| a little | 4 | degree |
| due to the acid attack | 2 | cause |
| tooth → be → softer | 29 |
| tooth → become → softer | 5 |
| tooth → get → softer | 4 |
| tooth → develop → softer | 4 |
| negative | neutral | positive |
| 0.384 | 0.486 | 0.130 |
| Raw frequency | 42 |
| Normalized frequency | 0.342 |
| Modifier score | 0.500 |
| Perplexity | 186.782 |