Regeneration and Repair 1

Question 1

regeneration

Answer 1

complete restoration of tissue architecture and function (good as new)

Question 2

repair

Answer 2

restoration of function but altered architecture (scars)

Question 3

Wound Healing phases

Answer 3

1- hemostasis (clot formation)
2- inflammatory- infiltration of immune cells/initiation of repair
3- reparative phase (proliferative)- migration of cells/ formation of granulation tissue
4- wound contraction and scarring (not always)

Question 4

Hemostastis

Answer 4

first stage, primary goal to stop bleeding, secondary initiate healing
transition of blood from liquid to fibrillar gel
platelet disruption leads to coagulation cascade
clot unites edges of wound, and fibrin provides a scaffold for futre cell migration and repai
clot in oral cavity softer and easier to displace

Question 5

primary hemostasis

Answer 5

platelet plug
vascular spasm (constriction) leads to initial platelet plug
Initiated by exposure of collagen to circulating von Willebrand factor, causes platelet aggregation
platelets also bid directly to collagen
fibrinogen anchors platelets together

Question 6

secondary hemostasis

Answer 6

blood coagulation
extrinsic (tissue factor) and intrinsic (contact activation, damaged endothelium) pathways
both convert prothrombin to thrombin which turns fibrinogen into insoluable fibrin (requires calcium)
fibrin cross links and forms mesh, trapping red and white cells= clot

Question 7

secondary hemostasis

Answer 7

blood coagulation
extrinsic (tissue factor) and intrinsic (contact activation, damaged endothelium) pathways
both convert prothrombin to thrombin which turns fibrinogen into insoluable fibrin (requires calcium)
fibrin cross links and forms mesh, trapping red and white cells= clot

Question 8

inflammation

Answer 8

tissue injury and plasma protein leakage attract macrophage and lymphocyte (t cell)
resident cells. cells from vessel and diapedesed cells

Question 9

neutrophils

Answer 9

first to arrive
activated by antibody antigen, lps, complement
bacterial and tissue destruction

Question 10

macrophage

Answer 10

secon to arrive, clear damaged tissue and foriegn material

Question 11

reparative/proliferative phase

Answer 11

mobilization of adjacent cells to clot to form granulation tisue
epthelial cell migration: forms new basal lamina, redistributes integrin receptors, new hemidesmosomes
fibroblast recruitment ovvers from mesenchymal progenitor cells
collagen begins to fill defect
endothelial cell proliferation and angiogenisis

Question 12

wound contraction

Answer 12

myofibroblasts with increased actin and myosin
draw wound edges together
initial collagen deposition: immobile scar tissue, can be remodled

Question 13

wound contraction

Answer 13

myofibroblasts with increased actin and myosin
draw wound edges together
initial collagen deposition: immobile scar tissue, can be remodled

Question 14

periodontal disease

Answer 14

bacteria induced imflammation causes destruction of CT
apical migration of JE
if source of inflammation is removed it may be the formation of a fibrin clot that stimulates reattachment
gingivitis will repair once infection is removed
periodontitis wont repair

Question 15

periodontal repair

Answer 15

same as skin
immediate remodling of collagen by ligament fibroblast=no scar
root planing and guided tissue regeration: membrane to prevent epithelial invasion
add growth factors to encourage ligament reattachment

Question 16

dental caries

Answer 16

outside = surface and body: surface remineralizes, body is primary zone of demineralization
dark zone= zone of increasing demineralization
translucent zone= leading edge, caused by micro pores which form enamel rod boundaries

Question 17

dentin bridge

Answer 17

dentin formed between surviving dentin and restorative material preventing microleakage

Question 18

tissue engineering

Answer 18

seeks to encourge the restoration of function and structure to a pre-injurt state
3 key components
cell source, material, bioactive componenet

Question 19

bioactive materias

Answer 19

materials designed to drive repair/regeneration through use of bioactive factors

Question 20

cellular tissue engineering

Answer 20

add cells

Question 21

acellular engineeing

Answer 21

add materials to existing cells