essay 49 - root Canal filling materials - soft non-setting and setting pastes - properties and indications

define soft non setting pastes

these are pastes intended to fill the entire root canal space, but they do not harden once inside the canal

give properties and indication of soft non setting pastes

• properties:

1. remain soft permanently after placement

2. resorbable: radio graphic studies have proven that these pastes can be resorbed from inside the root canal. the resorbability leads to transport of the paste away from its original placement site, worsening the seal

3. unstable: do not provide Long Term sealing. create empty spaces between the canal walls and filling over time

4. biological failure: pastes alone are not able to maintain an effective seal. they allow leakage, bacterial re entry, and treatment failure

• indications:

1. historically used when endodontic therapy was based heavily on chemical sterilisation rather than mechanical sealing and cleaning

2. currently their use is contraindicated: they should no longer be used for root canal obturation. they are considered anachronistic because they cannot guarantee biological success

3. today's standard: root canals should be obturated with solid or semi solid materials, NOT with an non-setting pastes

define setting pastes (cement sealers and cements)

• cement sealers are self hardening materials used along with a primary filling material (like gutta-percha).

• cements are self hardening materials used to completely fill the canal (though using them alone is discouraged)

get properties an indication for setting pastes

• properties:

1. set after placement in the canal, forming a more or less firm mass

2. primarily based on zinc oxide eugenol compounds

3. resorbable if used alone: even cements based on zinc oxide eugenol can resorb over time inside the canal. thus cements must not be used alone for root canal obturation

4. supporting role: their main role is to act as a sealer to improve the adaption of solid/semi solid material to canal walls

5. Should be used minimally: apply the thin microfilm only a few microns thick should not replace your main filling materials (like gutta-percha)

• indications

1. used always together with a solid or semi solid material (gutta-percha for examples)

2. indispensable for enhancing the seal of gutta-percha cones against dentinal walls

3. should never be relied upon alone for filling the entire canal

Requirements of an ideal Cement sealer

1. Biological Requirements

• Biocompatible with periapical tissues

• Non‑immunogenic, non‑mutagenic, non‑carcinogenic

• Bacteriostatic or does not support bacterial growth

• Inert (no chemical irritation or reaction)

• Non‑staining to tooth structure

2. Physical Requirements

• Dimensionally stable (no shrinkage; slight expansion desirable)

• Impervious to moisture

• Non‑resorbable after setting

• Radiopaque for clear radiographic visibility

3. Handling Requirements

• Easy to manipulate with adequate working time

• Fine particle size for thin, uniform application

• Adhesive to canal walls

• Removable with solvents if retreatment is needed

• Sets in a reasonable time