Osseous Regeneration Flashcards
When would you look to do surgery?
Pockets still severe (5mm or more) after SRP at recall
What is GTR?
Guided Tissue regeneration — allow the repopulation of periodontal defects by cells capable of forming new connective tissue attachment and bone
What are the guiding principles of GTR?
- Exclude unwanted (Gingival epithelium and CT)
- Protect the wanted (bone and PDL)
- Hold the space
What are the four criteria for the success of GTR?
- Primary closure of soft tissue
- Secluded space maintenance
- Membrane stabilization
- Adequate healing period
What is the adequate healing period for GTR?
Do not probe for 3 months
What are the qualities of an ideal membrane?
- Absorbable
- Bio compatible
- Cell occlusive
- Space maintenance
- Tissue integration
- Clinically manageable
T/F: ePTFE is a resorbable membrane material.
False
non-resorbable
What are the three types of membranes?
- Non-resorbable (ePTFE)
- Resorbable
- Stem cells, functionally graded membranes
T/F: Membrane resorption is predictable from person-person.
False
T/F: The pore size of the membrane should be smaller than the size of epithelial cells.
True
Should not let epithelial cells invade the area you want attachment to form
When should ePTFE be removed?
4-6 weeks post-op
T/F: Most PLA/PGA membranes will degrade in 4-6 weeks.
True
Why is it important for patients to know the source of the collagen membrane used?
Some are from pig or cow — may present an ethical issue to the patient
What is the point of tenting screws and titanium sheets on membranes?
Create a scaffold so the membrane does not collapse the new bone — holds the space
What are the three mechanisms by which grafts integrate?
- Osteogenesis — viable cells
- Osteoinduction — uncommitted CT cells induced
- Osteoconduction — non viable scaffold
What is an autograft? What properties does it have?
Taken from same patient and used immediately
Conductive, inductive, and genic
An __________ is from another human donor.
Allograft
Which of the three types of grafts are osteogenic?
Autograft only
____________ are synthetic graft materials, and ___________ are from a different species.
Alloplast; xenograft
Both have osteoconductive properties only
What are the disadvantages of autograft?
Second surgical site, insufficient material
What are the advantages and disadvantages of allografts?
Advantages: availability, no donor site, fewer complications
Dis: no antigenicity, longer healing, less volume
What is one of the biggest problems with allografts?
You have to overpack, it will rarely fill the whole defect
______________ can sometimes be added with the graft to help it along.
Biological mediators (enamel matrix proteins, rhBMP)
What type of incisions are made for GTR?
Always sulcular incisions — want to keep maximum amount of tissue
T/F: The membrane gets its own suture independent of the flap.
True
Suture the membrane -> suture the flap over it
What is emdogain and GEM 21S?
Both types of fillers to hold the space under the membrane to promote attachment gain
What are the three keys to GTR?
- Space maintainer — bone, retenting screw, reinforced membrane
- Exclude epithelium
- Protect and promote PDL growth
