1. Dental Liners, Bases, and Bonding Systems
Chapter 44
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2. Introduction
Dental liners, bases, and bonding systems are a supplemental classification of dental materials that provide additional protection for the health and well-being of the tooth being restored.
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3. Prepared Tooth Structures
Design of the Cavity Preparation
Gives strength within the tooth
Helps determine how the tooth will hold the restoration in place
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4. Pulpal Responses Types of Stimulus Examples of Stimulus
Physical Thermal, electrical
Mechanical Handpiece, traumatic occlusion
Chemical Acid from dental materials
Biologic Bacteria from saliva
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5. Dental Liners
Dental liners provide a thin barrier to protect the pulpal tissue from irritation caused by physical, mechanical, chemical and biologic elements.
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6. Calcium Hydroxide Indications for Use
Protects the pulp from chemical irritation by its sealing ability.
Stimulates the production of reparative or secondary dentin.
Compatible with all types of restorative materials.
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7. Calcium Hydroxide-cont’d
Application Process
May be an advanced function in your state
Placed directly over the deepest portion of the preparation
Placed only on dentin
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8. Fig. 44-1 Location for placement of calcium hydroxide
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9. Varnish
A liquid consisting of one or more resins in an organic solvent applied to the internal preparation structure.
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10. Varnishes Indications for Use* Seal dentinal tubules
Reduce leakage around a restoration
Act as a barrier to protect the tooth from highly acidic cements such as zinc phosphate
* This material is contraindicated in its use under composite resins and glass ionomer restorations
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11. Varnishes-cont’d Application Process
Applied with either a small disposable applicator or cotton pellet
Thin coating of varnish placed on the internal walls, floor, and margin of a cavity preparation
Allowed to air dry
A second application is recommended
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12. Fig. 44-3 Location for placement of cavity varnish
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13. Dentin Sealer Indications for Use Treat or prevent hypersensitivity
Used instead of a varnish
Seal the dentinal tubules
Ideal for use under all indirect restorations
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14. Dentin Sealer-cont’d Application Process Use material sparingly
Do not allow to contact soft tissues (HEMA and glutaraldehyde)
Apply the dentin sealer with the cotton-tipped applicator
Apply over all areas of exposed dentin
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15. Dental Bases
Dental bases provide different types of pulpal protection:
Protective Base: Protects the pulp from a large restoration.
Insulating Base: Protects the tooth from thermal shock.
Sedative Base: Soothes a pulp that has been damaged by decay or irritated by mechanical means.
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16. Types of Base Materials
Zinc Oxide Eugenol (ZOE)
Zinc Phosphate
Polycarboxylate
Glass Ionomer
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17. Fig. 44-5 Location for placement of a base
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18. Dental Bonding
Dental bonding improves retention by creating a micromechanical retention between the tooth structure and the restoration.
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19. Enamel Bonding
Enamel bonding is placed directly on the intact enamel surface.
Examples of Enamel Bonding
Sealants
Bonded orthodontic brackets
Resin‑bonded bridges
Bonded veneers
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20. Dentin Bonding
Dentin bonding is placed on the prepared dentin for the bonding of a restorative material to tooth structure.
Smear Layer
Thin layer of debris
“Nature's bandage”
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21. Etching Systems
Etching Systems remove the smear layer in preparation for bonding.
Supplied as:
Liquid/Gel
Maleic acid
Phosphoric acid
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22. Clinical Application of the Etchant and Bonding Systems
Plaque or debris is removed before the bonding process.
Etchant is applied to remove the smear layer.
Rinsing and Drying of tooth structure (avoid overdrying etched teeth).
Bonding solution covers all surfaces.
Too much bonding is better than too little.
Contamination with saliva requires the entire procedure to be redone.  
Allow time for bonding material to mature before completing the restoration.      
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23. Table 44-1 Supplementary Dental Materials and Application in Order of Use
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