Insight in the Chemistry of Laser‐Activated Dental Bleaching

Abstract

The use of optical radiation for the activation of bleaching products has not yet been completely elucidated. Laser light is suggested to enhance the oxidizing effect of hydrogen peroxide. Different methods of enhancing hydrogen peroxide based bleaching are possible. They can be classified into six groups: alkaline pH environment, thermal enhancement and photothermal effect, photooxidation effect and direct photobleaching, photolysis effect and photodissociation, Fenton reaction and photocatalysis, and photodynamic effect.

Spectrophotometric and Morphologic Comparison of Bleaching with LED and Diode Laser

“…Lazerler, dişlerdeki renkli moleküllerin foto oksidasyonu veya fotokimyasal reaksiyonlar yoluyla ağartma jeli bileşenleri ile etkileşime girerek ağartmayı artırabilmektedir. 16 Diyot lazer, ağartma işlemleri için kullanılması Amerikan Gıda ve İlaç Dairesi tarafından onaylanmış bir cihazdır. 17 Ağartma ajanını etkinleştirmek için dalga boyu 790 nm'den 980 nm'ye kadar değişen diyot lazer sistemleri, uygulanan güce bağlı olarak farklı sürelerde kullanılmaktadır.…”

Biomodification of Tooth Discolouration

“…Erbium and Alexandrite enhanced bleaching process leads to smoother enamel surface as compared to Nd: YAG. [23][24][25] When selecting a laser for enhancing the bleaching potential, the wavelength and the target substrate must be considered. Each wavelength has a different chromophore where the absorption is maximum and which in turn will potentiate the desired outcome.…”

“…The pH will determine the kind of and quantity of free radicalsliberated. 25 The buffering of peroxide to a pH range of 9.5 to 10.8 provides a greater amount of perhydroxyl free radicals For stubborn tetracycline stains, the laser which isadvocated is the KTP laser (potassiumtitanyl-phosphate) which is a Nd: YAG frequency-doubled laser. Initially, the laser effuses a 1064nm wavelength visible green light, which is passed through a KTP crystal and the resultant lased light is KTP laser in which the original wavelength of Nd: YAG is halved to 532nm.…”

Er: YAG Laser Assisted Bleaching Procedures Effect on Enamel Topography

“…They tend to get an electron by oxidation of stains present in adjacent enamel and dentin and more whiter tooth structure [8]. Many researches mentioned that accelerating peroxide bleaching treatment can be achieved by shortening the chemical redox reactions with different sources of light energy such as, lasers, light-emitting diodes (LED), plasma arc lamps, and halogen curing lights, in a variety of wavelengths and spectral power [9][10][11][12][13][14]. The Er:YAG laser wavelengths (2940 nm) is highly diffused in hydroxyapatite and the highest absorption of water of any dental laser wavelengths [15] .…”

“…Many studies stated that bleaching procedures have some adverse effects on tooth structure as enamel changes in micro-hardness, surface roughness and modulus of elasticity. All bleaching adverse effects attributed to chemical and morphological changes of dental hard tissues [11,17,18,19,20,21].…”