. 2019 Oct 17;19:222. doi: 10.1186/s12903-019-0914-2

Table 1.

The deviation of total error, longitudinal error, and angular error in the 5 drilling tests

Grade	VS	CR	R3	DI	DC	P-value^a	Multiple comparison^b
Grade	Mean ± SD	Mean ± SD	Mean ± SD	Mean ± SD	Mean ± SD	P-value^a	Multiple comparison^b
Total error (mm)	2.00 ± 1.24	1.92 ± 0.90	1.66 ± 0.89	2.40 ± 0.87	2.10 ± 0.85	0.054
Longitudinal error (mm)	1.65 ± 0.98	1.24 ± 0.99	0.98 ± 0.53	0.92 ± 0.76	0.64 ± 0.46	< 0.0001	VS > DC VS > DI VS > R3 CR > DC
Angular error (degrees)	5.38 ± 2.45	5.12 ± 2.48	3.48 ± 1.76	5.53 ± 1.81	4.31 ± 2.13	0.0011	DI > R3 VS > R3 CR > R3
Elapsed time (secs per drill)	112 ± 13.13	136 ± 17.47	144 ± 5.29	170 ± 5.59	180 ± 4.49	0.0029

^aOne-way ANOVA (P < .05)

^bTukey-Kramer HSD

CR: Chief resident; DC: Dental clerk; DI: Dental intern; R3: Third year resident; VS: Visiting staff