Gutta-percha points are prepared for insertion by disinfecting them in sodium hypochlorite. They are then air dried, condensed, compacted and inserted into the root canal after the canal walls are coated with sealer.

TEMPORARY FILLINGS. - Temporary filling is a temporary restorative material used to seal the access cavity in the tooth between appointments. It may be a commercially available material packaged in a tube, or an intermediate restorative material such as ZOE.

ROOT CANAL SEALERS. - The root canal sealers most commonly used in dentistry are packaged in cement and paste form. The zinc oxide and eugenol type is the cement most often used. The liquid eugenol, and a typical zinc oxide powder formula may contain several ingredients as follows:

Zinc oxide-main ingredient

Resins-vegetable or mineral oil types

Anhydrous sodium borate

Bismuth subcarbonate or subnitrate

Besides the main ingredients, some formulas contain silver particles or barium sulfate, which add radiopaque (ability to stop radiant energy such as X-rays) qualities. These ingredients are mixed in much the same way as in zinc phosphate cement. Using a sterile glass slab and noncorroding spatula, incorporate the powder into the liquid until a thick, creamy consistency is reached.

INSTRUMENTS AND ACCESSORIES

Endodontic instruments and accessories often are prepared in sterile packs or kits. A basic instrument setup can be established for endodontic procedures. The standardized setup can be used during each phase of treatment and supplemented with items needed for a specific phase of treatment. Items that make up a rubber dam setup must be included since the rubber dam is essential to provide isolation and maintain a sterile field. Figure 7-2 illustrates a typical instrument endodontic tray setup. Small endodontic instruments and supplies are generally placed in a metal compartmentalized box that can be sterilized and maintained in an orderly fashion. Figure 7-3 identifies such an example and figure 7-4 list the contents. A variety of accessory items, such as instruments, filling materials, irrigation solutions, cements, and medications used in the endodontic treatment must be readily available during the procedure.

Endodontic Explorers

Endodontic explorers (fig. 7-5) have long, narrow working ends. These explorers are angled from their shank in such a way that they provide easy access to the pulp canal. They are used to locate canal openings and explore the pulp chambers and canals.

Endodontic Cotton Forceps These instruments resemble the cotton forceps. The major difference is that the endodontic cotton forceps are grooved to allow easy grasping and manipulation of paper points and gutta-percha. They are also available in locking or nonlocking design.

Endodontic Excavators These instruments are long, double-ended spoon excavators designed for endodontic treatments. They allow the removal of coronal pulp tissue, caries, or cotton pellets that may be deep in the tooth's crown

Broaches

A root canal broach (fig. 7-6) is usually one of the first instruments used in the pulp canal during endodontic treatment. Broaches are thin, flexible, usually tapered and pointed, smooth or with a series of sharply pointed barbed projections curving backward and obliquely. The identification symbol of barbed broaches is an eight-pointed star formed by the barbs.

Smooth broaches can be used as explorers to get the feel of the canal. A barbed broach is used primarily for the removal of intact pulp tissue from large canals. The broach is introduced slowly into the root canal until gentle contact with the canal walls is made. It is rotated 360 degrees in either a clockwise or counterclockwise manner to entangle the pulpal tissue in the protruding barbs. It is then withdrawn directly from the root canal. If successful, the entire pulp comes with it. Because these instruments are fragile and prone to breakage, exercise great care in their use. There are several sizes: coarse, medium, fine, X-fine, XX-fine and XXX-fine. Discard each broach after each use.

Reamers

Root canal reamers (fig. 7-7) are used to enlarge the pulp canal after broaches have been used. Reamers may be used with a reaming action (rotary cutting) or a filing action (scraping or pulling stroke). Reamers are