This study aimed to compare the intracanal lateral force and cutting efficiency associated with two engine-driven nickel-titanium (NiTi) systems during root canal shaping. Bovine single-rooted teeth models were assembled to a custom-made splitting force measuring platform while being endodontically treated with rotary (ProTaper Gold [PTG]) or reciprocal systems (WaveOne Gold [WOG]) by two clinicians. The cutting efficiency test was run for each group by a free-falling endomotor on dentin discs for 3 min. The resulting force, files, and stroke force peaks were recorded. Data were analyzed by the Shapiro-Wilk test and ANOVA. Statistical significance was set at alpha = 0.05. Intracanal lateral forces (p < 0.01), cutting efficiency (p < 0.01), and time efficiency (p < 0.01) were significantly different between the NiTi groups. The maximum lateral splitting force was detected using the PTG shaping full-length file (S1) and during the WOG final stroke. Thus, caution is advised when reciprocating single-file systems approach the apical third or when using a large taper and wide-diameter rotatory instruments. The WOG had significantly less maximum horizontal splitting force and significantly greater cutting efficiency but less time efficiency than the PTG system.

This study aimed to compare the intracanal lateral force and cutting efficiency associated with two engine-driven nickel-titanium (NiTi) systems during root canal shaping. Bovine single-rooted teeth models were assembled to a custom-made splitting force measuring platform while being endodontically treated with rotary (ProTaper Gold [PTG]) or reciprocal systems (WaveOne Gold [WOG]) by two clinicians. The cutting efficiency test was run for each group by a free-falling endomotor on dentin discs for 3 minutes. The resulting force, files, and stroke force peaks were recorded. Data were analyzed by the Shapiro-Wilk test and ANOVA. Statistical significance was set at alpha = 0.05. Intraracanal lateral forces (p < 0.01), cutting efficiency (p < 0.01), and time efficiency (p < 0.01) were significantly different between the NiTi groups. The maximum lateral splitting force was detected using the PTG shaping full-length file (S1) and during the WOG final stroke. Thus, caution is advised when reciprocating single-file systems approach the apical third or when using large taper and wide-diameter rotatory instruments. The WOG had significantly less maximum horizontal splitting force and significantly greater cutting efficiency but less time efficiency than the PTG system.