Obturation of the Radicular Space PDF

Obturation of the Root Canal Space 9/10/2023 1  Course outline Introduction Ideal requirements for root canal filling materials When we have to fill the canal Clinical creteria for time to fill the canal Solid core obturation mater...

Obturation of the Root Canal Space 9/10/2023 1  Course outline Introduction Ideal requirements for root canal filling materials When we have to fill the canal Clinical creteria for time to fill the canal Solid core obturation materials Different obturation materials Obturation techniques Root canal sealants Single visit root canal treatment 9/10/2023 2  Introduction Definition According to the American Association of Endodontists “Obturation is the method used to fill and seal a cleaned and shaped root canal using a root canal sealer and core filling material The function of a root canal filling is to obturate the canal and eliminate all portals of entry between the periodontium and the root canal The better the seal, the better the prognosis of the tooth Achieving the ideal seal, is as complex as the anatomy of the root canal system itself. 9/10/2023 3  Requirements for an Ideal Root Canal Filling Material The material should be easily introduced into the root canal  It should seal the canal laterally as well as apically  It should not shrink after being inserted  It should set slowly  It should be impervious to moisture  It should be bactericidal or, at least, should discourage the growth of bacteria  It should be radiopaque  It should not stain the tooth structure  It should not irritate periradicular tissues or affect the tooth structure.  It should be sterile, or easily and quickly sterilized immediately before insertion 9/10/2023 4  It should be easily removable from the root canal 9/10/2023 5  When To Obturate The Root Canal A root canal may be obturated when the tooth is asymptomatic and the root canal is reasonably dry Obturation after obtaining a negative culture and closure of an existing sinus tract have been suggested in the past However, this concept is no longer valid 9/10/2023 6 Clinical Criteria For Timing Of Obturation The canal should be reasonably dry, with no “weeping” of fluids in the form of bleeding or discharge of serous fluids Optimal shaping and cleaning of the canal can be easily achieved in a tooth with vital pulp tissue Extra care and attention should be given while cleaning a canal with necrotic and infected pulp Failure of treatment is more common in teeth with pre-existing periradicular radiolucency than in teeth with no periradicular changes When seepage into the root canal is excessive, it can be treated and eliminated by reinstrumentation and enlarging the canal, irrigating and sealing it with an intracanal medicament, such as calcium hydroxide paste 9/10/2023 7  Solid Core Obturating Materials silver cones Historical solid core filling materials silver cones For the past 50 years, silver cones have been used to fill root canals A silver cone is stiffer than gutta-percha and can be easily inserted into a fine, tortuous canal Nevertheless, silver points start corroding when they come into contact with saliva or periradicular fluids The corrosion products are toxic and lead to the failure of the endodontically treated teeth Specialized instruments like the Stieglitz forceps are needed to retrieve the silver points from the root 9/10/2023 8 9/10/2023 9 Currently used solid Core Filling Materials A. Gutta-Percha Over the years, many different filling materials have been used to seal root canals None have proved to possess all the ideal characteristics Currently, the material used most often as a solid core filling is gutta-percha Composition 20% gutta-percha (matrix) 66% zinc oxide (filler) 11% heavy-metal sulfates (radiopacifier) 3% waxes or resins (plasticizer) 9/10/2023 10...cont’d Characteristics Gutta-percha is a rigid natural latex produced from the sap of rubber trees of genus Palaquium gutta It is a trans-isomer of polyisoprene and exists in alpha and beta crystalline forms The material is solid in the beta phase and does not shrink On heating the material, beta phase changes into the alpha phase that is tacky and flowable under pressure The thermoplasticized alpha phase shrinks as it sets into a solid mass The solid mass alpha phase gutta-percha melts at a temperature above 65°C and turns into the beta phase on slow cooling This exhibits less shrinkage and more dimensional stability than when the beta phase is heated 9/10/2023 11...cont’d Properties It does not shrink after insertion unless it is plasticized with a solvent or heat It is easily sterilized prior to insertion and does not encourage bacterial growth It is radiopaque, nonstaining, and impervious to moisture It can be removed easily from the root canal if necessary compared to silver cones It is probably the least toxic and least irritating root canal filling material 9/10/2023 12  Sizes and Tapers Gutta-percha is available in conventional and standardized sizes Extra fine Fine Medium fine Fine medium Medium Large Extra large 9/10/2023 13...cont’d The standardized sizes are designed to match the size and taper of the corresponding stainless steel or nickel–titanium instruments employed for shaping the canals(files) ISO 2% from size Nos. 15 to 140 Greater taper gutta-percha cones like 4 or 6% tapered Variable taper gutta-percha points suiting the taper of variable taper shaping instruments like the Protaper F1, F2, and F3 9/10/2023 14 b. Resilon Resilon is a high-performance polyurethane introduced recently as an alternative to gutta-percha composition of Resilon – A polycaprolactone core material with difunctional methacrylate resin – Bioactive glass – Bismuth – Barium salts as fillers, and pigments – A resin sealer is always employed with the core filling material for obturation 9/10/2023 15  C. MTA Mineral trioxide aggregate (MTA) can be used as a canal obturation material because of its superior physiochemical and bioactive properties Indications MTA obturation combined with root-end resection Teeth with open apices Retreatment with MTA obturation Internal resorption Dens in dente Limitations Difficulty in retreatment following MTA obturation, especially in curved canals Potential for discoloration, especially when used in the anterior esthetic zone 9/10/2023 16  Gutta-percha Obturation Techniques 1. Cold lateral compaction 2. Warm compaction (warm gutta-percha) (a) Vertical (b) Lateral 3. Continuous wave compaction technique 4. Thermoplasticized gutta-percha injection 5. Carrier-based gutta-percha (a) Thermafil thermoplasticized (b) SimpliFill sectional obturation 6. McSpadden thermomechanical compaction 7. Chemically plasticized gutta-percha 8. Custom cone 9/10/2023 17  I. Cold Lateral Compaction Technique This has been one of the most commonly practiced obturation techniques However, in contemporary endodontics, it is not the best technique to achieve a three-dimensional seal Clinical Considerations 1. Sealer considerations: Sealer application on the canal walls can also be performed using a lentulo spiral or with the master gutta-percha cone itself 9/10/2023 18 9/10/2023 19 9/10/2023 20...cont’d 2. Spreader considerations The size of the spreader is determined by the width of the prepared canal and the lateral fit of the primary cone; the greater the space between the canal wall and the end of the gutta-percha, the larger (wider) the spreader used The spreader size should reach within 1–2 mm of the working length in order to obtain optimal apical compaction 9/10/2023 21...cont’d 3. Master cone considerations: Selection of the master cone should be similar to the master apical file size Minimal judicious force should be used on the spreader during the compaction process in order to avoid root fractures Additional secondary cones are inserted until the spreader cannot be reinserted, an indication that the root canal is fully compacted laterally A sealer coating is not mandatory for secondary cones Several radiographs must be taken while one obturates the canal to check the accuracy of the procedure Limitations The presence of voids in between the filling 9/10/2023 22  II. Warm Compaction Method (Warm Gutta-percha) A. Warm vertical Compaction Principle The warm vertical condensation or “warm gutta- percha” technique of filling root canals was introduced with the objective of filling the main root canal as well as lateral and accessory canals Using heated pluggers, one applies pressure in a vertical direction to the heat-softened gutta-percha and thereby causes it to flow and to fill the entire lumen of the canal The requirements are A continuous tapering funnel should be present from the root canal orifice to the root apex The root canal should be prepared so that it flows with the shape of the original canal 9/10/2023 23 9/10/2023 24...cont’d The apical foramen should be kept as small as is practical so that excess gutta-percha will not be forced through it during vertical compaction Indications As an alternative to the cold lateral compaction technique When the fitting of a conventional master cone to the apical portion of a canal is impossible, as when there is unusual canal curvatures, internal resorptions, or large lateral canals 9/10/2023 25...cont’d Technique A primary gutta-percha cone corresponding to the last instrument used is fitted in the canal in the usual manner The canal wall is coated with a thin layer of root canal sealer The primary gutta-percha cone or master cone is inserted up to the working length The coronal end of the cone is cut off with a heated instrument A “heat carrier,” such as a root canal plugger, is heated to redness and is immediately forced into the coronal third of the gutta-percha This is repeated until the plasticized gutta- percha seals the larger accessory canals and fills the lumen of the canal in three dimensions up to the apical foramen 9/10/2023 26...cont’d Advantages Excellent seal of the canal apically and laterally Obturation of the larger lateral and accessory canals Disadvantage The amount of time it takes The risk of vertical root fracture resulting from undue force Periodic overfilling with gutta-percha or sealer that cannot be retrieved from the periradicular tissues 9/10/2023 27  A. Warm lateral Compaction This technique provides the advantages inherent to thermoplastic techniques as well as length control during obturation The technique involves placement of the master cone and lateral compaction using heat carriers such as Endotec II tips (Medidenta) and EndoTwinn tips (Hu-Friedy) The device is placed beside the master cone and activated followed by placement of an unheated spreader in the space Accessory cones are then placed and the process repeated until the canal is filled 9/10/2023 28  III. Continuous Wave Compaction Technique The technique employs the use of gutta-percha cones and pluggers that mimic the tapered preparation. Clinical technique Pluggers are selected in consistence with the size of the shaping instruments used Tapered pluggers #.06, #.08, #.10, and with a tip diameter similar to the tapered gutta-percha points, respectively, are employed The procedure is carried out with a heat carrier system 9/10/2023 29 9/10/2023 30  IV. Thermoplasticized Gutta-percha Injection Techniques Principle This technique comprises a pressure apparatus consisting of an insulated electrically heated syringe barrel and a selection of needles ranging from 18 to 25 gauge size The plunger is designed to prevent backward flow of the gutta-percha The degree of heat is regulated to provide proper extrusion of the gutta-percha according to the size of the needle 9/10/2023 31...cont’d Technique The Obtura III is an example of this technique The Obtura III heats the gutta-percha to 200°C. The canal preparation is similar to any other technique After drying the canal, sealer is coated on to the canal walls The gutta-percha is electrically heated in a hand held gun that contains a chamber surrounded by a heating element where the gutta-percha pellets are loaded A suitable gauge needle is selected to be positioned at 3–5 mm short of the working length Gutta-percha is gradually injected by squeezing the trigger of the gun and the needle is gradually withdrawn as the canal gets filled apically 9/10/2023 32...cont’d The gutta-percha is then compacted using pluggers of appropriate size The rest of the canal can be filled in one to two increments using the same technique Torabinajed and colleagues found that injection of plasticized gutta-percha from a pressure syringe produced satisfactory obturation as compared to cold lateral compaction Gutmann and Raskin have recommended a meticulously tapered preparation of the root canal in order to minimize the flow of the gutta-percha 9/10/2023 33 9/10/2023 34  Limitations One common defect in all injection techniques is the lack of precision in delivering the gutta-percha near the apical foramen and not beyond The injection technique relies on the heated and plasticized gutta-percha to flow apically with minimal compression When compared to the force or pressure used in lateral and vertical compaction Unless vertical pressure is combined with the injection method of obturation, the interface seal between the gutta-percha and the canal wall is weakened and voids occur in the final set filling 9/10/2023 35 V. Carrier-based Gutta-percha Techniques Thermafil thermoplasticized technique Thermafil is a carrier-based gutta-percha obturation system comprising a plastic core carrier coated with alpha phase gutta-percha Thermafils are available in ISO standardized sizes as well as variable tapered sizes suitable for canals prepared with nickel–titanium tapered instrument These obturators are used in conjunction with a heating device known as the Thermaprep plus Oven 9/10/2023 36...cont’d After preparation of the canal with suitable instruments, the size of the canal is assessed with a thermafil verifier instrument which helps in the selection of the appropriate sized obturator The canals are dried and a light coat of sealant is applied The silicon stopper on the carrier is adjusted to the working length and the carrier is loaded into the Thermaprep plus Oven for approximately 10 seconds The carrier is then inserted into the canal and placed up to the working length with a firm uniform apical pressure without rotating The position of the carrier is verified radio graphically and the gutta-percha is allowed to cool for 2–4 minutes before resecting the carrier at the level of the canal orifice 9/10/2023 37 9/10/2023 38  SimpliFill sectional obturation technique SimpliFill is a carrier based sectional gutta-percha obturation system used in conjunction with the light- speed rotary instruments The SimpliFill carrier has an apical 5 mm plug of gutta-percha which performs cold sectional obturation of the root canal The carrier size is chosen according to the diameter of the master apical file (MAF) After drying the canal and applying the sealant, the carrier is introduced up to the working length The handle of the carrier is rotated quickly in the counterclock-wise direction three to four times to disengage the apical plug of gutta-percha from the carrier 9/10/2023 39 9/10/2023 40  VI. Mcspadden Thermomechanical Compaction Method Uses heat to decrease gutta-percha viscosity and increase its plasticity The heat is created by rotating a compacting instrument in a slow-speed contra-angle handpiece at 8,000–10,000 RPM alongside gutta- percha cones inside the root canal The compactor whose spiraled 90° flutes are similar to the flutes on a Hedstroem file, but in reverse, forces the softened gutta-percha apically and laterally 9/10/2023 41...cont’d As the compactor blade breaks easily if it binds, this method should be used to fill straight canals only Using the step-back method, the canal should be enlarged to at least the size of a No. 45 instrument Gutta-percha cones are inserted in the prepared canal short of the root apex, and a compactor blade, selected according to the width and length of the prepared canal, is inserted between the gutta - percha and the canal wall With a stop on the compactor blade, the rotating tip of the blade is guided to within 1.5 mm of the root apex Restriction of the blade within the canal prevents the forcing of thermoplasticized gutta-percha through the root apex 9/10/2023 42...cont’d Advantages Ease of selection and insertion of gutta-percha cones Economy of time Rapid filling of canals apically and laterally, including irregular spaces within the canal if one uses a sealer Disadvantages Inability to use the technique in narrow canals Frequent breakage of compactor blades Frequent overfilling of the canal 9/10/2023 43  VII. Chemically Plasticized Gutta percha Technique (Eucapercha, Chloropercha) Gutta-percha can be plasticized by chemical solvents such as chloroform, eucalyptol, or xylol The disadvantage of using a chemical-solvent filling material is its inability to control overfilling, with resultant periapical tissue reaction and shrinkage of the filling after setting, resulting in a poor apical and lateral seal 9/10/2023 44  VIII. Custom Cone Technique Custom cone technique is a chair-side procedure employed for customizing the gutta-percha in wide canals where traditional master cone cannot be adapted The clinician has to customize a gutta-percha point to achieve a tug back Technique Soften an appropriate-sized gutta-percha with one or more accessory cones with the help of heat and roll together between two glass slabs A spatula may also be used as an alternative A single master cone of increased diameter is created which is then sized within the canal Soften the tip of the master cone with chloro- form, eucalyptol, or halothane for few seconds and gently place it to the working length with a locking plier 9/10/2023 45 9/10/2023 46  Root Canal Sealers  Definition: Root canal sealers are used in conjunc tion with biologically acceptable semisolid or solid obturating materials to establish an adequate seal of the root canal system Criteria for an Ideal Root Canal Sealer  Provide an excellent seal when set  Šƒ Produce adequate adhesion between itself, the canal walls, and the filling material  Be radiopaque  Be nonstaining  Be dimensionally stable  Be easily mixed and introduced into the canals  Be easily removed if necessary  Be insoluble in tissue fluids  Be bactericidal or discourage bacterial growth  Be nonirritating to periradicular tissues  Be slow setting to ensure sufficient working time 9/10/2023 47 Classification of Currently Employed Root Canal Sealers 1. Zinc oxide eugenol based sealers A. Grossman’s formula B. Roth’s 801 C. Tubliseal II. Calcium hydroxide based sealers A. Sealapex B. Apexit III. Glass ionomer based sealers IV. Resin-based sealers A. AH plus B. AH26 C. Epiphany D. Diake 9/10/2023 48  a. zinc oxide eugenol based sealers Most of the sealers in common use contain zinc oxide resin as a base ingredient of the powder Included in this group are Grossman’s cement, Roth’s Sealer (Roth International), Tubli-Seal (SybronEndo; and Wachs Sealer (Balas Dental) The liquid usually consists of eugenol alone or in combination with other liquids such as Canada balsam Grossman developed a nonstaining cement that meets most of the ideal requirements for a root canal sealer Grossman’s cement hardens in approximatel 2 hours at 37°C and 100% relative humidity Its setting time in a canal is less It begins to set in the root canal within 10–30 minutes because of the moisture present in dentin 9/10/2023 49  B. Calcium Hydroxide based sealers Some zinc oxide eugenol cements have been modified by incorporating calcium hydroxide Calcium hydroxide sealers were developed for their antimicrobial potential Sealapex has been described as noneugenol, calcium hydroxide polymeric resin root canal sealer available in a base catalyst system The base contains zinc oxide, calcium hydroxide, butyl benzene, sulfonamide, and zinc stearate The catalyst contains resin, isobutyl salicylate, barium sulfate, titanium dioxide, and aerosol 9/10/2023 50  C. Glass ionomer based sealers Glass ionomers have been advocated as root canal sealers for their dentin-bonding ability Ketac Endo (3M ESPE) is an example of a glass ionomer sealer They are not popular because of the difficulty in removing the sealer from root canal walls during retreatment 9/10/2023 Solvents are ineffective against them 51  D. Resin-based sealers AH26 (Dentsply DeTrey) is an epoxy resin containing a nontoxic hardener Radiopacity is imparted to it by bismuth oxide It has strong adhesive properties and contracts slightly while hardening Composition Paste A Šƒ Epoxy resin Šƒ Calcium tungstate Šƒ Zirconium oxide Šƒ Silica Šƒ Iron oxide Paste B ŠƒAdamantaneamine-N Šƒ Calcium tungstate Šƒ Zirconium oxide Šƒ Silica–silicone oil 9/10/2023 52...cont’d Advantages Good sealing ability Biocompatibility to periapical tissues Moderate antimicrobial activity Dentinal adhesion Long working time and ease of manipulation Disadvantage It was found to release formaldehyde during setting Bad test and bad odour Discolour tooth 9/10/2023 53  Single-visit Endodontics Indications Vital teeth Physically compromised patients who have to make an effort to come to the dental clinic Medically compromised patients who require antibiotic prophylaxis and sometimes alteration in the medication they take Fractured anteriors where esthetics is a concern Apprehensive but cooperative patients 9/10/2023 Patients who require sedation or an operation room54...cont’d Contraindications Patients with temporomandibular joint (TMJ) disorders and inability to keep open the mouth for long periods Teeth with limited access Nonsurgical retreatment cases 9/10/2023 55 9/10/2023 56