Week 4 Tulio- Implant Physiology

Question 1

How does smoking impair healing?

Answer 1

• Reduced O2
• Angiogenesis is affected (blood vessels reduced)
• Deprivation of nutrients

Question 2

Are implants completely covered by bone?

Answer 2

No, only maximum 65% by bone. Rest is covered by fibrous tissue

Question 3

How can you measure quality of bone?

Answer 3

• CBCT
• When you drill can tell how soft/hard it is by how much resistance there is (D1-D4 classification)

Question 4

How does quality of bone impact implant abutment placement?

Answer 4

• When bone quality is high you can place abutment after 1 week
• If when you drill, bone is soft wait a few months for bone remodeling until placing abutment

Question 5

What is required distance between implant and neighbouring tooth?

Answer 5

At least 1.5mm- otherwise no vasculature

Question 6

Should there be mobility in implant? What is it likely to be if mobile?

Answer 6

No- should not be any micromovements (essentially ankylosed). Could be loose crown component or failed implant

Question 7

Describe importance of crown length to implant ratio?

Answer 7

• Excessive crown length to implant ratio reduces resistance to occlusal forces
• Don’t use 6mm implant to replace 20mm crown

Question 8

What are the 3 different connectors for implants?

Answer 8

• External hexagon
• Morse taper
• Internal hexagon

Question 9

How does thickness of mucosa impact implant placement?

Answer 9

• Thicker mucosa (4mm)- can place implant at level of bone (crestal placement)
• Less mucosa- need to place implant deeper

Question 9

How long does it take for complete bone healing?

Answer 9

+6months

Question 10

Why avoid class I cantilevers?

Answer 10

Too much force on implant. Avoid distal cantilevers (esp molar area)

Question 11

What is osteoinduction vs osteoconduction?

Answer 11

• Osteoinduction: undifferentiated cells are stimulated to develop into bone forming cell lineage
• Osteoconductive surface: permits bone growth on surface

Question 12

What is intramembranous ossification and endochondral ossification?

Answer 12

• Intramembranous ossification: direct conversion of mesenchymal tissue into bone (bones of skull)
• Endochondral ossification: mesenchymal cells differentiate into cartilage and is later replaced by bone

Question 13

What happens when you insert implant?

Answer 13

• Implant inserted
• Release of inflammatory cytokines
• Clot forms which is filled with fribrin
• Fibrin forms network to allow migration of cells toward implant surface (different implant materials react differently)
• Undifferentiated cells become osteoblast like cells and form first layer of highly mineralised cement and then bone on implant surface

Question 14

What do we use as material for implant screw?

Answer 14

Titanium alloy (not pure titanium)

Question 15

What systemic factors can affect healing process of implants?

Answer 15

• Diabetes
• Smoking

Question 16

What happens if fibrin clot is not in contact with surface of implant?

Answer 16

Bone won’t be formed on surface of implant- instead there will be fibro-osseointegration.

Question 17

What do bone cells come from?

Answer 17

Mesenchymal stromal cells

Question 18

What is immediate loading?

Answer 18

Placing abutment on the same day-1 week after implant placement

Question 19

Where is poorest bone quality?

Answer 19

Near maxillary tuberosity

Question 20

What is the purpose of surgical stent?

Answer 20

Used to position dental implants to ensure that the implant is placed in the most ideal location, angulation and depth into the bone

Question 21

What are the components of implant?

Answer 21

• Crown
• Abutment
• Screw
• Fixture/implant

Question 22

Why is detailed records of implant and prosthetic components?

Answer 22

So you know exactly the brand and type of implant components are used so the tools used are compatible if patient comes back

Question 23

Why does thickness of mucosa impact implant placement?

Answer 23

Need to make sure biological width isn’t encroached. There will be bone loss otherwise

Question 23

Why does thickness of mucosa impact implant placement?

Answer 23

Need to make sure biological width isn’t encroached. There will be bone loss otherwise

Question 24

What can you do if patient has relatively stable bone but not stable enough for immediate laoding?

Answer 24

Can place healing abutment to allow soft tissue to remodel around this. Won’t need to incise soft tissue later on and can just screw crown abutment on one osteointegration is achieved