Dangers lurk in equine dentistry

The use of motorized dental equipment has become quite popular and is now commonly used by many veterinarians and equine dental technicians around the world.

The use of motorized gear began at least 60 years ago in Germany with rotary grinding wheel stones used to shape and cut teeth. During World War II, this type of technology was lost; and as the importance of horses fell, following the war, the art and science of equine dentistry withered to the occasional manual removal of enamel points.

Equine dentistry was not considered to be very important and received very little attention by veterinary educational programs.

As horses have regained importance and numbers over the past 20 years, so has the demand for more thorough and advanced equine dental procedures.

Manual floating of teeth is usually very effective for routine dental maintenance, which includes the floating of points, leveling waves and establishing bit seats; but it may be more time-consuming and tiring.

Good dental prophylaxis requires strength, dexterity, very good coordination and technique. Motorized equipment can speed the work and reduce physical wear and tear on shoulders, elbows and wrists. Motorized equipment is very helpful on big jobs, like reducing big hooks, ramps, and reducing incisors and canines. The use of motorized equipment can promote better work and encourage more people to want to provide equine dental services.

Are there dangers with the use of motorized equipment? Motorized equipment can actually be safer for the horse if used properly, since it greatly reduces the use of cutters, which may fracture teeth. Good technique may reduce soft-tissue trauma caused by hand floats that may accidentally scrape the gums and tissues around the teeth.

Danger lies in poor technique. Rotating burrs can grab the tongue or cheek, causing superficial or deep abrasions. Rotary disc floats are very unlikely to cause significant soft-tissue damage. Grinding a single tooth for a long time without water cooling can overheat a tooth and damage the inner pulp tissue. This can be easily avoided by only grinding or using a cutting wheel for very short periods of time on each tooth (going from tooth-to-tooth) or using water-drip cooling. The use of sharp carbide, titanium-coated or diamond-chip burrs and discs greatly reduces heat production and the time needed to reduce and shape teeth. Thermal damage has received a lot of attention in equine dentistry articles in horse-related magazines, so practitioners should be very aware that clients may be afraid of motorized dentistry. This fear may be exaggerated, since almost all practitioners are aware of this potential hazard and avoid it. I personally have been using motorized equipment for 20 years and have not seen any cases of thermal damage — signs of which might be seen years later as an open dead pulp chamber —caused by myself or others.

Horses are often sedated for motorized dentistry, and sedation occasionally leads to problems. Narcoleptic horses may fall down. Intracarotid injections still occur rarely, as do idiopathic seizures. Manual floating of unsedated horses can avoid the risk of sedation, but unsedated horses may flip over and hurt themselves or strike and hurt the practitioner. Some horses allow the use of motorized equipment without sedation.

"Over floating" is probably the most common problem that is seen with motorized dentistry. This results from taking too much off the occlusal surface of the cheek teeth leading to dysmastication, potential loss of weight or TMJ discomfort. Over floating can also be done with manual tools. It takes time to learn the principles of occlusion and how to balance the mouth while maintaining or increasing the functional grind of the cheek teeth. Obviously, when making cheek teeth malocclusion corrections, incisor work is often needed. This over floating gives motorized dentistry a bad name and hurts our profession. Hopefully, these over-floated horses can be maintained on pellets until their teeth erupt back into occlusion.

Learning to perform dental maintenance with manual floats first is a big help. When we use motorized equipment we have to keep in mind that we are trying to achieve the same result as hand tools — motorized doesn't mean more. Motorized dentistry is still hard work, but is often portrayed as an easy way to float horses' teeth and is attracting newcomers to the field. The danger lies in incomplete or improper training. Two-hour or even two-day courses in the use of motorized gear for beginners often leads to trouble.

Another possible danger is the exposure of pulp tissues when reducing large hooks, ramps, canines or incisor teeth. I believe this is fairly common, but rarely leads to an infected tooth. Practitioners may want to reduce some of these protuberant teeth in stages to avoid potential problems and watch carefully for pink spots, so the reduction can be stopped before the pulp is exposed. In general, the use of motorized gear is better than cutters to avoid pulp exposure.

All precautions should be taken to avoid possible electric shock or electrocution. I have not heard of any deaths of horses or practitioners from this hazard, but I have experienced some stray voltage. The use of a ground-fault interrupter (GFI) is needed. Keep all your electrical equipment and connections dry. Air-driven equipment can reduce electrical hazards.

Inhaling tooth dust is hazardous to the operator and assistants — it causes lung damage and irritation. Using a vacuum greatly reduces the hazard while improving visibility. Protective eyewear should be worn to prevent tooth particles from striking the operators' or assistants' corneas or lodging in their conjunctivas.

Recent advances in equipment design, including headlights, headstands, improved speculums and the use of vacuum suction to reduce tooth dust, and water-drip cooling, have made motorized work easier to perform with fewer complications.

As in most endeavors, ignorance and lack of caution is the cause of most danger.

Dr. Hyde has been in general equine practice for 26 years and is a certified equine dentist. He operates a general mobile equine practice and is part owner of the R.E.A.C.H. (Regional Equine Associates Central Hospital) Equine Referral Hospital in Clark County, VA.