Table 4.
Intraoral foetal and breast doses with effect of the lead shield expressed as a relative dose reduction in percentages. Dose conversion factors are calculated as the foetal or breast dose divided by the corresponding dose–area product value
| Modality | Foetal dose |
Breast dose |
||||
|---|---|---|---|---|---|---|
| No shield | Lead thyroid shield (Shield 1) | Lead apron and thyroid shield (Shield 2) | No shield | Lead thyroid shield (Shield 1) | Lead apron and thyroid shield (Shield 2) | |
| Intraoral (μGy) | ||||||
| Upper occlusal | 0.553 | 0.022 | 0.017 | 1.882 | 0.994 | 0.016 |
| Dose reduction (%) | 96 | 97 | 47 | 99 | ||
| Conversion factor (μGy Gy cm−2) | 27.0 | 1.1 | 0.8 | 91.7 | 48.5 | 0.8 |
| Mandibular incisor | 0.009 | 0.006 | – | 0.602 | 0.283 | 0.002 |
| Dose reduction (%) | 39 | 53 | >99 | |||
| Conversion factor (μGy Gy cm−2) | 1.0 | 0.6 | 67.7 | 31.8 | 0.3 | |
| Maxillary premolar (right) | 0.012 | 0.005 | – | 0.659 | 0.512 | 0.004 |
| Dose reduction (%) | 57 | 22 | 99 | |||
| Conversion factor (μGy Gy cm−2) | 0.7 | 0.3 | 39.3 | 30.5 | 0.2 | |