Design, metallurgy, mechanical properties, and shaping ability of 3 heat-treated reciprocating systems: a multimethod investigation

ObjectiveThis study aimed to compare 3 reciprocating systems regarding design, metallurgy, mechanical properties, and shaping ability.Materials and methodsNew Reciproc Blue R25, WaveOne Gold Primary, and REX 25 instruments (n=41 per group) were analyzed regarding design, metallurgy, and mechanical performance, while shaping ability (untouched canal walls, volume of removed dentin, and hard tissue debris) was tested in 36 anatomically matched root canals of mandibular molars. Results were compared using one-way ANOVA post hoc Tukey and Kruskal-Wallis tests with a significant level set at 5%.ResultsAll instruments showed symmetrical cross sections with asymmetrical blades, no radial lands, no major defects, and an almost equiatomic nickel and titanium ratio. The highest R-phase start temperatures were observed with WaveOne Gold (46.1 degrees C) and REX (44.8 degrees C), while Reciproc Blue had the lowest R-phase start (34.5 degrees C) and finish (20 degrees C) temperatures. WaveOne Gold had the lowest time to fracture (169 s) and the highest maximum load (301.6 gf) (P <0.05). The maximum torque of Reciproc Blue (2.2 N.cm) and WaveOne Gold (2.1 N.cm) were similar (P >0.05), but lower than REX (2.6 N.cm) (P <0.05). No statistical differences were observed among instruments in the angle of rotation (P >0.05) and in the shaping ability in both mesial and distal canals (P >0.05).ConclusionAlthough the overall design, temperature transition phases and mechanical behavior parameters were different among tested instruments, they were similar in terms of shaping ability.

Automated summary

This study aimed to compare 3 reciprocating systems in terms of design, metallurgy, mechanical properties, and shaping ability. The results showed that although there were differences in design, temperature transition phases, and mechanical behavior parameters among the tested instruments, they were similar in terms of shaping ability.