Effect of HeNe and pulsed Nd:YAG laser irradiation on intradental nerve responses to mechanical stimulation of dentine

Inhibitory Effects of Laser Irradiation on Peripheral Mammalian Nerves and Relevance to Analgesic Effects: A Systematic Review

“…72 However 632.8 nm (cw, *1 mW), LI used as an aiming beam for Nd:YAG laser, did not inhibit SSEPs when ferret tooth pulp was mechanically stimulated. 45 Similarly, pulsed 632.8 nm (5 mW, pulse rate not reported) LI for 5 min failed to inhibit the nociceptor Ad and C fiber response in excised rabbit cornea following mechanical, thermal, or chemical noxious stimuli. 60 IR LI.…”

“…Nine studies 22,29,36,[39][40][41][42]44,45 used standardized protocols for assessment of electrophysiology. [46][47][48][49][50][51][52][53][54][55] Ten studies used maximal or supramaximal electrical stimuli, to ensure all axons were stimulated prior to LI and to establish consistent baseline responses for each participant.…”

“…Noxiously evoked potentials were elicited by mechanical, thermal, or chemical stimulation, 45,60,65,71,72 or by formalin, turpentine, or bradykinin injection 25,62,[64][65][66] (Table 3).…”

Surgical lasers and hard dental tissue

“…[46][47][48][49][50][51] The use of the Nd:YAG laser in developing pulpal analgesia, possibly through interference with the 'gate theory' of neural stimulus propagation, has been suggested, although investigation into the subjectivity or placebo effect has rendered its application inconsistent. [52][53][54] Perhaps of greater signifi cance in addressing claims of pain avoidance during laserassisted tooth preparation is the lack of tactile and thermal stimulation compared to rotary instrumentation. In addition, there is the patient-centred factor of previous experience of turbine use together with other emotional and conditioning states.…”

Treatment of dentin hypersensitivity with a low‐level laser‐emitting toothbrush: double‐blind randomised clinical trial of efficacy and safety

“…The effects of middle output lasers such as Nd:YAG , Er:YAG and CO 2 lasers occur by occlusion or narrowing of dentinal tubules. It has been shown that Nd:YAG lasers can block depolarization of rapidly conducting A‐ β fibres , and Nd:YAG laser radiation can block an action potential conduction in a simulated intra‐dental nerve . More recently, low‐level laser therapy (LLLT) has gained attention as a new method to control pain .…”