TABLE 1. Classification of the groups according to severity of dye penetration.
| Groups | Mean (%) | Rate of dye penetration |
|---|---|---|
| C | 16.20 | Low |
| B | 17.24 | Low |
| F | 17.84 | Low |
| E | 22.08 | Intermediate |
| A - control | 24.33 | Intermediate |
| H | 26.82 | Intermediate |
| D | 31.89 | High |
| G | 32.12 | High |
| I | 38.30 | High |
A: 90° apicoectomy with bur, ultrasonic root-end cavity preparation and filling with MTA; B: A + apical surface treatment with CO2 laser; C: 90° apicoectomy with bur and apical surface treatment with Nd:YAG laser; D: 90° apicoectomy with bur and apical surface treatment with CO2 laser; E: apicoectomy with Er:YAG laser, ultrasonic root-end cavity preparation and filling with MTA; F: apicoectomy with Er:YAG laser and apical surface treatment with Nd:YAG laser; G: apicoectomy with CO2 laser, ultrasonic root-end cavity preparation and filling with MTA; H: apical end irradiation with CO2 laser; I: apical end irradiation with Nd:YAG laser. Source: Study data, Instat 3.0 for Windows.