Table 3. Various instrumentation techniques and their assessments pertaining to the time interval in the sample size.

SD: standard deviation

Time interval (hours)	Step-back preparation	Crown-down preparation	Hybrid technique	Conventional instrumentation (control group)
6	Mean: 4.2 (SD: 0.7)	Mean: 3.8 (SD: 0.6)	Mean: 3.9 (SD: 0.7)	Mean: 4.1 (SD: 0.6)
12	Mean: 3.8 (SD: 0.6)	Mean: 3.5 (SD: 0.5)	Mean: 3.6 (SD: 0.6)	Mean: 3.7 (SD: 0.5)
24	Mean: 3.4 (SD: 0.5)	Mean: 3.1 (SD: 0.4)	Mean: 3.2 (SD: 0.5)	Mean: 3.3 (SD: 0.5)
48	Mean: 2.9 (SD: 0.4)	Mean: 2.7 (SD: 0.4)	Mean: 2.8 (SD: 0.4)	Mean: 2.8 (SD: 0.4)
72	Mean: 2.5 (SD: 0.3)	Mean: 2.3 (SD: 0.3)	Mean: 2.4 (SD: 0.3)	Mean: 2.4 (SD: 0.3)