Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Presentation1

1,533 views

Published on

Published in: Business, Health & Medicine
  • Be the first to comment

Presentation1

  1. 1. Enamel & Dentin Adhesives
  2. 2. Introduction  Advent of composite resin has shifed us to the age of adhesive dentistry  Adhesives have modified cavity preparation concept from “ extension for prevention” to “restriction with conviction” with the invention of acid etching with 85% phosphoric acid in 1955 by Bunocore.
  3. 3. Adhesion  Refers to micromechanical coupling of restoration to tooth structure  Dental adhesive system consists of a conditioner ,primer and bonding agent
  4. 4. hydrophobic hydrophilic compdentin Dentin bonding agent
  5. 5. Ideal Bonding Agent  Eliminates post-operative sensitivity  Thin film thickness  No marginal discoloration  Ease of use  Reasonable shelf life  Bond strength  Moderate cost (Christenseen 2005)
  6. 6. Generations of Adhesives  8 generations :  1st & 2nd without etching  3rd acid etch,separate primer margin staining  4th hybrid layer, concept of wet bonding  5th primer and adhesive in 1 bottle  6th self –etchprimers,decreased sensitivity,bond strength lower than 5th  7th All in one  8th self-etch self-adhere flowable composite (Optibond [Kerr]
  7. 7. New Classification  Etch and Rinse system  Self –Etch - Two bottles applied separately - Two bottles mixed as one solution - All -in-one
  8. 8. Interaction With Dental Hard Tissues  With Enamel  With Dentin  Quality of dentin bonds thought to be determined by the depth of demineralization and extent of the diffusion and impregnation of the monomer (Tay FR et al 2001)  This zone of exposed collagen may be unstable and subjected to hydrolysis (Sano H et al)
  9. 9. - To avoid this ,self etching systems that donot require smear layer removal these latest adhesives based on simplification and application time (Oper Dent 2003)
  10. 10. Smear layer 0.5-5Um
  11. 11. Self-Etching Scheme
  12. 12. Single bottle two-step total etch (wet bonding technique) -Acid etching to remove smear layer - Application of primed adhesive
  13. 13. Total etch
  14. 14. Mode of Demineralization and Hybridization
  15. 15. Adhesion depends upon  Surface area  High surface energy  Wettability
  16. 16. Nano Interaction Zone  Verse hybrid layer  G Bond a type of the 7th generation
  17. 17. Ion Exchange Layer
  18. 18. • Although the smear layer thickness had no effect on resin-dentin bond strength, thick smear layers adversely affected the mean gap width,The etch-and-rinse adhesive systems showed higher microBS and lower mean gap widths (Kenshima et al 2005) • the one-step, low pH, acetone-based self- etching adhesive promoted the higher bond strength values, which were statistically similar to those obtained with the two-step, water-based self-etching adhesive (Pegado et al 2010)
  19. 19. Glass Ionomer Adhesives  Based on resin-modified GIC  Conditioner polyalkanoic acid hybrid layer 0.5um  The shear bond strength of the glass-ionomer adhesive to dentin proved to be independent of the smear layer thickness (El Askary et al 2008)
  20. 20.  Newer generations of adhesives appear to be more tolerant of saliva contamination (Dunn 2004)  Shear bond str. & numbers of gap-free restorations increased significantly with drying time (Jacobsen et al 2006)  Following a correct application procedure, the etch-and-rinse, self-etch and self- adhesive luting agents are equally effective in bonding to enamel and dentin (Van Merbeek 2007)
  21. 21.  Wettability is similar between self-etching and total-etch adhesives.The smear layer affects slightly the wettability of self-etching adhesives (Rosales et al 2008)  Enamel bonding was generally more effective with phosphoric-acid etching. Enamel bonding performance of 2-step self-etching adhesives was improved when phosphoric acid was applied on enamel selectively (Frankenberger et al 2008)
  22. 22. Bond Strength
  23. 23. Thank You

×