LASER is an acronym for 'Light Amplification by Stimulated Emission of Radiation.' 'Zur Quantum Theorie Der Stralung' (Notion of Wavelength) a work by Albert Einstein's, published in 1916, is widely credited with the invention of the concept of spontaneous emission of radiation. Testing with microwaves, Charles Townes created a system in 1953 that allowed this radiation to be amplified when passed through ammonia gas. In 1960, Miaman was the first to introduce laser dentistry and its hard and soft tissue applications. A collimated and coherent beam of light is emitted by lasers.1 Laser is a photon of a single wavelength. Laser emits light by optical magnification. Light is a form of energy produced by electromagnetic radiation which moves at a constant speed by wave motion. The photon or light particle is the fundamental unit of radiant energy. Soft tissue applications include healing of wounds, excision of hyperplastic tissue of impacted teeth, photodynamic therapies for tumors and removing restoration, prevention of caries, bleaching, curing, dentinal hypersensitivity, preparation of cavity, growth modulation, and diagnostic needs are among the hard tissue applications Diode Laser, , Neodymium:YAG, Erbium Chromium:YSGG ,He:Ne and Erbium:YAG (Er:YAG) Laser are the most often used lasers in endodontics. Despite the fact that lasers are somewhat more expensive than traditional therapy, they are an useful tool for increasing the efficiency, specificity, convenience, and comfort of dental treatment

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