LO 5 Flashcards
What is film processing?
- Steps that produce a visible image on a dental radiograph
- Converts latent image to visible image
- Preserves the image so it is permanent
______ absorb x-radiation during x-ray exposure
Silver halide crystals
______ is the pattern of stored energy on exposed film
Latent image
What is the process from latent to visible image?
- Film is placed in developer solution - silver halide crystals that were exposed to x-rays turn into black metallic silver
- Black metallic silver creates dark areas on radiogrpah - radiolucency
- Unexposed silver halide crystals unaffected by developer
- Fixer solution removes unexposed silver halide crystals to create white (radiopaque) areas
- Fixer solution also fixes image to film plate
- Film plate then washed in water to remove any traces of chemicals
- Fully dried before touching
Describe the visible image of the dental radiograph
- Made of black, white, and grey areas - shows contrast of various densities
- Radiolucent areas - appear black, readily permitted passage of x-ray beam
- Radiopaque - appears white, resisted passage of x-ray beam
Development ______ the film emulsion while fixation _______ the film emulsion
- Softens
- Hardens
When working with an automatic film processor, what is important to keep in mind?
- Solutions should be replenished daily
- Solutions fully changed every 3-4 weeks (every 2 weeks in a really busy office)
- Normal use defines as 30 intraoral films per day
Describe the darkroom
- A completely darkened environment within which x-ray film can be handled and processed to produce diagnostic radiographs
- Must be properly designed and equipped - no white light can enter
Describe the lighting situation in the darkroom
- Needs to be light tight
- Can be no light leaks
- Needs room lighting for procedures not associated with processing film
- Safe lighting - long wavelengths of res-orange portion of the visible spectrum
Describe safelighting
- Lamp with low wattage bulb (7.5 or 15 watts)
- Light equipped with safelight filter - removes short wavelengths in the blue/green portion of spectrum
- Safelight at least 4 feet from working area
Describe an automatic processor
- Automated all film processing steps - may be limited to certain sizes of film and may require a dark room
- Daylight loader - may be used in a room with white light
How do you properly use processing solutions?
- Follow the manufacturer’s instructions for storage, mixing, and use
- Know that solutions deteriorate with - exposure to air, continued use, chemical contamination
What should you keep in mind about developer solution?
- It is depleted from evaporation and removal of small amounts
- Exhausted developer does not fully develop the latent image and produces non-diagnostic radiographs with reduced density and contrast
What should you keep in mind about fixer solution?
- Depleted from evaporation and removal of small amounts
- Exhausted fixer doesn’t stop chemical reaction enough to maintain film clarity
- Films turn a yellow-brown, transmit less light, and lose diagnostic quality
Why is automatic film processing typically preferred over manual processing?
- Less time required
- Time/temp automatically controlled
- Less equipment
- Less space needed
Describe the component parts of the automatic processor
- Uses a roller transport system to move x-ray film through various stages
- Processor housing
- Film feed slot
- Roller film transporter
- Developer compartment
- Fixer compartment
- Water compartment
- Drying chamber
- Replenisher pump
- Film recovery slot
What are the steps of automatic processing?
- Prepare darkroom or daylight loader
- Prepare films
- Insert each unwrapped film into the film feed slot
- Retrieve processed radiographs
What is the routine care and maintainance of the automatic processor?
- Need cleaning and replenishment schedule (may require daily or weekly cleaning)
- Use “cleaning film” in the system to clean the rollers (panorex film)
- Check levels of processing solutions daily and replenish as needed
A film with damaged emission is called _______
Reticulation
Underdeveloped film appears ______
Light
Developer spots appear _______
Dark or black - use clean work area in dark room
Fixer spots appear _______
Light or white - use clean area in darkroom
A film with damaged emulsion appears ________
Cracked - check temps of processing solutions and water bath, avoid drastic temp differences
An error where you can see one film on top of another
Overlapped film - ensure separation so no contact during processing
A fingernail artifact appears as a ______
Black, crescent shaped mark - hold film at edges gently
Static electricity appears as ________
Lack branching lines - touch conductive object before unwrapping films
The exposed area of a light leak appears _______
Black - examine film packets for defects before using & never unwrap a film in white light
What are quality control tests?
Specific tests used to maintain and monitor: dental x-ray equipment, supplies, film processing
What x-ray equipment and supplies need to be inspected for quality?
- X-ray machines - periodic inspections are important
- Dental x-ray film - screens and cassettes
- Viewbox - the light source used to view x-rays
Describe the fresh film test
- Prepare a film
- Unwrap one unenexposed film from newly opened box - clear with slight blue tint
- Process film using fresh chemicals
Describe fogged film
Processed film is fogged and may be expired, improperly stored, or exposed to radiation
Describe quality control for screens and cassettes
- Screens - extraoral intensifying screens should be examined for dirt and scratches, should be cleaned monthly
- Cassettes - examine for worn closures, light leaks, and warping
Darkroom lighting should be checked every _____
6 months - ensure no light leaks, correct with weather stripping if needed
Describe the coin test
- Prepare darkroom
- Prepare a film
- Place coin on unwrapped, unexposed film
- Turn on safelight for 3-4 mins
- Remove coin and process film
- Should be no visible image on processed radiograph
- Safelighting is bad is image of coin with fogged background
Describe automatic processor test films
- Prepare films by unwrapping 2 unexposed films - expose 1
- Process both films in automatic processor
- Functioning processor if unexposed film comes out clear/dry and exposed film is black/dry
- Non-functional if unexposed film is not clear/dry etc.
What are the 3 methods of test developer strength?
- Reference radiograph - one processed under ideal conditions (fresh chemicals and correct settings/temp)
- Stepwedge radiograph - device of layered aluminum steps that produce varying densities (make. Daily stepwedge radiograph and compare to a control)
- Normalizing device - commercially available device to test strength
If a reference radiograph does not match densities with daily radiographs, what is happening?
- Daily radiogrpahs are lighter than reference - developer solution is weak or old
- Daily radiogrpahs darker than reference - solution is either too concentrated or too warm
If the density on a daily stepwedge radiograph by more than _____ from the standard, the developer solution is depleted
2 steps
How can you tell us the fixer strength is correct?
- Fast clearing - film clears in 2 mins fixer is adequate
- Slow clearing - if film does not clear in 3-4 mins the solution is depleted
What are the diagnostic criteria for intraoral radiographs?
- Must show images with optimum density, contrast, definition, and detail
- Must show images with the least amount of distortion possible
- The cmrs (complete mouth radiographic series) must include radiographs that show all tooth-bearing areas
- Periapical radiographs must show the entire crowns and roots of teeth being examined, as well as two to three mm beyond the route apices
- Bitewing radiographs must show open contacts
When should radiographs be prescribed?
- Based on the individual needs of the patient
- A complete mouth radiographic series (CMRS) is appropriate when a new adult patient presents with clinical evidence of generalized dental disease or a history of extensive dental treatment
Infection control methods prevent the transmission of infectious diseases from:
- Patient to operator
- Operator to patient
- Patient to patient
What are the conditions necessary for the transmission of infectious disease?
- Susceptible host
- Pathogen with sufficient infectivity and numbers to cause infection
- Portal through which the pathogen may enter the host
Describe hand hygiene and hand care
- Hand hygiene - routine hand wash, antiseptic hand wash, antiseptic hand rub
- Hand care - hand lotion, nail/ cuticle maintenance
What are the infection control procedures used before exposure?
- Preparation of the treatment area - x-ray machine, dental chair, work area, lead apron
- Preparation of supplies and equipment - film, film-holding devices
- Preparation of the patient - chair adjustment, headrest adjustment, lead apron
- Preparation of the dental radiographer - hand hygiene, gloves, mask and eyewear, film holding devices
What are the infection control procedures used after exposure?
- Disposal of contaminated items
- Film holding devices
- Hand hygiene
- Lead apron removal*****
- Surface disinfection
What are the infection control procedures used for processing?
- Film transport
- Dark room supplies
- Film handling with barrier envelopes
- Film handling without barrier envelopes
- Disinfection of dark room and daylight loader procedures