Dental Materials and Tissue Engineering Flashcards
What is the goal of a restoration (4 things)?
- esthetics
- restore function
- biologic function
- mechanical function
T/F: Current dental materials are largely biologically inert.
True
What is the goal of tissue engineering?
Recreate natural tissues
Stimulate body to regrow tissues
T/F: Natural tissue is always superior.
True
Name three common BIOactive dental materials.
Glass Ionomers
ZOE
Ca(OH)2
T/F: The pH of GI liquid is 1.0.
True
T/F: GI liquid is 50% polyacid copolymer and 50% aqueous solution.
True
ZnO is the _____ component and Eugenol is the _____ component .
zinc oxide POWDER eugenol LIQUID (oil)
T/F: Reinforced ZOE shrinks when set.
False, it EXPANDS in order to seal
T/F: ZOE cannot be used under composite.
True!
T/F: ZOE enhances polymerization.
FALSE FALSE FALSE
An indirect pulp cap with _____ helps to initiate reparative dentin.
Calcium Hydroxide
How long does it take to form reparative dentin?
15 days- cells differentiate
30 days- microscopic reparative dentin
100 days- radiographic reparative dentin
In order to heal or regenerate tissues, ____ must be suppressed, the _____ must be regulated, and specific cells must be recruited.
inflammation suppressed
immune response regulated
What are the three methods of tissue engineering?
- Cellular based (genetic manipulation, growth factors)
- Scaffold based (cells, growth factors)
- Distraction Osteogenesis
T/F: Injection of cells and growth factors at a site that needs regeneration will cause cells to regrow tissue.
True, this is cellular Tissue Engineering
What is the problem with cellular TE?
- cells can die quickly
- produce tumors
- source issues
T/F: Cellular engineering can induce tumor formation.
True
____ ____ can be totipotent, pluripotent, multipotent, poligopotent, and unipotent.
Stem Cells
T/F: A fertilized egg is a stem cell.
FALSE, they cannot continuously replicate
_______ stem cells can differentiate into any cell type
Pluripotent
Pluripotent stem cells are derived from ____
embryos or embryonic tumors.
Pluripotent stem cells can replicate and self-renew or they can form _____
neurons
T/F: Embryonic stem cells show quick growth in culture.
False, slowwwww
T/F: Stem cells have surface markers.
True
T/F: Adult or Multipotent stem cells can only differentiate into a specific subset of cells.
True
T/F: Multipotent stem cells are slow.
True
T/F: Multipotent stem cells are easy to obtain.
True
T/F: Multipotent stem cells produce soft tissues only.
False, most hard or soft tissues
Induced stems cells are a new practice which employs adult stem cells and changes them to ____.
pluripotent stem cells
(babies Pee a lot…embryo = P (pluripotent))
(Men = M (multipotent))
What does SHED stand for?
Stem-cells from
Human
Exfoliated
Deciduous teeth
What does SCAP stand for?
Stem
Cells from
Apical
Papilla
Dental Pulp Stem Cells (DPSC) are _______ stem cells from dental pulp of permanent teeth.
mesenchymal
How are lasers being used to regenerate dentin?
- laser generated ROS
- ROS will stimulate TGF-beta1
- TGF activation will stimulate production of tertiary dentin
T/F: Scaffolds promote the body’s ability to heal and regenerate.
True
T/F: The problem with natural scaffolds is the batch-to-batch variation.
True
What is an autograft?
tissue is removed from one site and placed at another within the same host
What is an allograft?
Harvested tissues (usually cadavers) -can be bone, skin, connective tissue
T/F: Cornea allografts can be acquired from a cadaver.
True
What is a xenograft?
tissue obtained from a different species
T/F: Xenografts are the most plentiful natural supply source
True
Synthetic scaffolds can be either ____, ____, or ____.
polymer, ceramic, or metal
T/F: It is difficult to achieve a biocompatible scaffold.
True
What are alloplasts?
synthetic scaffolds
What is the most common tissue engineering done clinically?
periodontal (guided tissue regen)
What makes a good TE scaffold?
- biogradable
- nontoxic
- promotes regeneration
- can modulate properties
T/F: The advantage of polymers is that they can be easily processed.
True
T/F: At the micro level, TE polymers should have no porosity.
FALSE, porosity allows for diffusion of nutrients and cells for growth
Pore Sizes:
Fibroblast ingrowth _____
Skin _____
Bone _____
fibroblast = 20 microns skin = 20-125 microns bone = 100-250 microns
When using salt leaching, salt is added to PLA (polyLactic acid) solution, solvent is evaporated, salt is extracted with water, and eventually pore interconnect. What % porosity is needed for interconnection to occur?
70%
T/F: Most amino acids are optically active.
True
T/F: Amino acids have functional groups and sites for drug delivery.
True
T/F: Amino acids regulate cell/biological functions
True
_____ is a peptide sequence to promote cell adhesion.
RGD
T/F: Both RGD and RDG have the same adhesion effects.
False,
R-G-D = adhesion (ReallyGooD)
R-D-G = no adhesion (Really Don’t Go)
T/F: The degradation timing of PLGA does not matter.
False, scaffold must disappear as the tissue is regrowing
T/F: Degradation of PLGA is controlled via the ratio of lactic acid and glycolic acid.
True,
P…L (lactic)…G (glycolic)…A (acid)
T/F: Degradation of PLGA is controlled by water diffusion.
True
T/F: Anything that affects water diffusion will affect the degradation rate of PLGA.
True
Which two properties of scaffolds are most important?
- bioactivity
- degradation