Root Canal Obturation fillings

• Obturation fills the root canal system with hermetic sealing agents.

Objectives for Obturation

• To achieve total obliteration of the root canal space and prevent ingress/egress of bacteria and body fluids.
• To attain a fluid-tight seal to prevent bacterial leakage.
• To replace the empty root canal space with inert filling material to prevent recurrent infection.
• To seal the root canal up to cavo-surface margins for long-term success.

Time for Obturation

• When the root canal(s) is cleaned and shaped to optimum size.
• The tooth should be asymptomatic and comfortable.
• Absence of any sign of infection, foul odor, exudate, or sinus tract.
• Obturation is completed in a single visit with irreversible pulpitis if the main source of pain (pulp) has been removed.

Materials for Obturation

• Grossman grouped acceptable filling materials into plastics, solids, cements, and pastes.

Properties of Root Canal Obturation Materials

• Easy to introduce in the canal.
• Seals canal laterally and apically.
• Dimensionally stable after being inserted.
• Impervious to moisture.
• Bacteriostatic, or at least should not encourage bacterial growth.
• Radiopaque and non-staining to the tooth structure.
• Non-irritating and sterile/easily sterilized.
• Removed easily from the canal if required.

Materials Used for Obturation

• Plastics: Gutta-percha & Resilon
• Solids or metal cores: Silver points, gold, stainless steel & titanium.
• Cements and pastes: sealers, Hydron, MTA, calcium phosphate & Gutta flow.

Gutta Percha

• Derived from Indonesian words GETAH meaning gum and PERTJA the name of the tree. Is a dried coagulated extract derived from Brazilian trees.
• Chemically, the natural form is 1, 4-polyisoprene. Is a trans isomer of natural rubber used for coating the first transatlantic cable and for the cores of golf balls.

Phases of Gutta-Percha

• Exists in two different crystalline forms, Alpha and Beta, that differ in molecular repeat distance and single bond form.
• Natural gutta-percha coming directly from the tree is in alpha form, while most commercially-available products are in beta form, and these phases are inter-convertible.
• Alpha form is pliable and tacky at 56°-64°C with lower viscosity, used in bars or pellets and is used in many thermoplasticized obturation techniques.
• Beta form is rigid and solid at 42°-44°C, compactable and elongatible with higher viscosity, and is used in the manufacturing of gutta-percha points and sticks.
• Gutta Percha expands slightly on heating, so condensation is recommended during heat techniques to compensate for cooling shrinkage.
• Gutta-percha gets brittle on aging because of the oxidation process.
• Storage in a refrigerator extends the shelf life.
• Gutta-percha cannot be heat sterilized, so immerse in 5.25% sodium hypochlorite (NaOCl) for one minute, then rinse in hydrogen peroxide or ethyl alcohol to remove crystallized NaOCl.
• Gutta-percha should always be used with sealer and cement, as it lacks adhering qualities.
• Gutta-percha is soluble in solvents like chloroform, eucalyptus oil, and orange oil.

Composition of Gutta-Percha

• Gutta-percha 20% as the matrix.
• Zinc oxide 65% as the filler.
• Metal salts 10% for radiopacity.
• Waxes/resins 5% for plasticity.
• Available as standard cones of the same size and shape as ISO endodontic instruments.
• Auxiliary points: non-standardized cones.
• Greater taper gutta-percha points: available in taper 4%, 6%, 8% and 10%.
• Gutta-percha bars and pellets: used in thermoplasticized gutta-percha obturation techniques.
• Precoated core carrier gutta-percha: stainless steel, titanium or plastic carriers are precoated with alpha-phase gutta-percha
• Syringe systems: they use low viscosity gutta-percha powder
• Gutta flow has gutta-percha powder incorporated into silicone-based sealer.
• Gutta-percha sealers like chloropercha and eucopercha, where gutta-percha is dissolved in chloroform or eucalyptol.

Advantages of Gutta-Percha

• Compactable and plasticity that adapts to irregular contour of canal.
• Softened by heat or chemically ;Inert and tissue tolerant.
• Dimensionally stable and radiopaque.
• Easily removed from the canal when necessary.

Disadvantages of Gutta-Percha:

• Lacks rigidity and adhesive quality, can be easily distorted, and shrinkage on cooling

Medicated Gutta-Percha

• Calcium hydroxide-containing gutta-percha is made by combining 58% of calcium hydroxide in a matrix of 42% gutta-percha, available in ISO size of 15-140, and its action is activated by moisture in the canal.
• Include Iodoform-containing and Chlorhexidine diacetate-containing gutta-percha.

Resilon

• A synthetic resin-based polycaprolactone polymer used as a gutta-percha substitute with Epiphany sealer intended to form an adhesive bond to create a "monoblock".
• Available in standardized ISO sizes and shapes with handling properties similar to those of gutta-percha.
• Contains polymers of polyester, bioactive glass and radiopaque fillers (bismuth oxychloride and barium sulfate) with a filler content of around 65%.
• Being resin-based, it is compatible with current restorative techniques where cores and posts are placed with resin-bonding agents.

Activ GP

• Consists of gutta-percha cones impregnated on the external surface with glass ionomer, and single cones are used with a glass ionomer sealer.
• Available in .04 and .06 tapered cones.
• The single cone technique is designed to provide a bond between the dentinal canal wall and the master cone

Root Canal Sealers

• Semi-solid (solid) cone or core cemented into the canal with root canal cement, or sealer.

Role of Root Canal Sealer

• Close interfaces by filling irregularities and minor discrepancies between filling material and dentin.
• Antibacterial properties act against organisms.
• Act as lubricant facilitating the seating of filling cones.
• Can fill accessories canals and multiple foramina.
• Consist of Zinc-oxide-eugenol based sealers, Medicated Zinc-oxide eugenol sealers, Calcium hydroxide sealers, Resin-based sealers, Glass ionomer sealers, Silicone-based sealers, and Bioceramic sealers

Preparation for Obturation

• Root canals are irrigated thoroughly and dried with paper points equivalent to the size of master apical file and adjusted to proper working length.
• Follow manufacturer instructions for mixing the sealer.

Preparation of the Sealer

• To test for proper consistency, a drop test is applied where the cement should not drop off the spatula edge in less than 10-12 seconds.
• Use string out test, where the cement should string out one inch (2.5 cm) before breaking.

Fitting of master cone

The size of the master cone should be equivalent to the size of the largest file reaching and the length equal to the predetermined working length.

• The size of the master cone should be equivalent to the size of the largest file reaching the full working length (master apical file).
• Based on those criteria, the selected master cone will be inserted until reaching the full working length.

Fitness of The Master Cone

• Fit tightly in the apical 1/3 of the canal (good tug-back)
• Fit the full working length.
• Cannot be forced beyond the apical foramen.

Master Cone Possibilities Based on Radiograph

• If cone fits to or within 0.5-1mm of working length, tug back and presence of space is visible in x-ray lateral to master cone it is ok.
• If cone fits short, dentin chips packed in the apical portion. Remove it with small file and irrigation. Ledge formation so renegotiate the canal. Curved canal so precurve gutta-percha. Or improper 3D shaping of the canal so we have to reshape the canal again.
• If cone fits to or within 0.5-1mm of working length, tug back and absence of space lateral to master cone, so we have to reshape the canal.
• If cone passes beyond the apex so use a larger size or cut 1 mm from the tip that till master cone reaches the accurate working length and the tip diameter is increased by 0.02mm.
• If the cone shows S- shape by x-ray, which means the cone is too small, use a larger cone.

Obturation Techniques

Gutta-percha is the most universally used solid core filling (solid core + sealer).

• Used in a non-softened or softened form.

Non-Softened Techniques

• The lateral condensation technique uses gutta-percha in a non-softened state and it's indicated in most cases except for severely curved canals.

Steps Involve

• Selection of master cone and obturating instruments.
• Mixing and application of sealer.
• Slow insertion of master cone.
• A premeasured spreader is introduced inside the canal alongside the primary point to maximum penetration.
• The spreader is moved back and forth
• An auxiliary gutta-percha cone equivalent to the size of the spreader is inserted in the space created by the spreader.
• Spreaders are repeated until a spreader can no longer be introduced inside the canal.
• Protruding points are severed at the level of the canal orifice with a hot instrument.
• A plugger vertically compacts the gutta-percha mass.
• Pulp chamber is cleaned from sealer and remnants of gutta-percha.
• Finger spreaders provide better tactile sensation and are less likely to induce fractures compared to hand spreaders. Spreaders made from Ni-Ti increase flexibility, reduce stress and better penetration compared to stainless steel spreaders, when applying light pressure.

Efficacy of Lateral Compaction

Advantage is excellent length control.

• Disadvantage is that process laminated and remain separate, and the technique may not fill canal irregularities.

Modifications of The Lateral Condensation Technique

• Used efficiently with mature canals, but modified in immature canals where no apical constriction exists (tubular canals) or when canals diverge apically (blunderbuss canals).
• The inverted cone technique is used when the largest gutta-percha cone is loose in the canal and is recommended in cases of tubular canals.
• Serrated butt end of the cone needs to be removed with a scalpel and introduce in canal

Radiographic Evaluation of Obturation

• Radiolucencies: are voids within the body of obturating material representing incomplete obturation.
• Length: obturating material should extend to working length apical to gingival margin and canal orifices of anterior and posterior teeth
• Density: obturating material should be of uniform density from coronal to apical aspect and reflect canal taper.
• Restoration should contact enough dentine surfaces to ensure coronal seal.

Chemically Softened Techniques

• Ability to soften gutta-percha chemically, where chloroform is the most popular one
• Three techniques are Johnson-Callahan, Placement of master cone tip in dipping dish, Nygard-Ostby technique.
• Should be used a lot, as is highly Irritating to periapical tissues and dimensionally unstable where shrinkage when the evaporation of the chemical used happens

Heat Softened Techniques

• Warm lateral condensation technique is similar to the non-softened one except is done hot.
• Warm vertical condensation includes a dry root canal and proper gutta-percha fitting, heat it canal in 5mm intervals and fill it

Injection Systems

• High-temperature thermoplasticzed injection technique (Obtura) involves a pistol like delivery unit through 23 gauge silver injection tips to a desired temperature.
• Low-temperature thermoplasticzed injection technique (Ultrafil 3D) involves canules filled with separate unit, injection with sealer and perfect stop, and use multiple viscosity.

Thermomechanical Compactors

Introduce heat to plasticity.

• McSpadden compaction technique uses heat to lower viscosity of gutta percha.
• Heat is produced to friction, blade brakes occur if binds, in Europe a new condenser was made.
• Developed construciton to minimize the extrusion.

Solid Core Gutta-Percha Carriers

• Composed of alpha-phase gutta- percha molded around metal core resembling an endodontic file, usually the central carrier is made of stainless steel, plastic may be used.
• Process of heating carriers introducing through the canal, cutting the shaft in the canal, compact

Intercanal Medication

• Includes antimicrobials and antiseptics.
• When treatment cannot be completed in one appointment, intracanal medication is used.
• Antiseptics can be Alcohols, Phenolic compounds, and Halogens Calcium is increasingly uses with an antimicrobial action towards the endodontic infection, also an osteogenic effect.
• Triple-Antibiotics Paste: Mixture of antibiotics is sufficient, composed of metronidazole, ciprofloxacin, and minocycline for sterilization Bioactive Glass can new in the use of bioactive glass, found to kill bacteria.

Important Factors

• Factors such as Clinician knowledge, tactile sensation, radigraphic,Apex locator, Apical building which will help establish of constriction.

Ideal Features of Sealer

• Should be fine powder, lack of shrinkage, should have antimicrobial and establish
• A good hermatic seal, good radiopacty but not set

Important thing to use the Epiphany system and Resilon

• Self ester primer/thinning, light for 40 sec, the lose the first
• You ont want to lose them, may need to do water of saline