Table 1 Agreement of repeated measurements for four methods in terms of ΔE and ΔE₀₀ related to a single tooth

Paired observations, number

840^a

840 ^a

839 ^b

840^b

Mean ΔE (standard deviation)

1.12 (1.95)

1.99 (1.95)

0.97 (1.41)

1.55 (2.11)

Agreement within ΔE < 2.7, proportion (95% CI)

80.1 (77.3–82.8)^**,***

59.4 (56.0–62.7)^*,**

90.9 (88.8–92.8)^***,†

71.7 (68.5–74.7)^**

Agreement within ΔE < 3.7, proportion (95% CI)

84.6 (82.0–87.0)^***

77.9 (74.9–80.6)^**,***

92.8 (90.9–94.5)^***,†

83.3 (80.6–85.8)^***

Mean ΔE₀₀ (standard deviation)

0.92 (1.60)

1.59 (1.58)

0.80 (1.19)

1.27 (1.74)

Agreement within ΔE₀₀ < 2.7, proportion (95% CI)

84.2 (81.5–86.6)^***

69.5 (66.3–72.6)^**

92.1 (90.1–93.9)^***,†

77.4 (74.4–80.2)^**,***

Agreement within ΔE₀₀ < 3.7, proportion (95% CI)

91.9 (89.8–93.7)^***,†

88.1 (85.7–90.2)^***

96.3 (94.8–97.5)^†

86.4 (83.9–88.7)^***