The Impact of Multiple Autoclave Cycles on the Surface Roughness of Thermally Treated Nickel-Titanium Endodontic Files

Table 2

Comparison of SR parameters between the instruments (means ± standard deviation).

Cycle	0	1	5	10
Ra
TN	17.00 ± 4.7^a	9.68 ± 1.80^a	11.36 ± 2.80^a	12.92 ± 1.12^a
PTG	16.52 ± 2.84^a	8.33 ± 1.66^a	8.80 ± 1.65^a	8.23 ± 0.83^b
ETP	15.99 ± 5.14^a	8.16 ± 0.88^a	11.66 ± 1.47^a	10.19 ± 1.54^b
Rq
TN	22.51 ± 6.057^a	13.13 ± 2.28^a	15.62 ± 3.53^a	17.84 ± 1.38^a
PTG	22.46 ± 4.13^a	11.44 ± 2.25^a	11.96 ± 2.15^a	11.51 ± 1.04^b
ETP	21.04 ± 6.50^a	11.28 ± 1.05^a	16.21 ± 2.05^a	13.81 ± 1.85^b
Rz
TN	51.84 ± 21.20^a	39.81 ± 8.54^a	45.28 ± 9.81^a	68.26 ± 7.25^a
PTG	64.85 ± 12.34^a	35.70 ± 12.00^a	35.99 ± 6.95^a	38.60 ± 7.38^b
ETP	63.88 ± 19.32^a	43.89 ± 8.85^a	82.09 ± 22.22^b	55.69 ± 3.05^a

a, b, and c indicate groups with the same letters have no significant differences. 0 cycle is the pre-autoclaving cycle.