Histologic evaluation of three endodontic instrument/preparation techniques.

Area of Science:

• Endodontics
• Dental Anatomy
• Histology

Background:

• Root canal preparation aims to clean and shape the root canal system.
• Different instrumentation techniques are used to prepare curved root canals.
• Evaluating canal enlargement and debris removal is crucial for treatment success.

Purpose of the Study:

• To compare the effectiveness of three different root canal instrumentation techniques.
• To quantify the increase in canal area and predentin removal in the apical region of curved canals.
• To assess the clinical significance of observed differences in canal preparation.

Main Methods:

• 33 curved root canals were prepared using three techniques: step-back (K-flex file), balanced force (Flex-R file), and Canal Master system.
• Histological cross-sections were analyzed at 1 mm and 3 mm apical levels.
• The Bioquant image analysis system was used to measure canal area and predentin removal.

Main Results:

• No statistically significant difference in canal area increase or predentin removal was found at the 3 mm level between the techniques.
• At the 1 mm level, the step-back technique showed a significant increase in canal area and greater predentin removal compared to the other two techniques.
• Despite statistical significance, the actual differences observed were minimal, suggesting limited clinical relevance.

Conclusions:

• The step-back technique demonstrated superior canal enlargement and predentin removal at 1 mm from the apex.
• Differences in canal preparation among the tested techniques were not clinically significant at 3 mm apical level.
• The choice of instrumentation technique may have limited impact on clinical outcomes in curved root canals.