6 - Periodontal Pocket Formation and Bone Loss Flashcards
what xray detects peri-radicular pathology and uses a long cone paralleling technique
periapical
what bitewing for early to moderate bone loss
horizontal BW
what BW for severe bone loss
vertical BW
what xray best evaluates bone loss amount and least interproximal bone distortion
BW
what is a pathologically deepened gingival sulcus with CAL
periodontal pocket
what are the two pocket classifications
- gingival pocket (pseudopocket)
- periodontal pocket
what is formed by gingival enlargement WITHOUT destruction of underlying periodontal tissues
gingival pocket (psudopocket)
what occurs with destruction of supporting periodontal tissues (gingival collagen fibers, PDL fibers, bone)
periodontal pocket
A
gingival pocket
B
suprabony pocket
C
intrabony pocket
what are 2 types of periodontal pockets
- suprabony (supracrestal)
- intrabony (infrabony, subcrestal)
what perio pocket has bottom of pocket CORONAL to underlying alveolar bone
suprabony (supracrestal)
what perio pocket has bottom of pocket APICAL to level of adjacent alveolar bone
intrabony (infrabony, subcrestal)
where does intrabony pocket wall lie
between tooth surface and alveolar bone
the initial lesion in the development of periodontitis is what
inflammation of gingiva in response to bacterial challenge
in pocket formation, what is destroyed?
gingival collagen fibers apical to junctional epithelium
steps in pocket formation
- inflammation in CT wall of gingival sulcus
- gingival collagen fibers apical to JE destroyed
- loss of collagen results JE proliferation and migrates apically along root
- coronal portion of JE detaches from root and sulcus bottom shifts apically
how does pocket affect root surface
- cementum facing pocked becomes exposed to oral environment
- bacteria penetrate the cementum and dentinal tubules
T/F: scaling and root planing should remove some cementum to DETOXIFY root surface with pockets
TRUE
is bacteria capable of evading the host defense and scaling and root planing efforts by hiding in the root surface
YES
___ + ___ = CAL
PD + GM (gingival margin)
can you have same pocket depths with different gingival margins
YES
gingival margin positions are relative to what
CEJ
gingival margin APICAL to CEJ is called what? positive or negative number?
recession; positive number for gingival margin
if gingival margin CORONAL to CEJ, is this positive or negative number?
negative
if gingival margin is at CEJ, is this a positive or negative number?
just 0
what CEJs are easily detected? what is more difficult?
facial and lingual are easily detected
interproximal CEJ is more difficult to detect
what is used to detect subgingival CEJ? how?
use perio probe
Insert probe into sulcus to feel for the CEJ.
Helps to hold probe at 45° angle when detecting CEJ’s.
Measure where the gingival margin crosses the probe.
Record gingival margin as a “negative” number.
the interproximal CEJ is located where in health?
subgingival
what tells you how much attachment loss there is from CEJ
CAL
what is the distance from CEJ to the base of the pocket
CAL
what are periods of exacerbation and quiescense?
periodontal disease activity
is perio disease site specific?
YES
Periodontal destruction does not occur in all areas of the mouth at the same time
Active destruction occurs at some teeth at a time at any given time
Periodontitis becomes more severe by the development of new disease sites or increased breakdown of existing diseased sites
what marks the transition from gingivitis to periodontitis
- Clinically measurable attachment loss
- Bone loss as a result of inflammation reaching the bone
what are mechanisms of bone destruction
bacterial and host mediated bone destruction
what bacterial products induce differentiation of osteoclasts
LPS
what are host factors released by inflammatory cells that induce bone resorption
IL-18
IL-6
TNF-a
alveolar bone responds to inflammation how?
bone formation and resorption
what occurs when resorption dominates formation
periodontal bone loss
factors that increase risks for periodontal bone loss
Smoking
Occlusal trauma
Osteoporosis
Open contacts (Food impaction)
Close root approximation to adjacent root
Overhanging restorations
what increases risk for perio, is dose dependent, duration is important, and measured in pack years
smoking
pack years equation
(# cigs/20) * # of years
what bone destruction pattern:
Most common pattern
Bone is reduced in height
Bone margins remain perpendicular to root
horizontal bone loss
what bone destruction pattern:
Bone loss is oblique to root surface
Intrabony pockets
vertical (Angular) bone loss
what type of bone loss
horizontal
what type of bone loss
vertical/angular
radiographs [overestimate; underestimate] bone loss by up to ___mm
underestimate 1.6 mm
how to determine bone loss
Measure distance from CEJ to osseous crest on bitewing radiograph
Subtract 2 mm (Supracrestal Attached Tissues)
bone loss severity levels and percentage
- slight: <20% (<2mm bone loss)
- moderate: 20-40% (2-4 mm bone loss)
- severe: >40% (>4mm bone loss)
how to determine facial and lingual bone loss on radiograph
- difficult to visualize radiographically
- look for horizontal lines across the roots
what is an early radiographic change in periodontitis
loss of crestal bone lamina dura
signs of occlusal trauma
- Widened PDL
- Angular (vertical defects in bone
- Mobile teeth
- Thickened lamina dura
- Root resorption
- Fremitus
advantages of digital radiography
- Speed
- Lower radiation exposure
- Digital manipulation (Enhancement, Magnification, Contrast)
- Ease of transfer/storage
when can a vertical defect only occur? why?
if interproximal space is wider than 2.5 mm
because radius of action for bone resorption factors is 2.5 mm (spaces </= 2.5 mm have horizontal bone loss)
how is close root proximity measured? is bone loss vertical or horizontal
measured from CEJ to CEJ of adjacent teeth (</= 0.8 mm) so bone loss will be horizontal because not enough space for vertical defect
what are the classifications of vertical defects
- one walled
- two walled
- three walled
does a narrow or wider defect have a better prognosis? why?
Narrow vertical defect has a better prognosis
than a wide vertical defect.
Narrow defects have greater bone fill after bone graft procedure.
Vertical defect must be at least 3 mm deep to place a bone graft.
[vertical or horizontal] defects CAN be grafter. [vertical or horizontal] defects CANNOT be grafted
Vertical defects can be grafted. Horizontal
defects cannot be grafted.
what are concavities in the interdental bone between the facial and lingual plates
osseous crater
what are the different osseous architecture
- Positive - Interproximal bone crest is coronal to facial and lingual crests of bone
- Negative (Reversed) - Interproximal bone crest is apical to facial and lingual crests of bone
- Flat - Interproximal bone crest is at the same level as the facial and lingual crests of bone
type and location of furcations for max 1st molar
- Mesial Furcation - 3 mm apical to CEJ
- Buccal Furcation - 4 mm apical to CEJ
- Distal Furcation - 5 mm apical to CEJ
what is distance from CEJ to furcation entrance
root trunk length
type and location of furcations of mandibular 1st molar
Buccal Furcation - 3 mm apical to CEJ
Lingual Furcation - 4 mm apical to CEJ
when do you suspect furcation involvement for mesial maxillary 1st molar
3 mm CAL
location of furcations on max 1st premolar? birfurcations how many % of the time? clinical implications
- furcations on mesial and distal
- bifurcation 40% of the time (8 mm apical to CEJ)
- clinical implication: Severe bone loss and CAL before exposing the furcations
what is buttressing bone that may be related to excessive occlusal forces
exostosis
what is classified by number of walls fo bone remaining
vertical bone loss
