Surgical aspects of implantology Flashcards
Describe the early tissue response in an implant wound
Initial wound
Following days - Blood clot, granulation tissue, vascular invasion
1w - osteoclast invasion
2w - early woven bone
4w - 1st phase of true integration
4m - fully matured and remodelling
What are the different type of surface alterations available on implants?
Grit blasting
Blasting and etching
Etched
Hydroxyapatite coated
Oxidised surfaces
Titanium plasma sprayed surface
Straumanns - wet vial
What is the purpose of alterations?
Provide better stability in bone
Greater contact area for integration
Surface that retains better blood clots
Stimulation of bone healing process
Implants thread in an compress bone - delays osseointegration
What is an isotropic implant?
Surface structure without a dominating direction
What is an anisotropic implant?
Other processes such as turning or milling produces a surface that has a distinct regular pattern
Which primary views are needed for implants?
IOPA
Panoramic (25% mag)
What are the secondary views needed?
CT scans
Allow segmental measuring of jaw
Identifies structures such as nerves
What are the different qualities of bone?
Type I - thick and avascular, almost entire bone comprises homogenous cortical bone
Type II - Thick layer of cortical bone surrounding a core of dense trabecular bone
Type III - Thin layer of cortical bone surrounds a core of dense trabecular bone of favourable strength
Type IV - Thin layer of cortical bone surrounding a core of low density trabecular bone
Qualities of bone
A - most of alveolar ridge is present
B - Moderate residual ridge resorption has occured
C - Advanced residual ridge resorption has occurred and only basal bone remains
D - Minimal to moderate resorption of basal bone has occurred
E - Extreme resorption of the basal bone has occured
How much bone should an implant ideally be surrounded by?
1mm circumferentially and 2mm above ID nerve
Sinus at max of 4mm
What is the concept of guided tissue regeneration?
Placement of barrier membrane
Creation of a secluded space beneath membrane
Space can only be invaded by bone cells
Creation of new bone
PTFE/Gortex/Collagen
Dropped or pinned
Which type of bone graft lasts longest?
Chin, wisdom tooth area lasts longer than hip bone graft
What are the 3 types of sinus lift?
- Insufficient bone/pneumatisation
- Internal sinus lift
- Lateral sinus lift
What is an autogenous graft?
Graft harvested from somewhere else in the patient
What is an allograft?
A graft harvested from another patient
- mineralised and irradiated, sterilised and freeze dried
- synthetic bone substitutes
What is a xenograft?
Harvested from other species.
This means that these people cannot be blood donors
Which local sites are grafts harvested from?
- From within implant prep site
- From mandibular ramus
- From mandibular symphysis
From which distant sites are grafts harvested from?
From tibia
From iliac crest
Vascularised free flaps
What are the advantages of block bone grafts?
Good incorporation
Less volume loss
Shorter healing times
Better bone quality
What are the endosteal graft disadvantages?
Fibia or hip - much more bone resorption
Require a high vascular state of the recipient tissue
What are the advantages of a tibial graft?
GA/LA
30-40 mins - quick
20-40cm3 non-compressed cancellous bone
Minimal blood loss
Immediate post op weight bearing
Minimal bruising/scarring
Trephine core out bone - biopsy including bone marrow
What are the disadvantages of a tibial graft?
Unable to obtain bone block
Pts with history of knee injury/trauma
Patients with RA or degenerative arthritis
Patients with metabolic bone disease
What is the site of bony harvest for cleft palate?
Gerdy’s tubercle
What are the advantages of an iliac crest graft?
Block and cancellous bone available
Large quantities
Relatively accessible - risk of damage to gut
Small scar
What are the disadvantages of iliac crest graft?
Hospital admissions for GA
Short term altered gate
Bleeding potential
Post op pain
Paraesthesia
Which flaps are raised in the harvesting of bone from distant sites?
Vascularised free flaps
Which artery is taken with an iliac crest graft?
Deep circumflex iliac artery - replace jaws in cancer
Which artery is taken in a fibular graft?
Deep peroneal artery (used in jaw replacement surgery after cancer)
Where is the deep circumflex iliac artery joined?
Facial artery which anastomoses to internal jugular
