Dental equipment and materials (Proceedings)

The good news is that dental instrumentation is affordable and "do able." The old belt driven dental engines are in museums and air driven high speed equipment is the standard.

The veterinary dental market is being flooded with good equipment. The first entry into the market on a large scale is the Schein "Vet Base" put together by Jerry Morris Associates. These units are every bit as good today as they were 10 years ago. Other features such as fiber optics, suction, additional light sources, light cure guns, and multiple air lines have been added by most manufactures to their units. All dental equipment suppliers share one common problem—providing quiet compressors that delivers sufficient air to drive the hand pieces. Most compressors are converted refrigerator motors that deliver 2.5 cfm. The minimum required is 3.0 cfm thus most compressors are under powered. This results in continuous operation with the tendency for overheating. Some of the newer compressors, such as the IM3 "Hurricane", Vet Base "Silent Surge", and Matrix Oil Less have less of a tendency to overheat. However, maintenance is a must with all compressors and if not performed on a regular basis dental operations will soon come to an abrupt stop. Despite these few short comings "high speed" equipment is the best choice for companion animal dentistry.

Other options for power equipment include the electric micromotor. This is a slow speed device that can be used for dental prophylaxis and endodontics. The major deficiency of micromotors is the heat generated by the working surface of the operative instrument such as a dental bur. This heat is damaging to vital tissue and if the micromotor is used incorrectly iatrogenic problems occur. Micromotors are a good choice for veterinary dental practices limiting their operative procedures to dental prophylaxis and nonsurgical extractions.

Hand instrumentation for periodontal therapy is as important as high speed equipment. The basic includes 1) scalers, 2) curettes, 3) periosteal elevators, and 4) #15 surgery blades. The best scaler for veterinary dentistry is the universal scaler. This scaler has a three sided blade that allows both a push and pull stroke. The working tip also has a point that allows scaling of fissures. As a rule, curettes are numbered according to the location of use on the arcade—the higher the number the further back in the mouth the instrument is used. The author prefers the Columbia #13/14 curette. Periosteal elevators are essential in gingival surgery. The least damaging to soft tissue is the Molt #9 periosteal elevator. This instrument allows the veterinary dentist to reflect attached gingiva, especially in felines, without shredding the tissue. Care should be taken to preserve the sharpness of the working surface. Dull instruments are worthless and create more problems than they solve. Because most of these instruments are inexpensive, if one doesn't feel right during use it can be easily replaced by another of a different design.

Prophy angles, pastes and cups again are a matter of personal preference. As a rule the screw type prophy angles are easier to clean and the autoclavable type more durable. Pastes can range from a slurry of fine pumice (inexpensive) to prepackaged individual containers (the authors preference). The ribbed hard rubber type prophy angle tends to last longer and do a better job than the soft rubber type. For the person who prefers disposable units to help prevent cross contamination, single use prophy angles are available. Unfortunately it usually takes several angles to complete the prophylaxis in the canine patient (some of the products are a bit wimpy because of the plastic gears and drive shafts).

Ultrasonic scalers remain a popular device to help in the removal of gross calculus from crown surfaces. The down side still remain with heat generation and microetching as the problems. Most commercial units have more than enough power to quickly remove gross calculus. However, in the unskilled hand damage to the crown surface and the subgingival area is a real problem. Air driven sonic scalers (especially the Titan S) are being favored because of the non heat generation at their working tip and tendency for minimal damage to the tooth surface. Air sonic scales are used on the high speed air line already in place on the dental unit. Pieseo electric scalers are the next generation of electric sonic scalers. The advantage to these units is the elliptical pattern of the working tip which is reported to minimize hard tissue damage. Because the units operate at a much higher frequency (45k cps) the efficiency of calculus removal is much greater. In addition, units such as the Neosonic by Amadent have endodontic attachments that greatly shorten the operative time of endodontic procedures. The variety of working tips allows the veterinary dentist to complete many different procedures that otherwise would have taken extraordinary amounts of time to finish. As with all power equipment proper use is the corner stone for effective therapy. Iatrogenic damage is a huge concern for the untrained operator.

The next level in instrumentation is dental radiology. As in other veterinary disciplines accurate visualization of internal pathology is mandatory. The good news is that dental x-ray machines are inexpensive (compared to 500ma machines) and provides as much information for pennies. Used dental machines range from $800 to $1000 and new machines from $2500 to $3500. The author suggests purchasing a new machine to take advantage of the legislated safety regulations and manufacturers warranty. The dental films can be developed in existing darkrooms, some automatic processors and in chair side developers. Most veterinary dentists prefer chair side developers because of the convenience and cost effectiveness. The two dental film most commonly used are the periapical and occlusal. Ultra speed film is compatible with chair side developers and is the speed used. The technique is written on the box although some trial and error is used to fine tune the technique. With the advent of digital radiology the ability to diagnosis disease has now markedly improved. There are many systems available – the author prefers the Scan X system because of the availability of size 4 films.

The materials used in veterinary dentistry that is the most confusing and difficult to keep up with is the area of restoratives. For decades dental amalgams and alloys were used to repair teeth and few real improvements were made in these materials. However, in the last twenty years polymers have exploded onto the scene gradually displacing "metal" as the material of choice in crown repair. The biggest frustration is that the technology improves daily and what is being recommended today will be changed tomorrow. Given this fact the current recommendation is made: for restorations a "light cure" composite is preferred. The composite should be used with at least a third generation dentin bonding system to assure adhesion to the tooth surface. The composite should be easy to manipulate allowing creation of smooth margins, elimination of air voids, and complete finishing. Most manufacturers have switched to hybrid fillers so particle size in the resin is becoming less of an issue. More of an issue is the strength and durability of the composite. Kerr's Optibond System is the authors current bonding system of choice and Cosmodents Renamel hybrid is the composite of choice.

Other restoratives that have use in veterinary dentistry include the combination glass ionomer composite materials such as Geristore by DenMat. These products attempt to combine the best characteristics of both materials. The composite resin is used for strength and the glass ionomer is used for adhesion. Because the best characteristics of both materials are compromised when combined the use of this compound should be limited to nonocclusal surfaces. An excellent area is Class V lesions in felines (for those lesions that are suitable for repair) or subgingival fractures lines in both canines and felines. This material is technique sensitive and the best type to use is the light cure.

It is beyond the scope of this paper to discuss all current materials available for restorations. Every veterinary dentist will have a material they feel is superior. The best recommendation is to find a product that is readily available with the fewest steps and follow the manufacturers directions. Most failures occur due to operator error, not material error.

Regardless of the type of composite used a light cure system is the system of choice. The clear advantage is the flexible working time and reduced setting time. The differences between the various manufacturers light cure guns are minimal thus price and ease of repair becomes the chief concern. The author has found little clinical difference between the most expensive and least expensive light cure gun.

Other equipment worth mentioning that should be included in the basic operatory are sharpening stones (the Premier Disc is a good one), gloves (Schein's Biogel Dedicated gloves are excellent), magnifying loops (Aseptico's are inexpensive), and anesthesia (sevoflurne is the agent of choice).