Diagnostic image quality in intra-oral radiography, comparison of hand held and wall mounted X-ray devices; A non-inferiority study with the Nomad Pro hand held X-ray device.

Hand held X-ray devices (HH) potentially provide advantages for dental
intra-oral radiography over fixed wall mounted devices (WM). They can be used
when visiting non-mobile patients or in part time dental clinics in remote,
sparsely populated areas in developing countries. Moreover, in the dental
office, one HH device can serve multiple suites instead of one WM device for
each suite. This limits financial investments in devices and cabling. This
potentially improves the accessibility of dental care. Recent studies have
proved that with judicious use, Conformité Européenne (CE) approved devices
such as the Nomad Pro, do not pose a threat for the operator or patient. An
issue that has not been clarified in an adequate clinical study is whether the
diagnostic image quality of HH devices is not inferior to WM devices.

To test if diagnostic quality of radiography with portable devices is
non-inferior to that of radiography with wall mounted devices.

We compare the 2 diagnostic modalities in a clinical experimental non
inferiority study. Bitewing (BW) exposures are made twice, once with HH and
once with WM in random order without changing any other factor. Blinded
observers rate the pairs of images displayed side by side for their preference
regarding diagnostic quality. Three outcomes are possible: preference for WM,
for HH or no preference. The hypothesis of non-inferiority will be rejected by
a difference found larger than 10% (p <.05)

performing extra bitewing exposures, one on right side and one on the left
side

The inconvenience for the patient exists in the fact that the sensor holder has
to stay in the mouth longer to facilitate the second ecxposure with the other
modality. This will be less then a minute.
The extra dosage that is administered is the dose needed to perform the extra
exposures. The dose and risk of these exposures is trivial being 0.4 µSv per BW
exposure. The extra dose a participant of this study receives is 0.8 µSv. The
individual risk for the participant of a lethal stochastic event from this dose
would be 1 in 25 million.(ICRP 2007)
There are no direct benefits for the health of the participant, the yield lies
in advancing knowledge about dental radiography which could in the log run
indirectly benefit the participant.
The group relatedness is exellent as portable X-ray devices will be deployed
for the targeted patiënts in daily general dental practice.