Removal of the Previous Root Canal Filling Material for Retreatment: Implications and Techniques

Abstract

Adequate removal of the previous filling material may be pivotal to a favorable outcome of root canal retreatment of teeth with post-treatment periodontitis in order to permit the access of irrigants and medicaments to persistent bacteria. However, even with recent technological advances, including the introduction of specially designed instruments, no technique has been shown to predictably promote complete filling removal. Supplementary approaches used after chemomechanical preparation, including the use of finishing instruments, ultrasonics and laser, have shown promising results in enhancing root canal cleaning and disinfection. This narrative review addresses the importance and implications of maximal filling removal during retreatment and discusses the effectiveness of different techniques and supplementary approaches used for this purpose.

Intracanal removal and apical extrusion of filling material after retreatment using rotary or reciprocating instruments: A new approach using human cadavers

“…The absence of significant differences between the systems for extrusion and intracanal removal of filling material may also be associated with the standardized conditions of root canal anatomy, irrigation and working length (Alves et al., 2022). In these conditions, studies have shown that differences in taper, tip and cross sectional shape, as well as the operation mode and the number of instruments used, fail to promote significant differences in filling extrusion and removal (Alves et al., 2014; de Siqueira et al., 2016; de Souza et al., 2015; Nevares et al., 2017; Rios Mde et al., 2014; Rödig et al., 2014; Silveira et al., 2018).…”

“…One of the most critical and challenging steps during root canal retreatment is removing the previous filling material, because of the risk of accidents such as zip, deviations and extrusion of debris (Alves et al., 2022). Extruded debris can lead to post‐operative pain, flare‐up or even compromise the long‐term healing of apical periodontitis (Siqueira, 2003).…”

Reciprocating System for Secondary Root Canal Treatment of Oval Canals: CBCT, X-rays for Remnant Detection and Their Identification with ESEM and EDX

“…The CBCT evaluation demonstrated that the presence of the remnants is predominantly localized into the lingual and buccal sides of the root canals. Previous studies have demonstrated the presence of a large amount of remnants corresponding to the roots apical third [24,25], suggesting that the conventional manual or rotary systems used to remove filling materials may induce the formation of an apical critical area [25]. In a similar way, remnants may still also be detectable using a self-adjusting file (SAF) and a hollow, compressible NiTi instrument, through which a continuous flow of an irrigant can be provided [26].…”

Micro-CT evaluation of the removal of root fillings using rotary and reciprocating systems supplemented by XP-Endo Finisher, the Self-Adjusting File, or Er,Cr:YSGG laser

“…Therefore, supplementary techniques have been proposed to increase the cleanliness of root canals during retreatment. Considering the limitations of instruments in removing filling material from the root canal, newer approaches as supplementary steps are currently being proposed [ 12 ]. The XP-Endo Finisher (XPF; FKG Dentaire, La Chaux-de-Fonds, Switzerland) has recently been shown to enhance the removal of root canal fillings [ 13 ].…”