Scanning Electron Microscopic Analysis of the Integrity of the Root-end Surface after Root-end Management Using a Piezoelectric Device: A Cadaveric Study

Abstract

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. (J Endod

Microsurgical re-treatment of an endodontically treated tooth with an apically located incomplete vertical root fracture: a clinical case report

“…It is known that VRFs can evolve over time, extending apically or coronally and involving the other side of the affected root, thereby limiting the possibility of surgical treatment to a significant extent 116. Unfortunately, the extent of the VRF can be appropriately diagnosed only through direct observation after the creation of an exploratory flap with the aid of magnification devices and/or staining dyes.…”

Evaluation of apical preparations performed with ultrasonic diamond and stainless steel tips at different intensities using a scanning electron microscope in endodontic surgery

“…These instruments required a certain angle of entry for the apical resection that could jeopardise the root remnant, reducing the corona/root proportion and affecting the periodontium (21). The introduction of ultrasonic tips in endodontic surgery has facilitated a better treatment of the root apex (13,15). However, despite the excellent results obtained using ultrasonic tips, there has also been an elevated incidence of cracks detected when apical preparations are performed using these tips (2,15,19).…”

“…These microfractures could influence the healing process around the root, and could lead to failure due to microleakage (11-14). Several different studies have analysed the effects that these ultrasonic instruments have on the root surface during endodontic surgical procedures, using light microscopes, scanning electron microscopes (15), and endoscopy (16). …”

Etiology of Vertical Root Fractures

“…The small cracks in the canal wall or at the root surface seen in in vitro studies following instrumentation with various NiTi instruments together with previous studies regarding the existence of cracks in the dentin even in the untreated tooth [23][24][25] are considered precursors to the development of incomplete and complete fractures at a later stage [36]. Dentinal cracks also occur after root end preparation with ultrasonic retrotips [37]. These cracks can be an etiological factor in the future success of endodontic surgical treatment.…”