Week 13 - Bone defects and Periodontitis Flashcards
(25 cards)
What is periodontitis
- All periodontitis begins as untreated gingivitis (not all gingivitis progresses to periodontitis)
- Periodontitis involves connective tissue attachment loss.**
- Clinical signs: periodontal pockets, tooth mobility, pus, and gingival recession.
Tissue damage in periodontal pockets is caused by what
- Subgingival microbiota e.g.
- Virulence factors: ammonia, butyric acid, hydrogen sulfide.
- Key pathogens: P. gingivalis, A. actinomycetemcomitans.
- Enzymes: Gingipains, fimbriae, bacterial DNA.
- Host immune inflammatory response
e.g. - TNF, IL-1, IL_6, IL-17
- enzymes: MMPs
- chemokines: IL-8
How does host immune inflammatory response cause tissue damage
- Inflammation is associated with the overproduction of various pro-inflammatory cytokines: TNF, IL-1, IL-6, IL-17 → cause excessive bone degradation mainly due to hyperactivation of osteoclasts (although some cytokines can also impair osteoblast function.
What is the involvement of bone homeostasis in tissue damage in periodontitis
- Key molecules in osteoclast differentiation and activation include: RANK, RANKL, and macrophage colony-stimulating factor
- In periodontitis there is increased RANKL and decreased OPG in comparison to healthy periodontal health
↑ RANKL, ↓ OPG → ↑ bone resorption.
What are factors affecting bone loss
- Bone thickness, width, crestal angulation of the interdental and buccal/lingual bone
- Proximity to another tooth surface
- Root position within the alveolar process
- Alignment of the teeth
- Presence of fenestrations and dehiscence
What is Fenestration
localized “window-like” defect in the alveolar bone where the root surface of a tooth is exposed, but the alveolar crest remains intact
What is dehiscence
loss of alveolar bone that extends from the crest (marginal bone) down along the root surface, creating a long vertical defect that exposes the root surface
What are the different types of bone defects
- horizontal bone loss
- Vertical (angular) bone defects
What are Suprabony Defects
Where the periodontal pocket is located coronal to the alveolar crest.
What are infrabony defects
Where the periodontal pocket is located apical to alveolar crest.
What are pseudo pockets
no bone defect
Where a false periodontal pocket forms due to gingival enlargement without any loss of connective tissue attachment or bone
What are the different types of wall defects
- 3 walled
- 2 walled
- 1 walled
- combined - mixed walls has 2.5 or 1.5
What are osseous craters
A type of 2 walled vertical bone defect where buccal and lingual walls remain – a bowl shaped defect in the interproximal alveolar bone (depression in the middle)
What is reverse architecture
Where interproximal bone lower than buccal/lingual – creating abnormal slope of bone around teeth
What are the ways which bone defects can be diagnosed
- Radiographic: IOPA, OPG, Bitewing (2D); CBCT (3D)
- Clinical:
o Indirect – Pocket configuration (not reliable)
o Bone sounding: Assessing with probe under LA
o Direct: Open flat surgery
What is furcation involvement
condition where periodontitis has progressed to the point of damaging the bifurcations and trifurcations of multirooted teeth
What is the most common tooth to get furcation involvement
- Mandibular 1st molar
What is the least common tooth to get furcation involvement
Maxillary premolar
What tooth is the most difficult to treat for furcation involvement
Upper molar
What is a furcation involvement class 0
no furcation involvement
What is a furcation involvement class 1
Incipient – horizonal loss of periodontal tissue support up to 3mm
What is a furcation involvement class 2
Partial – Horizontal loss of supporting exceeding 3mm but not encompassing the total width of the furcation area
What is a furcation involvement class 3
Complete – probe passes completely through, horizontally “through and through” – destruction of the periodontal tissue
What are radiographic signs of occlusal trauma
- widening of PDL space
- Lamina dura thickening.
