Periapical Diseases

Periapical DiseasesIntroductionAs a consequence of pathologic changes in dental pulp, the root canal can harbor numerous irritants.Egress of these irritants into the periapical tissues can initiate periradicular lesions. Depending on the nature and quality of these irritants as well as the duration of exposure of the periradicular tissues, a variety of tissue changes can occur. Radiographically: Radiolucent areas are seen around portal(s) of exit of main canal or lateral and/or accessory canals.

CLASSIFICATION:

According to GROSSMAN

1) Acute periradicular diseases Acute alveolar abscess Acute apical periodontitis - Vital - Nonvital 2) Chronic periradicular diseases with areas of rarefactionChronic alveolar abscess GranulomaCyst3) Condensing osteitis4) External root resorption 5) Diseases of periradicular tissues of nonendodontic origin

Ingles classification

1. Acute apical periodontitis2. Advanced stages of acute periodontitisa. Acute apical abscessb. Phoenix abscess c. Chronic apical abscess Nonpainful pulpo-periapical pathoses3. Condensing osteitis 4. Chronic apical periodontitis a) Periapical granuloma b) Apical cyst c) Suppurative apical periodontitis

ACUTE PERIRADICULAR DISEASES

ACUTE ALVEOLAR ABSCESS:(Synonyms: Acute periapical abscess, Acute dentoalveolar abscess)Definition:Localised collection of pus in the alveolar bone at the root apex of tooth following death of pulp, with extension of infection through apical foramen into periradicular tissues.Causes:Bacterial invasion , trauma, chemical or mechanical irritation. Symptoms: First symptom - is tenderness.Later - patient has severe throbbing pain with swelling of the overlying soft tissue.As the infection progresses, swelling becomes more pronounced and extends beyond the original site.

Tooth becomes more painful, elongated and mobile.If untreated - progresses to osteitis, periostitis, cellulitis or osteomyelitisSinus tract - opens to buccal mucosa.When Maxillary anterior teeth - swelling of upper lip (extend to both eyelids).When Maxillary posterior teeth - the Cheek may swell distorting facial features. Mandibular posterior teeth - swelling extends around border of jaw into submaxillary region. Gutta-percha is placed in the sinus tract - points to involved tooth:Sinus tract tracing: General Systemic reaction is seen (Septic products)Patient appears - Pale, Irritable & Weakened from pain and loss of sleepDiagnosis:Early stage - difficult to locate tooth. Once infection progresses to process of periodontitis & extrusion, a radiographic evaluation shows thickening of periodontal ligament space & breakdown of bone.Electric test & thermal tests: No responseTooth is tender on percussion.Apical mucosa is tender on palpation.Tooth may be mobile & extruded.Differential diagnosis: Periodontal abscess & Irreversible pulpitis. Periodontal abscess: is accumulation of pus along root surface that originates from infection in supporting structures of tooth. Associated with periodontal pocket, pus may exudate through the sulcus. Swelling is present opposite to midsection of root and gingival border.

Histopathology:Marked infiltration of PMNL Inflammatory exudate & Clumps of microorganism are seenTreatment:- Establish drainage & control systemic infection.- Main objective is to relieve pain (drainage can be established through root canal or soft tissue and bone) , incision and drainage is instituted.Prognosis: Is favourableON FIRST VISIT: Tooth is left open for drainage. Thorough instrumentation & irrigation before medicating and sealing.Once the swelling and pain subside endodontic treatment is done.If diffuse swelling: Antibiotic coverage is prescribed along with hot mouth rinse. Once area is localised incision and drainage is instituted.

Prognosis: Is favourable

ACUTE APICAL PERIODONTITISIs a painful inflammation of periodontium as a result of trauma, irritation or infection through root canal regardless of pulp is vital or non-vital.Histopathologic Classification:1) Acute apical periodontitis (PMNL): Primary & secondary2) Chronic apical periodontitis (Lymphocytes, macrophages, plasma cells}3) Cystic lesions - True cyst, Pocket cyst

Apical PeriodontitisCausesOcclusal trauma Wedging of foreign object between teeth Non-vital tooth (diffusion of bacterial by products)Iatrogenic: during over instrumentation & extrusion of irritating medicaments Perforation of root

Symptoms - Pain and tenderness- Tooth may be slightly sore, when percussed.- Tooth may be extruded, making closure painful.Diagnosis Tooth is tender to percussion Symptoms are due to overinstrumentation, irritating medicament or overfillingRadiographically: thickened periodontal ligament or small area of rarefaction

HistopathologyInflammatory reaction in apical periodontal ligament Blood vessels are dilated, PMNLs are presentAccumulation of serous exudate distends the periodontal ligament Osteoclasts are present

Treatment Consists of determining the cause and relieving the symptomsWhen acute phase has subsided the tooth is treated with conservative means

Prognosis: Is favourable.

ACUTE EXACERBATION OF A CHRONIC LESION(PHOENIX ABSCESS)An acute inflammatory reaction superimposed on an existing chronic lesion, such as a cyst or granuloma Cause1. Noxious stimuli from a diseased pulp with chronic periradicular disease. 2. Because of influx of necrotic products or bacteria and their toxins, the dormant lesions (granuloma & cyst) may become reactive & cause an acute inflammatory response. 3. Lowering of the body's defenses in the presence of bacteria - may also trigger an acute inflammatory response.4. Mechanical irritation during root canal instrumentation Symptoms Tooth - tender to touch & elevated in its socket Mucosa - sensitive to palpation & appears red & swollenDiagnosis - Acute symptoms - Radiographically: Well-defined periradicular lesions.- Lack of response to vitality tests - Electric pulp test: May show positive response

Differential diagnosis: Acute alveolar abscess, Acute irreversible pulpitis.Histopathology: Liquefaction necrosis with disintegrating PMNL & cellular debris (pus), surrounded by infiltration of macrophages, lymphocytes & plasma cellsTreatment - is same as that of an acute alveolar abscess. Prognosis is good (once the symptoms subside).

CHRONIC PERIRADICULAR DISEASES WITH AREAS OF RAREFACTION(Includes: Chronic alveolar abscess, Granuloma and Radicular cyst)

CHRONIC ALVEOLAR ABSCESS(Chronic Suppurative Apical Periodontitis)Definition - A chronic alveolar abscess is a long-standing, low-grade infection of the periradicular alveolar bone. Cause 1. Death of the pulp with extension of the infective process periapically 2. A pre-existing acute abscess.Signs & symptoms - Asymptomatic tooth - Associated with little discomfort- Sinus tract associated with Mandibular anterior teeth - opens near the symphysisMandibular posterior teeth - inferior border of mandible - If the sinus tract drainage becomes blocked pain & swelling- Range of sensitivity to percussion & palpation depends on the sinus tract is open, draining or closed.A radiograph with a gutta-percha cone into the sinus tract often shows involved tooth by tracing the sinus tract to its originDiagnosis Chronic abscess may be painless or mildly painful. First sign - osseous breakdown (radiographically) seen during routine examination or discoloration of tooth. Radiographically - a diffuse area of bone rarefactionPeriodontal ligament is thickened. Vitality tests NegativeClinical examination shows: a cavity, composite, acrylic or metallic restoration a gold or jacket crown.Histopathology

Histopathology Periodontal fibers at root apex are detached / lost destruction of the apical PDLApical cementum may be affected. Lymphocytes, plasma cells at the periphery & PMNLs at the centerFibroblasts - form a capsule at periphery.Treatment Treatment consists of elimination of infection The sinus tract ultimately heals by granulation When sinus tract does not heal while the tooth is under endodontic treatment, it is curetted with a small spoon excavator.Prognosis Depends on proper cleaning, shaping and obturation of the root canalsGood

PERIAPICAL GRANULOMA

Is a growth of granulomatous tissue continuous with the periodontal ligament resulting from death of pulp & diffusion of bacteria and bacterial toxins from root canal into the surrounding periradicular tissues through apical and lateral foramina. Cause 1) Is death of the pulp, followed by a mild infection or irritation of the periapical tissue that stimulates a productive cellular reaction.2) A granuloma is preceded by a Chronic alveolar abscess.

Clinical features Mild pain / Sensitive to percussion Tooth slightly elongated Sinus tract may or may not present Vitality test negative History of subsided pulpalgiaDiagnosis Radiographically: Well defined radiolucency, with lack of continuity of the lamina dura. Diameter Varies from a fraction of a millimeter to a centimeter or even larger. Exact diagnosis - by microscopic examination. No mobility. Mucosa- May or may not be tender to palpation.Tooth does not respond to thermal or electric pulp tests

ZONES OF A WELL-ESTABLISHED GRANULOMA (FISH ZONES)

Zones of a well established Granuloma (Fish Zones)

Kronfelds mountain pass conceptKronfeld: Granuloma is not an environment in which bacteria live but one in which they are destroyed. ZoneI compares bacteria in the root canals with an invaders entrenched behind high and inaccessible mountains Foramina: Mountain passes.Granulomatous (proliferative) tissue: mobilized army defending plains (periapex) from invaders. Major battle (b/w invaders + WBCs) - acute inflammation (zone II) Local destruction created by battle is repaired (granulation tissue - zone III)

Histopathology Granulomatous tissue replaces alveolar bone & periodontal ligament.Consists of rich vascular network, fibroblasts, lymphocytes & plasma cells.Macrophages & foreign-body giant cells. Foam cells, macrophages containing lipid material & cholesterolAlveolar bone shows resorption (osteoclasts). Incidence of epithelium derived from cell rests of Malassez is high. Treatment Root canal treatment / surgery Prognosis: Good.

CYSTS

Definition: A cyst is a closed cavity or sac internally lined with epithelium, the center of which is filled with fluid or semisolid material. Classification: Odontogenic, Non-odontogenic & Non-epithelial.

I) Odontogenic cysts arise from odontogenic epithelium Classified as: 1. Inflammatory- Radicular, Paradental cyst2. Developmental- Dentigerous, Odontogenic KeratocystII) Nonodontogenic cysts classified as:1) Fissural cyst2) Nasopalatine cystIII) Pseudocysts or nonepithelial cysts: are bony cavities that are not lined with epitheliumDivided into: Traumatic cysts, Idiopathic bone cavities, Aneurysmal bone cyst. . RADICULAR CYST

Is a slowly growing epithelial sac at the apex of a tooth that lines a pathologic cavity in the alveolar bone. The lumen contains a low-concentration of proteinaceous fluid

Cause:Physical, chemical or bacterial injury (death of pulp), followed by stimulation of epithelial rests of Malassez.

Symptoms:No symptoms, except those seen in necrosis of pulp. A cyst may become large enough, to be obvious as a swelling.Pressure of cyst causes movement of affected teeth

Teeth are mobile. If left untreated - continues to grow at expense of maxilla or mandible.Diagnosis- Tooth does not react to electrical or thermal stimuli.- Radiographically - Loss of continuity of lamina dura with an area of rarefaction.- Radiolucent area - round in outline except where it approximates adjacent teeth in which case it is flattened & oval shaped. - Larger than granuloma & may include more than one tooth.- Radiographic examination - not sufficient for diagnosis.

HistopathologyShows central cavity lined by stratified squamous epithelium.Connective tissue is infiltrated by lymphocytes, plasma cells, PMNL, cholesterol clefts, macrophages, & giant cells. Cystic cavity contains cellular debris and pale eosinophilic fluid.According to PNR Nair, two types of radicular cysts: (1) Those containing cavities completely enclosed in epithelial lining &(2) Those containing epithelium-lined cavities that are open to the root canals - (periapical pocket cysts)Differential Diagnosis Periapical granuloma, Globulomaxillary cyst. TreatmentTrue cyst: Root canal treatment of the affected tooth, together with surgical enucleation may be attempted.Pocket cyst: Conventional RCT, followed by periodic observation.Surgical enucleation of radicular cysts is not necessary in all cases. It is indicated if a lesion fails to resolve or if symptoms develop.Prognosis:Depends on extent of bone destroyed & accessibility for treatment.

CHRONIC PERIRADICULAR DISEASE WITH AREA OF CONDENSATION

CONDENSING OSTEITIS

Condensing osteitis is the response to a low grade, chronic inflammation of periradicular area as a result of a mild irritation through the root canal.Characterized as a localized overproduction of apical bone. Cause Mild irritation from pulpal disease - stimulates osteoblastic activity

SymptomsUsually asymptomatic, discovered during routine radiographic examination.

Diagnosis Radiographically: a well-circumscribed radioopaque area around one or all of the roots Mandibular posterior teeth - frequently affected.Tooth may or may not respond to electrical and thermal stimuliHistopathology An area of dense bone with trabecular borders lined with osteoblasts. Chronic inflammatory cells, plasma cells and lymphocytes are also seen.TreatmentEndodontic treatment.Prognosis Good. Lesion may persist after endodontic treatment.

EXTERNAL RESORPTION

Classification (By James L. Gutmann et al in 1999 )1. External surface resorption2. External inflammatory root resorption3. Dentoalveolar ankylosis4. Replacement resorption1) External surface resorptionSpontaneous destruction & repair of root surfaceIt is a normal physiologic response to minor injuriesMechanical damage to the cementum Localized area of resorption & repairComplete periodontal healing & root surface healing in - 14 daysSymptomless, cannot be detected in routine radiographs Does not require any treatment.

External inflammatory root resorption

Injury or irritation to periodontal tissues where inflammation is beyond repair.

Causes Trauma Orthodontic tooth movement - excessive forces.Trauma from occlusionPeriodontal pathology Avulsion & luxation injuriesClinical FeaturesH/o traumaNecrotic pulp / irreversible pulpitisTooth mobilityPercussion sensitivityIf resorption communicates with gingival sulcus- leads to pocket formation

Radiographic features

Bowl like radiolucency with ragged irregular area on the root surface and loss of tooth structure and alveolar bone. Treatment Endodontic treatment with calcium hydroxide intracanal medication.3) Dentoalveolar ankylosis

Union of tooth & bone with no intervening periodontal ligament & connective tissue. Etiology Trauma, Intrusive luxation, Reimplantation of avulsed tooth (damage to PL cells & cementum)Clinical features Lack of mobility, lack of mesial driftDull metallic sound on percussion Infraocclusion Radiographic featuresMoth eaten appearance with irregular border. Absence of periodontal ligament & lamina dura.Treatment: No treatment

4) Replacement Resorption

Cause: luxation injuries There is presence of an intervening inflamed connective tissue. Clinical features Lack of mobility, lack of mesial driftHigh pitched response to percussionInfraocclusion Radiographic featuresDisappearance of PDL, with progressive rot resorption followed by bne replacementDefect margins - irregularTreatment of ankylosisUsually progresses until there is little or no root left, and tooth extractin is necessary.

NONENDODONTIC PERIRADICULAR LESIONS

Many of the nonendodontic lesions mimic endodontic pathema, with similar symptoms and radiographic appearance.Many of the nonendodontic lesions are symptoms and are detected only on radiographs.To avoid errors, the dentist must approach all lesions with caution, whether symptomatic or not. Lesions of the jaws: Odontogenic or Nonodontogenic

ODONTOGENIC CYSTS

Dentigerous Cyst Derived from reduced enamel epithelium of an impacted or embedded tooth. (Eg: Crowns of impacted third molars, maxillary canines or mandibular second premolars)Common in mandibleMost remain small & asymptomatic (potential to become aggressive lesions)Continued enlargement may involve large areas of the jaws, with displacement of teeth & expansion of cortices.Radiographically:- Unilocular radiolucency with well-defined sclerotic margins- Present at the apex of involved toothDifferential diagnosis: Chronic apical periodontitis or acute apical abscess.

Lateral Periodontal Cyst

Arises at the lateral surface of a tooth, usually in the mandibular premolar-canine area.Arise from remnants of the dental lamina & represents the intraosseous analog of the gingival cyst of the adult. Clinically Asymptomatic Involved tooth is Vital. Radiographically Lesion is < 1 cm in diameter & may or may not have a surrounding rim of dense bone. Differential diagnosis: Lateral radicular cyst (non-vital)

Odontogenic Keratocyst

Common lesionArises from remnants of the dental laminaClinically and radiographically - Resembles a periradicular lesion.- Unilocular or multilocular radiolucency in the lateral or apical region of teeth.- Usually in the mandible (mandibular ramus and angle)Differential diagnosis - Lesions of pulp origin (Histologic features)

Residual Apical Cyst- Represents a persistent apical cyst associated with an extracted pulpless tooth- Arises from epithelial remnants after extraction- Usually resolve spontaneously following nonsurgical root canal treatment- Toller and Torabinejad presented evidence that the epithelium may be antigenic and that it would therefore be eliminated by the immune mechanism- Very uncommon and uncomplicated. FIBRO-OSSEOUS LESIONSNormal bone is replaced by a tissue composed of fibroblasts & collagen, containing bony or cementum - like calcification.

PERIRADICULAR CEMENTAL DYSPLASIA (CEMENTOMA) - Usually involves mandibular incisors and lesions are multiple Etiology is unknown.

Clinically - Asymptomatic, - Teeth respond to vitality testing

Radiographically

An intact lamina dura is usually visibleNormal alveolar bone to bone resorption & fibrosis and finally to dense, a typical reossification.

Initially (Osteolytic stage): loss of bone & replacement by connective tissue

2) Intermediate stage (Cementoblastic stage): beginning of calcification in radiolucent area of fibrosis

3) Mature stage: deposition of calcific material, well-defined radiopacity bordered by thin radiolucent line.TreatmentNo treatment, harmless.

Osteoblastma & Cementoblastoma (True cementoma)

Benign neoplasms Cementoblastoma is an osteoblastoma with an intimate relationship with the root.Involved tooth ankylosed Radiographically Associated & continuous with the roots of teeth, usually a mandibular first molar. Tumor mass (radiopaque) is often surrounded by a thin, radiolucent zone that is continuous with the PDL space.Differential diagnosisCondensing osteitis It is diffuse (ill-defined borders) & is associated with chronic pulpal disease. Lamina dura and PDL space remain intact.

Cementoblastoma

Ossifying fibroma

Cementifying and ossifying fibromaBenign, neoplastic, fibro-osseous lesionOrigin from elements of the periodontal ligamentYounger patients, premolar-molar (Mandible)Asymptomatic, frequently undetectedFrequently grows to expand jaw bone Radiology Early lesion: well-demarcated radiolucent (bone resorption) Progressive calcification: RadiopaqueDifferential diagnosis - Vital teeth. - Final diagnosis is by excision and biopsy (shows elements of calcified structures within the stroma).

Odontogenic TumorsAmeloblastoma

Non odontogenic lesionsCentral giant cell granulomaNasopalatine duct cystSimple bone cystGlobulomaxillary cystEnostosis

Malignancies

Thank You