Influence of Apical Preparation Size and Working Length on Debris Extrusion

Abstract

The aim of this study was to quantitatively evaluate the amount of apically extruded debris by single-file reciprocating instruments with different working lengths and apical preparation sizes. Eighty human single-rooted mandibular incisors were used and conventional access cavities were prepared. Then, the specimens were divided into four groups (n=20), according to root canal instrumentation: Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used at the foramen; Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used 1 mm short of the foramen. Distilled water was used as an irrigant and the apically extruded debris were collected in pre-weighted glass vials and dried afterwards. The mean weight of debris was weighed with a microbalance and statistically analyzed using one-way analysis of variance and the post hoc Tukey multiple comparison test (p<0.05). The results showed that all experimental groups were associated with debris extrusion. No significant difference was found in the amount of apically extruded debris among all experimental groups (p>0.05). The present study demonstrated that the working length and the apical preparation size did not have a significant effect on debris extrusion when performing single-file reciprocating instrumentation.

Debris extrusion and foraminal deformation produced by reciprocating instruments made of thermally treated NiTi wires

“…Another clinically relevant aspect of these instruments/kinematics is their greater tendency to extrude debris through the apical foramen (AF) during the mechanical preparation of the root canal system, which can lead to postoperative pain 5 , 23 . This finding is not unanimous in the literature; however, it seems to be related to the design of the instruments (larger or smaller area for debris accumulation between the coils) and kinematics (release of the scrapings collected when the direction of movement is reversed) 1 , 3 , 17 , 21 .…”

“…Regarding the definition of the apical limit of instrumentation, Endodontics has been dedicated to investigating possible variations, and understanding the need to disinfect the entire root canal system, not only to a historically predetermined limit (i.e., 1.0 mm short of the AF), but throughout its entire extension, which means right up to the AF. Thus, apical limits considering the root canal length (RCL) of the tooth, or even beyond this, as being an ideal apical stop have appeared in the literature 17 , 19 , 25 . Although not consolidated, this practice could allow irrigation in the apical region and promote a more efficient mechanical debridement of the apical portion, including the AF, optimizing the disinfection of the root canal and favouring its repair 14 , 19 .…”

“…However, a major concern about extending the apical limits (i.e., beyond AF) is the possibility that larger quantities of debris, bacteria and irrigators could be extruded through the AF compared with those that could occur during conventional instrumentation 1 , 17 , 20 . This extrusion has commonly been associated with postoperative pain and/or delay in periapical repair 6 .…”

NiTi loss on the dentinal walls and instrument deformation during root canal preparation

“…Additionally, Ni and Ti particles could apically be extruded to the periapical tissues and their consequences still remains unclear. Several papers have reported that dentin chips, microrganisms and their by-products, pulp tissue and irrigants may extrude to the periapical tissues during canal preparation (Mittal, Singla, Garg, & Dhawan, 2015;Silva et al, 2016;Uzunoglu, Turker, & G€ orduysus, 2015). Apical extrusion of debris may lead to postoperative symptoms and impair the treatment outcome (Silva et al, 2016 (Shen, Haapasalo, Cheung, & Peng, 2009).…”

Debris Apically Extruded by Two Reciprocating Systems: A Comparative Quantitative Study

“…[8][9][10] Many variables may influence the occurrence of more or less apical extrusion of debris, such as root canal curvature, anatomic variations, patency approach, working length, increased apical preparation size, number of instruments used, and movement kinematics during instrumentation. 1,11,12 However, with the development of different designs and heat treatments for nickel-titanium alloys and their consequent superelasticity, faster access to the foramen, and possible foraminal enlargement became important factors to be considered in the amount of debris that can be apically extruded. 13 With the introduction of different reciprocating single-file instrumentation systems, it is important to analyze the behavior of these instruments during root canal preparation, and an aspect lacking scientific evidence is the amount of extruded debris.…”