DEPOSITION OF RADIOACTIVE STRONTIUM IN THE DEVELOPING ENAMEL AND DENTIN OF THE RAT
To study the fate of /sup 90/Sr in developing enamel and dentin, Long- Evans rats were injected with 2 mu C/kg body weight of /su 90/SrCl/sub 2/ (with the contaminart /sup 90/Y in equilibrium) intraperitoneally 25 days after birth. Body burden of /sup 90/Sr was monitored daily by placing each animal in a whole- body scintillation counter. The relative degree of mineralization was determined by the microdensitometric values and photographic-density values of soft x-ray radiographs, and the relative radioactivity was measured by autoradiographs. In the lower incisor region the enamel showed an irregnlar small increase in mineralization throughout the period of study, and dentin a more definite increase in mineralization. In the lower incisor region there was a definite drop in radioactivity in the dentin inltially, followed by a leveling off of the curve, with a final rapid drop as the hot spot was lost by attrition. In the upper incisor region a similar pattern was found, with littie increase in enamel mineralization but dentin first increased gradually in x-ray density and then become fairly constant. The loss of radioactivity in dertin and enamel was similar to thnt found for these tissues in the lower incisor region. In the upper molars there was an early drop in dertin activity, and the enamel remained at a constant level of radioactivity. In the incisor, as the degree of mineralization increased, the radioactivity fell, with both processes appearing to plateau within a few days of each other. In molars, however, the two plateaus came about 15 days apart. It appears that, once incorporated in the hard tissues, /sup 90/Sr was not readily removed. The reduction of radioactivity, observed in autoradiographs and by direct courting, that occurred as the dertin became increasingly mineralized, was only apparent. The results suggest that physical self-absorption, due to increase in mineralization during development, which masks the radiation, is an important factor in accounting for this reduction. (BBB)
- Research Organization:
- Eastman Dental Dispensary, Rochester, N.Y.
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-18-017438
- OSTI ID:
- 4059378
- Journal Information:
- J. Dental Res., Journal Name: J. Dental Res. Vol. Vol: 42
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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Related Subjects
BIOLOGY AND MEDICINE
BODY
BONES
CERAMICS
COATING
DENTIN
DEPOSITS
DIAGRAMS
DIFFUSION
DISTRIBUTION
ENAMELS
INTESTINE
LABELLED COMPOUNDS
MEASURED VALUES
METABOLISM
MONITORING
PERFORMANCE
PHOTOGRAPHIC FILM
QUANTITATIVE ANALYSIS
RADIOACTIVITY
RADIOAUTOGRAPHY
RADIOGRAPHY
RATS
SCINTILLATION COUNTERS
SENSITIVITY
STRONTIUM 90
STRONTIUM CHLORIDES
TEETH
TISSUES
TRACER TECHNIQUES
VARIATIONS
X RADIATION
YTTRIUM 90