1 British Dental Journal 2004 Vol: 197(8):455-464. DOI: 10.1038/sj.bdj.4811738

Endodontics: Part 5 Basic instruments and materials for root canal treatment

In this part the basic endodontic instruments necessary for effective root canal treatment are described. The properties of, and manufacturer's claims for, new instruments and techniques may be compared to these basic principles before they are purchased and introduced to clinical practice. Having the correct instruments for different clinical situations may make treatment both more efficient and more effective.

Figure 1: An endodontic instrument pack.From left to right; front surface reflecting mirror; DG16 endodontic probe; Western probe; CPITN probe; endo-locking tweezers; long shank excavator; flat plastic, artery forceps, endodontic syringe; plus clean stand, file stand, measuring device, sterile cotton wool rolls and pledgets. Figure 2: Conventional hand instruments; top – reamer with red stop; middle - Hedstroem file with black stop; bottom - K-flex file with yellow stop. Figure 3: A pack of hand files of greater taper, 12% taper (blue), 10% (red), 8% (yellow) and 6% (white). Figure 4: A low-speed, high-torque motor required for use with nickel-titanium rotary instruments. Figure 5: An EDTA paste which will usually be picked up on each instrument before use. Figure 6: Some of the burs specifically manufactured for endodontic treatment; a safe-tipped access bur; a long-shanked round bur; a swan-necked bur; a Gates-Glidden bur. Figure 7: CPR® ultrasonic tips, now available to fit different piezo-electronic machines.(b) Also shown are KiS tips for periradicular surgery. Figure 8: An electronic apex locator. Figure 9: A device for setting instruments at the correct working length Figure 10: Illustrations from the work on decontamination of endodontic instruments by Dr Andrew Smith, Glasgow: a) photomicrograph (x16) of an unused endodontic file; b) photomicrograph (x16) of a used instrument after sterilization; c) SEM (x500) of the file shown in illustration b. Figure 11: The symbol indicating instruments intended for single use only. Figure 12: A selection of file holders. Figure 13: During root canal treatment of a tooth diagnosed as having an irreversible pulpitis, the vital pulp has been extirpated on a barbed broach. Figure 14: Spiral fillers may fracture if the size is not verified passively before rotating in the canal. Figure 15: Some of the different gutta-percha points: standarized; greater taper; 04 and 06 taper; feather tipped. Figure 16: A selection of root canal sealers. Figure 17: A medicolegal case where a formaldehyde containing root canal sealer has been extruded into the inferior dental canal, causing paraesthesia of the lip. Figure 18: Mineral Trioxide Aggregate is commercially available as Pro-Root. Figure 19: Cold lateral compaction may be carried out with either finger spreaders or long-handled spreaders. Figure 20: Machtou heat carrier/pluggers for warm lateral and vertical compaction. Figure 21: The System B heat source for controlled warm gutta-percha techniques. Figure 22: The Obtura 11 system for injecting heat-softened gutta-percha into the root canal. Figure 23: A patient wearing safety glasses, a waterproof protective bib and a rubber dam. Figure 24: The use of magnifying loupes is increasing in restorative dentistry. Figure 25: A surgical microscope may be essential for some of today's intricate endodontic procedures. Figure 26: The rubber dam equipment; clamps, dental floss, forceps, sheet, punch, frame and napkin. Figure 27: A film holder for taking parallel radiographs, incorporating a cage device to fit over the rubber dam clamp. Figure 28: A manual radiographic processing unit being used and b) containing rapid developing and fixing chemicals. Figure 29: An automatic radiographic processor, with a simple device to bypass the drying cycle. Figure 30: An illustration of the computer screen produced by digital radiography, enabling immediate viewing and manipulation of the image The sensor plate or 'film' may be either loose, resembling a conventional periapical radiographic film, which must be inserted into the machine for processing, or linked by cable to the processor as in b). Figure 31: A radiographic viewer designed to eliminate extraneous light and magnify the image.
  1. National Radiographic Protection Board. Guidance Notes for Dental Practitioners on the safe use of x-ray equipment. 2001 Department of Health, London, UK , .
    • . . . Long-cone parallel radiography is a requirement for endodontics,1 because it gives an undistorted view of the teeth and surrounding structures and is repeatable, thus allowing more accurate assessment of periapical healing . . .
  2. Cameron JA. The synergistic relationship between ultrasound and sodium hypochlorite: a scanning electron microscope evaluation. J Endod 1987; 13: 541-545 , .
  3. Byström A, Sundqvist G. Bacteriological evaluation of the effect of 0.5% sodium hypochlorite in endodontic therapy. Oral Surgery, Oral Medicine, Oral Pathology 1983; 55: 307-312 , .
    • . . . Research has shown that the antibacterial effect is the same for a 0.5% and a 5.0% solution.3 However, the greater the dilution the less effective is the solution at dissolving organic debris in the root canal system. . . .
  4. Solovyeva AM, Dummer PM. Cleaning effectiveness of root canal irrigation with electrochemically activated anolyte and catholyte solutions: a pilot study. Int Endod J 2000: 33: 494-504 , .
    • . . . Researchers are constantly seeking improved methods of cleaning root canals; reports have appeared recently relating to the use of electro-activated water as an irrigant,4 and the use of high frequency electric current.5 These and others may prove interesting developments in root canal preparation and irrigation. . . .
  5. Haffner C, Benz C, Folwaczny A, Mech A, Hickel R. High frequency current in endodontic therapy; an in-vitro study. J Dent Res 1999; 78: 117 , .
    • . . . Researchers are constantly seeking improved methods of cleaning root canals; reports have appeared recently relating to the use of electro-activated water as an irrigant,4 and the use of high frequency electric current.5 These and others may prove interesting developments in root canal preparation and irrigation. . . .
  6. Ranta K, Haapasalo M, Ranta H. Monoinfection of root canals with Pseudomonas aeruginosa. Endod Dent Traumatol 1988; 4: 269-272 , .
    • . . . Firstly, to prevent the introduction to the root canal system of extraneous microorganisms, which may severely compromise treatment, for example pseudomonas.6 Secondly, if instruments and devices were to be used on different patients, to prevent cross-infection between patients . . .
  7. Smith AJ, Dickson M, Aitken J, Bagg J. Contaminated dental instruments. Journal of Hospital Infection 2002 (in press) , .
    • . . . Bacteria, viruses, fungi and prions may contaminate instruments and research has shown that some of these may not be destroyed by any method of sterilization.7Figure 18 illustrates this dramatically . . .
  8. Lowe AH, Bagg J, Burke FJT, MacKenzie D, McHugh S. A study of blood contamination of Siqveland matrix bands. BDJ 2002; 192: 43-45 , .
  9. Tronstad L, Barnett F, Flax M. Solubility and biocompatibility of calcium hydroxide-containing root canal sealers. Endod Dent Traumatol 1988; 4: 152-159 , .
    • . . . It has been shown, however, that the calcium hydroxide is prone to leakage,9 which may result in unwanted voids in the seal. . . .
  10. Torabinejad M, Hong CU, McDonald F, Pitt Ford TR. Physical and chemical properties of a new root-end filling material. J Endod 1995; 21:349-353 , .
    • . . . Mineral trioxide aggregate (Fig. 25) is a compound consisting of mineral oxides, (tricalcium silicate, tricalcium oxide, silicate oxide and traces of other mineral oxides), developed first by Mahmoud Torabinejad and co-workers at Loma Linda University.10 Although originally developed as a root-end filling material during periradicular surgery, researchers across the world have reported positive results when the material is used for the repair of perforations, as a pulp capping agent, and to induce apical closure of immature roots . . .