Effect of Centring Rings on Number of Retakes and Cone Cuts in Intraoral Imaging Performed by Dental Students: A...

To assess whether the use of centring rings for intraoral radiographic imaging reduces the number of retakes or the frequency and size of cone cuts in intraoral images performed by dental students.

Seventy-three dental students were randomly allocated to either a test or control group before training intraoral imaging on a phantom. Both groups used phosphor plate holders for periapical imaging of anterior and posterior teeth and for bitewings. Additionally, the test group used dedicated centring rings mounted to the holder (Kerr, Hawe, USA). After phantom training, the students performed intraoral imaging in 127 patients. Before patient examination, the number of planned periapical images and bitewings was recorded. After patient examination, the percentage of retakes was calculated in addition to the frequency and size of cone cuts. Differences between the two groups were tested with the Mann-Whitney U test (percentage of retakes and size of cone cuts) and chi-squared test (frequency of cone cuts).

The test group performed 920 intraoral images and the control 835. The percentage of bitewing retakes was significantly lower in the test group (p = 0.014), whereas there was no difference in periapical retakes (p = 0.37) between the groups. The frequency of cone cuts was significantly lower in the test group for both periapical images and bitewings (p < 0.001). The size of cone cuts was lower in the test group, although this was not significant (p > 0.20).

In general, it seems beneficial to use centring rings for dental students when learning to perform intraoral imaging since the percentage of retakes as well as the frequency and size of cone cuts were reduced.