How Does Fluoride Concentration in the Tooth Affect Apatite Crystal Size?
Bibliographic record
Abstract
Despite fluoride's (F) well-documented ability to prevent caries, the effects of F concentrations on enamel and dentin apatite crystals are unknown. The present study examined the hypothesis that tooth F concentration and tooth crystallite size correlate. One hundred human unerupted third molars were studied-53 from Fortaleza-Brazil (F water 0.7 ppm), 23 from Toronto (1.0 ppm), and 24 from Montreal (0.2 ppm). F concentration was analyzed by Neutron Activation Analysis and apatite crystal size by powder x-ray diffraction. A positive correlation between dentin F concentration and enamel crystallite length and width was found. Enamel crystallite length was significantly greater in teeth from Fortaleza than in teeth from Toronto (p = 0.011) and Montreal (p = 0.003). Enamel crystallite widths were significantly greater in Fortaleza teeth compared with those from Toronto (p = 0.020) and Montreal (p < 0.001). No difference in the dentin crystallite size was seen in the 3 regions. Thus, tooth F concentration and crystallite size correlate.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".