Pre Prosthetic Bone Graft Flashcards
When may pre-implant surgery be required?
Too little bone to support implant
Too much bone
When is ridge reduction used?
Bone of poor quality
Need additional restorative space
Remove knife edge ridge
Different types of augmentation?
Autograft - bone taken elsewhere on pt
Allograft - bone taken another person
Xenograft - bone from animal
Inorganic material
What is osseoinductive?
Promotes bone formation
What is osseoconductive?
A scaffold is placed - something else needed induce bone formation
Example osseoinductive and osseoconductive materials?
Inductive - bone chips taken from pt
Conductive - bovine chips
What techniques can be used to alter width of bone?
Guided bone regeneration
Ridge split
Block graft
Use appropriate implant e.g narrow/ angled
What techniques can be used to alter height of bone?
Onlay graft
Inlay graft
Osseodistraction
What can be good choice of implant if inadequate bone height?
Short implants
Zygomatic implants
Give example of when can have reduced bone width?
Buccal bone resorption following loss of central incisor
General principles of bone width surgery?
Plan - diagnostic wax up and stents
Evaluate and stimulate graft site
Fix graft
3-6 month - intergration of graft material
What can be used if only a small difference to bone width is needed?
Guided bone regeneration - 50% implants have GBR
Adv of GBR?
Can be done simultaneously w/ implant and in general practice
What is GBR?
Missing bone replaced w/ particulate and collagen membrane - acts by tricking bone into thinking fractured
How to bone chips osseoinduce?
Have high surface area which intorduce osteoblasts and proteins
What is natural healing process following GBR?
Fracture initially form haematoma
Cause release inflammatory mediators - IL1/2 (interleukin)
Bone morphogenic proteins and cytokines induce bone formation
What is dual layer GBR?
Flap raised expose thin bone - bur holes next to implant
Initial layer of bone chips placed over exposed threads of implants
Second layer bovine particulates placed
Aim of dual layer GBR?
Bone chips are conductive
Then absorption of bone-conditioned blood makes bone substitute oseoinductive
Why need membrane in GBR>
Prevent soft tissue contacting and resorbing graft material
What is alternative to GBR?
Split ridge
What to do when need place moderate-large amount bone?
Graft e.g buccal onlay graft
What is a modern bone graft technique?
Use ramus of mandible or symphysis to graft bone
Complication of symphysis grafts?
Reduced sensation
Scaring in buccal sulcus
Chin ptosis
Damage incisor/ canine roots
Where can bone be taken if large amounts needed?
Iliac crest