Intraoral Conventional Films Overview

Intraoral Conventional Films

• Double emulsion film, meaning emulsion is coated on both sides
• Available in one or two film packets
• Two film packets allow for a duplicate record
• Different standard sizes are available
• Have occlusal dot on the tube side for film orientation
• Dot helps distinguish between left and right sides of the patient
• Useful for film mounting

Film Packet Components

• X-Ray film
• Black paper wrap/ paper film wrapper
• Lead foil sheet
• Outer wrapping(soft packet):
  • Tube side(white surface)
  • Label side(color coded)

Intraoral Film Packet Surface Details

• Tube side:
  • White color
  • Has raised dot
  • Must face the tooth surface
• Label side:
  • Color coded side should face the tongue
  • Mentions speed and name of manufacturer
  • Number of films inside

Additional Film Packet Components

• Paper film wrap: protective sheet that shields film from light
• Lead foil sheet:
  • Single piece of lead sheet
  • Located behind the film and paper
  • Protects from back scatter
  • Has embossed pattern if the film is placed backward and exposed

Film Base

• Made of polyester plastic for support
• 0.2mm thick and flexible
• Uniformly translucent with a blue tinge

Adhesive Layer

• Thin layer of adhesive material placed on both sides
• Serves to attach emulsion to the base

Film Emulsion

• Coating applied to both sides of the base
• Sensitive to x-rays
• Homogeneous mixture of Silver halide and gelatin
• Gelatin serves as a carrier vehicle to disperse silver halide crystals
• Gelatin absorbs chemicals during processing to react with silver halide

Film Sizes

• Three sizes: 0, 1, and 2
  • 0 - 22 x 35 (small children)
  • 1 - 24 x 40 (anterior teeth)
  • 2 - 31 x 41 (adult film)

Digital Intraoral Sensors

• Small detectors placed intraorally to capture radiographic images
• Can be wired (direct) or wireless (indirect)
• Sensors connected by fiberoptic cable are called solid-state detectors

Direct Digital Imaging

• Charge-coupled device (CCD):
  • First digital image receptor used for intraoral imaging (1987)
  • Uses a thin wafer of silicon for image recording
  • Silicon crystals form the pixel matrix
• Complimentary metal oxide semiconductor (CMOS):
  • Similar to CCD – silicon semiconductors
  • The charge pattern is directly connected to a transistor as a small voltage
  • The voltage is read by a frame grabber and displayed as a digital gray value

Indirect Digital Imaging

• Photostimulable phosphor (PSP)
  • Wireless system
  • Absorbs and stores energy from x-rays and then releases the energy as light (phosphorescence) when stimulated by another light of an appropriate wavelength.
  • “Europium-doped” barium fluoro-halide is used
  • Combined with polymer and coated on a plastic base as a conventional film

Phosphor plates and Scanner:

• Used with PSP imaging

X-ray Film Holders

• Rinn's film holders, also called XCP (X-tension C-one P-paralleling), are devices used for intraoral radiographs applying the paralleling technique
• Ensure that film will be perpendicular to X-rays.
• Colors:
  • Yellow for posterior teeth (molars and premolars)
  • Blue for anterior teeth (incisors and canines)
  • Red for bite-wing radiographs
  • Green for radiographs with the rubber dam is still on

Other Film Holders

• Snap-A-Ray
• Phosphor plate holder