Pulp Protection Part I Flashcards
Define pulp protection therapy
the treatment that maintains pulp tissue in a healthy and functional state, whenever the dentin-pulp complex has been compromised by caries, trauma, or restorative procedures
What are the three different categories of pulp irritants
- microbial
- mechanical
- chemical
Two different diseases caused by microbial irritants that can damage the pulp are
- dental caries
- periodontal disease
Tooth preparation falls under what category of pulp irritants
mechanical (or operative)
The degree of plural reaction to operative procedures is dependent on what two factors
the amount of friction and desiccation
How can tooth preparations lead to plural damage
frictional heat generated by the drill can cause burn lesions in the pulp and access formation
what are the three different operative procedures that can cause pulpal damage
- Tooth preparation
- Orthodontics
- Periodontal curettage (scaling and root planing)
What is one mechanical (not operative!) irritant that can cause plural damage
trauma
What are the objectives of pulp protection therapy
- sealing the dentinal tubules
- Thermal protection
- Mechanical protection
- Chemical protection
- Electrical protection
Ideal pulp protecting agents should be (biologically/chemically) compatible
both
What are the ideal requirements of Pulp protecting Agents
- Biologically/chemically compatible
- Capable of forming a non-permeable layer on cut dentin with thickness, which does not affect the bulk or mechanical properties of a restoration
- The pulp protection material should not discolor either the tooth or restorative material
- The material should attain the hardness quick enough to allow the final restoration completed in adequate time
- It should have low solubility in oral builds
- Should have ease of use and manipulation during mixing and insertion
The best pulp protection is provided by what part of the tooth
the dentin
The remaining dentinal thickness (RDT) determines what
the effect of insult on pulp due to various irritants
The classification of pulp protection is based on what
the extent of the caries
What sorts of pulp protection should be employed for moderate carious lesions
- sealers
- liners
- bases
What sorts of pulp protection should be employed for deep carious lesions
- Direct pulp capping
- Indirect pulp capping
what is the difference between direct and indirect pulp capping
Indirect has less calcium-hydroxide than direct
what are the components of the direct and indirect pulp caps
- Composite filling
- Glassionomer lining
- Calcium-hydroxide
What are cavity sealers
materials that provide a protective coating to the walls of a prepared cavity and a barrier to leakage at the interface of the restorative material and the walls
What are the two types of sealers
tarnishes and adhesive sealers
What is a varnish sealer
a natural rosin or gum (copal) or synthetic resin, dissolved in an organic solvent (acetone, chloroform, or ether)
what is an adhesive sealer
provides sealing as well as bonding at the interface between the restoration and the preped walls
Varnish is composed of a solid and liquid component what are they
- Solid= copal resin
- Liquid= organic solvent (ether, acetone, or chloroform)
What are the indications (or the positives of) for varnish sealer
- Can be applied to every prepped all to prevent post operative sensitivity and discoloration of the tooth
- Apply on the pulpal floor under zinc phosphate cement to prevent acid penetration
What are the contraindications of varnish sealer
- No thermal protection provided
- Can’t be used under GIC as it prevents their adhesiveness to the tooth
- Can’t be used under resin restorations as the residual monomer will dissolve the varnish
- H2O soluble
Examples of adhesive bonding agents are
glass ionomers
resin luting cements
What are the indications of using adhesive sealers
- treat or prevent hypersensitivity
- seal dentinal tubules
- ideal for use under all indirect restorations
What are liners
cement or resin coating of minimal thickness to achieve a physical barrier to bacteria and their by products and/or provide a therapeutic effect such as an antibacterial or pulpal anodyne effect
what are the 4 different types of liners
- Calcium hydroxide
- Zinc oxide eugenol
- glass ionomer (type III)
- Flowable composite
What are the functions of liners
- thereupetic benefits
- fluoride release
- antibacterial action to promote pulpal health
calcium hydroxide is (self/light) curing
both
What are the advantages of calcium hydroxide
- Causes dentin mineralization by activating the enzyme ATPase
- Stimulates reparative dentin formation
- Biocompatibility
- High pH (12.5), neutralizes acidity which in turn is bactericidal
What are the dis advantages of Calcium hydroxide
- low strength
- high solubility
- dissolves rapidly
(T/F) Calcium hydroxide is ONLY placed on dentin
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Where is Ca(OH)2 placed in the prep
over the deepest portion of the prep because it lacks strength
The addition of a glass ionomer to Ca(OH)2 is often necessary why?
because it adds strength to allow the Ca(OH)2 to sustain the restoration
There are 6 different types of glass ionomers- what type is a liner and base
type III
Glass ionomer type III has a powder and liquid component- what are they
- Powder= aluminum silicate glass
- Liquid= polyalkenote acid, light cure resin
What are the advantages of glass ionomers as liners
- adhesive to the tooth
- anticariogenic
- semi translucent color helps in esthetic restorations
- fluoride release
What are the disadvantages of glass ionomers as a liner
- water sorption causes leakage and discoloration
- Low wear or abrasion resistance
The composition of flowable composite is similar to regular composite, except that it
has a lower amount of fillers
Since flowable has a reduced number of fillers, what does this do to alter its physical properties compared to fully filled composites
- more fluid consistency
- less strength
- less stiffens
What are bases
materials to replace missing dentin, used for bulk buildup and/or for blocking out undercuts in indirect preps
The usual thickness for a base is
0.5-1 mm
There are two types of bases low and high strength- list the high strength ones
- Zinc phosphate
- Zinc polycarboxilate
- Glass ionomer (Type III)
- Reinfored zinc oxide
There are two types of bases low and high strength- list the low strength ones
- Calcium hydroxide
- Zinc oxide Eugenol
What are the functions of a base
- chemical insulator
- Thermal insulator at minimum 0.75 thickness
- Provides mechanical support to the restoration by distributing stresses to the underlying dentin
What is the oldest luting cement
zinc phosphate
What are the advantages of Zinc phosphate
- good mechanical properties
- thermal insulator
What are the disadvantages of zinc phosphate
- Doesn’t adhere to the tooth
- Produces an exothermic creation at initial setting, which can damage the pulp
- More opaque in color- not recommended for esthetic restorations
- Dissolves in mouth
- Acidic in nature
There is a powder and liquid component to Reinforced Zinc Oxide Eugenol what are they
- Powder= zinc oxide and natural or synthetic resin
- Liquid= Eugenol, acetic acid, and thymol
what are the properties of Reinforced Zinc Oxide Eugenol
- Better strength than regular zinc oxide cement
- less irritating to pulp
- It has anodyne effect on the pulp
what are the guidelines of the use of bases, liners, and sealers
- Don’t remove sound tooth structure to provide space for bases
- Maintaining the sound dentin will enhance restoration support and provide maximal pulp protection
- Use base material for build up materials and block out materials for cementing indirect restorations
- If bases are used under amalgam or resin then minimize the extent of the base
- Use minimal thickness of liner necessary to achieve desired result
Look at the chart on slide 40
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Look at the videos on slide 41
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