Unprepared areas and centralization of oval canals prepared with WaveOne Gold or XP-endo Shaper: microcomputed tomographic analyses.

Current instrumentation systems cannot fully prepare oval root canal systems. This may cause accumulation of hard tissue debris and fail to eliminate bacteria from areas inaccessible to instrumentation, which could perpetuate periapical inflammation and jeopardize the success of endodontic treatment.

Aim: To evaluate the performance of two endodontic systems in oval canals by investigating the changes in volume, unprepared areas, and centering ability of XP-endo Shaper (XPS) and WaveOne Gold (WOG) in oval canals using microcomputed tomography (micro-CT).

Materials and method: Thirty mandibular canines were scanned before and after preparation with WOG (25/.07 and 35/.06) or XPS (30/.01) to evaluate the volume, surface area, and canal centralization at 4 mm and 10 mm from the apical foramen.

Results: Volume and surface area increased significantly after preparation with both systems (p<0.05). However, no significant difference was observed in the unprepared areas, regarding either the entire canal (26.21% for WOG and 30.10% for XPS), or the apical segment (18.82% for WOG and 14.63% for XPS) (p >0.05).

Conclusions: Both systems maintained canal centralization, with no difference between them. XPS and WOG had similar shaping abilities in the mandibular canine, but left almost one third of the unprepared areas.