Root Canal Sealers

A short presentation covering the basics. For UG students only. Only for a quick overview of the important points.

1. Root Canal Sealers Dr Aaron Sarwal

2. Root Canal Sealers Root canal sealers are used in conjunction with biologically acceptable semi-solid or solid obturating materials to establish an adequate seal of the root canal system. (Grossman)

3. Root Canal Sealers Sealers are the binding agents use to fill up the gap between the root canal walls and the obturating materials. They also fill up the irregularities, discrepancies, lateral canals and accessory canals.

4. Grossman’s Criteria for an Ideal Root Canal Sealer Should form a hermetic seal Provide good adhesion between itself, and the canal walls, and the filling material. Be radio opaque Should not stain the tooth structure. Should be dimensionally stable. Be easily mixed and introduced into the canals. Should be easy to remove if necessary. Be insoluble in tissue fluids. Bactericidal or bacteriostatic . Nonirritating to periradicular tissues. Should set slowly to provide working time.

5. What does a Sealer do? Antimicrobial Agent Binding Agent A filler A lubricant Provides radiopacity As canal obturating material

6. A. Zinc Oxide Eugenol Based Sealers Most common sealers use ZnO as a base ingredient for the powder. The liquid usually contains eugenol either alone or in combination with other liquids. Grossman’s Non-staining cement was developed to meet most of his criteria for an ideal RC sealer.

7. Non Staining Cement (Grossman 1958) POWDER LIQUID ZnO 42% Eugenol Staybelite Resin 27% Bismuth Subcarbonate 15% Barium Sulphate 15% Sodium borate, anhydrous 1%

8. Non Staining Cement (Grossman 1958) Setting time: 2 hours (37 °C @ 100% humidity) Sets in the root canal within 10-30 mins due to the moisture of dentin. Quality of ZnO and pH influence setting. Plasticity and low setting time. Good sealing potential and small volumetric change on setting.

9. Grossman’s Sealer Root canal cement is mixed on sterile glass slab with spatula. Two or 3 drops of liquid is used and slowly small increments of cement powder is added to the liquid and spatulated to a smooth creamy consistency. Consistency is tested by raising the spatula from the slab and checking for a “string out” about 1 inch long.

10. Correct consistency of mixed sealer Mix should coat the GP cone well. It should not be too thick and neither too thin. A thick sealer will not allow the GP cone to seal the apex. A thin sealer will not be able to coat the walls properly and may be pushed periapically .

11. B. Calcium Hydroxide Based Sealers The use of Ca(OH) 2 paste as a root-canal filling material is based on the assumption that there is formation or hard structures or tissues at the apical foramen.

12. Advantages Of Ca(OH) 2 Based Sealers Calcium hydroxide and/or calcium hydroxide sealers can: • Induce mineralization • Induce apical closure via cementogencsis •Inhibit root resorption subsequent to trauma •Inhibit osteoclast activity via an alkaline pH • Seal or prevent leakage as good as or better than ZOE sealers • Less toxic than ZOE sealer.

13. Sealapex by Kerr Non eugenol calcium hydroxide polymeric resin root canal sealer. It is delivered as paste to paste formulation.

14. Sealapex by Kerr BASE ZnO with Ca(OH)2 Butyl benzene Sulfonamide CATALYST Barium sulfate, Titanium dioxide as radioopacifiers with proprietary resin Isobutyl salicylate and Acrocil R 972. Zinc stearate

15. Calcium Hydroxide Based Sealers Howland and Dumsha reported the same amount of microleakage in Sealapex , Proscol and Tubliseal . Cox et al reported better healing at 6 months with Sealapex as compared to AH26 and Rickert’s Sealer. Another calcium hydroxide based sealer is CRCS ( calcibiotic root canal sealer) which when set contains 14% by wt of calcium Hydroxide.

16. C. Glass Ionomer Based Sealers Advocated as root canal sealers due to their ability to bind with dentin. Ketac Endo by 3M ESPE is an example. Not popular as they are difficult to remove during retreatment. Solvents are ineffective against them.

17. D. Resin Based Sealers AH26 ( Dentsply DeTrey ) is an epoxy resin containing a nontoxic hardener. Radio-opacity is imparted by bismuth oxide. Strong adhesive properties and contracts slightly while hardening.

18. AH26 vs. AH Plus AH Plus Paste A: BADGE Calcium tungstate Zirconium oxide Silica Iron oxide pigments AH Plus Paste B: Adamantane amine Silica Silicone oil AH26 was found to release formaldehyde during setting. AH Plus is a modified formulation of AH26 and doesn’t release formaldehyde.

19. AH Plus Advantages: Good sealing ability Biocompatibility to periapical tissues Moderate antimicrobial activity Dentinal Adhesion Long working time and ease of manipulation.

20. Conclusion No root canal filling material is entirely innocuous. Any extrusion reduces the chance of healing by as much as 25%. ZoE cements are irritating due to eugenol . Epoxy resin sealers are more bio- compatibile . Irritation caused by overfilling is, fotunately , generally mild for most materials. Confining filling to the canal is the best.