Root canal filling materials and sealers
- Dental material
Canals are filled with gutta-percha, a rubbery core, plus a sealer that fills the gaps. Materials pushed into the jaw near the nerve can cause numbness.
See it in 3D: Inferior alveolar nerve
What it is
After cleaning, the canal space is filled to stop bacteria from regrowing and fluids from entering. Gutta-percha, a natural rubber-like polymer with zinc oxide, forms the core because it is inert, can be compacted and can be removed for retreatment. A sealer fills the irregularities between the gutta-percha and the canal wall. Calcium silicate (bioceramic) sealers and cements are also used for root-end fillings, perforation repair and open apices.
Composition and properties
- Gutta-percha: inert, compactable, removable; placed by cold lateral or warm vertical compaction, or on a carrier.
- Sealers: zinc oxide–eugenol, epoxy resin, calcium hydroxide, glass ionomer and calcium silicate types.
- Calcium silicate materials set in moisture, are alkaline and biocompatible, and seal well.
- Silver points are obsolete: they corrode and leak.
- Paraformaldehyde-containing pastes are not acceptable: they can cause lasting nerve and bone damage if extruded.
Uses, limits and safety
- Material pushed into the inferior alveolar canal can cause numbness or pain of the lip and chin and needs urgent assessment.
- A root filling that is short, has voids or is not sealed at the crown leaks and can fail.
- Overfilled sealer in the maxillary sinus is a rare cause of sinus symptoms.
Next step / Initial management
- Check every root filling on a radiograph for length, density and voids.
- New numbness of the lip or chin after a lower molar or premolar root canal: refer urgently to the endodontist or oral surgeon the same day.
- Older teeth with silver points or paste fillings and symptoms: refer for retreatment assessment.
Test yourself
Think of the answer, then tap the question to see it.
Why is gutta-percha the standard root filling core?
It is inert, can be compacted into the canal and can be removed if retreatment is needed.
What should be done for new lip numbness after a lower molar root canal?
Urgent same-day referral, since material may have reached the inferior alveolar canal.
Which root canal materials are no longer acceptable?
Silver points and paraformaldehyde-containing pastes.
Connections
See it in 3D1
The structures of Durgical's 3D anatomy where it is found.
Educational content; it does not replace assessment by a dentist or doctor and is not a clinical instruction. For facial or neck swelling with difficulty swallowing or breathing, a knocked-out tooth or bleeding that will not stop, go to an emergency department at once.
Sources: Endodontic Materials Used To Fill Root Canals (StatPearls Publishing (NCBI Bookshelf), 2023); Dental Materials: Biodentine, a Calcium Silicate Bioactive (StatPearls Publishing (NCBI Bookshelf), 2024).
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Representative model, for educational purposes only.