1. BONE LOSS&PATTERNS OF BONE DESTRUCTION
BONE DISTRUCTION DUE TO GINGIVAL INFLAMMATION
Most common cause
Periodontitis is always preceded by gingivitis
Not all gingivitis progress to periodontitis

2. BONE DISTRUCTION DUE TO GINGIVAL INFLAMMATION
Advancedcases:
no.of motile organism&spirochetes se where as coccoid rods &straight rods se
Fibroblast&lymphocyte se in stage I gingivitis
No. of plasma cells&blast cells ses gradually
T-lymphocyte predominate(contained gingivitis)

3. BONE DISTRUCTION DUE TO GINGIVAL INFLAMMATION Contd….
Extension of inflammation supporting tissue modified pathologic potential plaque Resistance of the host Degree of fibrosis of gingiva Width of attached gingiva Fibrogenesis&osteogenesis

4. BONE DISTRUCTION DUE TO GINGIVAL INFLAMMATION Contd….
HISTOPATHOLOGY
Inflammation extends through collagen fibers
Loosely arranged tissue around alveolar bone
Inflammatory infiltrate concentrated in the marginal periodontium&results crestal resorption/loss of attachment

5. BONE DISTRUCTION DUE TO GINGIVAL INFLAMMATION Contd….

6. BONE DISTRUCTION DUE TO GINGIVAL INFLAMMATION Contd….
inflammation bone marrow spaces replaces by leucocyte+fluid exudate,new blood vessels&proliferating fibroblast multinuclear osteoclast&mononuclear phagocytosis &bone surface (hawship lacunae)

7. RADIUS OF ACTION
Locally produced bone resorption factors may have to be present in the proximity of the bone surface to be able to exert their action(Grant&Cho)
Plaque can induce bone loss within mm beyond 2.5mm there is no effect(Waerhaug’s measurement)
I/P angular defects can appear in spaces wider than 2.5mm

8. RATE OF BONE LOSS Acc to Loe&co-workers
8% severe periodontal diseases,yearly loss of attachment 0.1-1mm
81%moderate periodontitis,CAL mm
11%mild Periodontitis, mm

9. PERIOD OF DESTRUCTION
Loss of collagen&alv bone with deepening of periodontal pocket
Theories…
Bursts of destructive activity associated with subgingival ulceration
Brusts of distructive activity coincide with conversion of T B lymphocyte-plasma cells
Period of exacerbation associated with
*increaseof loose,unattached,motile,gm-ve,anaerobic pocket flora.Periods of remission coincide with the formation of
*dense,unattached,nonmotile,gm-positive flora with a tendency to mineralize.
4.Tissue invasion by one/several bacterial species is followed by an advanced local host defence

10. MECHANISM OF BONE DESTRUCTION
Bacterial & Host mediated factor
Bacterial plaque bone progenitor cells
mediators gingival cells osteoclasts
Host induced factor(prostaglandin&their precursors,IL-1alpha&beeta,TNF-alpha)inducing bone resorption(in vitro)
NSAID such as ibuprofen inhibit PGE-2 production
slowing bone loss

11. BONE FORMATION IN PERIODONTAL DISEASE
Areas of bone formation are also found immediately adjacent to active bone resorption
The response of alveolar bone to inflammation includes bone formation &resorption
New bone formation retards the rate of bone loss,compensating in some degree for the bone destroyed by inflammation

12. BONE DESTRUCTION CAUSED BY TRAUMA FROM OCCLUSION
TFO caused destruction in the +ce/-ce of inflammation
In the absence of inflammation: se compression &tension of the PDL& se osteoclasis of alv bone to necrosis of PDL &bone & resorption of bone & tooth st.
Persistent TFO funnel shaped widening of the crestal portion of the PDL with resorption of the adjacent bone
With inflammation TFO aggravates the bone destruction & causes bizarre bone patterns

13. BONE DESTRUCTION CAUSED BY SYSTEMIC DISORDER
Bone factor in periodontal disease: systemic influence on
the response of alv bone (Irving Glickman 1950)
Bone factor is not in current use
The possible relationship between periodontal bone
loss&osteoporosis,osteopenia,hyperparathyroidism,
leukemia or langerhans’cell histiocytosis

14. FACTORS DETERMINING BONE MORPHOLOGY IN PERIODONTAL DISEASE
Normal variation in Alveolar bone
Exostoses
Trauma from occlusion
Buttressing Bone formation(Lipping)
Food Impaction
Aggressive Periodontitis

15. BONE DESTRUCTION PATTERNS IN P.DISEASES
Horizontal bone loss
Osseous defects
Vertical/Angular defects

16. VERTICAL/ANGULAR DEFECTS

17. BONE DESTRUCTION PATTERNS IN P.DISEASES Contd
Osseous Craters o.c.
Bulbous Bone Contours
Reverse Architecture

18. BONE DESTRUCTION PATTERNS IN P.DISEASES Contd
Ledges
Furcation Involvements

19. MCO-1
Which of the following is related with advanced stage of periodontal diseases
Fibroblast and lymphocyte predominate
No.of plasma cells and blast cells decreases gradually in C.T.
No.of motile organism and spirochete decreases
No.of coccoid rods and straight rods decreases

20. MCQ-2
On interproximal surface of tooth ,the pathways of inflammation from gingiva to supporting structures in periodontitis is
(a) Bone to gingiva
(b)Periodontal ligament to bone
(c)Gingiva to periodontal ligament
(d) Periosteum to bone

21. MCQ-3
Which is one of the following have better prognosis of periodontal regeneration
(a)One walled defect
(b)Two walled defects
(c)Three walled defects
(d)Horizontal defects

22. MCQ-4
According to Waerhaug’s concept the bacterial plaque can induce loss of bone in a range of
(a) mm
(b) mm
(c) mm
(d) mm

23. MCQ-5
What are the changes can be observed in the periodontal ligament due trauma from occlusion
Widening of periodontal ligament
Thinning of periodontal ligament
Necrosis of periodontal ligament
Shortening of periodontal ligament