tailieunhanh - Ebook Fundamentals of laser dentistry: Part 2

(BQ) Part 2 book “Fundamentals of laser dentistry” has contents: Laser-assisted cosmetic dentistry, laser application in pediatric dentistry, laser-assisted periodontal therapy, laser in oral and maxillofacial surgery, low level laser therapy, photo-activated disinfection, and other contents. | ` Ìi`ÊÜ Ì ÊÌ iÊ`i ÊÛiÀÃ Ê vÊ v ÝÊ*À Ê* Ê ` Ì ÀÊ / ÊÀi ÛiÊÌ ÃÊ Ì Vi]ÊÛ Ã Ì\Ê ÜÜÜ° Vi °V ÉÕ V ° Ì Fundamentals of Laser Dentistry 62 INTRODUCTION Tooth discoloration can be defined as changing of the color of the tooth in a way that it differs markedly from the adjacent teeth. In most cases it is deviation to the darker hues. Genetic malformations and developmental disorders can affect several teeth of the dentition or may cause general discoloration. Average tooth color varies from whiteyellow to yellow with gray, brown, green and pink shades. Tooth shape and tooth color are the main factors of influence in the esthetics of a dentition. Tooth discoloration interferes with normal esthetics. Bleaching techniques have eliminated the need for invasive treatments and has became the treatment of choice. The indications for bleaching and the outcome of a treatment is highly dependent on the etiology of the discoloration. CAUSES OF TOOTH DISCOLORATION Tooth discolorations are classified as – Extrinsic and Intrinsic. Extrinsic discolorations are caused by factors outside of a tooth. Intrinsic discolorations are caused by internal factors. Extrinsic Discolorations It consists of a discolored superficial layer on the surface of the teeth. It occurs due to lifestyle habits and poor oral hygiene. They are removed primarily by conventional means such as prophylaxis, ultrasonic scaling, abrasive pastes or root planing. Several Kinds of Extrinsic Discolorations a. Plaque: It appears as white-yellow to green-brown b. Tartar: Dental plaque calcifies to create tartar. It can appear both supra and subgingivally. The absorption of pigments found in various foods can change inherent yellow to white color of tartar to brown and black. c. Deposit of tar: Smokers and tobacco chewers often show a brown to black deposit of tar especially on lingual surfaces. d. Tea and wine: Both contain tannin, causing a brownish-black stain. e. Chlorhexidine: Often used as .