Laser Doppler Flowmetry
A non-invasive diagnostic technique that measures microvascular blood flow within the dental pulp by detecting the Doppler shift of laser light scattered by moving red blood cells.
Full Definition
Laser Doppler Flowmetry (LDF) is a non-contact or contact-based optical measurement technique used in dental research to assess pulpal blood flow (PBF) as a direct indicator of pulp vitality, in contrast to conventional sensibility tests that measure neural function. A low-power laser beam is directed at the tooth surface, and light scattered by moving erythrocytes undergoes a frequency shift proportional to their velocity; this is translated into a flux value representing tissue perfusion. LDF is considered a more biologically accurate measure of pulp vitality than thermal or electrical tests, particularly in recently traumatised, immature, or heavily restored teeth where neural responses may be unreliable. In manuscripts, editors should ensure that probe placement, measurement duration, environmental controls, and reference flux values are described in the methods section. LDF is typically contrasted with EPT and cold testing in diagnostic accuracy studies.
Usage
Usage note: The abbreviation LDF should be expanded at first use. Distinguish clearly from 'pulse oximetry', which, although also measuring oxygen-rich blood flow, uses a different mechanism and has distinct limitations in the dental context.
In Context
- "Laser Doppler flowmetry was used to confirm pulpal blood flow in all study teeth prior to randomisation." — Methods section of a pulp biology clinical study
- "LDF values were significantly lower in teeth with confirmed periapical lesions compared with contralateral controls." — Results section of an endodontic diagnostic accuracy study