Chapter 1: Dental Radiography

Dental radiographs:
- Images or pictures produced by x-rays.
- Remain the basis for many diagnostic procedures.
- Play an essential role in oral health care.
Radiography:
- The process of making radiographs by exposing an image receptor, either film or digital sensor.

Objective: Provide oral health care team with radiographs of the best possible diagnostic quality.
Goal: Achieve high-quality radiographs while maintaining the lowest possible radiation exposure risk for the patient.

Oral radiology:
- The study of x-rays and techniques used to produce radiographic images.
Wilhelm Conrad Roentgen:
- Discovered x-rays on November 8, 1895, while experimenting with a Crookes tube.
- Awarded the first Nobel Prize for Physics in 1901.

X-ray:
- The letter 'x' represents the unknown.
Roentgen ray:
- Named in honor of Roentgen’s discoveries.
Roentgenograph:
- The image produced on photosensitive film.
Radiograph:
- Similar to a photo negative (x-ray film).
- X-rays resemble radio waves.
- The term is formed from the prefix "radio" and the suffix "graph".

Image Example:
- Famous radiograph purported to be of Roentgen’s wife Bertha’s hand taken on December 22, 1895.

Otto Walkhoff:
- First exposed a prototype of a dental radiograph with little diagnostic value; film movement was difficult during long exposure times (25 minutes).
- The dangers of radiation overexposure were unknown at the time.
C. Edmund Kells:
- A New Orleans dentist credited with the practical application of radiographs in dentistry.
William David Coolidge:
- Introduced the hot cathode tube which significantly advanced radiation exposure reduction efforts.
Howard Riley Raper:
- Authored the first dental radiology textbook titled "Elementary and Dental Radiology" and introduced the bitewing radiographic technique.

Name	Event	Year
W. C. Roentgen	Discovered x-rays	1895
O. Walkhoff	First prototype of a dental radiograph	1896
C. E. Kells	First dental radiograph in the U.S.; advocated for radiation safety	1896
A. Cieszyński	Applied “rule of isometry” to bisecting technique	1907
W. D. Coolidge	Introduced the hot cathode tube	1913
H. R. Raper	Wrote the first dental x-ray textbook and introduced bitewing	1913, 1924
F. W. McCormack	Developed the paralleling technique	1920
G. M. Fitzgerald	Designed a “long-cone” for paralleling technique	1947
Blank	Introduction of panoramic radiography	1948
Blank	Introduction of “D” speed film	1955
Blank	Introduction of “E” speed film	1981
Francis Mouyen	Developed the first digital imaging system (RadioVisioGraphy)	1987
Blank	CT imagery introduced for dentistry as CBCT	1997
Blank	Introduction of “F” speed film	2000

Safe x-ray equipment is now available in dental offices across the U.S.
Early x-ray machines posed electrical hazards due to open, uninsulated high-voltage supply wires.
Shockproof dental x-ray machines:
- Introduced by Coolidge and General Electric.
Improvements in x-ray technology:
- Reduction in size of x-ray beam; replaced the pointed cone with a position indicating device (PID).

Panoramic radiography:
- Capable of exposing the entire dentition and surrounding structures on a single image.
Tomography scan:
- A computed tomography (CT) scan imaging a single selected plane of tissues but delivers a high dosage of radiation.
Cone Beam Volumetric Imaging (CBVT):
- Cone beam computed tomography (CBCT) uses lower doses of radiation and is purported to become the gold standard.

Early dental x-ray film packets consisted of glass photographic plates wrapped in black paper and rubber.
Machine-wrapped dental x-ray film packet:
- First introduced by Kodak in 1919.
- Had a one-sided emulsion coating requiring longer exposure times.
Modern dental films now feature both sides coated, which significantly reduces exposure times.

Digital imaging systems now replace film as the image receptor, utilizing a sensor instead.
Frances Mouyen:
- French dentist who introduced digital radiography in 1987 (RadioVisioGraphy).

Improved overall quality of image sensors; comparable to traditional film.
Advantages of digital imaging include:
- Reduction in radiation dosage.
- Elimination of film and processing chemistry.
- Elimination of film packaging disposal.

Bisecting Technique:
- The first and earliest method applied by A. Cieszyński in 1907, incorporating the rule of isometry.
Paralleling Technique:
- Developed by Franklin McCormack in 1920, this technique is less complicated and more practical than the bisecting technique.

There has been significant radiation dose reduction due to advanced imaging systems including both 2D and 3D imaging technologies.
The computed approach in radiography is expected to enhance the quality of oral health care.

Wilhelm Conrad Roentgen's discovery of the x-ray revolutionized the practice methods in both medicine and dentistry.
The use of radiographs has become essential for medical and dental diagnostic procedures.
The impact of improved equipment, advanced techniques, and educated personnel allows for minimally invasive radiography, significantly reducing radiation risk.
Digital imaging technologies are increasingly being adopted by dental practices, offering several advantages over conventional film.
The two fundamental techniques for acquiring dental images are bisecting and paralleling, with advancements like CBCT providing both 2D and 3D images for accurate dental diagnosis.