Chapter 37

1. Dental Cements, Bases, Liners, and
Bonding Agents
Chapter 37

2. Introduction
• Materials generally divided and categorized
according to functions
• ADA and FDA regulate dental materials

3. Introduction
• ADA Council on Dental Materials,
Instruments, and Equipment
– Responsible for information and testing of
dental materials

4. Role of the Dental Assistant
• Depends on expanded functions of individual
state practice acts
• Generally, assistant prepares and mixes
materials
• Some states allow assistant to place
materials in oral cavity

5. Properties of Dental Materials
• Acidity
• Adhesion
• Biting forces
– Tensile
– Compressive
– Shearing FF
FF
F
F
Tensile Compressive Shear
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6. Properties of Dental Materials
• Corrosion
• Dimensional
• Elasticity
• Flow
• Galvanism
• Hardness
Courtesy of Dr. Gary Shellerud

7. Properties of Dental Materials
• Microleakage
• Retention
• Bonding
• Solubility Enamel
Dentin
Salivary fluids
Amalga
m
restorat
ion
Saliva
ry
fluids
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8. Properties of Dental Materials
• Thermal properties
– Conductivity
– Expansion
• Viscosity
• Wettability

9. • What term describes the ability of a
material to flow?
– Viscosity; the thicker the material, the less it
flows

10. Types of Restorative Dental
Materials
• Liners, bases, cements, and bonding agents
• Amalgam, composite, and glass isomers

11. Dental Cements
• Variety of forms:
– Powder/liquid
– Two-paste system
– Capsule
– Dispensing syringe
• Self-curing
• Light-cured

12. Terms Used in Conjunction
with Dental Materials
• Luting
• Liner
• Base
• Sedative or palliative effect
• Varnish

13. Dental Cements
• Zinc phosphate
– Permanent cementation and insulating base
– Composition
– Properties
– Manipulation considerations

14. Zinc Phosphate Luting
Consistency
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15. Zinc Phosphate Base
Consistency
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16. Dental Cements
• Zinc oxide eugenol (ZOE)
– Temporary cementation and restoration,
low-strength base, periodontal dressing,
and root canal sealer
– Composition
– Properties
– Manipulation considerations

17. ZOE Luting Consistency
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18. Dental Cements
• Reinforced zinc oxide eugenol
– Permanent cementation, insulating base,
and temporary restoration
– Composition
– Properties
– Manipulation considerations

19. Dental Cements
• Polycarboxylate cement
– Permanent cementation and insulating base
– Composition
– Properties
– Manipulation considerations

20. Cobwebs from Mixing Too
Long
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21. Dental Cements
• Glass ionomer
– Permanent cementation, high-strength
base, and low-strength liner; root canal
sealer, restorative material, and core
buildup material
– Composition
– Properties
– Manipulation considerations

22. Glass Ionomer
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23. Dental Cements
• Resin-modified glass ionomer
– Sensitive to light
– Stronger
– More water soluble
– More adhesive
– Releases fluoride
– Comes in many forms

24. Dental Cements
• Calcium hydroxide
– Low-strength liner
– Composition
– Properties
– Manipulation considerations

25. Dental Cements
• Varnish
– Thin liner
– Composition
– Properties
– Manipulation considerations

26. Dental Cements
• Resin cement
– Permanent cementation
– Composition
– Properties
– Manipulation considerations

27. Dental Cements
• Compomer
– Cements all types of dental restorations
– Composition
– Properties
– Manipulation considerations

28. Dental Cements
• Etchants
– Enhance retention/bonding qualities
between tooth surface and dental materials
– Used before bonding agents, restorative
materials, dental cements, and sealants
– Used on enamel and dentin surface

29. Bonding Agents
• Also known as adhesives and bonding resins
• Improve retention between tooth structure
and restoration
– Enamel bonding
– Dentin bonding

30. • Which is more challenging: dentin or
enamel bonding?
– Dentin, due to higher water content, more
organic than inorganic, proximity to pulp, and
smear layer

31. Restorative Dentistry
• Classification
• Cavity detection
• Caries detection
• Cavity cleaners/disinfectants
• Desensitizers
• Cavity preparation identification

32. Restorative Dentistry
• Elements of cavity preparations
– Outline form
– Resistance form
– Retention form
– Convenience form
– Finishing or refinement
– Cleansing or debridement

33. Restorative Dentistry
M
B
D
L
Pulpal floor or wall
1
6
2
8
4
7
3
5
1. Mesiobuccal line angle
2. Mesiolingual line angle
3. Distobuccal line angle
4. Distolingual line angle
5. Buccopulpal line angle
6. Mesiopulpal line angle
7. Distopulpal line angle
8. Linguopulpal line angle
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34. Advanced Chairside
Functions
• Placing cements, bases, and liners
• Cavity preparation/pulpal involvement
– Depends on amount of decay and types of
materials used to restore tooth
• Treatment of cavity preparations
– Varies with amount of enamel and dentin
removed and how near prep is to pulp

35. Advanced Chairside
Functions
• Treatment of cavity preparation
– Ideal
• Minimal dentin and enamel removed
– Beyond ideal
• Dentin restored with base

36. Treatment of Cavity
Preparations
• Near-exposure
– Restoration occurs close to pulp
• Exposed pulp
– Concerned about vitality of tooth

37. Cavity Liners
• Placed in deepest portion of cavity
preparation
• Placed on axial or pulpal walls
• Form cement layers with minimum strength
• Protect pulp from chemical irritants
• Provide therapeutic affect to tooth

38. Cavity Varnish
• Used to seal dentin tubules
– Prevents acids, saliva, and debris from
reaching pulp
• Used under amalgam restorations
– Prevents microleakage

39. Cavity Varnish
• Used under zinc phosphate
– Prevents penetration of acids to pulp
• Placed after or on top of cavity liners or
medicated bases

40. Cement Bases
• Thick putty placed under cavity preparation
– Protects pulp and provides mechanical
support for restoration
• Placed on floor of cavity
– Raises floor level to ideal height