Film 101

Terminology

• “Film” is the correct term to use before it has been processed: The film is in the packet, the film is placed in the bite-block, and the film is exposed and processed. 
• After the film has been processed, it becomes
  a radiograph.

Who is most often responsible for processing film? (The dental assistant.)

Types of Film Holder and Beam Alignment Devices

• A wide variety of types of intraoral film holders are available on the market today. 
• One basic film holder is a disposable Styrofoam bite block with a backing plate and a slot for film retention.
• The Snap-A-Ray (formerly the Eezee-Grip) is a double-ended instrument that holds the film between two serrated plastic grips that can be locked into place. 
• The Endoray device is used to take radiographs when instruments are in the canal.
• Uni-bite devices are made by the Rinn Corp.

What is a film holder?

How do film holders reduce exposure? (In two ways: by preventing cone cuts, thereby reducing retakes; and by allowing the film to be held in place without the aid of the patient’s finger in the field of radiation.)

Unibite is more commonly referred to as XCP, which stands for “extension-cone paralleling.”

Plastic and Styrofoam disposable bite-block film holders. 

What is the advantage of using the Styrofoam bite-block? (It is disposable and does not need to be sterilized.)

The Snap-A-Ray film holder (formerly the Eezee-Grip).

This device is used with the bisecting technique.

It has the advantage of being able to be adjusted on the film for patients with jaws too shallow to accommodate the full depth of the film.

The Endoray is designed for use in radiographs of teeth involving endodontic instruments in the canal.

How would an endodontic x-ray be taken if this device were not available? (It is not uncommon to have patients use a finger or a hemostat to hold the film in place.)

Rinn XCP instruments are color-coded for easier assembly. Red instruments are for bite-wing placement, yellow for posterior placement, and blue for anterior placement.

The yellow (posterior) XCP requires the ring to be flipped when opposite sides of the mouth are exposed (upper right/lower left vs. lower right/upper left).

Therefore the yellow ring lines up differently, depending on which way it is put on. The bite-block portion of the XCP should be in the center of the yellow ring after it has been assembled.