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Diseases of the Pulp & Peri-apical Tissues

An encounter between root canal infection and host response

Prepared by Dr Lea Foster

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e.g. Shallow caries, leaking rest.

Persistent irritationBacterial invasion

Irreversible pulpitis

Reversible pulpitis

Reversible pulpitis

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Reversible Pulpitis

Vital pulpLocal areas of inflamed tissue – will heal after irritant is removed

Restore caries, re-do leaking rest., treat exposed dentine

Symptoms can be misleadingOn thermal stimulation – may be no, to very intense sharp response

Reversible pulpitis

Symptoms – Patient often reports sens. to cold foods/drinksSigns

TestsCold: increased response compared to normalPossible slight sens. to percussion

RadiographyNormal appearance – normal perio. ligament width

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Reversible pulpitis

Irreversible pulpitis

Irreversible Pulpitis

Pulp is vital but severely inflamedHealing is unlikely with conservative treatmentPulp necrosis and infection in the root canal is the likey outcome if conservative treatment is attemptedIf untreated will lead to apical periodontitis

Irreversible PulpitisSymptoms – can be misleading

May be asymptomatic? 26 – 60% cases 4See this reference for more detail on how this can occur

If symptomatic – tooth is very sensitive to thermal changes

Cold, hot and pain will often linger after stimulation4

See this reference for more detail on how this can occur

The longer it has been symptomatic, the more severe the pain & any history of spontaneous pain – more likely irreversible pulpitis

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Irreversible pulpitisSigns and symptoms

TestsCold: increased responseHot: increased responseLingering pain after thermal stimulationSpontaneous pain

Radiographic signsNormal or possible widened ligament

The more long-standing the condition the more potential for inflammation of apical tissues

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a) Clinically normalNo symptomsNo signs

Normal PDL widthNo loss of lamina duraNo loss of bone density periapicallyNo resorption of dentineResponds WNL to tests

Clinically normal

Thin PDL

Apical Periodontitis

Peri-apical tissue reactions are directly related to the bacterial invasion of the root canal5

b) Apical periodontitis

Acute1.Primary - 1°2.Secondary -

2° (or acute exacerbation)

Chronic1.Granuloma2.Condensing

osteitis

Inflammation of the periapical tissues

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e.g. Shallow caries, leaking rest.Irreversible pulpitis

Reversible pulpitis

Granuloma

OR

Condensing Osteitis

Persistent irritationBacterial invasion 1° Acute apical periodontitis

In only on instance can be sterile – bruxism

OR if bacteria are involvedOccurs when bacteria invade the root canal for the first time

Bacterial invasion is a dynamic encounter with host tissueHost tissue can mobilise barriers anywhere inside the pulp spaceMore long-standing lesion – greater likelihood for bacteria to gain ground

1° Acute apical periodontitis

Signs & symptomsTooth becomes tender to percussion (TTP)

Tooth may still display signs of irreversible pulpitisTooth may be unresponsive to thermal/electric testing (completely non-vital)Radiographically – normal PDL or Slightly widened

1° Acute apical periodontitis

Slightly widened PDL7

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2° Acute apical periodontits

Acute exacerbation of a chronic condition

Pulp completely non-vitalTTPNo response to thermal or electric testing

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Chronic apical periodontits

Apical granulomaTooth is often symptom free but may have low grade symptoms that come and goTooth gives no response to thermal or electric testsMay exhibit slight TTP

Granulation tissue

Fibrous tissue –black arrows

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Granulation tissue

Fibrous tissue

Granulation tissue

Accumulation of neutrophils - microabscess

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Chronic apical periodontits

Condensing osteitisA possible response to long-standing irreversible pulpitis or a non-vital infected pulp space

Condensing osteitis

Signs and symptomsMay have mildly heightened sensitivity to thermal stimuli (irreversible pulpitis)May have no response to thermal / electric stimuli (non-vital)May or may not have sensitivity to percussionRadiopaque lesion associated with root apices

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c) Periapical cyst

True cyst Pocket cyst

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Periapical cysts

Cyst - a sequel to a peri-apical granuloma

Not every apical granuloma will become a cystPocket cyst – thought to have the potential to heal with conventional RCTTrue cyst – thought to require surgical treament to excise the lesion

29-43% contain cholesterol crystals –may prevent spontaneous repair

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Cholesterol crystals

CT – connective tissueNT – necrotic tissueD – dentineCC – cholesterol crystals

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Cysts

Signs & symptomsSimilar to other Chronic lesionsTTP or maybe notTender to palpation over buccal/labial aspect of alveolus or maybe notTooth not responsive to thermal/electric stimuliClearly demarcated, rounded lesion associated with apex of tooth

d) Periapical abscess

Acute abscess1. Primary (1°)2. Secondary (2°)

Chronic abscess (with sinus)

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1° Acute Apical AbscessSigns & symptoms

Tooth xt. sens. to percussion/touchNo response to thermal/electric (non-vital)Tender to palpation over buccal tissuesPossible radiographic lucency – widened ligament –diffuse appearance (unlike cyst)Accumulation of inflammatory exudate

Develops as a sequel to primary acute apical periodontitis

2° Acute Apical AbscessSigns & symptoms

Tooth xt. sens. to percussion/touchNo response to thermal/electric (non-vital)Tender to palpation over buccal tissuesRadiographic lucency – widened ligament –diffuse appearance (unlike cyst)Accumulation of inflammatory exudate

Develops as a sequel to 2°acute apical periodontits or chronic apical periodontitis

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Acute abscess (1° & 2°)

The abscess is ‘pointing’ but has not drained yetFluctuant swelling

Chronic apical abscessWith draining sinusSigns & symptoms

Low grade symptomsMaybe slight TTPNo response to thermal/electric testsPeriodic bad taste in mouthMay be slight to no tenderness to palpation

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e) Facial cellulitis

Firm swelling

Facial cellulitis

May be a sequel to:1° acute apical abscess2° acute apical abscessChronic abscess

Instead of draining via sinus to oral cavity or externally onto the face, spreads along fascial planes of the face, head and neckCan have serious complications

Systemic complications

Osteomyelitis, Ludwig’s angina, Actinomycosis, Orbital cellulitis, Cavernous sinus thrombosis, Brain abscess, Mediastinitis, Neural complicationsWhen bacterial toxins enter blood stream – Septic shock, Bacteraemia, Septicaemia

Cellulitis - radiographic appearance

Tooth may or may not exhibit apical radiolucency

Depends on whether it is a sequel to 1°apical abscess, 2° apical abscess

Tooth will exhibit necrotic infected pulp or will be pulpless with infected root canal systemSigns & symptoms

Similar to those of apical abscess

f) Extra-radicular infectionMicro-organisms establish colonies on external root surface within the periapical region1

Sequqel to infected root canal system or previous RCT – extra-radicular species similar to those found in the root canalSigns & symptoms

No symptoms or similar to those of apical abscess – acute or chronicRadiographic appearance similar to granuloma, abscess, cyst or peri-apical scar

Extra-radicular infection

Peri-apical actinomycosis

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Extra-radicular organisms found in the following situations

Apical abscess, long-standing draining sinus, infected radicular cysts (esp. pocket cysts), peri-apical actinomycosis and with infected dentine pieces that have been displaced into apical periodontal tissues during RCT

Extra-radicular infection Extra-radicular infection

Diagnosed by histological examination of the tissue removed during apical surgeryIf symtoms persist after conventional RCT – extra-radicular infection or cyst must be suspected

g) Foreign body reaction

Inflammatory response to foreign material in peri-apical tissues

Often root canal obturation materialOther materials – talcum powder from gloves, cellulose fibres from paper points

Not visible radiographically

Appearance may be radiolucent lesion similar to inflammation from an infectious process

Extruded obturation material does not always result in foreign body reaction

Foreign body reaction

Foreign body reaction to Cellulose

FB – paper pointRT – root tipEP – epitheliumBP – bacterial plaquePC – plant cell

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h) Periapical scarNeither disease or pathological condition

Healing response without bone deposition following treatment of a lesion which has caused bone resorption

Granuloma, cyst, abscess, extra-radicular infection or foreign body reaction10

Majority seem to be associated with surgical defects Appear as radio-lucencies located at a distance from the root apexMost commonly affected – upper laterals with ‘through and through’ defects – involving both palatal and labial cortical plates – heal with connective tissue ingrowth11

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References1. Classification, diagnosis and clinical manifestations of apical periodontitis Paul V Abbott

Endodontic Topics 2004:8:36-542. Sundqvist, Figdor Life as an Endodontic pathogen Endodontic Topics 2003, 6, 3-283.3. Apical periodontitis: a dynamic encounter between root canal infection and host response

p.N. Nair Periodontology 2000 1997:13:121-1484. Pulpal diagnosis Sigurdsson Endodontic Topics 2003:5:12-255. Pulpal and periapical tissue responses in conventional and mono-infected gnotobiotic rats

Kakehashi et.al. Oral Surg 1974:37:783-8026. Bacteriological studies of neccrotic pulps Sundqvist Umea University Odontological

Dissertations No. 7 19767. Urgent Care in the Dental Office: An Essential Handbook Terezhalmy, Geza T

QuintessencePublishing (IL), 011998. 7.2.2).8. Light microscopic study of periapical lesions associated with asymptomatic apical periodontitis

S.L. Kabak, Y.S. Kabak, S.L. Anischenko Ann Anat 187 (2005) 185—1949. Non-microbial etiology: foreign body reaction maintaining posttreatment apical periodontitis

P.N. RAMACHANDRAN NAIR10. Persistent Periapical radiolucencies of root-filled human teeth, failed endodontic treatments,

and periapical scars Nair PNR, Sjo¨gren U, Figdor D, Sundqvist G.. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999: 87: 617–627

11. A multivariate analysis of the influence of various factors upon healing after endodontic surgery Rud J, Andreasen JO, Mo¨ller Jensen JE.. Int J Oral Surg 1972: 1: 258–271