1. DHYG 113 Restorative Dentistry I
Adhesive Materials
DHYG 113
Restorative Dentistry I

2. Objectives
Describe the difference between micromechanical and macromechanical bonding
Discuss the benefits of bonded restorations
Compare the differences of enamel and dentin in regards to etching and bonding
Discuss the terms: ortho-phosphoric acid, enamel tags, smear layer, primer and adhesive
Summarize the differences between glass ionomer cements and dentinal bonding

3. Why use adhesives?
Strong adhesion increases retention of appliance or restoration
Eliminates need to remove tooth structure (undercuts) for mechanical retention
Seals margins, reducing chance of recurrent decay

4. Adhesion or Bonding
Joining together of two objects using a glue or cement
Micromechanical bonding – Superglue
Surface irregularities too small to be seen
Macromechanical bonding
Larger scale – wood glue

5. Acid Etch and Composites
Materials developed in the 50’s, ’60’s, ’70’s and 80’s
Bonded ortho brackets
Bonded bridges (Maryland bridge)
Porcelain, plastic & composite veneers – etched & bonded to facial surfaces
Composite materials used to reshape teeth
Periodontal splints, stabilize jaw fractures

6. Uses in Dentistry Retention of restorations Reduction of microleakage
Undercuts not necessary
Bond weak restoration to stronger tooth
Reduction of microleakage
Reduce postoperative sensitivity
Reduction of recurrent decay
Sealed margins more resistant to decay

7. Uses in Dentistry

8. Bond Porcelain Veneers
Before After

9. Attach Ortho Brackets

10. Surface Factors Cleanliness Biofilms – contaminated by oral fluids
Don’t want adhesive to bond to surface debris – poor bonding
Should be chemically compatible or adhesive will not “wet” adequately
Biofilms – contaminated by oral fluids
Enamel pellicle
Reduces or prevents bonding
Use rubber dam to keep surface dry

11. Testing Adhesion Adhesive Failure – comes cleanly off tooth
Orthodontic bracket may have been contaminated
Cohesive Failure – bonding material fails
Cement layer remains on both tooth & bracket

12. Acid Etching Etch is usually 37% ortho-phosphoric acid 15-30 seconds
Creates microscopically rough enamel surface
Micropores
Enamel tags
More effective to bond polymer resin to ends of enamel rods than to long axis of rods
Properly etched enamel appears ‘frosty’

13. Resin Systems
Resins “wet” the etched surface and flow into the microscopic irregularities
Enamel bonding resin – adhesive
Set by polymerization
Next step is to place the composite material – chemically bonds to the resin

14. Dentinal Bonding Micromechanical bonding and secondary atomic bonds
Bond to enamel and dentin to prevent leakage and recurrent decay
Etching removes dentin “smear layer” and decalcifies layer of dentin
Dentin is rinsed, but not thoroughly dried

15. One Step Dentin Bonding
Etch/prime and adhesive in one bottle

16. 2-Step Dentinal Bonding
Optibond solo
Prime and bond
Primer and Adhesive combined
May take longer than 3-step systems

17. 3-Step Dentin Bonding Etch Apply primer – wetting agent
Apply adhesive – low viscosity resin
Place the composite
Deep cavities – may use protective material to protect pulp from irritation

18. Polycarboxylate Cement
Chemically adhesive – ionic bonds between negative charge in cement and positive charge in tooth
Zinc oxide powder + polyacrylic acid dissolved in water = Polycarboxylate cement

19. Glass Ionomer Cements
Dentin surface “conditioned” with polyacrylic acid solution to remove smear layer and result in better bonding
No separate adhesive is used – chemically adhesive
Glass ionomers are the materials of choice for high caries risk & both dentin and enamel margins – fluoride-releasing

20. Glass Ionomer Material
Fuji Triage high-fluoride-release, command-set glass ionomer
Suitable as a surface-protection material for a root sensitivity.
Intermediate restorative material for cases of rampant caries. It light cures in 1 minute or can self cure.

21. Desensitization
Gluma desensitizer