What are the differences in success rates and extrusion risks between sealant and gutta-percha (GP) cones in root canal treatment?

Root Canal Treatment Success: Sealant vs Gutta-Percha Extrusion

Direct Answer

The evidence does not support that extrusion of root canal sealant or gutta-percha cones significantly impacts treatment success rates, as none of the available sealers can achieve a completely fluid-tight apical seal regardless of extrusion. 1 The focus should be on proper obturation technique and material selection rather than concerns about minor extrusion.

Sealing Ability and Material Performance

Comparative Sealing Outcomes

• No sealer completely prevents apical leakage: Studies comparing bioceramic sealers, AH Plus (resin-based), and GuttaFlow demonstrate that none achieve a completely fluid-tight seal at the apical foramen, regardless of technique. 1

• GuttaFlow shows superior sealing: GuttaFlow (a silicone-based flowable system) demonstrates significantly higher percentage of gutta-percha-filled area compared to traditional lateral or continuous wave condensation techniques (p<0.05). 2

• Bioceramic sealers perform comparably: EndoSequence BC sealer shows similar apical sealing ability to GuttaFlow, with both outperforming AH Plus in dye leakage studies. 1

Material Expansion and Volumetric Changes

• Eugenol-based sealers cause GP expansion: Zinc oxide-eugenol (ZOE) sealers produce volumetric expansion of gutta-percha, with powder/liquid ratios of 1:2 and 1:3 showing the highest expansion over a 1-month period. 3

• Expansion timing: Maximum volumetric changes occur within the first 7 days post-obturation, with continued expansion up to 1 month. 3

Clinical Implications of Extrusion

Sinus Complications (Relevant Context)

• Extruded endodontic material can cause fungal balls: Extrusion of root canal filling material into the maxillary sinus is associated with fungal ball formation, as copper and zinc elements in endodontic materials may serve as co-factors for fungal growth. 4

• Prior endodontic treatment increases risk: Patients with previous root canal treatment show significantly higher prevalence of maxillary fungal balls (89% vs 37%, p<0.01) compared to controls. 4

Retreatability Considerations

• All sealers leave remnants: None of the tested sealers (bioceramic, MTA-based, or resin-based) can be completely removed during retreatment procedures using ProTaper Universal Retreatment systems. 5

• MTA Fillapex allows faster retreatment: Single-cone technique with MTA Fillapex shows significantly shorter time to reach working length during retreatment compared to other sealers. 5

• Apical and middle thirds retain more material: Remnant filling material is consistently higher in apical and middle thirds compared to coronal thirds across all sealer types. 5

Recommended Obturation Protocol

Material Selection Algorithm

1. For standard cases: Use GuttaFlow or bioceramic sealer (EndoSequence BC) as both provide superior sealing without requiring accessory cones. 1, 2

2. For cases requiring retreatability: Consider MTA Fillapex with single-cone technique for easier future access if needed. 5

3. Avoid excessive eugenol: If using ZOE-based sealers, maintain powder/liquid ratio between 1:2 and 1:3 to optimize expansion without compromising handling. 3

Technique Considerations

• Single-cone technique is adequate: When using flowable sealers like GuttaFlow, accessory gutta-percha cones provide no additional sealing benefit (p>0.05). 2

• Conservative preparation: Maintain canal preparation to 40/0.06 taper to optimize sealer distribution and minimize unnecessary dentin removal. 1

Monitoring Requirements

Follow-up Protocol

• Radiographic assessment schedule: Obtain periapical radiographs at 3 months, 6 months, 1 year, and then annually for 3 years post-treatment. 4, 6

• Clinical signs to monitor: Evaluate for crown discoloration, gingival swelling, increased mobility, and sinus tract formation indicating pulpal necrosis. 4, 7

• Maxillary posterior teeth require vigilance: For upper posterior teeth, monitor for signs of sinusitis or fungal ball formation if material extrusion is suspected. 4

Critical Pitfalls to Avoid

• Do not assume complete apical seal: Even with optimal technique, expect some degree of microleakage with all current materials. 1

• Recognize sinus extrusion risk: In maxillary teeth with thin sinus floors, avoid excessive sealer placement that could extrude into the sinus. 4

• Plan for potential retreatment: Accept that complete removal of filling material is impossible, which may complicate future endodontic surgery if needed. 5