1. Endodontics Lecture: Periradicular Pathosis
Lecturer : Dr. Ghassan Zyoud

2. As a consequence of pulpal necrosis , pathologic changes can occur in the periradicular tissues .
In contrast to pulp periradicular tissues have an almost unlimited source of undifferentiated cells that participate in inflammation as well as repair .
In addition these tissues have a rich collateral blood supply and lymph drainage .
Depending on severity of irritation , duration and host response , periradicular pathoses may range from slight inflammation to extensive tissue destruction .

3. Classification of Periradicular Lesions
Periradicular Lesions have been classified on the basis of their clinical and histologic findings .
These lesions are classified into Five groups:
1) Acute Apical Periodontitis .
2) Chronic Apical Periodontitis .
3) Condensing Osteitis .
4) Acute Apical Abscess .
5) Chronic Apical Abscess .

4. Continue :
Lesions associated with significant symptoms such as pain or swelling are referred to as acute (symptomatic)
Lesions associated with mild or no symptoms are identified as chronic
( asymptomatic ).

5. (1) Acute Apical Periodontitis
- Described as symptomatic apical periodontitis .
- The first extension of pulpal inflammation into the periradicular tissues is called Acute Apical Periodontitis .

6. Etiology
Irritants
1= include inflammatory mediators from an irreversibly inflamed pulp .
2= egress of bacteria toxins from necrotic pulps .

7. Continue : b) Chemicals : such as irrigants or disinfecting agents .
c) Restorations in hyperocclusion .
d) Over instrumentation .
e) Extrusion of obturating materials .
The pulp may be irreversibly inflammed or necrotic
NOTE

8. Signs and Symptoms : Clinical features of AAP are moderate to severe .
Spontaneous discomfort as well as pain on mastication or occlusal contact .
If AAP is an extension of pulpitis , signs and symptoms will include :
Responsiveness to cold , heat and electricity .
If AAP is caused by necrosis , teeth don’t respond to vitality tests.
Application of pressure by fingertip or tapping can cause marked pain .
Thickening of periodontal ligament (PDL) space may be a radiographic feature of AAP.
Usually there is a normal PDL space and an intact Lamina dura .

9. Histologic Features
In AAP , PMN : Leukocytes and macrophages are visible within a localized area at the apex .
There may be a small area of liquefication necrosis .
Bone and root resorption may be present .
Resorption is usually not visible radiographically .

10. Treatment Adjustment of occlusion .
Removal of irritants or a pathologic pulp .
Release of periradicular exudate .
R.C.T .

11. (2) Chronic Apical Periodontitis:
Etiology
Result from pulpal necrosis .
Is sequel to AAP .

12. Signs and Symptoms Usually is asymptomatic .
Or associated with slight discomfort.
Teeth with CAP do not respond to
* electrical
* thermal stimuli
Percussion produces little or no pain
There may be slight sensitivity to palpation .

13. Radiographic Features
Range from interruption of the lamina dura to extensive destruction of periradicular and interradicular tissues .

14. Histologic Features CAP are classified as either * granulomas * Cysts
periradicular granuloma consists of
- granulomatous tissue infiltrated by mast cells , macrophages , lymphosytes , plasma cells and PMN leukocytes
multinucleated giant cells , foam cells ,cholesterol ,clefts and epithelium

15. Apical ( radicular) syst
Has a central cavity filled with an eosinophilic fluid or semisolid material
Lined by stratified squamous epithelium
The epithelium is surrounded by connective tissue that contains all cellular elements
Treatment - RCT or apical surgery or Extraction

16. condensing osteitis
Definition
Etiology
Sings and Symptoms
Treatment

17. Definition Etiology
Is an apical periodontitis represent an increase in trabecular bone in response to persistent irritation
etiology
the irritant diffusing from the root canal into periradicular tissues is the main cause
This lesion is usually found around the apexes of mandibular posterior teeth

18. Sings and symptoms Depending on the cause (pulpitis or pulp necrosis)
Condensing osteitis may be either
or associated with pain
May not respond to electrical or thermal stimuli
May or may not be sensitive to palpation or percussion

19. Radiographically:
presence of a diffuse concentric arrangement of radiopacity around the root of a tooth .
Histologically:
there is an increase in irregularly arranged trabecular bone and inflammation
Treatment : RCT result in complete resolution

20. Acute apical abscess Definition Etiology Signs and symptoms
Histologic features
Treatment

21. Definition Etiology
AAA is a localized or diffuse following liquefaction lesion that destroys periradicular tissues
It is a severe inflammatory response to--- ; microbial and
; non bacterial irritant from necrotic pulp

22. sings and symptoms
Depending on severity of the reaction patients with AAA
Have moderate to severe discomfort or swilling
They have systemic manifestation of an infective process such as
a) high temperature
b) malaise
c) leukocytosis

23. sings This disease associated with necrotic pulp
No response on electrical , thermal ,tests
Painful on percussion and palpation
Radiographically ;
depending on the degree of hard tissue destruction caused by irritants
The radiographic features of AAA range from --- thickening of the PDL space
__ frank resorptive lesion

24. sings Histologic features
- shows a localized destructive lesion of liquefaction necrosis
Contains – PMN leukocytes , debris , cell remnants and accumolation of purulent exudate
Treatment: removal of the underlying cause
release of pressure , RCT or EXTRACTION

25. Chronic Apical Abscess suppurative apical periodontitis
Definition
Etiology
Sings and symptoms
Treatment

26. Defintion Etiology
Is a chronic apical abscess result from a long –standing lesion that has caused an abscess which is draining to a surface
Etiology
CAA has a pathogenesis similar to that of AAA
Result from pulp necrosis associated with CAP
The abscess has ( burrowed ) through bone and soft tissue to form a sinus tract stoma on the oral mucosa or sometimes onto the skin of the face

27. Histologic findings are similar to those found in CAP
Sings and Symptoms
because drainage exists
CAA is usually asymptomatic except when there is closure of the sinus pathway which can cause pain
Clinical radiographic and histopathologic features of CAA are similar of the CAP
An additional feature is the sinus tract

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