PubMed Health⌕ Search

Biomedical subjects

J J Hefferren

Publications and source records attributed to J J Hefferren.

At least 37 records · Page 2Linked to original sources
PubMed1977

Synchronized crystal dissolution behavior for tooth enamel and synthetic (NBS) hydroxyapatite.

The synchronized cyrstal dissolution hypothesis previously proposed to explain the unusual dissolution behavior of human dental enamel and hydroxyapatite in partially saturated acidic media has been critically examined with dissolution-dialysis transport experiments. The findings are in accord with the hypothesis. A model based upon a variable effective solubility for the hydroxyapatite crystal is proposed.

Chemical Phenomena↗
PubMed1977

Unusual dissolution behavior of tooth enamel and synthetic HAP crystals under high partial saturation conditions.

The dissolution behavior of enamel and synthetic hydroxyapatite in acidic media possessing a high degree of partial saturation was found to be neither simple surface dissolution nor linear with time. Instead, a repetitive, stepwise dissolution pattern was observed. To explain this phenomenon, a model based upon a hypothesis that the crystals dissolve in a synchronized fashion was proposed.

Buffers↗
PubMed1976

Mercury: its relation to the dentist's health and dental practice characteristics.

Mercury and 12 clinical chemical determinations were done on the blood samples of 1,555 dentists. The dental practice characteristics of each participant were determined by questionnaires. Seventy-seven percent of all the dentists displayed blood mercury values in the range 0 to 10 ng/ml. The mean for all dentists was 8.2 ng Hg/ml blood. The means for general dentists and specialists were 8.8 and 6.3 ng Hg/ml blood, respectively. Overall, no significant correlations were found in a comparison of blood mercury levels with clinical chemical data and with dental practice characteristics. However, general practitioners with higher blood mercury values tended to show dental practice characteristics that were conducive to producing the higher values found. The data indicate that dentists in the United States, as a group, practice good mercury hygiene.

Blood Chemical Analysis↗