W7 - Flap Surgery Part II - Sharma Flashcards
T/F - Teeth with furcation involvement respond more favourably to non-surgical periodontal therapy
False
- Teeth with furcation respond less favourably and have reduced prognosis
What are the two surgical treatment options (big picture) for furcation involved teeth
Resective surgery
Regenerative surgery
What are the two types of resective surgery offered to furcation involved pts
Furcation plasty
Hemi-section / root resection / bicuspidization
3 Grades of furcation involvement
Grade I - Incipient, catch
Grade II - Bone loss, not through and through, “cul de sac”
Grade III - bone loss through and through
What affects the perio pocket in a furcation lesion (anatomy) (3)
- Anatomy of the soft tissue (thick, thin?)
- Bone - horizontal or angular loss
- Inter-radicular tooth anatomy
What does a furcation plasty involve? What is the purpose/outcome?
Odontoplasty
Osteoplasty
Gingivoplasty
Purpose is to improve access for pt to clean
Technique of furcation plasty
- Flap to access inter-radicular area
- Odontoplasty to widen furcation entrance
- Osteoplasty to reduce intra-bony defect and decrease thickness of the bone
- Position the flap at the level of the alveolar bone crest
Why should aggressive odontoplasty for furcation plasty be avoided on vital teeth?
Risk of hypersensitivity
Furcation plasty
- non surgical therapy did not help
- Exposed the furcation for better cleaning
What is a tunnel preparation? Purpose?
Exposing / clearing the furcation in deep grade II and III FI teeth
- Md molars only - mx molars will have palatal root in the way
- Allows for easier cleaning
- Delays the need for extraction
What is the rationale behind hemi-section, root-resection and bicuspidization?
Complete elimination of the furcation defect
- Multidisciplinary approach (endo and restorative)
- Endo usually done before surgery
What is going on here?
Hemi section
- Sectioning of tooth into two and removing half of it
- Remove the root where endo has failed
- Typically mesially half is extracted
What is a root resection?
Removal of one or two roots
- only done in the mx teeth
Technique of root resection and hemisection
- Create mucoperiosteal flap to expose furcation
- Sectioning of root or tooth with straight line cut
- Careful removal of root (root resection) or tooth section (hemisection)
- Re-positioning of the flaps at bone crest level
Outcome of root resection / hemisection
Remaining root(s) have improved/adequate bone support
Good prognosis if endo therapy and occlusion is sound
Why do root rections / hemisections most often fail?
Failures are usually due to endo complications and/or occlusion issues
- Not usually due to periodontal complications
Bicuspidization
- splitting the tooth into two and retaining both sections
Technique of bicuspidization
- Mucoperiosteal flap to expose furcation
- Section of tooth with straight line cut
- Re-position flaps at level of the bone crest
What is regenerative surgery?
Formation of new cementum, PDL and bone that was destroyed by periodontal disease
How can you confirm regeneration?
Cannot verify true regeneration without removing tooth and surrounding bone for histological evaluation
Decreased pocket depth may suggest it however this could just be due to tightly adapted gingiva with long junctional epithelium
What 4 tissues can fill the space after flap surgery
Epithelium (most common)
Connective tissue
Bone
PDL
What are the indications for bone grafts (4)
- Infra/intra bony defects (three and two walled) - vertical or angular BL
- Grade II furcation
- Preparation of implant placement site
- In combination with GTR (tissue regeneration)
What is GBR and GTR?
Guided Bone Regeneration
Guided Tissue Regeneration
Contra-indications for bone grafts (4)
- Horizontal bone loss (no walls to give support - physical and vascular)
- Lack of soft tissue coverage
- Poor OH / plaque control
- Systemic issues - smoking and poor general health
Rank the 4 types of graft materials from best to worse
-
Autogenous graft
* From self - Retromolar area if small, hips or ribs if large -
Allograft
* From other humans -
Xenograft
* From animals -
Alloplast
* Synthetic
Define osteogenic bone graft
Example?
Graft which can: provide the appropriate cellular elements which survive transplantation
and
synthesize new bone at the recipient site
Example: autografts
Define osteoinductive bone graft
Grafts that send signals to attract, proliferate and differentiate cells capable of forming bone
Ex - allograft
Define osteoconductive graft
Graft that serves as a scaffolding that bone cells can attach to and grow/divide
Ex. allografts and xenografts
Why are autografts considered the “gold standard” of graft materials (4)
Most compatible
Can pick shape - blocks or chios
Multiple sites - intra oral/extra oral
Forms new bone
Pros and cons of harvesting autografts from extra-oral sites
Locations?
Pro: can take out larger quantities
Cons: -increased morbidity (need GA),
-theatre cost
Common sites: Iliac crest (hips), ribs, fibula, tibia
Pros and cons of harvesting autografts from intra-oral sites
Locations?
Pros: lesser morbidity (under LA)
Cons: -limited quantity (smaller)
-surgical expertise
Possible sites:
Extraction sites, md retromolar area, ramus, tuberosity, tori
What tool is used to remove chips of/from bone for grafts
Bone scraper
2 Types of allograft materials
Freeze dried bone (FDB)
Decalcified Freeze dried bone (DFDB)
What is “Selective Repopulation”
Type of GTR
Placement of membrane allows for selective repopulation of space
- blocks off the epithelium and connective tissue
- only allows PDL and bone to fill space
What are the only two ways of obtain bone regeneration in the mouth
- Bone grafts
- GTR - Selective repopulation
What’s going on here?
Selective Repopulation
What are non resorbable membranes used for? (selective repopulation)
Disadvantages?
GBR
- requires second surgery to remove
- If not covered with soft tissue, can lead to infection
2 Examples of nonresorbable membranes
Goretex
Cytoplast
3 Examples of resorbable membranes
Advantage?
Collagen (Bio-Gide)
Polylactic acid
Polyglycolic acid
Advantages of resorbable membranes (4)
Second surgery for removal not necessary
More tissue-friendly
Enhance tissue coverage
Resist or prevent microbial colonisation (infection)
Disadvantages of resorbable membranes
May elicit immunologic or inflammatory reaction
Time of resorption can’t be controlled
What is “socket preservation”
GBR
usually done to allow for bone regeneration for implant placement
- Use of non-resorbable membranes at exo site
