Pathology of periapical periodontitis

Question 1

What is periapical periodontitis?

Answer 1

Inflammation of periodontal ligament and other tissues around tooth apex

Question 2

What are the 3 main causes of periapical periodontisis?

Answer 2

Usually due to spread of infection following death of pulp.
Extrusion of antiseptics through apex during root canal treatment.
A high filling or biting suddenly on a hard object sometimes cause an acute usually transient periapical periodontitis.

Question 3

What are some clinical findings of acute periapical peridontitis?

Answer 3

• History of pulpitis
• Escape of exudate into periodontal ligament causes a small amount of tooth extrusion
• Pain is well localised: tender to touch/percussion (patient can tell where pain is coming from)
• Tooth is not vital and not responsive to vitality tests unless pulpal necrosis is limited to a single canal in a multi-rooted tooth
• As inflammation becomes more severe, there can be intense throbbing pain
  Infection usually remains localised
• Abscess can develop
• Can spread in tissue planes causing facial swelling
• Rarely local lymphadenopathy
• Very rarely osteomyelitis or cellulitis (bone or skin infection)

Question 4

Acute periapical periodontitis - radiography?

Answer 4

bone resorption not likely time to happen so only radiographic change may be widening of the periodontal ligament space

Question 5

Acute periapical periodontitis - pathology?

Answer 5

Same as acute inflammation

Question 6

Management of acute periapical periodontitis?

Answer 6

• Endodontic treatment
• Extraction
• Open drainage through skin or mouth if needed due to abscess causing swelling (cut in skin or buccal mucosa)

Question 7

Clinical findings of chronic periapical periodontitis?

Answer 7

• Low grade infection
• May follow acute periapical periodontitis
• Tooth is not vital, unless very rarely pulpal necrosis is limited to a single canal in a multirooted tooth
• Symptoms may be minimal
• Can be tender to percussion

Question 8

What is the main thing found in a radiograph that diagnoses periapical radiolucency?

Answer 8

periapical radiolucency

Question 9

What is the main pathology of chronic periapical periodontitis?

Answer 9

Chronic inflammation and granulation tissue

Question 10

What is the sequelae of periapical periodontitis?

Answer 10

• Periapical granuloma and in some cases subsequently follows radicular cyst
• Acute exacerbation with suppuration/abscess, cellulitis and sinus (draining pathway that puss flows fro tooth to oral mucosa) formation
• Very rarely focal sclerosing osteitis

Question 11

Treatment of chronic periapical periodontitis?

Answer 11

Extraction or RCT

A radicular cyst needs to be ennuleated (removed minimally invasively)

Question 12

Give details on a periapical granuloma

Answer 12

• Most asymptomatic
• May be history of pulpitis.
• But can have coexisting pulpitis and therefore be symptomatic
• Tooth is not vital and will not be responsive to vitality tests unless the pulpal necrosis is limited to a single canal in a multirooted tooth

Question 13

What are radiographic features of periapical granulomas?

Answer 13

•75% of apical inflammatory lesions
•Most discovered on routine radiographs
•Tooth show s loss of apical lamina dura
•Bone resorption appearing as a radiolucency that may be circumscribed or ill-defined.
•Size variable:
•Small barely perceptible to 2 cm
- Larger lesions may represent radicular cysts
- Can’t definitely distinguish from a radicular cyst on size alone
- Root resorption can be seen rarely

Question 14

What is the pathology of periapical granuloma?

Answer 14

• Don’t confuse with granulomatous inflammation as in TB and Sarcoidosis etc. A periapical granuloma is not granulomatous inflammation
• See chronically inflamed granulation tissue at apex of a nonvital tooth
• Defensive reaction secondary to the presence of bacteria in the root canal with spread of related toxins into the apical zone
• Granulation tissue (loss of blood vessels)
• Neutrophils, lymphocytes, plasma cells, histiocytes multinucleated giant cells
• Cholesterol clefts and haemosiderin (Result of RBC breakdown)
• Small foci of acute inflammation with focal abscess formation may be seen but do not w arrant the diagnosis of periapical abscess (an abscess is an exudate consisting of neutrophils, the liquefied debris of necrotic cells and oedema fluid)
• Surrounding fibrous wall
• Bone resorption
• Tooth can be resorbed but generally more resistant than bone

Question 15

What is the relation of periapical granulomas to apical scar?

Answer 15

Defect created by periapical inflammatory lesions may rarely heal by filling with dense fibrous tissue than than normal bone.
- These fibrough periapical scars occur most frequently when both the facial and lingual cortical plates have been lost

Question 16

What is the relation of periapical granulomas to periapical absecess?

Answer 16

Periapical granulomas may arise after quiescence of a periapical abscess or may develop as the initial periapical pathology

Question 17

What is the relation of periapical granulomas to radicular cysts?

Answer 17

A cyst is an epithelial lined cavity.
Cell rests of Malassex (epithelial remnants from tooth development) lying in vicinity of periapical area may show reactive proliferation to inflammation/infection leading to a radicular cyst.

Question 18

What is focal sclerosing osteitis?

Answer 18

•Very rare
•Most frequent in children and young adults but can occur in older people
•Localized, usually uniform bone sclerosis (radiodense) adjacent to tooth apex of a tooth w ith periapical periodontitis
•Most occur in low er premolar and molar areas
Can resemble several other intrabony lesions
Does not exhibit a radiolucent border, as is seen in cases of focal cemento-osseous dysplasia (you will learn about this later in the course) , although an adjacent radiolucent inflammatory lesion may be present
Clinical expansion should not be present or consider another diagnosis!

Treatment and prognosis
•85% of cases of focal sclerosing osteitis w ill regress, either partially or totally, after root canal treatment or tooth extraction
•A residual area of condensing osteitis that remains after resolution of the inflammatory focus is termed a bone scar