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relevant contraindications in section 1.7 for details.
4 Product function and operation
4.1 Usage requirements
Apex locator should be precise, repeatable, and easy to operate. The following
requirements are necessary besides the proper operation method.
4.1.1 The operation should be according to the manual.
4.1.2 The dentists should have the knowledge of teeth position and average
length and the skill to operate the device.
4.1.3 An fully exposed access cavity to show the pulpal cabin.
4.1.4 A X-ray photo to show the whole length and root canal of the teeth.
4.1.5 The endo file should not be too big nor too small to avoid cutting through
the apical foramen.
4.1.6 Mark an anatomized symbol on the diseased tooth and memorize it on the
case history. This symbol should be marked on the health bridge or on the tooth
filled integrated. The position of the mark should be on the incisal edge of the
anterior tooth or on the spire of the molars. For those bridge that's broken obviously,
this symbol should be on the tooth surface supported by the dentin instead of on the
suspended enamel.
4.1.7 The acute inflammation surrounding the apex has been gone and the infected
material has been cleaned. It is also necessary to get rid of the pulp and necrosis
tissue.
4.1.8 The following cases are not suited for a normal measurement:
a) The size of the root similar to the size of apical foramen.
In this case, the measurement result of the length of the root canal will be shorter
than its real because of the hypoplasia of the root [Picture 12].
