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Biomedical subjects

H J Wilson

Publications and source records attributed to H J Wilson.

At least 55 records · Page 3Linked to original sources
PubMed1986

Comparison of the strengths of aluminous porcelain fired on to platinum and palladium foils.

The disc strengths of aluminous porcelain fired on to both platinum and palladium foil matrices have been determined. Also, the effect on strength of removing the matrices has been measured. The appearance of the separated metal and porcelain surfaces has been studied using scanning electron microscopy, and energy dispersive X-ray analysis has been used to evaluate the chemical composition of these surfaces. Reasons for the increase in strength observed when the matrix is left intact are discussed. Practical suggestions for obtaining stronger jacket crowns are presented.

Aluminum↗
PubMed1986

Force reduction of orthodontic elastomeric chains after one month in the mouth.

The effect of ageing activated orthodontic elastomeric chains for one month in the mouth is reported. Over this period the mean value of exerted force fell by about 50 per cent of the original value. All the materials tested underwent a decrease in stiffness which contributed to a reduction in the force exerted. After a four week treatment period space closures in the range 0-5 mm were produced by the specimens tested.

Dental Stress Analysis↗
PubMed1985

A laboratory investigation of orthodontic elastomeric chains.

The dimensions and force/extension characteristics of 13 commercially available orthodontic chain elastomeric materials are reported. The relationship between force and extension was not linear over the range investigated and there were two definite transition points in the curves. Over the first linear part of the curve the two-loop specimens had stiffness values from 0.9 to 1.6 N/mm. Stiffness fell as the number of loops increased so that four-loop chains produced 0.6-1.1 N/mm. One hundred per cent extension produced forces in the 4-5 N range for most specimens. It is suggested that an extension of between 50 and 70 per cent would provide the most satisfactory orthodontic force.

Dental Stress Analysis↗