Influence of cervical preflaring on apical file size determination

Area of Science:

• Endodontics
• Dental Anatomy
• Biomaterials

Background:

• Accurate determination of root canal anatomy at working length (WL) is crucial for effective endodontic treatment.
• The influence of cervical preflaring on the accuracy of assessing canal diameter at WL requires further investigation.

Purpose of the Study:

• To evaluate the impact of cervical preflaring using Gates-Glidden drills, Quantec Flare series instruments, and LA Axxess burs on the first file binding at WL in maxillary central incisors.

Main Methods:

• Forty maxillary central incisors were used, with WL established 1 mm short of the apex.
• Groups were preflared with Gates-Glidden drills, Quantec Flare instruments, or LA Axxess burs; one group had no preflaring.
• Canals were then instrumented with K-files to determine the first binding file at WL, and discrepancies were measured.

Main Results:

• Significant differences in anatomical diameter at WL and first binding file were observed between groups (P < 0.01).
• No preflaring resulted in the largest discrepancy (0.151 mm), while LA Axxess burs showed the smallest (0.016 mm).
• Gates-Glidden drills and Flare instruments yielded intermediate results (0.093 mm).

Conclusions:

• The instrument binding technique is imprecise for determining anatomical diameter at WL.
• Cervical and middle third preflaring enhances anatomical diameter determination accuracy.
• LA Axxess burs provided the most accurate relationship between file size and anatomical diameter at WL.