RECENT OBTURATION TECHNIQUES Introduction The final of endodontic treatment is to fill the entire root canal system and all its complex anatomic pathways completely and closely with non irritating hermatic sealing agents. Total obliteration of the canal space, perfect sealing of the apical foramen at the dentin cementum junction, accessory canals at location other than the root apex with an inert, dimensionally stable and biologically compatible material are goals for consistently successful endo treatment. Obturation of a root canal should result in a complete seal from the coronal aspect to the apex preventing the entry of microorganisms and fluid About gutta percha: Gutta percha is the most widely used material for obturation of root canals since it is relatively inert, non toxic and biocompatible. Gutta percha (GP) exists in two phases α and β. If the naturally occurring α phase GP is heated above 65°C it becomes amorphous and melts. Cooling this amorphous material extremely slowly at the rate of 5°C/hr will re crystallize the alpha form. Routine cooling of the amorphous melted material results in β form. This form is commercially used as it is solid, elongatible and compactable. The α phase gutta percha possess adequate rigidity to be placed to length along with a low melting temperature, low viscosity and increased fluidity to fill the root canal irregularity. β phase GP has a higher melting pt and viscosity that allow it to flow into canal intricacies when heated. GP harvested from trees is mainly α phase and is used in the latest thermoplasticized techniques. β from when heated to 42-49°C changes to α form. Old Techniques Lateral condesation - the most commonly used obturation technique was first advocated by Callahan in 1914. This method is time consuming difficult in curved or fine canals. In curved canals the gutta percha should be compacted by placing the spreader against the inner curve. So the more rigid spread follows the gentler outer curve. So that the spreads does not pull out the master GP. Also the success is more or less operator dependant. Vertical condensation – manually is also a method commonly used. Disadvantages of these – Pressure exerted in these two methods by the spreaders and pluggers in an attempts to condense the GP into a solid mass generates stresses. These stresses can deform the roots and create microfractures within the dentine. This deformation may propagate under occlusal load and manifest later as longitudinal root fractures especially after post preparation. These techniques may produce many irregularities in the mass of GP.
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