soft tissue- Grafting Flashcards
bone augmentation types
- block graft
- take block of bone from patient
- adding volume - GBR- guided bone regeneration
- cadaver or pt. bone mixed together and putting membrane on it
- adding volume - ridge split
- can do this if have VOLUME ALREADY
patient evaluation
importance of the dental or medical history
anything medical / patient factors that may not be aware of / contra-indications for various treatments
bone grafts are driven?
PROSTHETICALLY
have plan in mind first - restoration planned and deign and then determine if you need this
3 main grafing used in implant surgery
- soft tissue grafting
- bone augmentation
- sinus lift
stages of soft and hard tissue management
varies
- like may need to do soft tissue graft before bone tissue
soft tissue can be at multiple stages
hard tissue augmentation – 2 options – before or at time of placement
timing of hard tissue augmentation / bone graft
- BEFORE placement
- during
predictability of doing it once patient has the restoration is variable
height or width - harder to augment?
HEIGHT
width - easier
hardest when do not have height or width
vertical augmentation – do need to do it?? because risk of failure is higher
local risk factors for grafting
- previous history of graft failure
- scaring in the area of grafting
- frenums in the area to be grafted
- Pulls tissue and can open - volume and direction of grafting needed
- size/ span of defect
implication of scaring in area of graft
NO BLOOD SUPPLY AND WE NEED BLOOD SUPPLY FORO HEALING
soft and hard tissue augmentation go
hand in hand
- sometimes need one before the other and vise versa
hard area to restore with grafts
unilateral esthetici zone like 7 and 8 and not having to do 9 and 10
easier to do 7-11 vs the two
non vascularized bone grafts heal?
through a sequence of events
- grafts usually undergo partial necrosis - osteocytes death
followed by an inflammatory stage – existing bone is replaced with new bone by osteoblasts brought in by invading vessels
“creeping subsitution” -the slow process of vessel invasion and bony replcemetn
creeping subsitution”
in bone graft healing – the slow process of vessel invasion and bony replacement
bone that forms is of the origin (like bone graft with hip in maxilla will become maxillary bone)
all bone grafts we do for dental are
NON-vascularized
bone graft physiology
- clot / hematoma foramtion
- process of inflamamtion
- revascularization
- osteoconduction
- osteoinduciton
- osteogenesis
- remodeling
rate of revascularization in cancellous bone?
faster – b/c more architecture
occurs RAPIDLY AND COMPLETELY due to its open architecture that allows easy invasion of blood vessels
revascularization of cortical bone
SLOW AND INCOMPLETELY
- due to its dense lamellar structure
- vessels must penetrate along haversian and volkmann’s canal
remodels less
inlay vs onlay
inlay – inside bone
onlay - on top of bone
- so depending on vessels coming from beneath vs coming from within and around in inlay
- need the vascularization
INTERPOSITION/ INLAY – maintained violume and preserved significantly better than onlay grafts
interpiosition graft aka
inlay
BEST GRAFTING MATERIAL
EMBRIOLOGIC ORIGIN
- from the skull
- gets remodeled less
rigid fixation
use of rigid fixation in fracture repair results in primary bone healing
the effect of rigid fixation on bone grafts results in bone graft survival, greater bony union, increased primary bone healing and rapid re-vascularization by virtue of graft IMMOBILITY
dont want graft to move
- if have movement - wont get the re-vascularization and may get fibrous tissue in area / scarring- not good
graft orientation
cancellous – against bone
bone grafts had better survival when their cancelloous surfaces contacted the bone even though grafts with cancellous surfaces facing soft tissue revascularized sooner
cortical - against the periosteium
recipient site
grafts placed in avascular bed do NOT survivie well
other factors at the recipient site include prior irridation, infection, and tissue scarring
best grafts are
from head and mixture of cancellous and cortical
cancellous –> revascularization
cortical –> to resist resorption
sites block grafts often taken from
- chin
- ramus
- body of mandible
- hip
- calvarium
- best option
- used more for trauma
hip vs chin and ramus
we get more volume from the hip
technique often used
uses ultra-sonic and chisel
most comfortable (for patient) area to take bone from
ramus
- can take and cut into multiple pieces
fixate the bone grafts with
screws - score it and primary closure
rigid fixation for
vascularization – idealy 2 screws
4 maor things need for bone graft
- rigid fixation
- good adaption of the graft
- one of the most important things – may need to shave recipient side or the graft - passive soft tissue closure
- 4-6 months of healing
- want remodeling to occur - before place implant
soft tissue closure?
need to SCORE the periosteum to allow soft tissue to expand
graft blood upply dependent on
vascularization from the recipient side
ridge split - general
taking the bone we have and making it WIDER
use of an ultra-sonic machine to make cuts
- use chisel to lift up a little and spread it apart
____ needs to be longer than what your splitting with ridge split
IMPLANT
FOR PRIMARY STABILITY
works because bone is wider at bottom and opposite with the implant
need the width of bone where you place the implant
Guided bone regeneration
membrane to exlcude soft tissue from going in
healing is coming from the bone underneath the membrane
most predictable cases when doing guided bone regeneration
when there is adjacent bone around
so works well when have 3 wall defect (not as well when 1 wall defect)
when have 3 wall defect use?
guided bone regeneration
healing starts from those walls!
most remodeling occurs on buccal because thinner
healing of guided regeneration
same
allow about 6 months healing
from bone within
membrane excludes the periosteum
approaches to sinus augmentation
- crestal approach
2. lateral window approach
prerequisite for one stage implant placement and sinus lift
4-5 mm of bone HEIGHT
external sinus lift healing?
6-9 months then implant placement
if have less than 5 mm (residual height of bone) of bone height and sinus lift?
have to do external sinus lift - wait 6-9 months then implant placement
options if residual bone height is greater than 5 mm with sinus lift / external sinus lift
- simultaneous / immediate implant placement with sinus lift
- external sinus lift
- wait 6-9 months for healing
- implant placementn
