biocompatibility and intermediate restorative materials Flashcards
does the material affect the environment or does the environment affect the material
both
the material must be of benefit to the patient and the patient must be_____
safe from any adverse reactions
where can the biological reaction take place
either at a local level (injection site) or far removed from the site of contact (systemically)
systemically may not always be ____
readily apparent
what are cases where systemically the reaction is not readily apparent
dermatological, immune mediated or neural reactions
what is the most common reaction to dental staff
hand/facial dermatitis or respiratory symptoms
what are the possible interactions between dental restorative material and the biological environment
-postoperative sensitivity
-toxicity
- corrosion
-hypersensitivity/allergy
what is the concern about toxicity
nanomaterials. growing concern about their biosecurity and crossing the blood brain barrier and going into the CNS
what can amalgam cause
type 4 allergic reaction 24-48 hours after exposure on the oral mucosa
what are the most common allergies
metals- specifically nickel and cobalt
what did denture resins show in study
mucosal changes, contact stomatitis and burning sensations in the mouth
what can direct contact of mercury with the oral mucosa cause
oral lichenoid lesions (OLL)
what is OLL
chronic inflammatory lesion on the oral mucosa
what can amalgam tattoo cause
mucosal melanoma which is rare but highly aggressive neoplasm
what is nickel’s incidence of allergic reaction
-one of the most common causes of allergic contact dermatitis
-produces more allergic reactions than all other metals combined
where is nickel seen in dentistry
-several brands of orthodontic wires are made with nickel titanium alloy
-non-precious metal crowns contain high levels of nickel- some as high as 55%
where is titanium found
implants
who is responsible for the materials to which a patient will be exposed
dental practitioners
what is sargenti paste for root canals made with
paraformaldehyde
what can paraformaldehyde cause and where does it travel in the body
irreversible damage to connective tissue, bones nerves, chronic infection and pain
- material can travel throughout the body through blood, lymph nodes, adrenal glands, kidney and brain
what material has a positive effect on the pulp and what does it do
calcium hydroxide- stimulates tertiary dentin formation
what are intermediate restorative materials
materials that are applied to the dentin prior to the placement of the final restoration since a restoration may have an adverse effect on the pulp
what do intermediate restorative materials include
cavity varnishes, bases and liners that stay in place permanently
are intermediate restorative materials and temporary restorative materials the same
no
what is the role of intermediate restorative materials
-protective
-palliative
-or therapeutic
what is the goal of intermediate restorative materials
protect the pulp from chemical, electrical, thermal
what does zinc oxide eugenol do
sedative like qualities on hypersensitive pulp and is a good thermal insulator as well
what are the benefits of intermediate restorative material
-thermal insulator
- excellent abrasion resistance
- good sealing properties
- low solubility
- may be used under cements and restorative materials that do not contain resin components such as amalgams, inlays, onlays
should intermediate restorative materials discolor the tooth
no
intermediate restorative materials should harden____
quick enough to allow subsequent insertion of the restoration
intermediate restorative materials should withstand ______
the condensation of the over laying restoration
intermediate restorative materials should be easily _____
manipulated
what are liners and bases
materials placed between dentin and sometimes pulp and the restoration to provide pulpal protection or pulpal response
what do protective needs for a restoration vary depending on
the extent and location of the preparation and the restorative material to be used
the characterisics of the liner or base selected are determined largely by what
the purpose it is expected to serve
because liners and bases share similar properties/objectives, they are not always____
fully distinguishable in all cases but generalizations can be made
what are bases
thick mix of material which is placed in bulk. used as a dentin replacement to minimize final restorative mateiral
what are bases used for
to block out undercuts
when are liners applied
as a thin coating over exposed dentin
how thick are liners and what do they promote
0.5mm thick and promote the health of the pulp by adhesion or antibacterial action
what are liners used for
protect the pup
what do liners form a strong bond with
dentin to prevent fluid movement down the dentinal tubules
what do liners release
fluoride
what is vitrebond
a liner/base
- light cure resin modified glass ionomer
when can vitrebond be used
under composite, amalgam, metal and ceramic restorations
when is vitrebond not indicated
for direct pulp capping
when is vitrebond used as a base
if you are placing it in greater than 0.5 mm
how much is vitrebond placed
in 0.5 mm increments up to 2 mm
is vitrebond used more as a base or liner
a liner
what is calcium hydroxide and what is its pH
a liner with a pH of 11-12.5
what is the bactericidal activity of calcium hydroxide
retains its anti bacterial properties for about 2 months
what is calcium hydroxide used for
direct and indirect pulp capping
what does calcium hydroxide promote
formation of tertiary dentin
what is Dycal and how is it cured
calcium hydroxide liner
- can be self curing or light cured
what are varnishes
a natural gum (copal), rosin or synthetic resin dissolved in organic solvent
what do varnishes do
has some antimicrobial and antiviral properties
- easily seeps into open dental tubules
-prevents transfer of heat and cold into the dentin and pulp
what do we use instead of varnishes at UMKC
vitrebond
when are varnishes not to be used and why
-under composite restorations because it interferes with the setting reaction
-under glass ionomers because it interferes with fluoride release
what is copalite and what is it used for
a varnish used as an insultating layer under gold and amalgam restorations
what do you use in a shallow tooth prep
place nothing, vitrebond or varnish
what do you use in a moderate depth prep
liners may be placed for thermal protection and pulpal medication along with varnish
what do you use in a very deep prep
liner may be calcium hydroxide then the base vitrebond or IRM
