immediate implants Flashcards
What factors are important for immediate implant placement
Hamilton ITI consensus 2023
Patient factors:
1) medical status
2) esthetic risk and expectations
Site factors:
1) recession
2) periodontal phenotype
3) bone for anchorage
4) facial bone wall (>1mm)
5) no infection (no suppuration or fistula)
6) no periodontal disease
7) ideal prosthetic position
Treatment factors:
1) flapless
2) atraumatic extraction
3) jumping gap >2mm
4) primary stability
what factors are important for immediate loading
1) occlusal scheme (is it the main contact or main determinant for anterior guidance)
2) parafunction
3) bone anchorage to resist loading forces
4) tooth position (anterior vs posterior)
5) primary stability (30-45Ncm, but 20 is still good)
how much micromotion is tolerated
50-150 um
what happens if you have too much micromotion
deformation of osteoblasts (it gets stretched 10% of its size, then stops working) then fibroblasts take over
what primary stability do you feel safe immediately loading
25Ncm (Norton 2011), Trisi found that increasing the torque relates to decreasing the micromotion (below 40um). It also depends on the type of bone. For soft bone, micromotion was high even with increasing torque values. So 25 Ncm may be sufficient, but mostly for normal or dense bone.
ITI consensus states 20-45Ncm
esthetic risk considerations
-medical status
-smoking
-gingival display
-width of edentulous space
-periodontal phenotype
-soft and hard tissue defects
-bone level at adjacent teeth
-restoration status of neighbouring teeth
-infection
-pts expectations
what is an ideal site for immediate implants
-thick flat periodontal phenotype
-thick facial bone wall >1mm
-enough bone for primary stability and prosthetically driven
-no infection
-no recession
how much bone do you need for primary stability apical to the tooth
> =3-5mm height of bone
2mm width around the apex of the implant
How many sites would actually fulfill the criteria for immediate implants
Huynh-Ba 2010:
average of only 0.8mm facial bone thickness in the anteriors
87% of them are <1mm
3% of them are at 2mm
What is the advantages of the flapless approach?
-maintain the soft tissue profile, better esthetic outcomes, and reduce the risk for recession (Cosyn: flap surgery may be related to increased recession)
-prevent possible crestal bone loss from flap reflection (0.6mm Donenfeld) , although Lin found no difference in MBL and implant survival)
-maintain the blood supply
-simplier
-less time
-less pt discomfort
Why did you chose implants at 11 and 21 not 12 and 22
-placing 2 implants in the center with 2 cantilevers: is justified since lateral incisiors are small cantilevers and that the laterals are not heavily loaded on excursions
-it is possible that the lever arm is shorter when they are placed in the central spots, which minimizes bending forces
Tymstra - cantilevers show no affect on hard/soft tissues compared to single implants
Do you need to graft the gap?
You can get bone fill in a gap without grafting but there’s more horizontal resorption and its less predictable in larger gaps. Chen and Buser review in 2009 concluded that gaps <2mm heal spontaneously with defect resolution but gaps >2mm have a reduced predictability for bone fill. Not grafting was associated with more horizontal resorption (48 vs 16%)
-there is also better soft tissue stability. better esthetic outcomes were found (Morton), 0.58 mm less recession (Seyssons)
Testori 2018:
-if <4mm external wall to implant, you should graft
can you place implants in an infected site
Yes, chronic periapical infection is NOT a contraindication for immediate implants, provided that the infection can be completely debrided and there is enough bone for primary stability (Chrcanoic). You can give chx rinses and systemic antibiotics. they have the same survival rate
how does the regenerative potential compare to type 2 placement
type 2 placement has a higher regenerative potential than type 1
if you have a facial dehiscence, can you still place an immediate implant
depends on the type of defect. (Kan 2007) found that V shaped defects contained to the mid facial still had good outcomes, but wider defects that were U or UU shaped had more gingival recession of 1.5mm, even when GBR and CTG were carried out
When do you need a CTG
you should consider it if there is an elevated risk for recession
-thin gingiva
-<0.5mm buccal bone
-risk of having soft tissue level asymmetry is x12 without CTG
-CTG contributes to mid-facial soft tissue stability
(Seyssons)
describe healing of implant
-blood clot fills the site
-platelets arrive and adhere
-fibrin matrix forms and acts as a scaffold (osteoconduction)
-this brings in osteogenic cells and eventual differentiation (osteoinduction). this allows for de novo bone synthesis
-osteogenic cells secrete matrix, which begins to crystalize
-Woven bone formation
-Lamellar bone formation
Davies
What factors affect the dimension changes post extraction
-buccal wall thickness: more buccal bone loss if thin plate
-dehiscence: causes recession and buccal bone loss
-soft tissue thickness: thin is at risk of recession
-gap size: need >2mm on buccal for grafting and bone fill and not encroaching on buccal plate
-implant positioning: too buccal can cause buccal bone loss
how much bone do you want on the facial of your implant
> 1.8-2.0mm on the facial to prevent bone loss (Spray)
-4mm from implant to external surface of buccal bone at implant placement (Testori)
What techniques can be used to preserve/improve soft and hard tissue around implants
CTG
-bone grafts
-place implant just apical to mid facial bone to compensate for 0.5-1.0mm vertical bone loss from the extraction
-flapless
-immediate crown
should you submerge your implant
Cordaro 2009:
-no difference in submerging or not submerging for perio parameters including MBL
-at time of loading, non submerged has 0.3mm loss in KT and the submerged group lost 1.7mm KT
Soft and hard tissue changes after immediate implant placement
Chen & Buser, 2009
-48% horizontal resorption (20% if bone augmentation is done)
-vertical bone loss 0.5-1mm
-Recession of 0.5-0.9mm
implant positioning parameters
2mm facial wall
1mm lingual wall
1.5 from adjacent teeth
3mm from adjacent implants
3-4 mm from gingival margin
angulation through cingulum of the central incisor
(Saadoun 1999 and testori 2018)
Describe the healing of an extraction socket
(Amleret al.,1969)
Within 24 Hours: Blood clot formation in socket - this includes fibrin and blood cells
2-3 Days: The blood clot is gradually replaced with granulation tissue
4 Days: epithelial proliferation begins. young CT starts to form at the apical portion of the socket
7 Days: Granulation tissue. young CT and osteoid formation is occurring in the apical portion of socket.
3 Weeks: CT. Some mineralized osteoid.
24-35 Days: complete epithelial fusion over socket
38 days: ⅔ of socket filled with new trabecular bone
6 Weeks: CT continues to be replaced by osteoid/bone
