Bone Grafts & Implantology Flashcards
What are the four causes of bone loss?
- Congenital = born with deficiency in bone
- Traumatic
- Pathology
- Natural
Name some different types of bone grafts:
- autogenous
- xenograft
- allograft
- alloplastic
- bone bioengineering
What is an autogenous bone graft?
bone tissue is harvested from one areas of the pts own body & transplanted to another site
What are some common intra-oral/local areas of autogenous bone harvesting?
- chin
- ramus
- tuberosity
- coronoid process
- buccal cortex
What are some common extra-oral areas of autogenous bone harvesting?
- hip
- calvarium
- iliac crest [hip]
What is a xenograft?
type of bone graft material derived from a non-human source
What is commonly used for dental xenograft procedures?
Bio-Oss
- deproteinised bone
- used alongside allograft procedures to minimise bone resorption
What is an allograft?
bone graft material derives from human donors [cadaveric bone]
- donated bone is processed and sterilised to remove organic components
What can be used to perform an allograft?
irradiated sterilised free dried bone blocks
What is an alloplastic graft?
a bone graft using synthetic or manufactured grafting material
- proplast
- HA
- TCP
- TCS
What is used when performing bone bioengineering procedures?
bone morphogenic protein
What are the 2 principles of bone grafting?
- osteoconduction
- osteoinducation
What is osteoconduction?
the ability of bone graft material to provide a scaffold or framework for new bone formation [bone forming cells]
What is osteogenesis?
formation of new bone tissue, induced through the recruitment of immature cells (UMC) for bone formation
What are the basic principles of distraction osteogenesis?
- latency
- distraction
- consolidation
- remodelling
When are zygomatic implants indicated?
- severe maxillary atrophy
- sinus pneumotisation
- avoid harvesting of bone graft
- hemimaxillectomy
What are bone morphogenic proteins?
Group of growth factors that play a role in bone formation & regeneration
- active osteoinductive factors
- convert UMCs [undifferentiated mesenchymal cells] into osteoblasts
What is an example of congenital bone loss?
Cleft palate
What is an example of traumatic bone loss?
car crashes
What is an example of natural bone loss?
- Alveolar ridge resorption over the years
What type of bone grafts can be performed?
- onlay
- interpositional
- sinus lift
A low maxillary sinus poses a problem for implant placement, what can be done?
Implant lift
What is the most common distant donor site for bone?
iliac crest [hip]
Why is bone grafting from calvarium good?
membranous ossification [leads to less resorption when grafted into mouth]
What anatomical feature is at risk during buccal cortex grafting procedures?
Inferior alveolar nerve
Bone mill
take piece of bone & crush it into small places, then apply it as a “putty” to area needed
What are the steps of a maxillary sinus lift?
- cut a window in outer cortext
- lift membrane
- apply bone graft
- apply Bio-Oss
- apply guided tissue repositioning and suture closed
What is an interpositional bone graft?
graft is applioes between the inner and outer cortex to increase bone width
Guided tissue regeneration
What do you want the implants to do when placed?
osseo-integration
What is the gold-standard type of bone grafting?
Allograft procedures with local bone harvesting
How do you decide where to harvest bone from in Allograft procedures?
- pt preference
- availability of bone based on CBCT
- proximity of anatomical structures [eg mental foramen too close]
When might alveolar distraction osteogenesis be required?
for elderly pt who cant withstand harvesting procedure
What is latency?
inflammatory cells infiltrate into the area and soft tissue healing
How does distraction osteogenesis occur?
- cut bone & separate piece
- separate 1mm per day [half a mm in morning, half a mm in evening]
- any faster will leads to breaking of the soft tissue
- allow natural biologic depositon of bone in these areas
What is “vector” in reference to alveolar distration?
direction you want the bone to grow in
What is inferior dental nerve lateralisation?
put a stitch around the [IAN] nerve to pull it laterally so you can you place implants into remaining bone to lower risk to nerve
What are indications for zygomatic implants?
- severe maxillary atrophy
- sinus pneumotisation
- avoids harvesting of bone graft
- hemimaxillectomy [ one half of maxilla removed ]
Bone-bioengineering **
