Week 6 Tulio- Surgical Implantology

Question 1

What are the types of implant prostheses?

Answer 1

• Unitary implant
• Implant supported bridge
• Implant supported hybrid prosthesis
• Overdentures

Question 2

How does smile change as you age?

Answer 2

• More of lower teeth shown
• Loose collagen and tension in skin- not as flexible and elastic
• Smile is curved more downwards

Question 3

How are temp crowns used for preprosthetic surgery?

Answer 3

Placement of temp crowns can shape soft tissues to correct future emergence profiles (long process)

Question 4

What are factors for planning prosthetic design?

Answer 4

• Aesthetics
• Periodontal health
• Tissue reconstruction
• Support, stability and retention needs

Question 5

What are current strategies to achieve bone augmentation?

Answer 5

• Guided bone regeneration
• Bone block grafts
• Distraction osteogenesis
• Sinus lift
• Transposition of IAN

Question 6

What is an absolute CI for implants?

Answer 6

Recent radiotherapy pt of head/neck (angiogenesis affected, difficult to heal, fragile bone)

Question 7

What are partial CI for implants?

Answer 7

• Osteoporosis (fragile bone- if you drill bone it will be soft. Healing will be delayed- reduced osseointegration)
• Uncontrolled diabetes

Question 8

What is the principle of guided bone regeneration?

Answer 8

Perforate surface to create bleeding from base of bone. Mix bone particle and on top of that, place membrane. This will create isolation from soft tissue to encourage more bone formation.

Used more in horizontal bone defects

Question 9

What happens to implant crown if there is bone loss and implant is place?

Answer 9

Crown will appear very long

Question 10

4 types of grafts + example of each?

Answer 10

• Autograft: pts own tissue
• Allograft: freeze dried bone- other human
• Xenograft: freeze dried bone- bovine
• Alloplast: Bio-glas, hydroxyapatite, calcium phosphate

Question 11

How is distraction osteogenesis used in implants?

Answer 11

Activate distractor device on bone defect to fill the defect (need the vector of destruction in the correct direction so bone forms in correct location)

Question 12

What are 2 techniques for sinus lift?

Answer 12

• Transalveolar approach (need 6mm of bone to place implant and graft otherwise need to do lateral approach)
• Lateral

Question 13

What is principle of lateral sinus lift?

Answer 13

Used when there is pneumatisation of maxillary sinus.

• Buccal window made in the posterior maxillary bone,
• Careful elevation of the sinus epithelium
• Place bone graft (don’t perforate membrane)
• Wait 4-5 months and place implant

Question 14

What can happen to lip if prosthesis is too far B?

Answer 14

Lip can evert

Question 15

What factors influence whether pts condition is relative or absolute contraindication for implants?

Answer 15

• Type of prosthesis
• Age of patient
• Location of prosthesis (16, 26 bone is porous and not dense- avoid implant placement if pt has osteoporosis)

Question 16

What is the purpose of having titanium reinforced skeleton?

Answer 16

Maintains size and shape to prevent tissue shrinkage

Question 17

What can happen if membrane is not placed in bone defect?

Answer 17

Soft tissue occupies defect and collapses. More fibrous tissue rather than bone

Question 18

What are the types of membranes?

Answer 18

• Natural polymer (collagen- human, bovine, porcine)
• Synthetic polymer (PCL, PTFE)
• Metal (titanium)

Question 19

What are bioactive molecules?

Answer 19

BMP-2 triggers bone formation and increases angiogenesis (expensive)

Question 20

What are hemoderivates?

Answer 20

Autologous growth factors obtained from blood after centrifugation e.g. PRF (platelet rich fibrin)

• Can make bone graft more biocompatible and trigger more bone formation

Question 21

What is the basic concept of bone tissue engineering?

Answer 21

Relies on combination of cells, engineering materials (scaffold) and suitable biochemical factors to repair damaged tissues and organs

Question 22

What can scaffolds be made of for bone engineering?

Answer 22

• Bioceramic: hydroxyapatite, bi-calcium phosphate
• Natural polymers: collagen fibrin
• Synthetic polymers: PCL, polylactic/polyglycolic acid

Then do surface modification (calcium phosphate) to trigger bone formation

Can do this to avoid need for autogenous bone graft.

Question 23

What is the role of cells in bone tissue engineering?

Answer 23

MSC’s proliferate and differentiate into osteoblasts and fibroblasts

Question 24

What are autologous bone blocks used for?

Answer 24

Can be used for large defects (rather than using particular bone graft)

Question 25

What are tissue bank bone block grafts?

Answer 25

• Sterilized and preserved
• Retains osteoconductive properties

Question 26

What is the issue with screws being placed on tissue bank bone blocks?

Answer 26

More bone is placed than necessary as the bone resorbs substantially. Bone graft is screwed into place and will protrude out of bone block graft and can impinge on soft tissues as bone resorbs

Question 27

What is transalveolar/summer sinus lift?

Answer 27

Used when there is some height of bone but not enough

• Drill across alveolus from top
• Push membrane of sinus up
• Place bone graft
• Place implant

Question 28

What is the role of biochemical factors in bone tissue engineering + examples?

Answer 28

Stimulate cell response, differentiate MSC’s and inc blood vessel formation

• BMP-2
• Insulin like growth factor (IGF)

Question 29

What are advantages of bone tissue engineering?

Answer 29

• Biocompatible
• Space maintenance
• Tissue integration
• Suitable for vertical defects