Radiation Physics Question And Answers

Radiation Physics

Question 1. Write short note on LASER.
Answer. Light amplification by stimulated emission of radiation (LASER).

• It is a device which can operate in the infrared, visible and UV light of spectrum and which amplifies the electromagnetic waves by stimulated emission of radiation.
• When atoms or molecules absorb energy, then they can emit light spontaneously or they can be stimulated to do so by a light wave. If a body of atoms is raised to the excited state by pumping, then an incident light wave will stimulate photon emission and net amplification of the incident light beam results. The output is extremely powerful and mobilizes intense heat at close range as the atoms are stimulated to emit photons at an infinitely greater rate than would spontaneously.
• Laser light has four characteristics that distinguish it from the light produced from other sources, like the electric bulb and the sun. These are:
  • Laser light is highly directional and travels in a narrow beam, the sides of which stay almost parallel.
  • Laser produces coherent light, i.e. it has only one frequency.
  • Laser light is of a single color.
  • Laser light is very bright, and powerful with very high intensity.

Read And Learn More: Oral Radiology Question And Answers

Types of Lasers

In dentistry, two types of lasers are used:

• Soft Tissue Laser (800-990 nm), e.g. Argon soft tissue laser, CO2 Laser
• Hard Tissue Laser (2500-3000 nm), e.g. Er: YAG Dental laser system, Erbium hard tissue laser.

Lasers in Dental applications

• Surgical excision of benign tumors and small soft tissue growths (e.g. Epulis).
• Frenectomy
• Nerve regeneration.
• Sleep apnea (LAUP: Laser Assisted Uvula Palatoplasty).
• Cavity detection.
• Viewing of tooth and gum tissue (Optical coherence tomography).
• Treatment of Cold sores—low intensity lasers used to reduce pain.
• Treatment of temporomandibular joint for reduction of pain and inflammation.
• Treatment of ulcerative lesions.
• Oral biopsies
• Treatment of gummy smile
• Treatment of tooth sensitivity
• Treatment of melanin-pigmented gingiva.
• Local anesthesia free cavity preparation.
• Hard tissue roughening or etching.
• Enameloplasty, excavation of pits and fissures for placement of sealants.
• Osseous crown lengthening.
• Cutting, shaving and contouring of oral osseous structures.
• Ostectomy
• Apicectomy
• For early detection of dysplastic cells (optical coherence tomography)

Lasers Advantages

• Causes less pain thereby reducing need for anesthesia.
• Minimizes bleeding and most surgical procedures done with lasers do not require sutures, because the high-energy light beam aids in clotting (coagulation) of exposed blood vessels thus inhibiting blood loss.
• Bacterial infections are minimized and wound heals faster. The high energy beam sterilizes the area worked on.
• Damage to surrounding tissue is minimized.
• Wounds heal faster.