Apical Transportation and Centering Ability After Root Canal Filling Removal Using Reciprocating and Continuous Rotary Systems: A CBCT Study

Abstract

Objective To evaluate the apical transportation and centering ability promoted by reciprocating and continuous rotary systems after root canal filling removal. Materials and Methods After obturation, 40 mesial root canals of mandibular molars were distributed into four groups (n = 20) for filling material removal: PTU group–F2 instrument (25.08) of ProTaper Universal system; R25 group–R25 instrument (25.08) of Reciproc system; X2 group–X2 instrument (25.06) of ProTaper Next system and X3 group–X2 instrument (25.06) of ProTaper Next system, followed by X3 instrument (30.07). Cone-beam computed tomographic analysis was performed before and after filling material removal for acquisition of apical images. Apical transportation (AT) and its direction, and centering ability (CA), were assessed using the equations AT = (X1–X2)–(Y1–Y2) and CA = (X1–X2/Y1–Y2 or Y1–Y2/X1–X2), respectively. Data were submitted to the nonparametric Kruskal–Wallis and Dunn multiple comparison tests (p < 0.05) for statistical analysis. Results There was no statistically significant difference among groups for AT (p > 0.05), with a tendency toward transportation in the distal direction. Also, there was no statistically significant difference among groups regarding CA (p > 0.05). Conclusions The different systems, including ProTaper Next, caused AT within the acceptable clinical limit after filling removal. In addition, none of the tested systems presented adequate CA.

Safety and Effectiveness of Additional Apical Preparation using a Rotary Heat-treated Nickel–Titanium file with Larger Diameter and Minimum Taper in Retreatment of Curved Root Canals

“…5,6 Controlled memory (CM) heat treatment promotes an NiTi alloy martensitic phase at room temperature, 7 providing greater flexibility and resistance to cyclic fatigue, 8 thus enabling apical enlargement in curved root canals. 9 Although mechanized NiTi instruments have been used in endodontic retreatments because of their safety 10 and effectiveness in removing filling materials, [11][12][13][14] these materials cannot be fully removed from the root canal, [15][16][17][18][19][20][21][22] especially in the apical third of curved root canals. 23 Apical enlargement can improve removal of filling materials 13 ; however, an increase in the apical preparation of curved root canals using instruments with larger diameter may result in excessive dentin removal.…”

Comparison of Canal Transportation and Centering Ability of ProGlider and WaveOne Gold Glider in Curved Canals

“…2,5,19,24,25 In this study, four levels were chosen for the analysis of root canal transport and centralization: 1, 3, 5, and 7 mm from the foramen. 26 These measurements represent the foraminal, apical, middle, and coronal third segments of the root, which usually have canal curvatures resulting in a high vulnerability to iatrogenic accidents. The crowns were kept intact to reproduce the clinical situation in which the cervical dentin interference could produce tension or resistance during root canal instrumentation.…”

Endodontic management of a tooth with apical overfilling and perforating external root resorption: A case report

“…Several techniques have been introduced to remove filling materials from root canal system including H and K files, nickel titanium rotary instruments, gates glidden burs, heated instrument, ultrasonic instruments, laser, and use of adjunctive solvents 6 . All these techniques have some advantages and disadvantages, so a dentist should be expert enough to choose one or combination of techniques with respect to quality and quantity of root filling materials and complexity of root anatomy 11 …”