Periodontal Therapy Flashcards
rationale for perio therapy
to restore the periodontium to maintainable health
which type of patients should be referred and treated by a periodontist?
- generalized moderate to severe chronic periodontitis
- furcation involvement
- vertical/angular defects
- aggressive periodontitis
- periodontal abscess/other acute periodontal conditions
- mucogingival defects
- significant gingival recession esp in esthetic zone
- peri-implant disease
scaling
removal of calculus and plaque from a tooth surface
scaling and root planing is effective in edematous true pockets that are what?
≤ 5 mm
repeated root planning of healthy shallow sites (<3mm) results in what?
attachment loss
how does SRP result in pocket reduction?
by helping to resolve inflammation
pocket reduction is mainly through what?
interproximal recession and probing not as much into inflamed tissue, with possible formation of long JE
T/F: root planing does result in new attachment through formation of new collagen fibers inserting into new cementum
false, DOES NOT
gingival curettage
intentional removal of pocket epithelium and subjacent granulomatous tissue
T/F: true new connective tissue attachment with new collagen inserting into new cementum does not occur after non-surgical therapy
true
types of perio surgery
- resective
- conservative
- periodontal regeneration
- mucogingival surgery
what is the objective of resective perio surgery?
to achieve pocket elimination by tissue removal (usually results in surgical recession)
types of resective GINGIVAL surgeries
- gingivectomy
- gingivoplasty
- inverse bevel flap (excision)
gingivectomy
resection of gingival wall of periodontal pocket (~45 degree external bevel) with scalpel or laser
gingivoplasty
thinning of gingiva without a change in tissue level
inverse bevel flap (excision)
accomplishes gingival resection without open wound
types of resective perio surgeries
- gingival surgery
- apically positioned flaps
- osseous surgery resection
- root resections (hemisection and root amputations)
apically positioned flaps
method of surgical recession for pocket elimination or crown lengthening while preserving keratinized gingiva
when can apically positioned flaps be accomplished?
only where there is a mucogingival jxn (so not on palate of max. teeth)
types of osseous surgery-resection
- ostectomy
- osteoplasty
- osteotomy
ostectomy
removal of supporting bone (includes alveolar bone proper and PDL)
osteoplasty
surgical procedure that modifies the configuration of bone (removal of non-supporting bone)
osteotomy
implant term for removal of bone during implant placement
where is root resections best for max molars?
disto-buccal root because it has the least root surface area
T/F: mandibular teeth that receive root resections are prone to fracture
true
which is the best mandibular root to remove?
mesial root because mesial root concavities make restoration difficult
examples of conservative perio surgeries
- flap curettage-open flap debridement
- modified widman flap
- excisional new attachment procedure (E.N.A.P)
what is the objective of conservative perio surgery?
to gain access to the root for debridement and to reduce pockets by resolving inflammation and establishing a long JE
which perio surgery is good for esthetic zones due to less surgical recession as flaps are replaced, NOT apically positioned?
conservative
true peridontal regeneration results in what?
- new bone
- new cementum
- new functional PDL
overall objective of periodontal regeneration
recruit undifferentiated mesenchymal cells (progenitor, like stem cells, multipotential mesenchymal cells) of CT origin from PDL and adjacent endosteal bone to differentiate into osteoblasts, cementoblasts and fibroblasts that will regenerate new bone, new cementum, and a new fxnal PDL
periodontal regeneration can be proven only through what?
histology
what is the best success for regeneration?
moderately deep (greater than 3 mm vertical component provides more mm of regeneration than shallow defects, narrow vertical/angular defects with 2 or 3 remaining bony walls
what is the flap approach for perio regeneration?
a replaced or coronally positioned flap to cover the regenerative site and materials
what is the average bone fill into a defect?
60%
perio regenerative surgery is also used for what type of furcation involvement?
grade 2 furcations (facial and lingual but not maxillary proximal) with greater than 3 mm horizontal penetration
T/F: regeneration is successful in grade 3 (through-and-through) furcations
false
why is regeneration less successful in one-walled bony defects?
because graft materials are not well retained so it’s difficult to maintain needed space for barrier membranes (GTR) and there are fewer bony walls and PDL sources for progenitor cells
when is regenerative surgery not indicated?
- shallow infrabony (=intrabony) defects (2 mm or less)
2. minimal regeneration gain for cost
cost and time of procedure doesn’t warrant use in what?
shallow osseous defects (less than 3 mm) or shallow furcations (less than 3 mm horizontal penetration)
when performing perio regeneration, the flap must cover what?
regenerative material through a coronally positioned flap or replaced flap
all bone grafts serve as a what for new bone?
scaffolds
objective of placing bone grafts?
for them to be resorbed and allow for replacement with new host bone
osteogenic materials have what that can produce bone?
progenitor cells
osteoinductive materials induce what?
surrounding progenitor (undifferentiated mesenchymal) cells from the surrounding PDL and bone to migrate and differentiate into osteoblasts, cementoblasts and fibroblasts that produce new bone, cementum, and perio ligament
example of osteoinductive material
growth factors
osteoconductive materials allow what?
new bone to grow into a defect and provide scaffolding but have no inductive capability
types of bone grafts
- allograft (homograft)
- alloplast
- autogenous bone graft (autograft)
allograft (homograft)
graft between genetically dissimilar members of the same species
what are the most frequently used graft material at the current time?
de-mineralized freeze-dried bone allografts (DFDBA) and FDBA
what is the osteoinductive factor in de-mineralized freeze-dried bone allografts (DFDBA)?
bone morphogenetic protein
alloplast
synthetic inert graft foreign material implanted into tissue
T/F: alloplasts are osteoinductive and not osteoconductive
FALSE! it’s osteoconductive but not osteoinductive
autogenous bone graft (autograft)
tissue transferred from one position to another within the same individual
which type of bone is the most osteogenic?
cancellous bone (e.g. illiac crest)
intraoral sites to harvest autograft material
- maxillary tuberosity
- two-month post-extraction sites
- tori and bone removed during osseous recontouring (osseous coagulum)
xenograft (=heterograft)
graft taken from a donor of another species
T/F: xenografts are osteoinductive
false, osteoconductive
isograft
graft between genetically identical individuals
what is frequently incorporated into graft materials?
growth factors (“biologics”)
what is used in guided bone regeneration (GBR) for ridge augmentation prior to implant placement?
platelet rich plasma (PRP)
enamel matrix proteins (Emdogain) induces what?
new cementum formation and may play a role in bone and PDL formation
barriers used in guided tissue regeneration (GTR) are membranes that exclude what?
epithelium and gingival CT
role of barriers in GTR?
create and maintain space for regeneration and promote migration of progenitor cells from the PDL and possibly bone
when is guided tissue regeneration (GTR) best in?
grade 2 facial or lingual (not proximal) furcations and bony defects where space making between the membrane and the tooth is possible
what is critical in GTR?
- flap must cover the membrane
- must be space between membrane and bone to allow progenitor cells to come in and differentiate into osteoblasts, fibroblasts and cementoblasts
treatment of root surfaces with what?
- citric acid
- tetracycline
- fibronectin
- EDTA (calcium chelating agent)
mucogingival surgery
treatment of mucogingival defects and root coverage procedures
types of mucogingival surgeries
- coronally positioned flap
- free gingival graft (FGG)
- subepithelial CT
- acellular dermal matrix
- pedicle grafts
- guided tissue regeneration
- frenectomy
coronally positioned flap is indicated when?
for root coverage
T/F: coronally positioned flap can change the width of keratinized gingiva
false, can’t
T/F: free gingival graft (FGG) is a simple, predictable procedure for gaining keratinized tissue
true
survival of the graft in free gingival graft (FGG) depends on what?
plasmatic (diffusion from the underlying periosteum) until revascularization occurs
why are free gingival grafts (FCC) not indicated in esthetic zones?
they do not have a good color match and look like patches
which procedure is the most indicated procedure for root coverage and provide thicker dense fibrous CT that resist continued recession?
subepithelial CT (CT)
why are subepithelial CT (CT) more likely to survive over avascular roots?
because nutrient supply is provided both from the supraperiosteal blood vessels of the flap that is replaced or coronally advanced over the graft and by periosteum/bone that subjacent the graft
T/F: subepithelial CT (CT) are much more esthetic (looks less like patches, good color match) than free gingival grafts
true
T/F: subepithelial CT (CT) grafts are best for the anterior maxilla
true
CT grafts heal with a form of what?
new attachment to previous exposed root
acellular dermal matrix
human cadaver donor skin that has been rendered devoid of cells
pedicle grafts
laterally positioned flaps from adjacent tooth or edentulous area
guided tissue regeneration can be successful if the membrane can be what?
“tented” to provide space for progenitor cells to emerge from adjacent PDL
