Table 3.
Exploratory unadjusted item-level changes in dental radiology radiation safety knowledge among matched participants (n = 69)
| Item | Correct pretest n (%) |
Correct posttest n (%) |
Change, percentage points |
McNemar p |
|---|---|---|---|---|
| Panoramic dental films can be taken during pregnancy | 8 (11.6) | 23 (33.3) | + 21.7 | 0.0026 |
| Periapical dental films can be taken during pregnancy | 5 (7.2) | 31 (44.9) | + 37.7 | < 0.0001 |
| Radiologic examination during pregnancy is prohibited | 11 (15.9) | 13 (18.8) | + 2.9 | 0.8238 |
| Positioning of radiation-emitting equipment matters for protection | 25 (36.2) | 40 (58.0) | + 21.7 | 0.0107 |
| Rectangular collimation reduces patient dose | 5 (7.2) | 27 (39.1) | + 31.9 | < 0.0001 |
| Paralleling technique reduces thyroid dose compared with bisecting-angle technique | 6 (8.7) | 29 (42.0) | + 33.3 | < 0.0001 |
| The operator needs to wear a lead apron during dental radiographic procedures other than periapical imaging | 27 (39.1) | 36 (52.2) | + 13.0 | 0.1877 |
| A thyroid collar should be used for every patient during dental radiographic imaging | 11 (15.9) | 23 (33.3) | + 17.4 | 0.0042 |
| E/F-speed films are preferred over D-speed films | 5 (7.2) | 22 (31.9) | + 24.6 | 0.0002 |
| There is harm if the patient holds the radiographic film by hand during periapical radiography | 7 (10.1) | 31 (44.9) | + 34.8 | < 0.0001 |
| Digital radiography gives less dose than conventional radiography | 10 (14.5) | 30 (43.5) | + 29.0 | 0.0002 |
| Dental imaging uses X-rays | 26 (37.7) | 51 (73.9) | + 36.2 | < 0.0001 |
| Radiation is not harmful to living cells | 33 (47.8) | 44 (63.8) | + 15.9 | 0.0433 |
| Same exposure parameters are used for adults and children | 20 (29.0) | 38 (55.1) | + 26.1 | 0.0009 |
| Periapical radiography is completely safe and has no health effects | 12 (17.4) | 30 (43.5) | + 26.1 | 0.0014 |
Correct response rates were calculated among matched participants. McNemar’s test was used for paired categorical comparisons. Item-level analyses were secondary, exploratory, and unadjusted for multiple comparisons; these results should be interpreted descriptively rather than as confirmatory item-specific tests. For negatively worded items, the reported n (%) indicates the number and percentage of participants selecting the correct response