Quantitative transportation assessment in curved canals prepared with an off-centered rectangular design system

Area of Science:

• Endodontics
• Dental Materials Science

Background:

• Maintaining root canal anatomy during instrumentation is crucial for successful endodontic treatment.
• Different nickel-titanium rotary and reciprocating systems vary in their design and kinematics, potentially affecting their ability to preserve canal morphology.

Purpose of the Study:

• To evaluate and compare the canal transportation induced by the ProTaper Next (PTN) system against ProTaper Universal (PTU), Reciproc (R), and WaveOne (WO) systems.
• To assess the centering ability of these instrumentation systems in maintaining the original root canal profile.

Main Methods:

• Forty clear resin blocks with simulated curved root canals were used.
• Blocks were randomly assigned to four groups (n=10) for instrumentation with PTN, PTU, R, or WO systems.
• Pre- and post-instrumentation images were captured and analyzed using Fiji software to quantify canal transportation in straight and curved portions.

Main Results:

• All instrumentation systems significantly influenced canal transportation (p=0.000).
• The Reciproc (R) system showed significantly lower canal transportation compared to WO, PTN, and PTU (p=0.000).
• Canal transportation was greater in the curved portion than the straight portion (p=0.000). PTU exhibited the highest transportation, while R demonstrated the best centering ability.

Conclusions:

• The Reciproc system exhibited superior centering ability and induced less canal transportation compared to PTN, WO, and PTU.
• ProTaper Next (PTN) demonstrated less canal transportation than ProTaper Universal (PTU) and WaveOne (WO) but was outperformed by Reciproc (R).
• Instrumentation system choice significantly impacts the preservation of root canal anatomy, particularly in curved canals.