Authors: Schilder H.
Title: Filling root canals in three dimensions.
Journal: Dent Clin North Am
Date: Nov 1967
Citation: 1967 Nov;:723-44
Category: Obturation
Evidence-based Ranking: 5
Purpose/Objectives: To review the process of endodontic obturation in three dimensions and the many techniques used to accomplish this. Discussion: The final objective of endodontic procedures should be the total three-dimensional filling of the root canals and all accessory canals. In the final analysis, it is the sealing off of the complex root canal system from the periodontal ligament and bone which insures the health of the attachment apparatus against breakdown of endodontic origin. Review of root canal filling techniques: solvent techniques (GP w/chloroform, oil of eucalyptus, xylol; chloropercha, chlororosin) – result in a significant amount of shrinkage; lateral condensation (no solvents; used with sealer/cement and accessory points); lists Grossman’s 11 criteria for a good root canal cement; silver cone techniques (always used with a cement; non-resorbable, semi-rigidity permits apical wedging which is presumed to create a good apical seal; split-cone technique to accommodate post space); vertical condensation with warm gutta percha – “It would seem desirable to fill root canals with a homogenous, inert, dimensionally stable, physiologically acceptable material which could be manipulated with sufficient plasticity to form a permanent cast of the internal configuration of the root canal system.” Canal must be shaped so that a continuously tapering funnel is created, with the largest portion coronally. Use minimal amounts of sealer on master GP cone. Sear-off master cone at orifice; GP is then heated and forced apically in 3-4 mm increments until only the apical portion of the canal has GP. The remaining coronal portion of the canal is incrementally backfilled with warmed GP segments (2-4 mm in length). This part of the procedure can be stopped at any point to allow for a post, if needed. Pluggers should be pre-fitted so as to not bind with the canal walls. Canal system should be filled in three dimensions to within .5 to 1 mm of its radiographic apex. Overextension and underextension of the filling material refer solely to the vertical dimension of the root canal filling, beyond or short of the root apex. Underfilling refers to a tooth whose root canal system has been inadequately obturated in any dimension, leaving large reservoirs for recontamination and infection. Overfilling refers to a root canal system that has been filled in three dimensions, and where surplus material extrudes beyond the foramen. Reviewer’s Comments: This is a good review article of various obturation techniques, especially the warm vertical technique that is widely used today.