Automatic exposure compensation in intraoral digital radiography: effect on the gray values of dental tissues

BMC Medical Imaging

Table 2 Mean and standard deviation (SD) of the gray values of dental tissues in the RVG 6100 radiographic system distributed according to the group, exposure time, and kilovoltage

Dental tissues	Group	t = 0.06 s		t = 0.10 s		t = 0.16 s
Dental tissues	Group	60 kV	70 kV	60 kV	70 kV	60 kV	70 kV
Enamel	Control	135.0 (12.7) Aa	118.1 (13.8) Ab	139.2 (11.9) Aa	118.2 (12.9) Ab	141.7 (13.2) Aa	115.4 (13.3) Ab
Enamel	High-density	134.8 (12.7) Aa	118.4 (13.1) Ab	139.6 (12.1) Aa	119.2 (13.2) Ab	142.2 (13.3) Aa	116.1 (13.7) Ab
Crown dentine	Control	112.2 (11.8) Aa	93.1 (11.4) Ab	114.3 (10.5) Aa	91.9 (10.3) Ab	115.4 (11.3) Aa	88.5 (10.5) Ab
Crown dentine	High-density	111.7 (11.5) Aa	93.1 (10.7) Ab	114.6 (10.5) Aa	93.0 (10.8) Ab	116.0 (11.4) Aa	89.1 (10.9) Ab
Root dentine	Control	97.3 (6.5) Aa	78.9 (6.3) Ab	98.5 (8.4) Aa	77.4 (7.8) Abc	99.2 (9.1) Aa	73.8 (7.9) Ac
Root dentine	High-density	97.5 (6.1) Aa	79.3 Ab	99.6 (7.7) Aa	78.9 (7.1) Ab	100.5 (8.0) Aa	74.9 (6.8) Ab
Pulp	Control	49.7 (6.1) Aa	35.2 (5.1) Ac	47.2 (5.8) Aab	32.6 (4.3) Acd	46.2 (5.6) Ab	29.8 (4.1) Ad
Pulp	High-density	48.9(6.2) Aa	35.0 (5.0) Ab	47.7 (5.8) Aa	33.7 (4.7) Ab	47.0 (5.7) Aa	30.3 (4.1) Ac

Different uppercase letters indicate a statistical difference between the control and high-density groups, within each dental tissue (vertical comparisons)
Different lowercase letters indicate a statistical difference between kV at the same exposure time and between exposure times at the same kV, within each group (horizontal comparisons)

ISSN: 1471-2342