Cervical length and volume regeneration in relation with the four classes of cone length
| Cone length | n | Length regeneration | P value | Volume regeneration | P value |
| 1–9 mm | 43 | 91.9±4.6 | <0.001 | 85.0±20.4 | 0.074 |
| 10–14 mm | 70 | 90.0±6.4 | 90.0±5.8 | ||
| 15–19 mm | 44 | 88.0±5.9 | 83.0±12.2 | ||
| ≥20 mm | 8 | 80.3±6.3 | 82.2±12.1 |
Data are mean±SD as appropriate.