This document discusses techniques for intraoral periapical radiographs and bitewing radiographs. It covers the paralleling and bisecting angle techniques for intraoral periapical films. It also describes different types of bitewing radiographs and their indications. The document discusses digital radiography technologies including charge-coupled devices, complementary metal oxide semiconductors, flat panel detectors, and photostimulable phosphor plates. It compares the advantages of digital radiography over conventional films.

1. TECHNIQUES FOR IOPA
RVG,BITEWING

2. CONTENTS
 INTRODUCTION
 IOPA – TECHNIQUE
 BITEWING RADIOGRAPS AND ITS TYPES
 RADIOVISIOGRAPHY
 RVG RECEPTORS – SOLID STATE DETECTORS AND
PHOTOSTIMULABLE PHOSPHOR
 ADVANTAGE AND DISADVANTAGE OF RVG
 CONCLUSION

3. INTRODUCTION
 Generally radiographic technique is one of the most widely used
for the detection of internal defects . Clarity and accuracy of the
image can be obtained through proper orientation . The choice
of the appropriate radiographic technique is made on the basis
of geometry , size , sensitivity requirement and availability

4. INTRAORAL PERIAPICAL RADIOGRAPH
 Periapical views are used to record the crowns , roots , and surrounding bone
 Root canal treatment
 Assessment of root formation and completion
 Assessment of root morphology
 Assessment of relationship of roots to various vital structures
 Implant site assessment and placement

5. TECHNIQUES
 Paralleling angle technique
 Bisecting angle technique

6. PARALLELING ANGLE TECHNIQUE(RIGHT
ANGLE OR LONG CONE TECHNIQUE)
Principle- The central concept of the paralleling is that the x ray receptor is supported
parallel to the long axis of the teeth and the central ray of the x ray beam is directed at
right angles to the teeth and receptor
ADVANTAGE
Minimizes geometric distortion and presents the teeth and supporting bone in their
true anatomic relationships

7. RECEPTOR HOLDING INSTRUMENT AND PLACEMENT
These instruments are used to allow precise position of the receptor in the patients mouth
It is important to use a receptor holding instrument that has a external guiding ring .
This guiding ring is used to align the x ray aiming cylinder and ensures that the receptor
is centered in the beam behind the teeth and the receptor and teeth are perpendicular to
x ray beam
ANGULATION OF THE TUBE HEAD
Place the aiming cylinder of the x ray machine in the vertical and horizontal planes to
align with the aiming ring

8. BISECTING ANGLE TECHNIQUE
Receptor is positioned as close as possible to the lingual surface of the teeth
resting in the palate or in the floor of the mouth
The plane of the receptor and the long axis of the teeth form an angle with its
apex at the point where the receptor is in contact with the teeth an imaginary
line that bisects this angle direct the central ray of the beam at right angles to
this bisector

10. BITEWING RADIOGRAPH
Bitewing (also called interproximal) images include the
crowns of the maxillary and mandibular teeth and the
alveolar crest on the same receptor.
Bitewing receptors are particularly valuable for
detecting interproximal caries in the early stages of
development before it becomes clinically apparent
Bitewing projections are also useful for evaluating the periodontal
condition

11. INDICATION
 Interproximal caries i,e secondary caries below the restoration
 Overhanging restorations
 Alveolar bone crest
 Detect calculus deposit
TECHNIQUE
Parallel with the occlusal plane
The aiming cylinder is positioned about +10 Degree to project
the beam parallel with the occlusal plane

13. RADIOVISIOGRAPHY SENSORS
 It is a digital sensor which is connected by a wire to the computer
 The sensor transfers the image directly on the computer
 There is very less processing time involved as it is done by computer itself

14. A digital image is made up of a large number of discrete picture elements
(pixels).
The size of the pixels is so small that the image appears
smooth at normal magnification.
The location of each pixel is uniquely identified by a row and column
coordinate within the image matrix.
The value assigned to a pixel represents the intensity (gray level) of the
image at that location.

15. DIGITAL IMAGE RECEPTORS
 SOLID-STATE DETECTORS
Solid-state detectors collect the charge generated by x rays in a solid semiconducting material
The matrix and its associated readout and amplifying electronics of intraoral detectors are
enclosed within the plastic housing to protect them from oral environment
Three types of solid-state sensors are in common use.
 Charge-Coupled Device
 Complementary Metal Oxide Semiconductors
 Flat Panel Detectors

16. CHARGE-COUPLED DEVICE
The charge-coupled device (CCD), introduced to dentistry in 1987, the
first digital image receptor to be adapted for intraoral imaging.
A solid state detector that contains a silicon chip with an electronic circuit
embedded in it
The electrons that makes up the silicon CCD can be visualized as being
divided into an arrangement of blocks or picture elements known as
pixels(a small box into which the electrons produced by the x ray
exposure are deposited
The image is read by transferring each row of pixel charges from one pixel
to the next in a bucket brigade fashion.

17. CMOS(Complementary Metal Oxide
Semiconductors
 These detectors are silicon-based semiconductors but are
fundamentally different from CCDs in the way that pixel charges are
read
 Each pixel is isolated from its neighboring pixels and is directly
connected to a transistor.
 The charge is then transferred to the transistor as a small voltage.
 The voltage in each transistor can be addressed separately, read by a
frame grabber, stored and displayed as a digital gray value.
 CMOS technology is widely used in the construction of computer
central processing unit chips and digital camera detectors

19. FLAT PANEL DETECTORS
 Flat panel detectors are used for medical imaging but have also been used in several extraoral imaging
devices.
 The detectors can provide relatively large matrix areas with pixel sizes less than 100 μm
 This allows direct digital imaging of larger areas of the body, including the head.
 The electrical energy generated is proportional to the x-ray exposure and is stored at each pixel in a
capacitor.
 Flat panel detectors are expensive and likely to be limited to specialized imaging tasks, such as cone-beam
computed tomography (CT)

20. PHOTOSTIMULABLE PHOSPHOR
Also known as storage phosphor plates, image plates or computed radiography
PSP plates absorb and store energy from x rays and release this energy as light
(phosphorescence) when stimulated by another light of an appropriate wavelength
The PSP material used for radiographic imaging is “europiumdoped” barium fluorohalide.
Before exposure, PSP plates must be erased to eliminate residual
images from prior exposures.

21. STATIONARY PLATE SCANS
 It employs a rapidly rotating multifaceted mirror that reflects a beam of red light
 As mirror revolves red light sweeps across the plate. The plate is advanced and the
adjacent line of phosphor is scanned
ROTATING PLATE SCANS
 It involved a rapidly rotating drum that holds the multiple plate. The rotation of the
drum pass a fixed laser provides a rapid scan
 Incremental movement of the laser in the slow direction allow image data to be
acquire line by line

23. CONCLUSION
 The knowledge of advances regarding radiographic techniques and
proper use of them gives the opportunity to the practitioner for
improvement in diagnostic tasks and treatment planning