Which modality is used for permanent hair removal using the thermal effect of current?

The modality used for permanent hair removal that utilizes the thermal effect of current is thermolysis. Thermolysis works by employing a rapid alternating current that generates heat to destroy the hair follicle. This method is often referred to as 'shortwave electrolysis' and is characterized by its ability to treat hair permanently by targeting individual hair follicles with thermal energy.

Electrolysis, while also a method of permanent hair removal, specifically utilizes a direct current to chemically destroy hair follicles, rather than relying primarily on thermal effects. This makes thermolysis a distinct approach within the electrolysis category focused more intensively on utilizing heat.

Tweezing is not a method for permanent hair removal; it merely removes hair from the surface of the skin, requiring repetitive sessions for maintenance. Laser therapy, on the other hand, employs focused light beams to target the pigment in hair follicles, providing permanent hair reduction rather than relying on the thermal dynamics of electrical current. Thus, thermolysis is the correct choice for a technique that specifically uses the thermal effect of current for permanent hair removal.