Effect of larger apical size on the quality of preparation in curved canals using reciprocating instruments with different heat thermal treatments

Abstract

Aim To evaluate the influence of larger apical canal enlargement in curved canals using reciprocating systems subjected to various heat treatments. Methodology Ninety mandibular premolars with root curvatures ranging from 20° to 30° were selected and scanned by microcomputed tomography (micro‐CT) before and after root canal preparation with reciprocating systems (n = 30): Reciproc Blue (RB size 25, .08 taper and size 40, .06 taper; VDW, Munich, Germany), WaveOne Gold (WOG size 25, .07 taper and size 35, .06 taper; Dentsply Sirona, Ballaigues, Switzerland) and ProDesign R (PDR size 25, .06 taper and size 35, .05 taper; Easy Dental Equipment, Belo Horizonte, Brazil). Canal transportation, untouched areas, and apical and total root canal volumes were measured. Statistical analysis was performed with the nonparametric Kruskal–Wallis and Dunn's tests and a significance level set at 5%. Results The between‐group comparison revealed no significant difference in untouched areas, canal transportation, and apical root canal volume among the groups (P > 0.05). However, WOG size 35, .06 taper was associated with a significant increase in the percentage of total canal volume in comparison to the PDR size 35, .05 taper (P < 0.05). The within‐group comparison revealed a significant decrease in untouched areas, increase in apical and total root canal volume for all groups when using a larger instrument (P < 0.05). There was no significant difference in transportation among the groups and when a larger apical preparation was created (P > 0.05). Conclusions Larger apical enlargement of curved canals was associated with a decrease in untouched areas, an increase in root canal volume and maintenance of canal trajectory. In addition, all systems were safe and provided similar root canal shapes.

Can kinematics, file diameter, and PUI influence the intracanal decontamination and apical bacterial extrusion?

“…8,9 ProDesign Logic and ProDesign R are single-file mechanical systems (Easy Equipamentos Odontológicos, Belo Horizonte, Brazil) manufactured in control memory (CM) wire alloy. 9,10 The former performs continuous rotation or reciprocating motion and is available in four different tip sizes/tapers: 25.06, 30.05, 35.05, and 40.05 to be selected according to the initial diameter of the canals. The latter exclusively reciprocates with a variable helical angle and a counterclockwise cut.…”

“…It is available in two instruments with different tip sizes/tapers: 25.06 and 35.05. 10 Both systems presented S-shaped cross-sections with two cutting edges and inactive points. 9,10 Information regarding disinfection and apical debris extrusion is available for most systems.…”

“…10 Both systems presented S-shaped cross-sections with two cutting edges and inactive points. 9,10 Information regarding disinfection and apical debris extrusion is available for most systems. 11 Therefore, the present in vitro study aimed to comparatively evaluate the ProDesign Logic and ProDesign R files in both kinematics -rotation and reciprocating -and two file diameters in relation to apically extruded debris and also bacteria, using CSI or PUI.…”

Radiographic and Clinical Findings of Single-Visit Root Canal Treatments with Apical Enlargement in Necrotic Teeth: A Retrospective Cohort Study

“…In another study, chronic apical lesion healing in dogs' teeth was reported to be more favorable in teeth with apical enlargement [ 5 ]. Large apical preparations were associated with better cleanliness of the root canal and less untouched places within the root canal system in extracted teeth with curved root canals [ 44 ]. These results were compatible with the results of the present study.…”

Analysis of the quality of root canal preparation and retreatment using different instruments associated or not with different irrigant agitation protocols

“…In addition to the need for mechanized systems to be able to properly shape the canal, it is also important that the instruments have good mechanical properties such as good resistance to cyclic fatigue, especially in curved canals (DUQUE et al, 2019). Cyclic fatigue is characterized by successive tensile and compression loads that the metal undergoes at the maximum point of flexion until it exceeds the limit that the instrument supports, thus causing fracture (ALCALDE et al, 2018a;SILVA et al, 2018a).…”