Cleaning efficiency during root canal preparation remains one of the core goals of instrumentation. Regardless of the system used, the objective is straightforward: shape the canal effectively while removing debris and allowing irrigants to work efficiently throughout the canal length.
A recent laboratory investigation compared the cleaning ability of three commonly used rotary nickel–titanium (NiTi) systems — EdgeFile X1, WaveOne Gold, and Neo NiTi — to see how effectively they prepare and clean the canal space.
How the Study Was ConductedSixty extracted human mandibular premolars were used for the study. After removal, the teeth were stored in distilled water, and the crowns were sectioned at the cementoenamel junction to standardize the samples.
The teeth were then randomly divided into three groups:
Group I: Instrumented with EdgeFile X1
Group II: Instrumented with WaveOne Gold
Group III: Instrumented with Neo NiTi
To evaluate cleaning ability, each root was grooved longitudinally on the buccal and lingual surfaces and then split vertically. This allowed direct visualization of the canal walls.
A blinded examiner assessed the remaining ink in the coronal, middle, and apical thirds using a 10× stereomicroscope. Lower scores indicated better cleaning efficiency. Statistical analysis was performed using ANOVA, with significance set at p ≤ 0.05.
What the Results ShowedAcross all regions of the canal, WaveOne Gold demonstrated the best cleaning performance.
Coronal third
WaveOne Gold: 1.42 ± 0.06
Neo NiTi: 1.80 ± 0.12
EdgeFile X1: 1.94 ± 0.05
Middle third
WaveOne Gold showed the most effective cleaning with a mean score of 1.36 ± 0.01.
Apical third
WaveOne Gold: 1.30 ± 0.14
Neo NiTi: 1.70 ± 0.08
EdgeFile X1: 1.98 ± 0.20
The differences between the three systems were statistically significant at all levels (p < 0.001).
What This Means ClinicallyInstrumentation remains a critical determinant of canal cleanliness. Effective shaping improves irrigant penetration and creates the taper required for predictable obturation.
In this study, WaveOne Gold consistently showed superior cleaning performance compared with Neo NiTi and EdgeFile X1 in the coronal, middle, and apical thirds.
While no file system completely eliminates debris, the findings reinforce the importance of choosing instruments that provide efficient shaping while maintaining canal anatomy.
Nickel–titanium rotary systems continue to offer advantages because of their flexibility and ability to follow curved canals with reduced procedural errors. Creating a well-shaped canal allows irrigants to act effectively and supports the placement of obturation materials to achieve an adequate apical seal.
For clinicians, the key takeaway remains practical: instrumentation technique and file selection both influence the quality of canal preparation, which ultimately impacts the success of root canal treatment.
A file shapes the canal; irrigation completes the cleaning strategy
No rotary or reciprocating instrument touches every canal wall or eliminates tissue and biofilm by itself. Laboratory comparisons are influenced by tooth selection, anatomy, preparation size, operator protocol and the chosen cleanliness measure. A statistically better result in extracted teeth does not establish superior long-term healing.
| Evaluation domain | Clinical relevance | Safety control |
|---|---|---|
| Shaping ability | Maintains a path for irrigation and obturation | Glide path and anatomy awareness |
| Debris removal | Surrogate for cleaning | Irrigant delivery and activation |
| Transportation/separation | Procedural risk | Torque, speed, use history and inspection |
| Outcome evidence | Apical healing and tooth survival | Do not infer from one laboratory metric |
Link instrumentation with root-canal visit selection, coronal sealing evidence and persistent canal exudation.
Frequently asked questions
Which rotary file cleans every canal best?
No system cleans every anatomy completely; selection should include safety, shaping goals and a validated irrigation protocol.
Does more debris removal prove better healing?
No. It is a laboratory surrogate, not a direct patient outcome.
Can a file replace irrigant activation?
No. Mechanical preparation and chemical disinfection have complementary roles.