Root canal sealers / dental implant courses by Indian dental academy

ROOT CANAL SEALERS INTRODUCTION SEALERS : These are Cements / Resins / Semiliquid / Plastic-which are used as binding agents to fill up the gap between root canal and obturating material.

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It also fills up the irregularities, discrepancies, lateral canals and accessory canals.

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It helps to achieve a proper apical seal.

IDEAL REQUIREMENTS -

The requirements of a suitable sealers used for filling the dry canal in conjunction with gutta-percha / silver cone are as follows:

1) It should be TACKY, when mixed to provide good adhesion between the filling material and canal wall when set.

2) It should provide a HERMETIC SEAL (an excellent seal apically and laterally).

3) Should be RADIO-OPAQUE, so that it can be visualized in a radiograph.

4) Should not shrink upon setting (DIMENSIONALLY STABLE).

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5) Should not STAIN tooth structure.

6) Should be INSOLUBLE in tissue fluids.

7) Should be TISSUE TOLERANT i.e. non-irritating to peri-apical tissues.

8) Should be BACTERIOSTATIC / atleast not encourage bacterial growth.

9) Should not PROVOKE an immune response in peri-apical region (should be absorbable when extruded).

10)It should be neither mutagenic nor carcinogenic.

11)Should be easily mixed and introduced into the root canal.

12)Should SET SLOWLY to ensure sufficient WORKING TIME. 13)Film thickness should be as minimum as possible.

14)It should be SOLUBLE IN common solvents if it is necessary to remove the root canal filling.

FUNCTIONS 1) They exert GERMICIDAL / ANTIBACTERIAL activity after the placement.

2) They form a BOND between the filling material and the dentinal walls (acts as BINDING AGENT).

2

3) They act as LUBRICANTS when used in conjunction with semisolid material.

4) They exhibit RADIO-OPACITY as it may disclose the presence of accessory canals, resorptive areas, root fractures and the shape of apical foramen.

CLASSIFICATION There are a number of classifications of root canal sealers which can be discussed as: I ACCORDING TO THEIR COMPOSITION [MESSING] a) EUGENOL b) NON-EUGENOL i) Silver containing

c) MEDICATED

ii) Silver Free

1)

Rickett’s 1) Procos formula Kerr’s ol NonSealer (1931) staining G cement 2) Procosol (GrossmanRadio-opaque 1958) silver cement (Grossman2) Grossm 1936) an’s sealer (Grossman1974) 3)

4)

1)

DIAKET (1951)

1.

2)

AH 26 (1957)

2.

3)

Chloropercha Eucapercha

3.

Nogenol

4.

5)

Hydron

5.

Endofil

Tublise al (Kerr1961)

7)

Glass Ionomer

Wach’s Paste (Wach 1925-55)

9)

Ca PO4 cements

10)

Cyanoacrylate

8)

Polycarboxylat e

N2 (1970) Endometha sone

4) 6)

DIAKETA

Spad Iodoform paste

6.

Riebler’s paste

7.

Mynol cement

8.

Ca (OH)2 paste (Lanes, 1962)

9.

Ca (Frant, [BiocalexCa(OH)2)]

3

(OH)2 1962)

4

II ACCORDING TO GROSSMAN: 1) Zinc-oxide resin cements.

2) Ca(OH)2 cements.

3) Paraformaldehyde cements.

4) Pastes.

III ACCORDING TO COHEN Specification number 57 classifies endodontic filling materials as follows: Type I

–

Cl 1, Cl 2

Type II

–

Cl 1, Cl 2, Cl 3

Type III –

Cl 1, Cl 2, Cl 3, Cl 4

Type I : CORE (Standardized) auxiliary (conventional) points to be used with sealer cements.

Class 1 – Metallic.

Class 2 – Polymeric.

Type II : Sealer cements to be used with core materials.

Class 1 – Powder and liquid nonpolymerizing.

Class 2 – Paste and non-polymerizing.

Class 3 – Polymer resin systems.

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Type III : Filling materials to be used without either use materials / sealer cements.

Class 1 – Powder and liquid non-polymerizing.

Class 2 – Paste and paste non-polymerizing.

Class 3 – Metal amalgams.

Class 4 – Polymers.

V ACCORDING TO INGLE -

Cements.

-

Pastes.

-

Plastic.

VI ACCORDING TO CLARK -

Absorbable.

-

Non-absorbable

VII ACCORDING TO HARTY F.J 1. Pastes and cements may be divided into 5 groups.

1) Zinc-oxide eugenol based.

2) Resin based.

3) GP based.

4) Dentin adhesive materials.

5) Materials to which medicaments have been added.

Examples of ZnOE are already mentioned.

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2. Resin based: Consists of an epoxy resin base which sets upon mixing with an activator. Examples – AH –26 -

Diaket

-

Hydron.

3. Guttapercha based : Pastes and cements based on gutta-percha consists of solutions of gutta-percha in organic solvents well known products are: -

Chloropercha.

-

Encapercha.

4. Dentin adhesive materials: Adhesive cements have been tested in an attempt to improve the quality of sealers.

Examples: Cyanoacrylate cements.

-

Glass ionomer cements.

-

Polycarboxylate cement.

-

Calcium phosphate.

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Composite materials.

5. Materials to which medicaments have been added.

-

These may be divided into 2 groups: i.

Those in which strong disinfectants and antiphlogistics have been added in order to supports possible postoperative pain.

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ii.

Those in which Ca(OH)2 has been added with the purpose of inducing cementogenesis and dentinogenesis at the foramen, thus creating a permanent biological seal. Examples:

-

Paraformaldehyde.

-

Calcium hydroxide.

In the first group of pastes, the supplemented disinfectant is

paraformaldehyde and corticosteriod preparation is used as an antiphlogistic.

The most popular commercial Ca(OH)2 containing cements are: -

Calcibiotic root canal sealer (CRCS).

-

Sealapex.

-

Biocalex.

Antiphlogists : Agents which counteract inflammation.

INDIVIDUAL SEALERS A)

SILVER CONTAINING

1) Kerr root –canal sealer / Rickert’s Formula: Composition: Powder: ZnO

 34-41.2%.

Precipitated silver

 25-30.0%

Oleo resins

 30-16% 8

Thymol iodide

ďƒ 11-12%

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Liquid Oil of cloves ďƒ 78-80% Canal balsam ďƒ 20-22% Advantages: i.

Excellent lubricating properties.

ii.

It allows a working time of more than 30 minutes when mixed in 1:1 ratio.

iii.

Germicidal action and biocompatibility.

iv.

Greater bulk than any sealer and hence fills voids, auxillary canals and irregularities present lateral to gutta-percha cones.

v.

Prostaglanding inhibition property (Zn Eugenolate).

Disadvantages: i.

Stains dentin to dark grey colar.

Indication: i.

This is indicated to warm gutta-percha technique where lateral canals are present.

Manipulation: 1.

One drop of liquid + 1 pellet of powder.

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2.

Granular

appearance

remains

even

after

spatulation is completed because of precipitated silver.

3.

It completely sets and is inert within 15-30 minutes, so Grossman’s formula appeared in 1936; with the purpose of developing a sealer that afforded more working time.

2) Procosol Radiopaque – Silver Cement Powder: ZnO USP

 45%

Ppt silver

 17%

Hydrogenated resin  36% Magnesium oxide

 2%

Liquid: Eugenol

 90%

Canada balsam

 10%

To get rid of stain – use xylol to wash the pulp chamber after condensation.

Indications: 1.

Material of choice for lateral canals.

2.

For silver points.

3.

Vertical condensation of warm gutta-percha when bulk of material is required as a sealer.

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Packaging: -

Liquid in bottle (dropper).

-

Premeasured powder in pellet form.

Mixing: -

1 pellet to 1 drop (1:1).

A)

Silver Free : Grossman’s formula was revised to exclude Ag. 1) Procosol Non-staining Cement / Grossman’s Eugenol Cement (1958): This sealer is revised by Grossman again in 1974; by the addition of Na borate to the powder component and by the elimination of all ingredients except eugenol from the liquid.

Procosol Non-staining (1958)

Grossman’s Sealer (1974)

Composition:

Composition:

Powder:

Powder:

Zno (reagent) – 40%

Zno (reagent) – 40%

Staxybelite resin – 27%

Staybelite resin – 30%

Bismuth subcarbonate – 15%

Bismuth subcarbonate – 15%

Ba sulfate – 15%

Ba sulfate – 15% Na anhydrous – 1%

Liquid:

Liquid:

Eugenol – 80%

Eugenol – 5 parts.

Sweet oil of almond – 20%

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Grossman’s sealer is used widely because it provides good seal.

Commercial names: -

Procosol non-staining sealer.

-

Roth’s sol.

-

Endoseal.

Properties: i)

It has plasticity.

ii)

It has slow setting time in the absence of moisture and due to the presence of Na borate anhydrate.

iii)

It has good sealing potential and small volumetric change upon setting.

iv)

Zinc Eugenate is decomposed by H2O through continuous loss of eugenol which makes ZnOE; a weak unstable compound.

Because the use of Grossman’s sealer in bulk for retrofillings and

surgical root end repair is questionable.

This sealer if extruded apically gets absorped.

Disadvantages: 1) Resin is of coarse particle size and unless the material in spatulated vigorously during mixing, an increased piece of resin

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may lodge on the walls of the canal and prevent the root-canal filling from sealing at correct level.

Setting Time: -

This cement hardens in approximate 2 hours at 37째C.

-

Its setting time in canal is less: 10-30 minute because of the moisture present in dentin. The S.T. is influenced by: a) Quality of the ZnO and pH of the resin used. b) Technique used in mixing the cement. c) Amount of humidity in the temperature. d) Temperature and dryness of the mixing slab and spatula.

Manipulation: -

Two / 3 drops of liquid: small increments of powder.

-

Spatulation time depends on number of liquids drops.

-

Spatulated to a smooth creamy consistency on a sterilized; dried, cool glass slab.

a) Drop test

b) String out teeth

- 10-12 seconds

-

1 inch without breaking.

2) Tubliseal: 1961) -

Available in paste system containing base and catalyst.

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Composition: Base: ZnO

– 57-59%

Oleo resins

– 18.5 – 21.25%

Bismuth trioxide

– 7.5%

Thymol iodide

– 3.75% - 5%

Oil and waxes

– 10-10.1%

Barium sulphate Catalyst: Eugenol Polymerized resin Ammidalin.

It differs from Rickert’s cement in that the ZnO base paste also contains barium sulphate as a radiopacifier and mineral oil, corn, startch and lethin, catalyst is made up of polypale resin eugenol and thermol iodide.

Advantages: 1) Easy to mix.

2) Extensively lubricated.

3) Does not stain the tooth structure.

4) It expands after setting.

Disadvantages: 1) Irritant to peri apical tissue.

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2) Very low viscosity extrusion through apical foramen because shorter spatulation time is recommended.

3) W.T. is less than 30 minutes and even less in the presence of moisture.

Indications: i.

In apical surgery cases immediately after filling. The canal is overfilled intentionally with heavy condensation and the excess removed by curettage.

ii.

For filling the last millimeter of the prepared canal where the master cone may not reach because of its great lubricating property.

3) Giach’s Sealer (1955, Wach et al) Composition: Powder: Zno

10g

Tricalcium phosphate

2g

Bismuth subnitrate

3.5g

Bismuth subiodide

0.3g

Magnesium oxide (heavy) 0.5g Liquid: Canada balsam

20ml

Oil of cloves

6ml.

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Properties: a) Medium WT. b) Minimum lubricating quality. c) Minimum periapical irritation. d) It is sticky due to the presence of Canada balsam. e) It should be mixed to smooth creamy consistency and should string out at least one inch when spatula is raised from the glass slab. f) Increasing the thickness of the sealer lessens its lubricating effect (so this sealer is introduced when there is a possibility of over extension beyond the confines of the root canal. g) It is packaged as powder and liquid in separate bottles.

Advantages: a)

It is germicidal.

b)

Less peri-apical irritation.

c)

It has light body and thus does not defect the small gutta-percha cones.

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d)

It stays in position due to the tackiness at the tip of the cone.

Disadvantage: a) Odour of liquid.

Indications: a)

All lateral condensation methods especially when chance of overfilling is present.

b)

Small curved canals of minimum caliber because of its light body does not defect the small master gutta-percha cone used in such canals.

Contraindications: a)

When heavy lubrication is needed as with short master cone.

Packaging: Powder and liquid in separate bottles.

Mixing: -

Mixed to creamy consistency, mass drawn/ 1 inch from raised spatula.

-

Thicker for larger canals and for overfilling.

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Summary of ZnOE based cements: Basically ZnOE based cements have an advantage of: -

Ease of manipulation.

-

Adhesion to dentinal walls and limited dimensional changes.

-

Radioopaque, germicidal action, ample WT and minimal staining except Ag containing PROCOSOL.

Disadvantages: Pa irritation and not absorped easily from apical tissues.

Setting Reaction: It reacts because of a combination of physical and chemical reaction yielding a hardened mass of ZnO embedded in a matrix of long sheath like crystal of Zn eugenolate. Many factors is moisture; particle size; pH etc. are factors that influence the setting reaction.

-

Tissue culture study of ZnOE formulation are cytotoxic.

-

Inflammation at Pa region persists for years.

-

Until excess E ZnOE cement is phagocytosed.

NON-EUGENOL 1) DIAKET -

It is a polyvinyl resin (Polyketone), a reinforced chelate formed between ZnO and Diketone.

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-

Diaket consists of a fine, pure white powder and a viscous honey coloured liquid.

-

2 drops of liquid + 1 scoop of powder (changing the ratio of powder to liquid effects the hardness of the final set and radioopacity).

-

Diaket hardens rapidly.

-

S.T. is 6-8 minutes on glass slab and faster in the root canal.

-

Diaket is known for its resistance to absorption.

-

It is a superior to other sealers in tensile strength and resistance to permeability.

-

Modification of apical cementum and alveolar bone occurred with glass overfilling.

-

This cement is usually used for ENDOSSEOUS IMPLANT.

-

Diaket showed a greater tendency towards fibrous encapsulation where as AH-26 tends to disintegrate into fine granules which were phagocytosed.

2) AH-26 This is an epoxy resin recommended by SHROEDER in 1954.

Powder: Bismuth oxide

– 60% 20

Flexamethylene tetramine – 25% Ag powder

– 10%

Titanium oxide

– 5%

Liquid: Bisphenol diglycidyl ether The formulation has been altered recently with the removal of silver as one of the constituents to prevent tooth discolouration.

PROPERTIES / ADVANTAGES: 1.

It has good adhesive property.

2.

Antibacterial.

3.

It contracts slightly while hardening.

4.

Low toxicity and well tolerated by Pa tissues.

DISADVANTAGES: 1.

Parasthesia may occur following the use of AH-26, but partial recovery occurs within 1-2 years.

2.

Inhibits leukocyte migration.

PACKAGING Yellow powder and viscous resin, liquid and is mixed to a thick creamy consistency.

Its setting time:

36-48 hours at body temperature.

5 to 7 days at room temperature.

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TISSUE CULTURE STUDIES: -

The material was moderately to severe toxic when tested on human epithelial cells; blood, monocytes and lymphocytes etc.

Human studies: -

Well tolerated by Pa tissue.

-

Excess material in the PDL tends to become encapsulated.

-

Mandibular parasthesia may occur following filling.

EFFECTIVENESS OF SEALER: -

It is an effective sealing agent.

3) KLOROPERKA N.O. SEALER: This formula is given by Nyborg and Inllin in 1965.

Composition: Powder: Canada balsam

– 19.6%

Resin

– 11.8%

Guttapercha

– 19.6%

Zinc oxide

– 49%

Liquid: Chloroform -

It was first introduced in 1939.

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-

The powder is mixed with liquid chloroform.

-

After insertion the chloroform evaporates, leaving voids.

-

It is associated with a greater degree of leakage than other materials.

CHLOROPERCHA -

This is a mixture of gutta-percha and chloroform.

-

This chloroform paste has been used by some clinicians as the sole canal filling material.

-

As such the technique is improper because of the excessive shrinkage of the filling after evaporation of the chloroform.

INDICATIONS: -

Perforations.

-

Unusually curved canals.

-

Canals with ledge formation.

-

In conjunction with well fitted primary cone chloropercha can fill accessory canals and root canal space.

MODIFIED CHLOROPERCHA METHODS There are 2 modifications: 1.

Johnston – Callahan.

2.

Nygaard – Ostby.

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Johnston-Callahan method: -

The canal is repeatedly flooded with 95% alcohol.

-

Then dried with absorbent points.

-

It is then flooded with Callahan resin, chloroform solution for 2-3 minutes (more chloroform is added if the paste becomes too thick by diffusion / evaporation.

-

A suitable gutta-percha is inserted and compressed laterally and apically with a string motion of the plugger until the gutta-percha is dissolved completely in the chloroform solution in the root canal.

-

Additional points are added one at a time and dissolved in the same way.

-

Extrusion should be prevented because freshly prepared chloroform is toxic before evaporation of chloroform (as chloroform evaporates – it shrinks and apical seal is lost).

NYGAARD OSTBY -

The canal walls are coated with kloroperka the primary cone dipped in sealer is inserted apically.

-

Pushing partially dissolved tip of the cone to its apical seal.

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-

Addition cones dipped in sealer are packed into the canal to obtain satisfactory filling.

-

FDA has banned the use of chloroform since it has a carcinogenic potential.

1) NEWLY DEVELOPED CaPO4 TYPE SEALERS ARE: 1.

Tetra calcium phosphate (TeCP).

2.

Diacalcium phosphate dihydrate (DCPD).

3.

If modified MC II vains and buffer solution (TDM).

4.

TDM-S-Buffer solution + 2.6% chondrotin sulphate.

Composition: TDM-S Powder: a.

Tetracalcium phosphate.

b.

Dibasic Ca phosphate.

a.

Citric acid.

b.

Dibasic NaPO4.

c.

Chondrotin sulphate.

d.

Distilled H2O.

Liquid:

1.

Biocompatible.

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2.

3.

No peri-apical inflammatory reaction.

Chondrotin and other ingredients said to promote wound healing.

2) APPATITE ROOT CANAL SEALER – Hydrox Powder

Liquid

-

α-tricalcium phosphate

-

Polyacrylic acid.

-

Hydroxyl appatite.

-

Distilled H2O.

-

Iodoform.

-

Bismuth subcarbonate.

Type I

– ARS used for VITAL PULPECTOMY

Type II

– 30% iodoform used in INFECTED CANALS has radioopacity.

Bactericidal Bone invigoration effects.

Type III –

5% iodoform.

Treatment of accidental perforations.

Orthograde filling after apicectomy.

ADVANTAGES: -

Biocompatible.

-

Osteogenic potential.

-

Low tissue toxicity.

DISADVANTAGES: -

Sets quickly, hence multiple mix essential.

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-

Low radioopacity.

-

Low wetting ability.

1) ENDOFLOSS : ZnO based medicated cement.

Powder:

Liquid:

-

ZnO.

-

Eugenol.

-

Iodoform.

-

Parachlorophenol.

-

Ca(OH)2

-

BaSO4

-

Mixing is similar to PROCOSOL (ZnO sealer).

-

S.T. 30-45 minutes.

-

Biocompatible.

-

Induces severe inflammatory reaction in 48 hours and gradually reduces after 3 months.

-

Severe cytotoxicity along with coagulation necrosis was observed – which is attributed to the presence of iodoform and parachlorphenol.

2) TS-60 Powder

Liquid

-

ZnO.

-

Fatty acids.

-

Rosin.

-

Ortho ethoxy benzoic acid.

-

Magnesium oxide

-

Glycol.

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HYDRON : Wiehterle and Lim (1960): -

It is a rapid setting hydrophilic, plastic material used as a root canal sealers without the use of core.

-

Goldman-Aydron is a polymer of hydroxy-ethyl methacrylate (HEMA).

-

It is available as an injectable root-canal filling material.

-

Biocompatible and it conforms to the shape of the canal because of its plasticity.

-

When it comes in contact with moisture, the gel absorbs H 2O and swells.

-

W.T. is 6 to 8 minutes.

-

Less radioopaque than gutta-percha.

-

The syringe method makes it difficult to control the placement of plastic gel accurately and to control the formation of voids within its structure.

-

Long-term studies showed that it causes Pa irritation and inflammation with the activation of macrophages.

-

Hydron is thixotropic i.e. before polymerization occurs it changes from a gel to liquid for short-time.

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-

It can be removed only by burs i.e. peeso reamer.

ENDOFIL: -

A recently introduced injectable silicone resin endodontic sealant is known as Lee Endo-fill.

-

It can be used with gutta-percha as the core material or – as a sole sealant and filling material to be injected in the canal with a pressure syringe.

Endofill: a silicone elastomer – silicone monomer.

Catalyst – silicone based radioopacifier – bismuth subnitrate.

Active ingredients.

-

Hydroxyl terminated dimethyl polysiloxane.

-

Undecylenic acid.

-

Benzyl alcohol.

-

Hydrophobic amorphous silica (10-30µ particle size).

Catalyst – Tetra ethylorthosilicate polydimethyl siloxane: -

The mixed silicone has low working viscosity with good adaptation to the tooth structure.

-

Good penetration of accessory canals.

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-

It cures to a pale pink rubbery solid resembling gutta-percha in properties.

-

ST – 8 to 90 minutes (depending on the catalyst amount > catalyst, faster setting, > shrinkage.

-

The voids can be detected on a radiograph and can be repacked.

-

A moist cotton pellet is used for vertical condensation and the excess is removed.

-

H2O accelerates the S.T.

ADVANTAGES: 1. Ease of preparation.

2. Adjustable W.T. 3. Low working viscosity.

4. Rubbery consistency.

5. It is not a resorbable material.

DISADVANTAGES: 1. Cannot be used in the presence of H2O2.

2. Canal must be absolutely dry.

3. Shrinks upon setting but has an affinity for flowing into open tubuli.

4. Endo-fills bonding ability to the canal walls decreases if it is not used within about 20 minutes of mixing.

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BIOCOMPATIBILITY: -

Silicon elastomers are low in toxicity and inert to tissues.

GLASS IONOMER CEMENT (KETAC-ENDO) -

Saito introduced the endodontic glass ionomer.

-

He suggested using Fuji Type I luting cement to fill entire rootcanal.

-

Later Pittford and Stewart worked on this material to improve the properties.

-

Glass-ionomer cements are reaction product of an ion-leachable glass powder and a polyanion in aqueous solution.

-

On setting they form a hard polysalt gel which adhere tightly to enamel and dentin.

-

Because of their adhesive property they are used as root-canal sealers, provided they are not cytotoxic. It can be triturated and injected onto root-canal.

ADVANTAGES: -

It has best physical qualities.

-

It has best binding to dentin.

-

Fewest voids.

-

Lowest surface tension.

-

Best flow property.

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-

Less cytotoxic.

DISADVANTAGES: -

It cannot be removed in case of re-treatment (no known solvent for GI).

-

However Toronto / Osract group has reported that ketac-endo sealer can be effectively removed by – hand instruments, chloroform solvent followed by 1 minute with an ultrasonic no.

25 file.

NOGENOL: -

This was developed to overcome the irritating quality of Eugenol.

-

The product is an outgrowth of non-eugenol periodontal pack.

-

This ZnO non-eugenol cement nogenol have been advocated as it considered to be less irritating sealer.

-

It was found that after 24 hours all sealers showed considerable inflammation.

-

AH-26 hours nogenol was considerably less irritating than the other sealers.

-

Expands on setting and improve its sealing efficacy with time.

Base is ZnO with barium sulfate and vegetable oil.

-

Accelerator – hydrogenated rosin.

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-

Methyl abietable.

-

Lauric acid.

-

Chlorothymol.

-

Salicylic acid.

POLYCARBOXYLATE CEMENTS: -

It consists of modified ZnO powder and aqueous solution of polyacrylic acid.

-

The cement has chelating action.

-

Binds to both enamel and dentin.

-

Because of its adhesive and antibacterial properties, the cement has been tested as a root canal sealer.

-

Like any other sealer, this material also produces an inflammatory response when it is extruded into Pa tissues.

-

Apical seal is found to be inferior to other sealers.

ADVANTAGES: 1. It bonds well to dentine.

2. Antibacterial property.

3. Compounds like fluoride and Ca(OH)2 can be added.

DISADVANTAGES:

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1. Special plastic plugger is required for insertion since it has great adhesiveness to steel instruments.

CALCIUM PHOSPHATE CEMENT: -

It has been developed for use on exposed root surfaces of sensitive teeth.

-

Browne (1983) showed that this cement penetrated and occluded the radicular dentinal tubules and enhanced hydroxyapatite formation.

-

Wefel (1984) found that it effectively plugged the apical foramen and penetrated the dentinal tubules upto 10mm.

-

The biocompatibility of this cement in Endo-therapy has not yet been established

CYANOACRYLATE CEMENTS: -

These are composite type polymers that can be polymerized to hard products by the use of basic inorganic material that also serve as fillers.

-

A number of homologues including methyl, ethyl; n-butyl, isobutyl and isopropyl have been formulated in dental cements.

-

They have been reported to be biocompatible.

MEDICATED CEMENTS: 34

Examples: Diaket A: -

Chemically this sealer is similar to diaket but it also contains the disinfectant HEXACHLOROPHENE.

-

It is one of the few medicated cements which does not contain paraformaldehyde.

TISSUE CULTURE STUDIES: -

Diaket is moderately toxic to cells.

-

It has a strong cytotoxic effect upto 48 hours after insertion.

HUMAN STUDIES: -

Material is well tolerated by the Pa tissues (overfillings with Diaket-A causes no inflammatory reaction and are encapsulated by fibrous connective tissue).

Pb tetroxide – is toxic to human organism and is of little benefit to the properties of cement.

Paraformaldehyde – hereby irritating and destructive to tissue.

Corticosteroid – are supposed to reduce post-operative pain.

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N2 : -

It was introduced by SARGENT and RITCHER (1961/71).

-

N2 refers to the 2nd nerve (pulp is referred to as first nerve).

-

2 different types of N2 were available previously.

N2 normal

N2 apical

- Used for root filling.

- Used for antiseptic medication of the canal.

-

Recently N2 Universal has been introduced.

-

The formula has been cultured by removing hydrocortisone, prednisolone and barium sulfate.

Composition: Powder ZnO

– 68.51g

Pb tetroxide - 12.00g Radiopaquers - Paraformaldehyde –

4.70g

Bismuth subcarbonate

2.60g

Bismuth subnitrate

3.70g

Antiseptic – Titanium dioxide

8.40

Phenyl mercuric borate –

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0.04g

Liquid: Eugenol.

Oleum Rosae Oleum Lavandulal -

The corticosteroids are now added to the cement separately as hydrocortisone powder / terra-cortil.

-

The object of introducing formaldehyde within the root-filling is to obtain a continued release of formaldehyde gas – which brings prolonged fixation and antiseptic action.

TOXICITY: -

Because of irritation is severe if forced into maxillary sinus mandibular canal-caused persisting, paresthesia.

-

APICAL SEAL – is better when compared to procosol, nongenol and tubliseal and diaket.

ENDOMETHASONE: -

The formation of this sealer is similar to N2 composition:

Powder: ZnO

- 100.0gm

Bismuth subnitrate – 100.0g Dexamethasone

– 0.019g

Hydrocortisone

– 1.6g

37

Thymol iodide

– 25.0g

Paraformaldehyde – 2.20g Liquid: Eugenol -

A pink antiseptic powder is mixed with eugenol.

-

Sometimes endomehasone RC sealers gives rise to pain / discomfort after 6 to 8 weeks of insertion.

-

This occurs because the corticosteroid masks any inflammatory reaction until it is removed from the area.

-

Paraformaldehyde is not resorbed equally, quickly and the symptom of the inflammatory reaction becomes apparent.

SPAD: -

Known for one visit non-irritant radioopaque filler and sealer.

-

It is a resorcinol formaldehyde resin supplied as a powder and 2 liquids.

Composition: Powder: ZnO

– 72.9g

Ba Sulphate

–13.00g

Titanium dioxide

– 6.30g

Paraformaldehyde – 4.70g Hydrocortisone acetate – 2.00g 38

Ca(OH)2

– 0.94g

Phenyl mercuric borate – 0.16g Liquid: (Clear) Formaldehyde solution

– 87.00g

Glycerine

– 13.00g

Liquid (LD) (RED) Glycerine

– 55g

Resorcinol

– 25g

HCl acid

– 20g

-

Equal parts of the 2 liquids are mixed with powder.

-

Reaction in between the resorcinol and formaldehyde.

-

For this reaction, an acid pH is needed and this is provided by the HCl acid.

-

The large amount of ZnO in the powder is to control the pH and so prolong the S.T.

-

Setting time of spad is 24 hours during which small amounts of unreacted formaldehyde gas released.

INDICATIONS: -

Pulpotomies in Devi and permanent teeth.

-

Treatment of acute endo infections.

39

-

Pa within Pa infections – because it is thought that sterilizing affect accelerates healing.

-

Extrusion – bone necrosis.

IODOFORM PASTE: -

If alone / in combination with ether substances has been used as a cement / as sealer with core materials.

-

Walkhoff (1928).

-

It is a resorbable paste.

Consists of: 60 parts of iodoform.

40 parts of solution – 45% parachlorphenol, Antiseptic –

49% of camphor 6% menthol.

COMMERCIALLY aka  KRI – 1 paste.

-

When the pulp is necrotic, the apical foramen is intentionally widened during preparation and paste is deliberately filled into the region during filling.

-

If a sinus is present, paste is pushed beyond the canal until it extrudes through the sinus.

-

Large Pa lesions, paste is used to fill the Rl and also as antiseptic dressing.

40

-

It is not necessary to insert a guttpercha/silver points as core filling, if it is used, it should not touch the apex.

-

It stimulates the Pa tissues and even accelerates bone formation.

-

The filling material in the peri apex is removed by the action of phagocytosis and direct drainage to the associated lymphnodes.

DISADVANTAGE: 1) Pa irritation during construction of post crown (so call has to be filled with non-absorbable material according to Laws (1959) – apical quarter of the canal with a section of gutta-percha + paste and the remaining with nonresorbable material.

2) Discoloration.

3) Cannot be used in patients who have sensitivity to iodine.

RIEBLER’S PASTE: Powder: ZnO Formaldehyde Ba sulphate.

Phenol.

41

Liquid: Formaldehyde.

Sulphuric acid.

Ammonia.

Glycerine.

MYNOL CEMENT: Powder: ZnO. Iodoform.

Rosin.

Bismuth subnitrate.

Liquid: Eugenol.

Creosol.

Thymol.

-

These cements are used, without core materials and are introduced by means of lentulospiral / injection device.

APPLICATION OF A SEALER -

Sealer can be placed by :

-

Reamer.

-

Lentulo-spiral.

42

Reamer: -

To carry the cement apically – a counter clockwise turn is given to the reamer.

-

One size less than the last instruction is selected.

-

The safest is to use with a stopper to the approximate W.L.

-

A small amount of cement is gathered on the blade and is carried into the canal and is rotated in counter clockwise as it is withdrawn.

-

Spinning the sealer into the canal slow gentle pumping action + helps a lateral rotary motion of the instrument – helps to caat the walls thoroughly and dispersal air trapped in the canal.

Lentulospiral: -

It is turned clockwise either by fingers / handpiece.

-

It carries cement apically.

-

Not effective in marrow canals, easy breakage.

-

Causes extrusion of the cement when used with handpiece.

-

Causes cement to set rapidly as a result of its whipping action.

CALCIUM HYDROXIDE CEMENT: -

Ca(OH)2 has been used – as intra-canal medicaments.

43

-

As a sealant in conjunction gutta-percha.

-

As a root canal filling material.

-

Pure Ca(OH)2 can be used / + saline solution.

-

pH ďƒ 12.3 to 12.5.

-

Its use is based on the assumption that there is formation of hard structures / tissues at the apical foramen.

-

The alkalinity of Ca(OH)2, stimulates the induction of mineralized tissue.

-

Ca(OH)2 may be effective as an INTERIM treatment but should serve as a permanent RC filling material because it may disintegrate if leakage occurs.

-

Some ZnOE cements have been modified by incorporating Ca(OH)2.

(A)

Ca(OH)2 sealers are considered superior to ZnOE cements.

SEALAPEX – KERR COMPANY:

-

Non-eugenol Ca(OH)2 polymerize resin RC sealer.

-

It is delivered in paste form.

44

Composition: -

Base consists of ZnO with Ca(OH)2.

Butyl benzene Sulfonamide.

Zn stearate.

-

Catalyst

Ba sulphate.

Titanium dioxide – radioopaque.

Resin.

Isobutyl salicylate and Acrocil R972.

-

It never sets in dry atmosphere.

-

It 100% humidity – it takes 3 weeks to reach final set.

-

It expands while setting.

-

Healing is better with sealapex than other sealers.

CRCS (HYGEINIC) : 1982 -

Was first of the Ca(OH)2 based sealers.

-

Sealex was introduced later.

Composition: Powder: ZnO Hydrogenated rosin.

Ba SO4 Ca(OH)2 – 14% Bismuth subcarbonate.

45

Liquid: Eugenol Eucalyptol.

-

CRCS is a ZnOE eucalystol sealers to which Ca(OH) 2 has been added for its osteogenic effect.

-

CRCS – is powder : Liquid combination.

-

CRCS – 3 days to set fully in either dry / humid environment.

It shows may little H2O sorption i.e. quite stable.

-

The setting time, solubility; compressive strength and other properties of these and Ca(OH)2 sealers were compared with PROCOSOL.

-

They found that sealapex showed a typical behaviour on its pronounced volume expansion water absorption and change in radioopacity with time.

(B)

LIFE -

A Ca(OH)2 liner and pulp capping material and sealer.

-

Similar composition to sealapex.

(C)

VITAPEX -

Japanese have introduced.

-

Components are iodoform and silicone oil.

46

(D)

BIOCALEX -

Bernard (1952 as – Ocalex.

-

Powder: Liquid system.

-

Powder: Heavy Ca oxide, Zn oxide

-

Liquid: Glycol, H2O

-

The powder and liquid are mixed to a paste.

-

Acts as – RC medicament and RC filler.

-

After being sealed in the canal –expands 6 times its original volume.

-

CaO+H2O react within the tooth to form the Ca(OH) 2 which ionizes to release OH ions.

-

Decompose necrotic pulp tissue to form H2O and CO2.

-

The H2O by combining with residual CaO – leads to further Ca(OH)2 formation while CO2 reacts with Ca(OH)2 to form carbonate which is deposited in the RC walls.

-

The end result is that – the contents of the canals are subjected to chemical incineration with sterilization occurring by the action of OH ions and sealing of the canal by decomposition of Ca(CO3).

-

Efficacy of sealing the root canal with Biocalex is a controversy.

47

NEWER SEALERS 1. Endofloss.

2. Appetite root canal sealer.

3. RCS containing tetra-calcium dicalcium phosphate and 1% chondrotin sulphate.

1)

ENDOFLOSS: -

Recently introduced sealer consisting of P:L formulation.

Powder: ZnO. Iodoform.

Ca(OH)2 BaSO4 Liquid: Eugenol.

Parachlorophenol.

-

It is zinc oxide based medicated cement.

-

Mixing is similar to procosol (ZnO sealer).

-

S.T. – 30-45 minutes.

-

Biocompatible.

48

-

Induces severe inflammatory reaction in 48 hours and gradually reduced after 3 months.

-

Severe toxicity along with coagulation necrosis was observed which is attributed to the presence of iodoform parachlorophenol.

2)

APPETITE RCS: HYDROX - P:L Combination

Powder:

Liquid:

Îą-trica PO4

Polyacrylic acid.

Hydroxyl appetite.

Distilled H2O

Iodoform.

Bismuth subcarbonate.

3 types: - Type I; II and III: 1. Type I : ARS used for vital pulpectomy.

Type II : 30% iodoform used in infected canals that has radioopacity; bactericide and bone invigoration effects.

Type III : in between cases which contains 5% iodoform.

2. Treatment of accidental perforations.

3. Orthograde filling.

Advantages:

Disadvantages:

1. Biocompatible. essential.

1.

Sets

quickly;

hence

2. Osteogenic potential.2. Low radioopacity.

3. Low tissue toxicity. 3. Low wetting ability.

49

multiple

mix

Newly developed CaPO4 type sealers are: 1. Tetraca phosphate (TeCP).

2. Dicalcium phosphate dihydrate (DCPD).

3. A modified McII vains and buffer solution (JDM).

4. TDM-S buffer solution + 25% chondrotin sulphate.

Composition: TDM-S

TDM

Powder: Tetracalcium PO4

Tetraca phosphate

Dibasic Ca PO4

Dibasic Ca phosphate

Liquid: Citric acid

“

Dibasic NaPO4

“

Chondrotin sulphate

“

Distilled H2O

“

-

Studies have shown excellent biocompatibility.

-

No Pa inflammatory reaction seen.

-

Chondrotin and other ingredients said to promote wound healing.

50

BIOSEAL: Sealing ability of a new-hydroxyapatite containing endodontic sealer using lateral condensation and thermatic composition of guttapercha in vitro JOE, Vol. 22; No. 4: April 96.

Hydrox: 1. Is assumed to influence the apical healing.

2. It may effect the sealing ability of the cement because of its composite structure additive did not effect the sealing ability.

BIOSEAL : PCS. IEJ (97) 30; 205-209: Ca(OH)2 RCS : evaluation of pH Ca ion concentration and conductivity.

Sealapex

 Highest pH; ionic Ca and total Ca values.

Hygienic CRCS

 IInd.

Dentsply - Sealer 26  IInd Vivadent Apexit

 IIIrd.

Effect of sealer thickness on long-term sealing ability : a 2-year follow up study.

ZnOE  Roth

Thick layers > leakage than thin layers.

PCS – ENT AH-26; Ketac Endo; Sealapex  Thick and thin layers.

51