What are the indications, contraindications, technique, postoperative management, complications, and alternatives for a root canal (endodontic therapy)?

Root Canal Treatment (Endodontic Therapy)

Primary Indications

Root canal therapy is indicated when the dental pulp becomes irreversibly inflamed or necrotic, most commonly from carious lesions or dental trauma. 1, 2

Specific Clinical Scenarios Requiring Root Canal Treatment:

• Complicated crown fractures exposing pulpal tissue in mature permanent teeth (teeth >3 years post-eruption) 3, 4
• Complicated crown-root fractures 4
• Supra-crestal coronal third root fractures 4
• Pulpal necrosis with periapical pathology (acute alveolar abscess, periapical swelling, fistula formation) 3, 2
• Traumatic injuries where pulp necrosis is predictable AND root surface/periodontal ligament damage exists (to prevent external inflammatory resorption): avulsion, intrusion, lateral luxation with crown fracture, extrusion with crown fracture—all in fully developed teeth 4
• Grey tooth discoloration indicating pulpal necrosis or failed previous endodontic treatment 5

Important Exception for Immature Teeth:

For immature permanent teeth (within 3 years of eruption) with complicated crown fractures, conservative pulp treatment (pulp capping) should be attempted first if the tooth can be treated within hours of injury to preserve pulp vitality and allow continued physiologic root development. 3, 6 This represents a critical decision point—immediate intervention determines whether the tooth can continue normal root formation versus requiring traditional root canal therapy. 3

Contraindications

• Primary (deciduous) teeth should never be replanted after avulsion 3
• Non-restorable teeth should be extracted rather than treated endodontically 7
• Teeth with insufficient remaining tooth structure to support restoration 1

Technique

Diagnostic Phase:

• Obtain periapical radiograph using dedicated film holder and beam aiming device to assess pulpal and periapical status 3, 5
• For suspected carious lesions, bitewing radiography is the technique of choice, with periapical radiograph added if pulpal or apical infection is suspected 3
• CBCT is NOT indicated in the initial diagnostic phase for periapical swelling or routine endodontic diagnosis 3

Treatment Protocol:

The emphasis of each procedural step differs based on whether the pulp is vital (non-infected) versus necrotic with infection and periapical pathology. 2

• For vital pulp cases: Focus on aseptic technique to prevent bacterial introduction 2
• For necrotic/infected cases: Emphasis on mechanical and chemical debridement to eliminate infection 2

Intraoperative radiographs with beam aiming devices are indicated for partial or complete root canal treatment, pulp regeneration, or canal shaping prior to root filling. 3 This ensures all clinical maneuvers remain confined within the endodontium. 3

Key Technical Considerations:

• Mechanical and chemical preparation of the root canal affects tooth structure properties, requiring careful consideration of subsequent restoration 1
• Modern irrigation strategies may improve canal cleanliness even with minimal preparation 8
• Access cavity design and root canal preparation should balance tissue conservation with adequate cleaning 8

Postoperative Management

Radiographic Follow-up Protocol:

Follow-up intraoral radiographs should be obtained at 3 months, 6 months, 1 year, and then annually for 3 years after completion of endodontic therapy. 3, 6, 5 This protocol allows assessment of periapical healing and detection of complications such as root resorption. 5

Post-Replantation Management (Avulsed Teeth):

• Flexible splint placement for up to 2 weeks 3
• Root canal therapy must be instituted within 7-10 days after replantation 3
• Systemic antibiotics are mandatory: doxycycline for children >12 years; penicillin for children <12 years; clindamycin for penicillin-allergic patients 3
• Monitor for root resorption as sign of bodily rejection 3

Restoration Considerations:

Decisions regarding post placement and restorative materials depend on quantity and quality of remaining tooth structure, presence of ferrule, post cementation length, and final coronal restoration. 1 Endodontic treatment affects mechanical properties of tooth structure, influencing longevity of the restoration. 1

Complications

• Pulpal necrosis and infection of the root canal system leading to apical periodontitis 4
• External inflammatory resorption of the tooth 4
• Root resorption following replantation of avulsed teeth 3
• Grey discoloration from incomplete treatment or reinfection, indicating breakdown products of hemoglobin and necrotic tissue penetrating dentinal tubules 5
• Inadequate coronal seal allowing bacterial infiltration and recurrent infection 5
• Compromised mechanical properties of tooth structure affecting long-term survival 1

Alternatives

Conservative Pulp Treatments (for specific indications):

• Pulp capping for immature permanent teeth with vital pulp exposure when immediate intervention is possible 3, 6
• Partial pulpotomy or complete pulpotomy for complicated crown fractures in immature teeth 4

Extraction:

• Extraction is indicated for non-restorable teeth 7
• Extraction with incision and drainage for accessible abscesses when tooth cannot be salvaged 7

Critical Pitfalls to Avoid

• Never assume grey discoloration is purely cosmetic—it often indicates underlying pathology requiring intervention 5
• Do not delay root canal treatment in avulsed teeth beyond 7-10 days post-replantation 3
• Never replant primary teeth after avulsion 3
• Do not initiate root canal treatment as emergency management for most traumatic injuries except those specifically listed above—monitor pulp status regularly instead 4
• Avoid storing avulsed teeth in water, which causes osmotic lysis of root fibroblasts; use milk, balanced salt solution, or saliva instead 3
• For immature permanent teeth, do not perform traditional root canal therapy if conservative pulp treatment can preserve vitality and allow continued root development 3, 6