Size 1 Sensors Still Important For Optimal Radiology


Not all radiographic views are the same.  A size-2 sensor is specifically designed for a bitewing or posterior periapical view.   But where the dental arch narrows in the anterior region, a size-2 or size-1½ sensor may be too large.  So a narrower size 1 sensor is often needed to allow for proper geometry, to ease placement lingual to anteriors, and to properly break contacts.

Not all dental cases are the same.  A size-2 sensor has the optimal imaging area for posterior teeth.  But the size of a patient’s mouth may vary. The patient’s arch form may be narrow.  TMD issues may limit a patient’s ability to open.  Tori might limit positioning options.  Or the patient may simply be a gagger.  In these cases, a size-2 sensor may simply be too large.

Therefore, a size-1 sensor is often needed both for children and adults for optimal patient comfort and proper imaging geometry.



XDR designed its size-1 sensor to meet these needs.

  • The decreased width of XDR’s size-1 sensor (close to the width of some manufacturer’s size-0 sensor), allows for easier placement lingual to the anteriors, and therefore allows the sensor to conform to the arch form.  The sensor is nevertheless able to capture multiple anterior teeth, a couple premolars and the canine, or a full molar and a half – all from cusp to apex, making any radiograph achievable for even the toughest patients.
  • The length of the XDR’s size-1 sensor, sized to the average anterior teeth, allows it to be comfortably placed for the maxillary anterior periapical view, showing the periapical anatomy, root apex, and incisal edges of the teeth.
  • When a patient has a small mouth, narrow arch, large tori, limited opening, or a hyperactive gag reflex, the smaller size of the size-1 sensor makes it easier to place, and allows it to be positioned vertically, while still capturing from cusp to apex.


In practices where both the size-2 and the size-1 have been used for anterior radiographs, clinicians and patients generally agree that the size-1 can better capture anterior radiographs while providing more comfort.

Figure 1 - Size-1 sensor properly placed lingual to anteriors
Figure 1 – Size 1 sensor properly placed lingual to Anteriors

Figure 2 - Size 2 and Size 1 sensor dimensions
Figure 2 – Size 2 and Size 1 sensor dimensions

Figure 3 - Size 2 and Size 1 film
Figure 3 – Film and Sensor Sizes



Though some believe that a size-2 is suitable for all situations (perhaps due to experience with film’s flexibility), dental schools have long taught otherwise.  And experience shows that a size-1 sensor will result in better anterior radiographs, make a patient’s experience more comfortable, and is, in certain situations, the only way to get the most diagnostic radiographic view.