X _ray films

1. X_ray films Extraoral films Intraoral films Occlusal Periapical Cephalometric Panoramic Bite wing

2. Bitewing Film • This film shows the crowns of both maxillary and mandibular teeth on one film . • The bitewing film is used to identify interproximal caries

3. Occlusal Film The occlusal film is used to identify the extent of larger pathological conditions, to locate an object in the buccolingual direction Impacted maxillary canine Anterior dentition - Child

4. periapical pathology internal resorption caries Periapical Film • Periapical means “around the apex”. • This film is intended to show the entire tooth including the area around the root of the tooth.

5. Extraoral Film Extraoral films used in Dentistry include the Panoramic, Lateral oblique jaw film, Cepahalometric film.

6. The panoramic film is the most common extraoral film used in dentistry. It does not provide the detail that intraoral films do but it gives an overall view of the entire dentition, both maxillary and mandibular. It is very helpful for third molar extractions

7. Ortho-surg. patient – jaw realignment Surgery patient- mandibular implant Cephalometric films, such as the lateral cephs above, are used to identify both the bone and the soft tissue outline on the same film. This film is used routinely by orthodontists in developing treatment plans for their patients. It is also used by oral surgeons for evaluating trauma and conditions requiring surgical correction.

8. Contents of Film Packet 0 Black paper: surrounds film; protects emulsion. Film: raised dot in one corner used for film orientation. Lead foil: protects film from backscatter ; reduces patient exposure SO IT prevent: — Some of the residual radiation that has passed through the film from continuing on into the patient's tissues — Scattered secondary radiation, from X-ray photon interactions within the tissues beyond the film ,coming back on to the film and degrading the image

9. 0 Scatter (secondary)radiation is produced when the primary x-rays from the x-ray tube interact with the patient’shard and soft tissues. Backscatter radiation refers to those scattered x-rays that go “back” toward the film. Primary x-rays Scatter (secondary) x-rays

10. The film packet contents The contents of a film packet. A The outer wrapper. B The film. C The sheet of lead foil. D The protective black paper

12. Film Composition 0 An x-ray film is composed of a plastic (polyester) base covered on both sides with an emulsion; this is called a double-emulsion film. The emulsion contains silver halide crystals which are surrounded by gelatin. The silver halide crystals are affected by the x-rays and eventually form the image during film processing., The emulsion (gray lines below) is attached to the base with a very thin layer of adhesive (green lines below). The base has a slight bluish tint which makes viewing the films easier on the eye. The emulsion is covered with a thin layer of gelatin, a “supercoat,” which helps to protect the film (yellow lines below). Double emulsion (emusion on both sides) adhesive blue-tinted base supercoat emulsion with silver halide crystals and gelatin

13. The radiographic film cross_section Diagram showing the cross-sectional structure of double emulsion radiographic film

14. Film Sizes (Intraoral) • Intraoral film packets come in five basic sizes: • Child (#0) • Narrow anterior (#1) • Adult size (#2) • Extralong post. film (#3) • Occlusal(#4)

15. #2 #3 Adult PA, BW Extra-long BW Child occlusal #1 Adult ant. PA #4 Occlusal in adults #0 Child PA, BW

16. The white side of the film packet faces the tube. A, Size 4 occlusal film. B, Size 2 film;C size 1 film.

17. Extra_oral Film Cassettes • A cassette is a plastic or metal case used in extraoral radiography to hold the film and protect it from exposure to light. Cassettes are available in rigid or flexible styles. • A cassette holds two intensifying screens • (one on each side) in tight contact with the Film.

18. Rigid metal cassette Flexible vinyl cassette

19. Intensifying Screen Function • An intensifying screen intensifies or increases the effect of the radiation and thus decreases the amount of exposure time needed. • The intensifying screen is coated with a material called phosphor that gives off light when struck by x-radiation. • The film inside the cassette is sandwiched between the intensifying screens and is affected by both the light produced by the phosphor and the x-radiation.

20. Film Speed 0 • Film speed refers to the amount of radiation required to produce a radiograph of standard density (darkness). Film speed is determined by the following: • The size of the silver halide crystals. • The thickness of the emulsion. • The presence of special radiosensitive dyes.

21. The film speed determines how much exposure time is required to produce the image on the film. • A fast film requires less radiation, and the film responds more quickly because the silver halide crystals in the emulsion are larger. • The larger the crystals, the faster the film speed. This is the same principal as film speed on photographic film. • The “F” speed is the newestandfastest film on the market today and will reduce radiation exposure to the patient by 20% to 60% compared to E-speed film and D- speed film. dot # of films in packet #2 #2 #1 plastic plastic paper D-speed (Ultraspeed) F-speed (Insight) tab