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Biomedical subjects

E W Collard

Publications and source records attributed to E W Collard.

At least 19 recordsLinked to original sources
PubMed1981

In vitro analysis of self-shearing retentive pins.

Combining stress, analysis, microscopic examination, mechanical testing of the shear mechanism, and retention of the Reten Pin leads to the following conclusions: 1. The suggested 0.006 inch pin-channel mismatch induces high lateral and apical stresses. Microscopically, this was seen to correlate with injury to the dentin. 2. The degree of retention was increased by using a smaller pin-channel mismatch. This correlates with smaller stresses and reduced dentinal damage. 3. The shear mechanism acts in a uniform manner, with a relatively small variation from the mean. It is suggested that for the best results the manufacturer should supply larger twist drills and pins with a somewhat deeper self-shearing groove to minimize apical involvement during shearing of the handle from the pin.

Dental Pins↗
PubMed1976

Comparative stability of two removable die systems.

The comparative stability of two removable die systems was evaluated. Under controlled conditions, ten casts, each with two removable dies, were constructed for each system for a total of 20 casts and 40 removable dies. Base-line pre- and postsectioning measurements to within 0.0001 inch in horizontal and vertical planes were recorded and differences calculated. Each die was removed and re-placed 30 times prior to any postsectioning measurement. The results indicated small inconsistent horizontal deviations and consistent vertical deviations for both systems. The Pindex system deviations were slightly less than those of the Di-Lok system, although t test values preclude any conclusion of significance. The results of this investigation indicate the need for dentists and dental laboratory technicians to exercise care in the utilization of any removable die system so as to obtain optimum accuracy and stability in the relationships of the components of that system.

Dental Casting Technique↗
PubMed1976

Diagnosis and treatment of pulpal distress.

Both diagnosis and treatment of vital pulp tissues encompass some fairly comprehensive varieties of methods and materials. Diagnosis is arrived at in terms of probability. No one can be absolutely sure that the diagnosed degree of pulpal distress is in fact the actual state of affairs. Treatment, therefore, must be best be a probability also. There can be no guarantee that the treatment rendered will succeed in every instance. Any diagnosis and treatment of reversible pulpal distress is a gamble on the part of both practitioner and patient. However, utilization of every diagnostic means at his disposal, knowledge of the many treatment modalities available for use, and the ability to correlate both the diagnosis and treatment phases of a given case will result in a high probability of success. This is indeed rewarding to both the patient and the dentist.

Dental Cavity Lining↗