Document Type : Original Article
Authors
- Robab Farhang 1
- Fateme Vaseghi 1
- Saeedeh Galledar 1
- Kiarash Nematyata 1
- Sara Noorolouny 2
- Ahmad Nouroloyouni 3
1 Dept. of Endodontics, School of Dentistry, Ardabil University of Medical Science, Ardabil, Iran.
2 Dept. of Pediatric Dentistry, School of Dentistry, Ardabil University of Medical Science, Ardabil, Iran.
3 Dept. of Endodontics, School of Dentistry, Ardabil University of Medical Science, Ardabil, Iran. Dept. of Restorative Dentistry and Biomaterial Sciences, Harvard School of Dental Medicine, Boston, MA, USA.
Abstract
Background: Nickel-titanium rotary and reciprocating systems may generate stresses in root dentin during canal preparation, potentially contributing to dentinal crack formation. Although several systems have been investigated, evidence regarding crack formation associated with Reciproc Blue remains limited, particularly using stereomicroscopic sectioning methods.
Purpose: This study aimed to compare the frequency of dentinal cracks caused by root canal preparation with ProTaper Universal (PTU), ProTaper Next (PTN), Reciproc, and Reciproc Blue (RB).
Materials and Method: In this in vitro study, 75 single-canal mandibular premolars were randomly assigned to 5 groups (n=15) for root canal instrumentation with PTU, PTN, Reciproc and RB; the fifth group served as the control group (no instrumentation). Root canal irrigation was performed with full strength sodium hypochlorite after using each file. After instrumentation, the roots were sectioned perpendicular to the longitudinal tooth axis at 3-, 6-, and 9-mm distances from the apex by a diamond saw under water coolant. The sections were inspected under a stereomicroscope at 25× magnification for dentinal cracks. Data were analyzed by the Chi-square and Monte Carlo tests (alpha= 0.05).
Results: The highest crack frequency occurred in the PTU group at 6 and 9 mm from the apex, whereas no cracks were observed in the control group at any level. The frequency of cracked sections in the PTU, PTN, Reciproc, and RB groups was 19/45, 15/45, 8/45, and 5/45, respectively, indicating significantly more cracks in PTU and PTN than in Reciproc and RB (p Value< 0.05), while no significant differences were found among the systems at 3, 6, or 9 mm individually (p> 0.05).
Conclusion: Within the limitations of this in vitro study, all tested instrumentation systems produced dentinal cracks. Reciproc Blue generated the lowest overall crack frequency and may represent a favorable alternative to the other tested systems, particularly when preservation of root dentin integrity is a concern.
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