Impacts of Contracted Endodontic Cavities on Primary Root Canal Curvature Parameters in Mandibular Molars

Melissa A Marchesan; Adam Lloyd; David J Clement; Joseph D McFarland; Shimon Friedman

doi:10.1016/j.joen.2018.07.008

Impacts of Contracted Endodontic Cavities on Primary Root Canal Curvature Parameters in Mandibular Molars

J Endod. 2018 Oct;44(10):1558-1562. doi: 10.1016/j.joen.2018.07.008. Epub 2018 Aug 25.

Authors

Melissa A Marchesan¹, Adam Lloyd², David J Clement³, Joseph D McFarland¹, Shimon Friedman⁴

Affiliations

¹ Department of Endodontics, University of Tennessee Health Science Center, College of Dentistry, Memphis, Tennessee.
² Department of Endodontics, University of Tennessee Health Science Center, College of Dentistry, Memphis, Tennessee. Electronic address: alloyd@uthsc.edu.
³ The University of Oklahoma College of Dentistry, Oklahoma City, Oklahoma.
⁴ Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.

PMID: 30154004
DOI: 10.1016/j.joen.2018.07.008

Abstract

Introduction: The purpose of this study was to provide information regarding the debate on contracted endodontic cavities (CECs); their impacts on angle, location, and radius of the primary canal curvature (PCC) were assessed in type IV mesial root canals of mandibular molars at different stages of instrumentation. Impacts on treatment time were also assessed.

Methods: Twenty-four teeth were matched by radiographic and micro-computed tomographic criteria and accessed via CECs (CEC, n = 12) or nonextended traditional endodontic cavities (TECs, n = 12). PCC parameters were radiographically determined using a repositioning apparatus before glide path preparation (PI), after glide path preparation, and after final instrumentation (FI). Instrumentation was performed with PathFiles (13/.02, 16/.02; Dentsply Maillefer, Ballaigues, Switzerland) and ProFile Vortex files (Dentsply Tulsa Dental Specialties, Tulsa, OK) to size 30/.04 at the working length under copious irrigation. Changes in PCC were measured with ImageJ (National Institutes of Health, Bethesda, MD). The instrumentation time was recorded. Data were analyzed with 2-way repeated measures analysis of variance (α < .05) and Tukey honest significant difference tests.

Results: A significant (P < .001) decrease in the mean angle and increase in the mean radius were detected at each instrumentation stage for both CECs (angle: PI = 42.57°± 8.00°, FI = 32.61°± 5.17°; radius: PI = 6.48 ± 1.81 mm, FI = 10.55 ± 1.48 mm) and TECs (angle: PI = 38.80°± 7.15°, FI = 30.08°± 6.99°; radius: PI = 6.97 ± 2.31 mm, FI = 11.01 ± 2.20 mm). PCC location shifted apically (P < .001). Changes in PCC parameters did not differ significantly between CECs and TECs (P > .05). The treatment time was significantly (P < .0001) longer for CECs (83.17 ± 6.71 minutes) than for TECs (33.18 ± 9.20 minutes).

Conclusions: Instrumentation of curved mesial canals reduced the severity and abruptness of PCC and shifted the PCC location apically similarly in mandibular molars with CECs and those with nonextended TECs. The extended treatment time with CEC merits consideration when debating CECs versus TECs.

Keywords: Dental pulp cavity; endodontic cavity; instrumentation efficiency; nickel-titanium instrument.

MeSH terms

Dental Pulp Cavity / anatomy & histology*
Dental Pulp Cavity / surgery*
Humans
Mandible*
Molar / anatomy & histology*
Operative Time
Root Canal Preparation / instrumentation*