W4 - Implantology Intro - Tulio Flashcards
Osteoinduction vs osteoconduction
- Osteoinduction: undifferentiated cells are stimulated to develop into bone forming cell lineage
- Osteoconductive surface: permits bone growth on surface
2 types of osteogenesis
Intramembranous ossification
Endochondral ossification
Describe intramembranous ossification
direct conversion of mesenchymal tissue into bone (bones of skull)
Describe endochondral ossification
mesenchymal cells differentiate into cartilage and is later replaced by bone
How does smoking affect implant healing (3)
Angiogensis reduced
Reduced nutrients
Reduced O2
Are healed implants completely covered by hard tissues?
Not usually, only 60% covered by bone
40% is covered by fibrous tissue
How can you measure quality of bone for implants?
CBCT
When drilling - is it soft? Resistance?
Describe the 4 different time periods for implant loading
Depends on the quality of bone → if bad, wait longer for bone remodelling
Immediate loading
Same day - 1 week (if good bone)
Early loading
1 week - 2 months
Conventional loading
2-3 months
Immediate restoration
Within 1 week → if tooth not in occlusion
If patient has significant medical history (ex diabetes) but it is well controlled, are implants contraindicated?
No, not contraindicated
BUT modify tx plan → ex. wait longer for healing
Required distance between implant and neighbouring tooth
AT LEAST 1.5 mm
otherwise, no vasculature
Should there be any mobility in implant?
No → no pdl = no micromovements
Essentially ankylosed
Could be loose crown component
or
failed implant
How does amount of bone loss relate to strength of implant
More resorption = more vertical cantilever
- Implant not just replacing tooth, but also soft tissue
- Consider crown length to implant ratio
- Ex. dont use 6mm implant to replace 20mm crown
What are the 3 different implant / abutment connections?
How deep must the implant go? / How does mucosa level determine deepness?
Must go at least 4 mm from the top of the soft tissues
Ex. if thicker mucosa (4mm), can place implant at bone level
Extraction consideration for immediate implant loading
Section the tooth to minimise socket widening / bone loss
Why avoid class 1 cantilevers?
Too much force on implant
What types of prostheses should be avoided with implants
Class 1 Levers
Distal cantilevers (esp molars)
If required, only recommend lateral incisor lever
How does quality of bone impact implant abutment placement?
- 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
How long does it take for complete bone healing
+6 months
What happens when you insert implant?
- 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
What do we use as material for implant screw?
Titanium alloy (not pure titanium)
What systemic factors can affect healing process of implants?
- Diabetes
- Smoking
What happens if fibrin clot is not in contact with surface of implant?
Bone won’t be formed on surface of implant- instead there will be fibro-osseointegration.
What do bone cells come from?
Mesenchymal stromal cells / MSC
What is immediate loading?
Placing abutment on the same day-1 week after implant placement
Where is poorest bone quality?
Near maxillary tuberosity
