PA EFDA Board Final Exam 2025 Graded A+
Comprehensive Prep Guide with the Latest Questions!
Bases/Liners - Protect pulp or to aid in its recovery
Chemical Irritation - Pulpal irritant including chemicals that can seep through the dentinal tubules
and contact the pulp
Thermal Conduction - Measure of the amount of heat a substance can transfer
... - -Enamel + dentin = poor conductors of heat = natural thermal protectors of pulp
- Amalgam = good conductor of heat and cold = irritating to the pulp
- Composite = poor conductor of heat and cold= does not pose a problem with thermal irritation
Dimensional Changes - - When foods and liquids are placed in the mouth, the tooth structure and
restorative materials are subject to change
- Temperature changes bring expansion and contraction of materials
- The degree of expansion and contraction is different for amalgams, composities, dentin and enamel
Percolation (movement of the fluid) - A microscopic opening may occur between the tooth and
restorative material during expansion and contraction which allows oral fluids to enter at the
restoration/tooth structure margin. It creates the potential for bacterial invasion or leakage of fluids
into the dentin and pulp resulting in irritation
Lack of Marginal Seal - - The lack of adhesion of a restoration to the tooth structure allows further
invasion of oral fluids
- Note: Secondary caries associated with poor marginal seal accounts for the majority of failed
restorations
... - Bases and liners may be used as sealers, reinforcers, insulators, obtundents, and pulp stimulators
Sealers - -Function to seal off the cavity prep
-Used in very thin layers
-Also known as liners
, Function of Sealers - -Seal off the opening of cut dentinal tubules and prevent chemical irritants from
reaching the pulp
-May prevent mercury from amalgam restorations from entering the tubules and discoloring the
tooth
-Seal off microscopic space between the tooth surface and restoration
-CANNOT provide thermal insulation because they are too thin
Type of Sealer (Cavity Varnish) - -Composed of natural or synthetic resins
-Were placed under all amalgams but not as commonly used now
-Should NOT be used under resins since the solvent in the varnish may react and soften the resin and
the monomer of the resin may dissolve the varnish
-Varnish is soluble in the oral cavity and will dissolve in time near the cavosurface
Type of Sealers (resin cements) - -More recent addition
-Low solubility
-Used as liners in preps more commonly than varnishes
-Does not bond as well to deep dentin
-They can cause an inflammatory response from pulpal tissues
-NOT used as direct pulp capping agents
Reinforcers - -Bases used to protect the pulp from the pressures exerted on it during amalgam
placement (condensing)
-Can be a insulator and a reinforcer at the same time
Types of Reinforcers - -Can be any material that is placed in a relatively thick layer between the
restorative material and the dentin and may be referred to as a base regardless of its purpose
-Insulators are reinforcers
-Stimulators (calcium hydroxide) do not have the strength to be reinforcers, therefore they are liners
Insulators - -Referred to as bases (cements used in thick layers)
-Insultate the pulp from thermal irritation
-The material used must be a poor thermal conductor
Comprehensive Prep Guide with the Latest Questions!
Bases/Liners - Protect pulp or to aid in its recovery
Chemical Irritation - Pulpal irritant including chemicals that can seep through the dentinal tubules
and contact the pulp
Thermal Conduction - Measure of the amount of heat a substance can transfer
... - -Enamel + dentin = poor conductors of heat = natural thermal protectors of pulp
- Amalgam = good conductor of heat and cold = irritating to the pulp
- Composite = poor conductor of heat and cold= does not pose a problem with thermal irritation
Dimensional Changes - - When foods and liquids are placed in the mouth, the tooth structure and
restorative materials are subject to change
- Temperature changes bring expansion and contraction of materials
- The degree of expansion and contraction is different for amalgams, composities, dentin and enamel
Percolation (movement of the fluid) - A microscopic opening may occur between the tooth and
restorative material during expansion and contraction which allows oral fluids to enter at the
restoration/tooth structure margin. It creates the potential for bacterial invasion or leakage of fluids
into the dentin and pulp resulting in irritation
Lack of Marginal Seal - - The lack of adhesion of a restoration to the tooth structure allows further
invasion of oral fluids
- Note: Secondary caries associated with poor marginal seal accounts for the majority of failed
restorations
... - Bases and liners may be used as sealers, reinforcers, insulators, obtundents, and pulp stimulators
Sealers - -Function to seal off the cavity prep
-Used in very thin layers
-Also known as liners
, Function of Sealers - -Seal off the opening of cut dentinal tubules and prevent chemical irritants from
reaching the pulp
-May prevent mercury from amalgam restorations from entering the tubules and discoloring the
tooth
-Seal off microscopic space between the tooth surface and restoration
-CANNOT provide thermal insulation because they are too thin
Type of Sealer (Cavity Varnish) - -Composed of natural or synthetic resins
-Were placed under all amalgams but not as commonly used now
-Should NOT be used under resins since the solvent in the varnish may react and soften the resin and
the monomer of the resin may dissolve the varnish
-Varnish is soluble in the oral cavity and will dissolve in time near the cavosurface
Type of Sealers (resin cements) - -More recent addition
-Low solubility
-Used as liners in preps more commonly than varnishes
-Does not bond as well to deep dentin
-They can cause an inflammatory response from pulpal tissues
-NOT used as direct pulp capping agents
Reinforcers - -Bases used to protect the pulp from the pressures exerted on it during amalgam
placement (condensing)
-Can be a insulator and a reinforcer at the same time
Types of Reinforcers - -Can be any material that is placed in a relatively thick layer between the
restorative material and the dentin and may be referred to as a base regardless of its purpose
-Insulators are reinforcers
-Stimulators (calcium hydroxide) do not have the strength to be reinforcers, therefore they are liners
Insulators - -Referred to as bases (cements used in thick layers)
-Insultate the pulp from thermal irritation
-The material used must be a poor thermal conductor
