Scanning electron microscopic analysis of the integrity of the root-end surface after root-end management using a piezoelectric device : a cadaveric study

Introduction: The introduction of piezoelectric instruments in endodontic surgery allowed clinicians to manage the bone tissue with precision reducing the risk of damaging soft tissues. Although such instruments can also be used to prepare root-end cavity, few information is available on the effect of piezosurgery on dentine. This cadaveric study investigated the integrity of root apices after root-end cavity preparation by piezoelectric instruments at different device settings. Methods: Fifty maxillary anterior teeth underwent endodontic treatment and apical resection in situ. Ten teeth were used as control. Retrograde cavities were prepared in 40 teeth (10 per group). In three groups, the piezoelectric device was set at constant vibration mode (CV), and three power levels were used. In another experimental group (n = 10), vibration + pulsation mode (VP) was selected, and low power was used. Each root was duplicated and analyzed by scanning electron microscopy for the presence of cracks and marginal chipping. Results: The number of cracks was significantly higher in the VP group, whereas no significant difference was found among CV groups. No difference between groups was found for crack type. The VP group showed a significantly poorer quality of cavity margin respect to the CV groups. Conclusion: Constant vibration mode is recommended for retrograde preparation with piezosurgery.