IP Indian Journal of Conservative and Endodontics 2022;7(1):6–10 Content available at: https://www.ipinnovative.com/open-access-journals IP Indian Journal of Conservative and Endodontics Journal homepage: https://www.ijce.in/ Review Article Role of laser in conservative dentistry and endodontics Preeti Mishra 1, *, Shikha Jaiswal 1 , Sachin Gupta 1 , Vineeta Nikhil 1 , Shalya Raj 1 , Rohit Ravinder 1 1 Dept. of Conservative Dentistry and Endodontics, Subharti Dental College and Hospital, Swami Vivekanand Subharti University, Meerut, Uttar Pradesh, India ARTICLE INFO Article history: Received 26-02-2022 Accepted 02-03-2022 Available online 31-03-2022 Keywords: Argon CO2 Er:YAG Nd:YAG Laser ABSTRACT With dentistry in the high tech era, we are fortunate to have many technological innovations to enhance treatment, including intraoral video cameras, CAD-CAM units, RVGs and Air-abrasive units. However, no instrument is more representative of the term high-tech than the Laser. The rapid development of laser technology, as well as a better understanding of laser interaction with biological tissues, has widened the spectrum of possible applications of lasers in Conservative dentistry and Endodontics. This article reviews the basic mechanism and applications of each laser in conservative dentistry and endodontics. This is an Open Access (OA) journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given and the new creations are licensed under the identical terms. For reprints contact: reprint@ipinnovative.com 1. Introduction LASER is an acronym, which stands for Light Amplification by Stimulated Emission of Radiation. 1 The history of lasers begins similarly to much of modern physics, with Albert Einstein in 1917. Initially his papers were ignored by established physicist of that era but slowly his discoveries altered the course of modern physics. His paper “Zur Quantern Theorie der Strahlung”, was the first discussion of stimulated emission. The basic operating principles of laser were put forth by Charles Townes and Arthur Schalow from the Bell Telephone Laboratories in 1958. The first actual laser which was based on a pink ruby crystal was demonstrated in 1960 by Theodor Maiman. C.K.N Patel developed CO2 laser in 1963. J.E.Geusic and H.M.Marcos developed Nd:YAG laser in 1964. 2 * Corresponding author. E-mail address: preeti.prajesh@gmail.com (P. Mishra). 2. Laser Physics To understand stimulated emission, first we understand the Bohr atomic model that explains, an electrons orbit the nucleus of an atom. Under the right circumstances an electron can jump from its ground state to a higher state, or it can decay from a higher state to a lower state, but it cannot remain between these states. For an electron to jump to a higher quantum state, the atom must receive energy from the outside world. This can happen through a variety of mechanisms such as inelastic or semielastic collisions with other atoms and absorption of energy in the form of electromagnetic radiation. 3 Likewise, when an electron drops from a higher state to a lower state, the atom must give off energy either as kinetic activity (nonradiative transitions) or as electromagnetic radiation (radiative transitions).This process is called “Spontaneous emission” 3 Consider the same situation, before an electron has a chance to spontaneously decay, a photon happens to pass by whose energy is approximately E2-E1, there is a probability that the passing photon will cause the electron to decay in such a manner that a photon is emitted at exactly https://doi.org/10.18231/j.ijce.2022.002 2581-9534/© 2022 Innovative Publication, All rights reserved. 6