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Nearly all practitioners have an ultrasonic dental scaler. Unfortunately, few have an adequate dental polisher. No matter which method is used to remove supragingival calculus (ultrasonics, rotopro, hand scaling), grooves are left in the enamel surface. Unless the enamel surface is polished smooth, it will attract more plaque. There are many types of polishing units available. A prophy polishing cup attaches to the low speed handpiece in most delivery systems. The periodontal probe is as important in a dental examination as a a stethoscope is in a general physical exam. A perioprobe is marked off in millimeters. As a general rule, gum pocket depths greater than three millimeters in dogs and two millimeters in cats need closer attention -- radiography, root planing, curettage, and/or periodontal surgery.
Two other hand instruments, the sickle scaler and the curette, can be used effectively during dental prophylaxis. Sickle scalers are designed for supragingival use (above the gum line), whereas curettes are used subgingival (below the gum line). Sickle scalers that are double ended (mirror-image ends) are ideal. The scaler is triangular in cross-section. The most effective working angle is 45-90 degrees to the tooth surface. A pull stroke is always used. Proper use of a curette requires a gentle touch. When used properly, the rounded toe and back cause little damage subgingivally. The curette is angled acutely against the root surface, to remove gingival calculus, which is dark brown to black in color. The strokes are overlapped 10 to 20 times to plane the root surface until it feels glassy smooth, when checked with the explorer tip. For subgingival curettage, the opposite end of the curette is angled against the lining of the gingival sulcus. While the operator presses on the gingiva with the index finger of the opposite hand, the curette is used to scrape the lining of the gingival sulcus. Perhaps the most overlooked and important aspect of basic dentistry is charting what is abnormal and proposed treatment plans. There is no better way of learning, than sitting down with a dental chart and a sedated patient, evaluating each tooth's appearance, position in the arch, mobility and periodontal pocket depth. Equipment
Power equipment is necessary to enter the tooth's hard enamel surface without damaging the internal or supporting structures. The primary procedures performed with high speed drills are root canals, extractions, crown preparations, and restorations. If high speeds (200,000-400,000 RPM) are not used, the teeth could be injured through excessive heat and poor cutting control. Common ways of delivering dental power are electric and air. As with most choices each has advantages and disadvantages. Electric powered dental units are referred to as micrometers, Dremel Tools, laboratory bench engines or belt driven units. They are usually less expensive, smaller, deliver high torque, and are portable, which are good features. The tradeoffs are they are five to ten times slower than the air units causing the drill at times to "walk off" the tooth while drilling rather than cutting into it; they vibrate to some extent making highly accurate work more difficult: and electric powered units may produce harmful heat within the tooth due to the lack of water in the handpiece.
Air driven units are the most efficient and easiest to use with training. The modest increased cost between the air and electric units make little long term difference compared to faster speed of air and higher quality of dentistry capable, thanks to the increased speed, making the drill easier to control. In addition, the stream of water cools the high speed but prevents thermal damage to the teeth. The decision to use an air driven dental unit, compared to the slower machines, is like performing cell blood counts with an automated cell counting machine, compared to a hemocytometer. Both will work, but the automated machine will deliver the results easier, faster, and at times more accurately. If you are interested in performing the best dentistry possible, air units are the way to go. The decision should not be based on caseload -- enough cases are there, recognizing dental lesions that would benefit from the high speed equipment can be gained from numerous continuing education programs and fine veterinary dental texts. Where does the air power come from? Either from compressors which take the room air and deliver pressurized air to the handpieces. The bottled sources have the advantages of portability, and are generally less expensive on the initial purchase. Long term, the units using gas cylinders may be more expensive than the compressor driven air machines due to gas replacement costs.
The location of the compressor is an important consideration in human dental offices the air compressor is far away from the dental units which are connected with air hoses. In most veterinary offices the compressors are at the dental delivery table. Noise becomes an important concern. Some compressors cycle every two or three minutes with disagreeable roaring sounds. The "silent" compressors work best under the dental area because they are never heard. When considering the compressor location make sure the area is accessible for servicing and adding oil to cool the machine. Dental handpieces contain the mechanism to turn the bur at high speeds. The high-speed handpieces rotate at 200,000-400,000 times per minute. They are the "workhorse" of the dental unit. There are many systems used to attach the bur onto the end of the handpiece. We use the wrenchless push button type where thumb pressure is used to disengage the bur. Other systems require a wrench or key to place and replace the bur. Fiberoptic lighting is another helpful option on a high-speed drill. Illuminating the operating area is most helpful. Slow speed handpieces rotate the bur 5,000-20,000 times per minute in forward or reverse directions. They are mainly used to polish teeth (with the addition of a prophy angle). The contra-angle attachment redirects the working tip of the slow speed handpiece to 65 degrees to the horizontal, improving access to many awkward areas of the mouth. It is mainly used in filling root canals with lentulo spiral fillers, polishing, and restoration work. |
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