994

Optimization of the contact damping and stiffness coefficients to minimize human body vibration.

In this paper, a lumped mass human model is used to minimize the energy absorption at the feet/hip level when the body is subjected to vertical vibration. The contact forces are assumed unknown. By coupling the dynamic response of the body with certain objective criteria, the optimum damping and stiffness coefficients of shoes/chairs are sought. The optimization technique is based on the quasi-Newton and finite-difference gradient method and is used to seek optimum coefficients of the contact forces in the solution of the body's response in the frequency domain. The criteria of acceleration, displacement and internal forces response area swept for a range of 0-15 Hz form the basis of our simulation study. In the seated/standing postures it is found that for each criteria the frequency response shifts the peak of resonance of each body segment response from 4.5/3.67 Hz to 2.5/2.255 Hz. In addition, the total energy reduces drastically when the contact conditions are optimum. The method presented in this paper is useful in modeling the medium of contacts and especially in controlling the effects of human body vibration.

Compliance↗