Intra 102

Preparation Before Seating the Patient

• Prepare the operatory with all infection-control barriers. 
• Determine the number and type of films to be exposed.
• Label a paper cup with the patient’s name and the date.  
  • This is the transfer cup for storing and moving exposed films.
• Turn on the x-ray machine and check the basic settings.
• Wash and dry your hands. 
• Dispense the desired number of films and store them outside the room in which the x-ray machine is being used.  

Positioning the Patient

• Seat the patient comfortably in the dental chair, with the back in an upright position and the head supported. 
• Ask the patient to remove eyeglasses and bulky earrings. 
• Have the patient take any removable prosthetic appliances out of his or her mouth.
• Position the patient with the occlusal plane of the jaw being radiographed parallel to the floor when the mouth is in the open position. 
• Drape the patient with a lead apron and thyroid collar. 
• Wash and dry your hands and put on clean examination gloves. 

The Exposure Sequence

• When exposing radiographs, establish an exposure sequence, or definite order, for periapical film placement.
• Without an exposure sequence, there is a good chance that you will omit an area or expose the same area twice. 

The Anterior Exposure Sequence

• When exposing periapical films with the paralleling technique, always start with the anterior teeth (canines and incisors), because: 
  • The size 1 film used for anteriors is small, less uncomfortable, and easier for the patient to tolerate. 
  • It is easier for the patient to become accustomed to the anterior film holder. 
  • The anterior film placements are less likely to cause the patient to gag. 
  • Begin with the maxillary right canine (tooth 6). 
  • Expose all of the maxillary anterior teeth from right to left. 
  • End with the maxillary left canine (tooth 11). 
  • Next, move to the mandibular arch. 
  • Begin with the mandibular left canine (tooth 22). 
  • Expose all of the mandibular anterior teeth from left to right. 
  • Finish with the mandibular right canine (tooth 27).

The Maxillary Canine Region

• Insert the number 1 film packet vertically into the anterior bite-block. 
• Position the film packet with the canine and first premolar centered. Position the film as far to the posterior as possible. 
• With the film-holding instrument and film in place, instruct the patient to close his or her mouth slowly but firmly. 
• Position the localizing ring and PID, then expose the film. 

Maxillary Central/Lateral Incisor Region

• Insert the number 1 film packet vertically into the anterior bite-block. 
• Center the film packet between the central and lateral incisors and position the film as far to the posterior as possible. 
• With the film-holding instrument and film in place, instruct the patient to close his or  mouth slowly but firmly. 
• Position the localizing ring and PID, then expose the film. 

The Mandibular Canine Region

• Insert the number 1 film packet vertically into the anterior bite-block.
• Center the film on the canine. Position the film as far in the lingual direction as the patient’s anatomy will allow. 
• A cotton roll may be placed between the maxillary teeth and bite-block to prevent rocking of the bite-block on the canine tip and to increase patient comfort. 

The Maxillary Canine Region

 The Mandibular Incisor Region 

• Insert the number 1 film packet vertically into the anterior bite-block. 
• Center the film packet between the central and lateral incisors and position the film as far in the lingual direction as the patient’s anatomy will allow. 
• With the instrument and film in place, instruct the patient to close his or her mouth slowly but firmly. 
• Position the localizing ring and PID, then expose the film. 

Mandibular Incisor Region 

Things to remember:

The midsagittal plane should be perpendicular to the floor.

Always ask the dentist what size film to use and how many anterior films to take.

If size 1 films are used, seven or eight films are taken.

If size 2 films are used, six films are taken.

Is it OK to start on the left and work to the right? Stick to a sequence—do not change from patient to patient. Make this sequence a habit for all radiographic exposures.

Have the PID close to the patient so positioning of the ring will be quick.

Remind the patient to hold still during exposure. Move swiftly; remove the extension-cone paralleling device (XCP) as soon as possible from the oral cavity. 

It is very important to remove the XCP as soon as possible from the oral cavity.