New insights in the reproducibility of visual and electronic tooth color assessment for dental practice

Head & Face Medicine

Table 4 Comparing methods of measurements of the distance from 0M1 related to a single tooth: 2D versus 3D within visual or electronical measurement; visual versus electronical measurements within 2D and 3D

	Visual versus electronical		2D versus 3D
	within 2D	within 3D	within visual	within electronical
	Value	Value	Value	Value
Number of paired observations	839^a	840^a	1680^b	1679^c
Mean distance (SD) d₁ from 0M1 for the electronical measurement	15.8 (2.97)	13.1 (3.69)
Mean distance (SD) d₂ from 0M1 for the visual measurement	14.9 (3.28)	13.4 (2.88)
Mean distance (SD) d₁ from 0M1 for the 2D measurement			15.0 (3.25)	15.9 (2.96)
Mean distance (SD) d₂ from 0M1 for the 3D measurement			13.3 (2.82)	13.3 (3.71)
Difference d₂ – d₁ (standard deviation)	−0.89 (2.77)	0.22 (3.05)	−1.64 (1.98)	−2.58 (1.70)
Agreement within \|d(0M1)\| < 2.7, proportion (95% CI)	69.1 (65.9–72.2)^**	53.3 (49.9–56.7)^*	66.5 (64.2–68.8)^**	47.1 (44.6–49.5)^*
Agreement within \|d(0M1)\| < 3.7, proportion (95% CI)	86.3 (83.8–88.5)^***	86.3 (83.8–88.6)^***	80.9 (78.9–82.7)^,*	84.0 (82.2–85.8)^***
Limits of agreement	−6.33 – 4.55	−5.76 – 6.19	− 5.53 – 2.25	− 5.90 – 0.75
Number of observations outside the limits of agreement total (lower; higher)	58^d (33; 25)	60^d (30; 30)	82^e (21; 61)	49^e (34; 15)
ICC_(2,1) (95% CI)	0.58 (0.50–0.65)^,*	0.58 (0.53–0.62)^,*	0.69 (0.27–0.84)^-,***	0.67 (−0.06–0.88)^--,***
ICC_(3,1) (95% CI)	0.61 (0.56–0.65)^,*	0.58 (0.53–0.62)^,*	0.79 (0.77–0.81)^,*	0.87 (0.86–0.88)^***

^a V2 versus E1, V3 versus E3, V5 versus E5 acc. to the flow chart
^b D2 versus D3 measurements for V1 – V6 acc. to the flow chart
^c D2 versus D3 measurements for E1 – E6 acc. to the flow chart
^d expected number: 30–55
^e expected number: 66–102
Classifications for the interpretation of agreement
⁻⁻ poor < 20; ⁻ slight [20–40); ^* fair [40–60); ^** good [60–80); ^*** very good [80–92)
Classifications for the interpretation of reliability in terms of ICC
⁻⁻ poor < 0.2; ⁻ slight [0.2–0.4); ^* fair [0.4–0.6); ^** good [0.6–0.8); ^*** very good [0.8–0.92)

ISSN: 1746-160X