Biomedical subjects
Publications and source records attributed to C L Davidson.
The technology of finishing restaurative dental materials is discussed. With various techniques several different brands of composites are polished. Only high speed tools with abrasives fixed at the stone or paper can polish the surface to an acceptable level. The use of pastes always causes a surface with a roughness that is determined by the size and distribution of the anorganic particles in the composite material.
Physical properties with clinical relevance has been tested on a number of agar hydrocolloid impression materials For 1 hour an almost perfect dimensional stability can be maintained when the impression is stored in water. Elasticity and strength are poor. Only the use of much bulk material may prevent damage during manipulation of the gel. The detail reproduceability meets all standards. A good compatibility with dental stone subsequently allows sharp details in the model.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
In a preliminary experiment the paired radii and femora of dogs were tested for bone mineral mass and mechanical properties including the load at break, the ultimate bending strength and the modulus of elasticity; symmetry was observed for most of the parameters determined. The influence of the elasticity of materials used for the internal splintage of bone and its relationship to bone remodeling were then investigated for stainless steel and plastic plates applied to the femora of dogs. A significant decrease in bone mineral mass per centimetre length of bone and in mechanical properties was demonstrated for the femora plated with steel, and microradiography showed that this was due to massive endosteal resorption. A model for determining the influence of protection from stress in bone is presented.
The HPO2-4 and CO2-3 content was determined in sound enamel and in material collected from artificially produced carious lesions. The method described shows that the HPO2-4 content can be determined from the 875 cm(-1) infrared absorption band if correction for the CO2-3 contribution are made. The I.R. spectra show that the HPO2-4 content in sound human or bovine enamel is about 5% by weight. In artificially produced carious lesions (pH=4.0), the HPO2-4 content is in the order of 15 wt%. Most likely, the HPO2-4 ions in sound and carious enamel have a different enviroment.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.