Endodontic Obturation Objectives and Timing

• Obturation is the final stage of endodontic treatment, involving filling the root canal system with non-irritating, hermetic sealing agents.
• The success of obturation depends on the quality of cavity design and the thoroughness of canal shaping and cleaning.

Objectives for Obturation

• The objectives are: total obliteration of the root canal space to prevent bacterial ingress/egress, attaining a fluid-tight seal to prevent bacterial leakage.
• Also to replace the empty root canal space with an inert filling material to prevent recurrent infection.
• The final requirement is to seal the root canal space with a coronal seal up to cavo-surface margins for long-term success.

Time for Obturation

• Obturation should happen when the root canal is cleaned and shaped to its optimum size and the tooth is asymptomatic (comfortable).
• There should also be an absence of any signs of infection, foul odor, exudate (dry canal) and sinus tract.
• In cases of irreversible pulpitis, obturation can be completed in one visit after the pulp is removed.

Materials for Obturation

• Acceptable filling materials are grouped into plastics, solids, cements, and pastes.
  • Plastics include: Gutta-percha & Resilon
  • Solids or metal cores include: Silver points, gold, stainless steel & titanium.
  • Cements and pastes: Sealers, Hydron, MTA, calcium phosphate & Gutta flow.

Grossman’s Ideal Properties for Root Canal Obturation Materials

• Easy introduction into the canal
• Ability to seal the canal laterally and apically
• Dimensional stability after insertion
• Impervious to moisture
• Bacteriostatic, or at least not encourage bacterial growth
• Radiopaque
• Non-staining to the tooth structure
• Non-irritating and sterile/easily sterilized
• Easy removal from the canal if needed

Gutta Percha

• The name is derived from "GETAH" (gum) and "PERTJA" (tree name).
• It's a dried coagulated extract from Brazilian trees.
• The natural chemical form of gutta-percha is 1, 4-polyisoprene and it's the trans isomer of natural rubber.
• Historically used for coating trans-Atlantic cables and in golf ball cores.
• In it's pure form gutta-percha exists as Alpha and Beta crystalline forms, differing in molecular repeat distance and bond form; natural gutta-percha from the tree is alpha form.
• Most commercially available products are in beta form, and the phases are inter-convertible.
  • Alpha form is pliable and tacky at 56°-64°C, runny and sticky (lower viscosity), used in thermoplasticized obturation techniques.
  • Beta form is rigid and solid at 42°-44°C, compactable and elongatible (higher viscosity), and is used in manufacturing gutta-percha points and sticks.

Physical Nature of Gutta Percha

• Gutta Percha expands slightly on heating, therefore, condensation is recommended during heat techniques to compensate for cooling shrinkage.
• Gutta-percha gets brittle on aging due to oxidation.
• Refrigeration extends shelf life.
• Gutta-percha cannot be heat sterilized.
• For disinfection, immerse in 5.25% sodium hypochlorite (NaOCl) for one minute, then rinse in hydrogen peroxide or ethyl alcohol.
• Gutta-percha should always be used with sealer and cement because it lacks adhering qualities.
• It is soluble in solvents such as chloroform, eucalyptus oil or orange oil.

Gutta Percha Composition

• Gutta-percha comprises 20% of the material, functioning as the matrix.
• Zinc oxide makes up 65% as a filler.
• Metal salts make up 10% for radiopacity.
• Waxes/resins make up 5% for plasticity.

Gutta Percha Availability

• Gutta-percha points are standard cones with the same size and shape as ISO endodontic instruments.
• Auxiliary points are non-standardized cones.
• Greater taper gutta-percha points are available in tapers of 4%, 6%, 8% and 10%.
• Gutta-percha pellets/bars are used in thermoplasticized obturation techniques; i.e. the Obtura system.
• Other forms include precoated core carrier points, syringe systems, Gutta flow, chloropercha and eucopercha.

Gutta Percha Advantages and Disadvantages

• Advantages include compactability, plasticity, ability to be softened chemically or with heat, inertness and tissue tolerance, dimensional stability and radiopacity.
• Gutta percha is also able to be removed from the canal if necessary.
• Disadvantages include a lack of rigidity and adhesive quality which means gutta percha does not adhere to canal walls.
• Furthermore, it can be easily distorted and demonstrate shrinkage on cooling.

Medicated Gutta Percha

• Calcium hydroxide-containing gutta-percha: made by combining 58% of calcium hydroxide in a matrix of 42% gutta-percha.
• Available in ISO sizes of 15-140, calcium hydroxide's action is activated by moisture within the canal.
• Other medicated forms include iodoform and chlorhexidine diacetate

Resilon

• Resilon is a synthetic, resin-based polycaprolactone polymer and gutta-percha substitute to be used with Epiphany resin sealer.
• Proponents say that the bond to the canal wall and the core material creates a “monoblock."
• Handling properties are similar to gutta-percha and can be used with any obturation technique.
• Resilon contains about 65% polymers of polyester, bioactive glass, and radiopaque fillers.
• It can be softened with heat or dissolved with solvents like chloroform, and compatible with restorative techniques in which cores and posts are placed with resin-bonding agents.

Activ GP

• Activ GP consists of gutta-percha cones external surface impregnated with glass ionomer, used with a glass ionomer sealer
• It is available in .04 and .06 tapered cones.
• The single cone technique bonds between the dentinal canal wall and the master cone.

The Role of Root Canal Sealers

• Sealers close interfaces by filling irregularities and minor discrepancies between filling material and dentin.
• Sealers have antibacterial properties, acting against organisms, while functioning as lubricants facilitating the seating of filling cones.
• Can fill patent accessory canals and multiple foramina.

Types of Sealers

• Several types of sealers have been formulated for use in endodontics.
• The most common ones are based on zinc-oxide-eugenol formulations.
  • These include: Rickert's sealer; Wach's sealer (zinc oxide powder +oil of clove +Canada balsam) and Grossman's sealer.

Other Types of Sealers

• Medicated Zinc-oxide eugenol sealers: release paraformaldehyde, which causes prolonged fixation and antiseptic action.
  • Examples are: Endomethasone, N2, SPAD
• Calcium hydroxide sealers: CRCS, Seal apex
• Resin-based sealers: Diaket (Polyvinyl resin), AH26 & AH Plus, Epiphany
• Glass ionomer sealers: Ketac-Endo is able to form an adhesive bond with dentin.
• Silicone-based sealers: Roeko Seal - GuttaFlow(cold flowable matrix to be triturated) - its main component is polydimethylsiloxane and shows 0.2% expansion on setting.
• Bioceramic sealers: Composed of zirconium oxide, calcium silicates, calcium phosphate monobasic, calcium hydroxide, and various.

Techniques of Obturation Preparation

• Root canal is irrigated thoroughly, then dried with paper points equivalent to the size of the master apical file and adjusted to the proper working length.
• Follow manufacturer instructions for mixing the sealer.
  • For consistency, conduct a "drop test"- cement should not drop off spatula edge in less than 10-12 seconds.
  • Use a "string out" test where the cement should string out one inch (2.5 cm) before breaking.
• The master cone size should be equivalent to the largest file reaching the full working length.
• Insert the cone until it reaches the full working length.

Fitness of Master Cone

• For best fit, the cone should fit tightly in the apical 1/3 of the canal with good tug-back, at the full working length.
• The canal should never be forced beyond the apical foramen.
• Take a radiograph to confirm fitness.

Possibilities for Master Cone Fit

• If the cone fits to or within 0.5-1mm of working length, tug back and presence of space visible in x-ray lateral to master cone starting from the junction between apical and middle one third, this is OK.
• If cone fits short, this may be due to dentin chips packed in the apical portion, ledge formation or curved canal; meaning the canal must be negotiated.
• In cases of an improper 3D shaping of the canal the canal must be reshaped.
• If cone fits to or within 0.5-1mm of working length, tug back, but absence of space lateral to master cone, reshape the canal,
• If cone passes beyond the apex, a larger size is needed or cut 1 mm from the tip of the original master cone, this will increase the tip diameter by 0.02mm.
• Trial and error will be until working length is reached.
• If the cone manifests an "S-shape" by x-ray, a larger cone is needed.

Obturation Techniques

• Gutta-percha is the most universally used solid core root canal filling material, which has seen vast changes in materials and handling.
• Gutta-percha can be used in non-softened or softened form.
• The most popular technique for the use of gutta-percha in a non-softened state is The lateral condensation technique, recommended for most cases except severely curved canals.

Lateral Condensation Technique

• The standard is selection of master cone, selecting the obturating instruments (spreaders) and mixing sealer.
• The spreader size is the same as the master apical size so it can reach to within 1-2mm shorter than the working length.
• Sealer application inside the canal can be done by coating the master cone itself and using it to coat the dentin walls, also utilizing instruments like files, reamers or lentulo spirals.
• Slowly insert the master cone to allow the sealer to escape coronally and hold the cone in place for 20-30 seconds.
• After placement of the master cone, a premeasured spreader is then is inserted alongside the primary point (rotary vertical motion) until it reaches maximum penetration (1-2mm short of working length).
• Keep the spreader in place for one minute.

Finishing the Lateral Condensation Technique

• Move the spreader back and forth while withdrawing it from the canal to avoid disturbing the master cone.
• Finger spreaders provide sensation and are less likely to induce fractures when compared with the traditional hand spreader.
• Ni-Ti spreaders increase flexibility, reduce stress and provide deeper penetration when compared to St-St spreaders.
• Apply light pressure not exceeding 1.5kg to avoid fracture.
• Introduce an auxiliary gutta-percha cone equivalent inside the canal in the space created by the spreader.
• The spreading procedure is repeated until the spreader can not be introduced inside the canal.
• Protruding points are severed at the level of the canal orifice with a hot instrument.
• A plugger compacts gutta-percha vertically to ensure its tightness.
• Clean the pulp chamber to evaluate the quality of obturation.

Efficacy of Lateral Condensation

• Excellent length control, however, that the process does not produce a homogeneous mass.
• The accessory and master cones are laminated and frozen in a sea of cement, and the technique may not fill canal irregularities.

Radiographic Evaluation of Obturation

• Radiolucencies: voids within the body of obturating material represent incomplete obturation.
• Length: the obturating material should extend to the prepared working length, and be removed apical to gingival margins (anterior teeth) and canal orifices (posterior teeth).
• Density: obturating material should be of uniform density from coronal to apical aspect.
• Taper: gutta-percha follows the canal taper.
• Restoration should ensure coronal seal.

Modification in Lateral Condensation Technique

• Use in mature canals, however, in cases of immature canals with no apical constriction (tubular canals) or when canals diverge apically (blunderbuss canals) a modification must be done.

The Inverted Cone Technique

• Recommended in cases of tubular canals when the largest gutta-percha cone is loose.
• Select a coarse gutta-percha cone and the remove serrated butt end with a scalpel; invert and introduce it into the canal.
• If the selected inverted cone would reach the full working length, now the exact previous procedure for lateral condensation is followed.

Tailor-Made Cone Technique

• If the tubular canal is so large that the largest inverted cone is still loose in the canal, make a tailor-made cone, prepared by heating a number of gutta-percha cones and combining them to form a cone which can tightly fit the canal.
• On a glass slab, roll the gutta-percha cones together with a hot spatula until they combine and chill the roll with a spray of ethyl chloride or ice water to stiffen the gutta-percha.
• Insert a tailor- made cone inside the canal and use lateral condensation.
• Apply light pressure not exceeding to avoid fracture.

Softened Techniques

• Softenting of gutta-percha can adapt to irregularities better.
• A coherent mass of gutta-percha offers better sealing than compacted cones, softened by heat or chemically.

Chemically Softened Techniques

• A number of chemicals can to soften gutta-percha.
• Chloroform is popular, but irritant and carcinogenic; other chemicals include eucalyptus, xylene, halothane and rectified white turpentine.

Chloroform Softened Gutta-Percha Chloropercha

• Johnson-Callahan technique: The root canal is flooded with chloroform then the gutta-percha master cone is inserted and a regular lateral condensation technique is performed.
• Dipping dish with chloroform: Place master cone tip in a dipping dish filled with for a few seconds then introduce into the canal.
• Then flood the canal with irrigant preventing gutta-percha adherence to the canal walls.
• The softened cone fits the shape of the apical canal (spreader can be used); wait a few seconds then withdraw the master cone from the canal and wash it with water.
• Then coat it with sealer then perform the usual lateral condensation.
• Nygard-Ostby technique: Place gutta-percha cones in a dipping dish filled with chloroform for a few minutes until all cones form a creamy mix.
• Dip a prefitted master cone in this creamy mix and perform regular lateral condensation.

Disadvantages of Chemically Softened Techniquees

• The chemicals are irritant to periapical tissues.
• Chemically softened gutta-percha is dimensionally unstable where shrinkage(12%) occurs after the evaporation of the leaving voids.

Heat Softened Thermal Applicators

• Warm lateral condensation is similar to the non-softened -condensation; and utilizes hot spreaders.
  • An example found in the market - Endotec II
• Adapt a master cone manner identical to with traditional lateral compaction.
• The Endotec II tip comes in various taper and tip diameters.
• activate and the tip is inserted beside the master cone to within 2 to 4 mm of the apex, with light pressure.
• Rotate the tip is clockwise for 5 to 8 seconds then remove counterclockwise.
• Insert an unheated spreader in the channel and place an accessory cones.

Warm Vertical Condensation Technique Steps

• Dry the root canal with paper points
• Fit the appropriate gutta-percha cone to the radiographic terminus, with a tug back.
• Remove the cone, cut back about 0.5-2 mm of the tip, reinsert and look for the "tug back”.
• Choose the heat transferring material and prefit the three pluggers to the prepared canal at 5 mm intervals; use the widest (coronal), medium, and the narrowest (to within 3-4 mm of the apical constriction).
• Apply a sealer with a Lentulo spiral.
• With a heat transfer instrument, cut off excess of the cone in the pulp chamber, transferring heat to the coronal third of the gutta-percha cone.
• Separating medium, the gutta-percha compacted apiclly with pressure.
• This is the heatwave in which the gutta-percha temperature is raised 5 to 8 degrees above body temperature.
• Heat carry is reintroduced for 2-3 seconds.
• Mid-sized plugger is submerged apiclly.
• For the next 3-4 mm plug the heat transfer instruments warms the next 3-4 mm of gutta percha.
• The narrowest plugger the.
• The warmed gutta-percha is vertically compacted, sealing the apical canal.
• Complete apical "down-pack" is achieved and no need for further gutta-percha.
• Fill the rest by injecting plasticized gutta-percha from syringes.

Thermoplasticized Injection Technique (Obtura)

• The device is a pistol-like delivery unit for the introduction of the gutta-percha beta phase (pellets) through 23 gauge silver injection tips.
• It is connected to an electric unit (160-180 C).
• Apply the canal with sealer, and injection needle is placed 3-5 mm from working length.
• By heat the back pressure elevates canal.
• Compact gently with cold pluggers, repeating compaction until cooling and minimising small-voids from entanglement.
• This system can be used for internal resorption issues or to fill canals containing metallic posts.
• The disadvantages of this system include the affection of periodontium.

Low Temp Therm Injection Technique (Ultrafil 3D)

• Uses preloaded cannules with 22 gauge stainless steel needles, warmed at (70 C).
• For canals fitted with ultra, must have tapered canal large enough, 8-10 .
• Cannulas have a range of three d viscosities
• These include: *Endo Fil-Regular (white cannule), (30 mins)
• Endo Set (green (2 mins)
• Firm Set (blue. (4mins)
• The injection technique mirrors.obtura.
• McSpadden Compaction Technique
• Heat used to lower gp making it easier to create plasticity.
• The heat produced by friction softens the gp and designs of blade lateral.
• Should be used in only straight cases only.

Solid core GP

• Carriers made from stainless steel and plastics. Propoed technique: canal coated,gp carier w similar master gp introduced 2 above from canal opening with bur.
• cold plugger compacts around the 2 .
• Fast, Safe,Can be used in curved.

Important Notes on Canal Obturation

Factors That Determine Apical Constriction of Canal Includes:

• knowledge of apical.
• tactile sense.
• radio interpretation - apex locator

Properties of Ideal Seal:

• Tackiness
• Hermectic sel radiopacity
• very fine pdr
• no shrinkage
• biostatic, no infection
• slow set, insoluable tissue tolerable and solvent

Advantages Of ZOE Sealers

1- plasticity 2- Slow setting 3- Good sealing 4- Antimicrobial activity

Disadvantages ofZOE Sealers

1- Decomposed by water 2- Weak & unstable & Staining 3- Irritation by eugenol

Advantages of AH Plus

• A two part Better Radiopauqe and flow compared to A26, also not that toxic:

Sequence of System and Resiliion

C and dry and primer on etch the paper oit lenticical or spinal and light for 40

Learn about obturation, the final stage of root canal treatment. This involves filling the root canal system with non-irritating, hermetic sealing agents to prevent bacterial infection. Discover the objectives of obturation and when it should be performed for optimal results.