Trisha E. O`Hehir, RDH, BS
Power scalers have been around since the early 1950s. In the past, they were considered gross-scaling instruments, always to be followed by curettes. They were used for "knocking off the big stuff" when first introduced. As such, very little instruction was given to dental-hygiene students. Demonstrations of their use generally was limited to connecting the hoses and turning them on and off.
There were, of course, the two cardinal rules of Cavitron™ use. First, never point the tip toward the surface or it would gouge. That has resulted in generations of dental hygienists attempting to remove calculus with the middle of the tip. The second rule was always keep the tip moving to avoid the risk of pulpal damage to the tooth. That resulted in rapid tip movement, resembling an egg beater on high. With little or no instruction, we had to make up our own rules.
As a new hygienist, I was under the impression that we had only one pass around the mouth with a Cavitron. Once the power scaler handpiece had been put down, it was never to be picked up again. All the remaining deposit had to be removed with curettes or scalers. I have no idea where this notion originated.
Despite our use of ultrasonic scalers as gross-scaling instruments, research over the years repeatedly demonstrated that standard Cavitron tips were as effective as curettes for calculus removal. Later studies demonstrated that standard Cavitron tips achieved calculus removal more quickly than curettes. Tissue healing also was shown to be comparable between curettes and the Cavitron standard tips. One animal study actually demonstrated more rapid healing in the first week following Cavitron use. These findings went all but unnoticed as we clung to our curettes.
What finally changed our thinking was not research, not scientific findings, but new tip designs.
The new thin or Slimline™ tips have changed the way we look at power scalers. We now consider ultrasonic scalers to be subgingival instruments. Why did we think the standard tips could not be used subgingivally when research had demonstrated their effectiveness in that area? Despite their bulk compared to the newer thin tips, the standard tips are smaller than most curettes.
The research we use to support our shift from hand to power scalers was done with standard tips, not the Slimline tips. There are actually very few studies done with the thin tips. One study compared the Slimline tips to curettes on periodontal maintenance patients, with comparable results. The only difference was time. Instrumentation with curettes took longer. No clinical comparisons have been made between curettes and the thin tip inserts for calculus removal.
I am thrilled that the introduction of the Slimline tips has changed the way we view power scalers, but we must not give up the standard tips in favor of using only thin tips. Both designs have their place.
The standard tips are still the best for removing supragingival and subgingival calculus. Standard tips also provide many more design choices than the thin tips. My favorite standard tips are the beaver tail and chisel designs. With a flat end instead of a point, there is less worry about damaging the tooth surface. Maybe it`s all my years growing up in Minnesota winters, but scraping windshields with a broad flat surface is much easier than doing it with a bowed scraper that only contacts the window in two spots. The same is true in the mouth. If you can get a broad flat ultrasonic tip into the area, it will cover more surface than a narrow, pointed one.
When thin is better
These flat-tipped inserts are excellent for removing heavy calculus and stain from anterior lingual surfaces, but also are perfect for reaching interproximal areas. For clinicians unaccustomed to using an ultrasonic scaler, these tips are a good place to start. The broad flat tip is less likely to damage tooth surfaces, and the end of the tip is easier to adapt than a pointed tip. At first glance, these broad, flat tips appear to be too bulky to use subgingivally or interproximally. However, these tips easily insert subgingivally and comfortably reach interproximally just below the contact. Approach the interproximal area from either the facial or lingual, at a ninety degree angle to the long axis of the tooth, just the way a wooden interdental stick is inserted. Adapt the tip to the interproximal surface and move in and out, also the same movement used with the interdental stick. In contrast to use of an interdental stick, the broad flat ultrasonic tip must be adapted separately to each of the opposing interproximal surfaces.
The thin tips definitely have their place. Where access is a problem, the thin tips are appropriate. There are three designs offered as Slimline or thin tips. The basic design is a curve very similar to the standard Cavitron P-10. The other two are a complementary pair of right and left curved tips for access interproximally and in furcations.
The Slimline tips were not designed for heavy calculus removal. Manufacturers recommend they never be used on high power. They were designed as a fine scaling tool for narrow pockets and furcations where standard tips and curettes won`t reach. They were designed for deplaquing, not heavy calculus removal.
Take a look in the back of the drawer or in the closet where all the "old instruments" are stored and see if you can find some of the "old" standard Cavitron tips. You may be surprised at how effective they still are.
It seems the pendulum has swung from the use of standard ultrasonic tips to the use of thin tips. As it settles between the two extremes, we will use both standard and thin tips to provide the best possible care for our patients.
Trisha E. O`Hehir, RDH, BS, is a senior consulting editor of RDH. She also is editor of Perio Reports, a newsletter for dental professionals that addresses periodontics.The Web site for Perio Reports is www.perioreports.com. Her e-mail address is trisha @perioreports.com.