To be added: Information about cameras that use an intraoral mirror
Ambient and chair lighting is usually not enough to illuminate intraoral images. Therefore, intraoral cameras have a built-in light source. The light source can be in the base unit, the handpiece or the camera head. Light sources in the base unit require fiberoptic cables for transmitting the light to the camera. Such cables tend to be bulky and fracture-prone. A lightsource in the handpiece can increase the weight of the handpiece, which can result in increased operator fatigue. However, sometimes a heavier handpiece with a light cable is preferable to a lighter one with a heavy, bulky and inflexible cable.
The light-emitting diodes (LEDs) in the head of the camera are a new development that minimize some of the advantages of the other systems. However, LEDs tend to produce bluish light and thus distort colors (compared to scenes lit by daylight or fiberoptic light sources). In addition, they generate heat and require larger apertures, resulting in a reduced depth of field.
In most cameras, the base unit contains the power source. Wireless
cameras are battery-operated and have therefore a somewhat higher weight.
Many such systems can run on rechargeable batteries.
Wireless cameras do not require a cable to transmit images to the computer.
Usually, the handpiece has to be within a range of ##x-y ft for the
transceiver to receive the signal. All other cameras require a cable
for image transmission. The cable configuration also depends on the
location of the lightsource. Intraoral cameras that contain the lightsource
in the base unit tend to have bulkier cables.
Lenses
Cameras either come with a single lens or a set of interchangeable lenses.
Single-lens cameras have a simpler design, but are limited in the range
of camera-to-object distance and magnification. In addition, they tend
to distort images progressively more as the camera-to-object distance
decreases. Interchangeable lenses have the advantage that the operator
can pick the appropriate lens for the type of exposure, such as full
face, full arch or individual teeth.
Focus
Once an image is framed, it needs to be focused. Fixed-focus cameras
require the operator to vary the distance to the object until it is
in focus. Variable-focus cameras are focused using a slider or similar
mechanism. When assessing the ease of use of a camera, it is important
to test the ease with which the image can be focused.
Image Capture
Once the camera is switched on, it continuously records images and displays
them on the screen. Several systems switch themselves on automatically
when the handpiece is removed from its holder or cradle. When the operator
wishes to capture an image, he uses a capture button, foot pedal or
mouse to freeze the current frame. The system should make it easy to
trigger image capture to allow the operator to concentrate on framing
and focusing the image, not capturing it.
Sterilization
and Disinfection
Typically, only the intraoral part of the camera comes in direct
contact with saliva, blood or oral tissues. Cameras that can not be
sterilized use a sheath or protective plastic cover. Of the two, the
plastic cover is the more cumbersome method to use. Other handpieces
have detachable intraoral parts, which can be autoclaved, or are sealed
to the degree that they can be cold-sterilized.
Setup
To be added: connection to output device, types of connections, power
sources, etc.
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Question:
Identify the marked parts on the photograph of the intraoral camera
handpiece. Question: What type of intraoral camera connector is illustrated in the photograph? Question: What advantage do variable-focus intraoral cameras have? |