Hand and nickel‐titanium root canal instrumentation performed by dental students: a micro‐computed tomographic study

Abstract

The aim of this study was to evaluate root canals instrumented by dental students using the modified double-flared technique, nickel-titanium (NiTi) rotary System GT files and NiTi rotary ProTaper files by micro-computed tomography (MCT). A total of 36 root canals from 18 mesial roots of mandibular molar teeth were prepared; 12 canals were prepared with the modified double-flared technique, using K-flexofiles and Gates-Glidden burs; 12 canals were prepared using System GT and 12 using ProTaper rotary files. Each root was scanned using MCT preoperatively and postoperatively. At the coronal and mid-root sections, System GT and ProTaper files produced significantly less enlarged canal cross-sectional area, volume and perimeter than the modified double-flared technique (P < 0.05). In the mid-root sections there was significantly less thinning of the root structure towards the furcation with System GT and ProTaper (P < 0.05). The rotary techniques were both three times faster than the modified double-flared technique (P < 0.05). Qualitative evaluation of the preparations showed that both ProTaper and System GT were able to prepare root canals with little or no procedural error compared with the modified double-flared technique. Under the conditions of this study, inexperienced dental students were able to prepare curved root canals with rotary files with greater preservation of tooth structure, low risk of procedural errors and much quicker than with hand instruments.

Undergraduate Students Introduction to Manual and Rotary Root Canal Instrumentation

“…Regarding the time spent for preparation, as expected, rotary instrumentation was faster than manual, and the difference was statistically significant. Other studies also reported a higher speed with rotary instrumentation when performed by inexperienced students 7,14,19,22) . This greater speed is due to the difference in design of these two types of instrumentation.…”

Rotary Nickel-Titanium GT and ProTaper Files for Root Canal Shaping by Novice Operators: A Radiographic and Micro–Computed Tomography Evaluation

“…Previous studies suggested that undergraduate dental students can successfully prepare molar root canals with rotary instrument, and these instruments are increasingly being integrated into clinical courses (4,12,16,(24)(25)(26)(27).…”

“…In two earlier studies on NiTi rotaries, inexperienced dental students were able to prepare simulated root canals with Flexmaster (5) and mesial root canals in lower molars with ProTaper and GT (16) rotary files with lower risk of procedural errors and faster than with hand instruments.…”

State of the Art of Micro‐CT Applications in Dental Research

“…According to the results of these researchers, it was believed that variations in canal geometry before preparation have more influence on the changes during preparation than the techniques and instruments themselves , as nearly all instrumentation techniques left 35% or more of the canals' surface area unchanged. Furthermore different instrument types demonstrated few differences on the general effect of preparation ), but caused effects at different parts of the same root canal (Bergmans et al, 2003;Peters et al, 2003;Ozgur Uyanik et al, 2006;Peru et al, 2006). The majority of instruments enable easy access and can be manipulated safely with respect to different experience levels of users.…”

“…However, with the Micro-CT systems, the 3D evaluation of canal preparation has been made easy and convenient (Bergmans et al, 2001). A number of researchers have evaluated and compared different root canal instruments with Micro-CT, including K-files , K-flexofiles (Peru et al, 2006), Profile (Bergmans et al, 2001;Cheung and Cheung, 2008;Versiani et al, 2008), Protaper (Bergmans et al, 2003;Ozgur Uyanik et al, 2006;Peru et al, 2006;Versiani et al, 2008), Hero Shaper (Ozgur Uyanik et al, 2006;Cheung and Cheung, 2008), System GT Peru et al, 2006;Versiani et al, 2008), Lightspeed , K3 (Bergmans et al, 2003), Endo-Eze AET (Paque et al, 2005), RaCe (Ozgur Uyanik et al, 2006), and Flexmaster (Hubscher et al, 2003). With the data from such scans, it is possible to measure many changes before and after preparation, such as surface area and volume of root canal, amount of dentin volume removed, canal "thickness" (diameter), prepared surface, curvature, canal transportation, structure model index (SMI), transportation of centers of mass, canal straightening proportion of unchanged, canal centering ratio Peters et al, 2003).…”