Endodontic Orthograde Retreatments: Challenges and Solutions

Abstract

Endodontic orthograde retreatments are considered one of the possible treatment options in case of post-treatment diseases considering the promising results present in the literature. Despite this, a plethora of articles have been published on this topic, and drawing conclusions could be challenging. For this reason, this review aims to summarize the crucial points on each aspect of non-surgical endodontic retreatments, discussing and comparing the current protocols, techniques, materials, and indications. Taking into consideration data from the literature, in terms of diagnosis, CBCT should be considered the first choice, since it can thoroughly affect the diagnosis and treatment plan. Regarding the procedural phases, some conclusions can be drawn: when present, coronal restoration materials such as crowns, partial prostheses, post, and core should be removed; the use of magnification devices, ultrasonic instruments, and an in-depth interpretation of radiographic images with both 2D and 3D images are strongly recommended during the orifice location; additional protocols such as irrigants activation, ultrasonic cleaning, and rotary or reciprocating instrumentation of treated canals are strongly recommended for filling materials removal and to achieve a high-quality chemo-mechanical disinfection; perforations should be treated as soon as possible, and the material of choice to treat them is the MTA or other calcium-silicate-based repair materials; the presence of ledges does not intrinsically reduce the success rate of RCRts if properly managed; in case of instrument fragments, their removal should be considered as the first treatment option, however many variables should be considered to select the proper technique or consider the option of bypassing.

Keywords: diagnosis; endodontic retreatment; endodontic retreatment outcome; filling material removal; instrument fragment removal; ledge; missed anatomy; perforation.

Figure 1

Schematic representation of the decision-making process for root canal retreatment.

Figure 2

Clinical example in which the root canal treatment was performed without coronal disassembling.

Figure 3

Clinical example of prefabricated metal post removal associated with a composite core.

Figure 4

Clinical example of RCRt with several problems: fiber post in the distal root (yellow arrow), instrument fragment in the mesio-buccal canal (red arrow), apical part of the endodontic system non-instrumented and obturated, chronic periapical lesion (green arrow).

Figure 5

Clinical example of RCRt with fiber post removal.

Figure 6

Intra-operative photos showing a particular anatomy of the mesio-buccal system of an upper first molar with different angulations.

Figure 7

RCRt case of a central lower incisor characterized by three different orifices and three canals with a single port of exit.