obturation of the root canal system_part i [lecture by dr.ahmed labib @amcofam]

Obturation of the Root canal System By Ahmed labib

Why do we obturate?•Fidgor (2002) stated 3 functions of root canal obturation:1- Prevent coronal leakage of bacteria.2- Entombing remaining bacteria.3- Prevent the influx of apical tissue-derivedfluids and accumulation of stagnant fluids.

Functions of Obturation•Cohen et. al. stated that a 3D obturating

material is essential to:1- Prevents percolation and microleakage

of periapical exudate.2- Prevents reinfection.3- Creates a favorable biologic environment

for the process of tissue healing.

Where the obturating material should end?

•Apically, at the apical constriction.

•Coronally, 1-mm beyond orifice of the root canal.

When to obturate?

•After the completion of root canal cleaning and shaping, the root canal is ready to be filled when:

1- Tooth is asymptomatic.2- The canal is dry.3- There is no sinus tract.4- There is no foul odor.5- No swelling6- Temporary filling is intact.

Root Canal Filling Materials:

•Basically, root canal filling is composed of:

1- Core material.2- Sealer.

Core Materials: Ideal Requirements of Core materials:

1. It should be easily manipulated.2. It should be dimensionally stable.3. It should seal the canal laterally and apically.4. It should not irritate the periapical tissues.5. It should be impervious to moisture.6. It should be unaffected by tissue fluids.7. It should not support bacterial growth.8. It should be radiopaque.9. I t should not discolor tooth structure.10. It should be sterile.11. It should be easily removed from the canal if

necessary.

Core Materials:

1- Pastes:Zinc oxide-eugenol cements with various additivesEpoxy resins (AH-26)Acrylic, polyethylene, and polyvinyl resinspolycarboxylate cements

2- Semisolid Materials:Gutta PerchaResin based core filling MaterialsCombinations

3- Solid Materials:Silver PointsTitanium points

Core Materials:

Materials of choice:1- Silver Points.2- Gutta Percha3- Resin based core filling materials4- Combinations.

Silver Points

•Introduced by Jasper in 1940.•Rigid so, easily introduced into canals, especially in narrow curved canals, but impossible to adapt to canal irregularities.•When leakage occurs and the points contact tissue fluids, they corrodes, further increasing leakage. •Corrosion products are toxic which impede healing.

Gutta Percha

•Derived from dried juices from trees of the family Sapotaceae.•Crystalline gutta-percha may occur in α- or β-phase.•Popularized by Bowman in 1867.

Gutta Percha The gutta percha filling material was discovered by Bomann1867 could be one of the most accepted obturation materials forRoot Canals because it fulfill previous criteria of good condensedinside the root canal either by lateral or vertical condensationtechniques & either if it is cold or warm.

Gutta Percha

•Supplied as standardized or non-standardized forms.•Standardized forms are used as a primary cones,•Non-standardized forms are used as auxiliary cones , because they have greater taper, thus being more rigid and more controllable.

Gutta Percha

•In their final form, gutta-percha points consist of some 20% gutta-percha and up to 65% zinc oxide.

•A dye and metal salts are added for color and radiographic contrast.

•Some manufacturers add antimicrobials.o e.g. calcium hydroxideChlorhexidineiodoform

Gutta Percha

•Advantages of gutta percha:1.Adapts excellently to the irregularities.2.Can be softened and made plastic by heat

or organic solvents.3.Inert.4.Dimensional stability.5.Tissue tolerant.6.will not discolor the tooth structure.7.Radiopaque.8.Easily removed from the canal when

necessary.

Gutta Percha

•Disadvantages of gutta percha:1.lacks rigidity.2.lacks adhesive quality.3.It can be easily displaced by pressure.

Resin Based Core Filling Materials:

•Resilon material points, an apparently viable alternative to gutta-percha in clinical practice, has emerged.

•Physical and handling characteristics similar to gutta-percha.

•main advantage, bonding to sealers.

Resin Based Core Filling Materials:

•Resilon is a polyester core material with bioactive glass, bismuth and barium salts as fillers.

•Presented as cones (like gutta percha), to be used for CLCT, pellets to be used in thermoplastic, vertical condensation techniques and apical plugs to be used with Simplifil system.

Resin Based Core Filling Materials:

•Resilon is the central component of many endodontic obturation systems:

I. RealSeal System.II. Resilon-Epiphany System.III. Resinate System.

Resin Based Core Filling Materials:

•These systems include three primary components:

1. The Resilon core material.2. The resin sealer.3. The primer. (Self-etchant)

Resin Based Core Filling Materials:

• Because Resilon is a synthetic polymer, the resin sealer attaches to it, as well as to the bonding agent/primer used to penetrate into the dentin tubules.

• As a result, a ‘monobloc’ is formed, consisting of filling material, resin sealer-bonding agent/primer-dentin.

Resin Based Core Filling Materials:

•Through the formation of the monoblock, coronal micro leakage has been decreased and root fracture resistance has been increased.

Resin-coated gutta percha points:

•EndoREZ points.•Points are standard ISO-sized gutta percha points

overlayed with a thin layer of polybutadiene-diisocyanatemethacrylate resin coating.

•Bonds chemically with EndoREZ and other resin-based sealers. (creating a monobloc).

Glass-Ionomer-coated gutta percha points:

•Activ GP.•Uses a glass ionomer-impregnated and

coated gutta-percha cone that can bond to a sealing agent made of barium aluminosilicate glass powder and polyacrylic acid. (creating a monobloc)

Glass-Ionomer-coated gutta percha points:

•Supplied in two forms; Activ GP (employs a traditional gutta percha design) and Activ GP Plus (employs calibration rings for easy depth measurement and a unique barrel handle)

Root canal sealers

• Functions of root canal sealers:

1. Sealing off of the root canal system,2. Entombment of remaining bacteria3. Filling of irregularities in the prepared

canal.

A sealer is what should meet hard and soft tissues; the percha is merely a piston.

Root canal sealers• DESIRABLE PROPERTIES1. Tissue Tolerance2. No Shrinkage with Setting3. Slow Setting Time4. Adhesiveness5. Radiopacity6. Absence of Staining7. Solubility in Solvent8. Insolubility to Oral and Tissue Fluids9. Bacteriostatic Properties10.Creation of a Seal

Root canal sealers• Types of root canal sealers:1. Solvent-based sealers2. Zinc-oxide-eugenol-based sealers3. Glass-ionomer-based sealers4. Resin-based sealers5. Materials with calcium hydroxide6. Silicone-based sealers

Solvent-based sealers

• •Rosin-chloroform (Johnston-Callahan technique)

• •Chloropercha techniques

• •Kloroperka

Solvent-based sealers

• •Pro’s1. Biocompatible2. Clinical documentation?

• •Con’s1. Leakage2. Shrinkage

Zinc-oxide-eugenol-based sealers

• Rickert’s sealer⇒Kerr PCS (Silver)

• Grossman’s sealer⇒Roth’s, ProcoSol (bismuth, barium salts)

• Robin’spaste⇒N2, Endomethasone (Paraformaldehyde)

Zinc-oxide-eugenol-based sealers

• Pro’s• Used for a century• Clinical documentation• Good seal

• Con’s• Local toxicity• Allergen• Poor stability

Glass-Ionomer based sealer• Endion

• Ketac-Endo

• Activ GP Glass Ionomer Sealer

Glass-Ionomer based sealer• Pro’s• Biocompatible• Chemical Bonding to dentin

• Con’s• Leakage• Shrinkage

Resin Based sealers• Epoxy-bis-phenol resin⇒ AH-26, AH-

Plus, TopSeal.

• BisGMA, UDMA and hydrophilic methacrylates⇒ Epiphany.

• UDMA ⇒ EndoREZ. (hydrophilic, doesn’t need primer)

• Epoxy-bis-phenol resin, metheneamine, enoxolone, calcium hydroxide ⇒ Acroseal

Resin Based sealers•Pro’s1. –More than40 years2. –Clinical documentation3. –Stable

•Con’s1. –Toxic when fresh2. –Allergen3. –Leakage?

Sealer based on Calcium hydroxide:•Toluene salicylate, calcium oxide,

Sealapex

•Salicylates, calcium hydroxide, Apexit

•CRCS

Sealer based on Calcium hydroxide:• Pro’s1. Clinical documentation2. Good seal3. Biocompatible

• Con’s1. Inhomogeneous setting2. Poor x-ray contrast3. Lack of physical sturdiness

Silicone based RCS:

•Polydimethylsiloxane, silicone oil, zirconium oxide, RoekoSeal.

•Polydimethylsiloxane, silicone oil, zirconium oxide, gutta-percha, Guttaflow.

Silicone based RCS:

• Pro’s:1. Very good documentation2. Very good biocompatibility3. Clinically tested

• Con’s1. No antibacterial effect2. Poor mechanical strength3. Short history