1 / 17

Caries prevention

Caries prevention. Dr.alhadi 19.2.2009. The caries process is well understood F eatherstone et al 2000. Primary caries preventive agents are fluoride and fissure sealant. (Ogaard B 1990). laser.

errin
Download Presentation

Caries prevention

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Caries prevention Dr.alhadi 19.2.2009

  2. The caries process is well understood Featherstone et al 2000

  3. Primary caries preventive agents are fluoride and fissure sealant. (Ogaard B 1990)

  4. laser

  5. laser application in preventive Dentistry • Maiman 1960 ruby • Stern and Sognnas first in long list of investigators. To use ruby to reduce subsurface demineralization • These studies were primitive :optical properties of dental tissues at respective laser wavelength and the laser pulse shape and characteristic were not investigated

  6. Scattering and absorption parameters • Materials with high absorption coefficient>100 cm-1 the laser energy is absorbed within 100µm of the surface and converted to heat . • further penetration of heat is done via heat conduction and it is determined by thermal conductivity and heat capacity of the tissue

  7. Mineral component of enamel and dentin is carbonated hydroxyapetite it contain calcium ,sodium ,phosphate ,carbonate ,hydroxyl and fluoride ion. • Water content of enamel is 12% and of dentin is 25% • Carbonate content 3% and 5% (E&D) • Absorption band for water is 3µm ,hydroxyl 2.8µm ,carbonate 7µm ,and phosphate 9-11µm

  8. Mechanism of laser irradiation and improved Caries Resistance • Change in enamel composition: Theories range from physical seal achieved by melting the surface through partial fusion and recrystaliztion of enamel prisms ,to change in enamel composition only

  9. CREATION OF MICROSIVE OR MICROPORE SYSTEM • The creation of micro pores act as site for re-precpitation or means of trapping of calcium ,phosphate and fluoride. • The loss of water ,carbonate and organic substances from enamel would have caused the formation of microspaces. • It has been shown that irradiation with an argon laser produces a changes in the surface layer of enamel by producing micro porosities admixed with globular surface coating . • So there is an enhanced uptake of fluoride ,calcium and phosphate from endogenous and exogenous sources in lased dental hard tissues

  10. The caries preventing effect of CO2 laser • CO2 produces radiation in the infrared region that coincides closely with some of apatite absorption bands. • Mainly phosphate groups has strong absorption at 9-11µm • There are four vibrational emission bands which are centered at 9.3,9.6,10.3 and 10.6µm

  11. In contrast to most other laser wavelength scattering is negligible in dental enamel at mid IR wavelengths 3-12µm. • so the energy deposition is determined by (a) the absorption coefficient and (b) tissue reflectance. • absorption coefficient of enamel at 9.6µm is 8.000 cm and for 10.6µm is 800 cm.

  12. caries inhibition by CO2 is affected by wavelength ,pulse duration ,pulse number, repetition rate ,pulse energy and spot size.

  13. The caries preventing effect of Argon lasers. • The caries preventing effect of Nd:YAG laser. • The caries preventing effect of Er:YAG,Er,Cr:YSGG,Ho:YAGan

More Related