Power Scalers: A win-win for patients & clinicians By Trisha E. O’Hehir, RDH, BS, Editorial Director, Hygienetown Magazine

Introduction

Power scalers have made a significant contribution to the oral health of patients and to the physical comfort and ergonomics of the dental hygiene clinician. Hard and soft deposits above and below the gingival margin are removed with less pressure and in less time. The fluid lavage flushes toxins and deposits from the subgingival areas, enhancing tissue healing. Exchanging the stress and strain of hand instruments for power scalers has allowed some dental hygienists to add additional work days without adding physical stress. It’s a win-win for patients and clinicians when power scalers are part of the instrumentation selection.

History

If you graduated from dental hygiene in the past decade, it may seem that power scalers have always been an integral part of dental hygiene instrumentation. That’s not exactly the case. If you graduated more than a decade ago, your dental hygiene clinic probably had only one power scaler for use by the entire class.

Rather than instructions on power scaler technique, you were surely warned to avoid gouging the tooth surface with the instrument tip and to avoid heat build-up by constantly moving the tip. If not heeded, the gouging and heat build-up would lead to tooth damage and perhaps even pulp death! Such warnings led to generations of hygienists using the side of the blade in a rapid eggbeater motion, to prevent gouging and avoid heat build-up. Unfortunately, this technique usually burnished calculus, as the tip of the power scaler blade is the most powerful and must be adapted to the edge of the deposit to effectively remove it. Significant heat builds up only when the tip is held in one place for an extended period of time, not when careful, slow movements are used. The warnings overshadowed the value power scalers bring to periodontal treatment.

The first textbook on ultrasonic scaling was written by Dr. Sol Ewen and published in 1968. A wide variety of inserts were described and pictured in the book, including an ultrasonic knife for surgical procedures, diamond-coated inserts, and operative files for overhang removal. Detailed instructions complete with diagrams and clinical photos were provided for supragingival scaling, subgingival root planing, soft-tissue curettage, surgical procedures, overhang removal and drug administration in the fluid lavage using a separate pressurized container. What seems to be new technology today was actually presented in great detail nearly 40 years ago by Dr. Ewen, a New York periodontist and an accomplished computer artist before his death in 2004.

Three types of power scalers are available today, magnestostrictive, piezoelectric, and sonic; with popularity following in that order.

Two concerns were raised in several conversations on Hygienetown.com – which power scaler is the best and what should the balance be between power scaler use and hand instruments? Researchers have analyzed the technology and compared various power scalers and hand instruments. Despite research findings, clinical preference will depend on experience and confidence with these instruments.

Research

According to the research, no power scaler is superior to another. It is clear that power scalers and hand instruments are equally effective for deposit removal. Several studies over the years (Dr. Badersten in 1981 and 1984, Dr. O’Leary in 1986, Dr. D’haese, in 2003, Dr. Rühling, in 2003, and Dr. Obeid, P. in 2004) have reported similar tissue healing when comparing hand and power scalers, regardless of the type of power scaler used. The sonic scaler, despite its lack of popularity, fares quite well in the research arena.

For many years, the goal of root planing was to remove cementum as it was assumed that cementum-bound endotoxins prevented healing. In1961, Drs. Stende and Schaffer published research showing the Cavitron to be as effective as curettes for the removal of calculus on anterior and posterior teeth scheduled for extraction. Because of the cementum-bound endotoxin assumption in those days, the authors overshadowed their important finding and stated that hand instruments should always be used following ultrasonic scaling, as curettes left a smoother surface than the Cavitron, thus removing the critical toxins. It wasn’t until 1993 that Dr. Schwarz published a study demonstrating the ease with which endotoxins are removed from cementum. Other studies followed that showed root surface roughness was not a factor in tissue healing. As long as the bacterial plaque, and plaque retentive calculus are removed, the tissue will heal. Unfortunately, the concept of hand instruments always being used after power scaling still remains.

In 1988, Dr. Walmsley reported the cavitational effect associated with ultrasonic scalers to be more effective against subgingival bacteria than sonic scalers. Cavitation is caused by rapid movement of air bubbles creating shock waves that seemed to be responsible for bacterial cell death. This was demonstrated by measuring the effects of sonic and ultrasonic scaling on bacteria in a test tube. The peizoelectric scaler destroyed more spirochetes than the sonic scaler. The researchers concluded that this result was probably due to the higher frequency of the piezoelectric scaler and the resulting cavitational effect of the vibrations. However, when compared clinically by Dr. Baehni in 1992, bacterial sampling before and after instrumentation revealed that both scalers were equally effective in reducing bacterial counts.

In 2000, Dr. Shenk showed that excessive heat buildup during ultrasonic scaling in a test tube actually caused the cell death, not cavitation. To control for heat buildup, test tubes were immersed in ice water during testing. Bacterial counts did not change after use of either the sonic or ultrasonic scaler when the bacterial samples were kept at a constant temperature. It seems the heat build-up in the test tube actually caused cell death in the earlier study, not cavitation.

Besides the conflicting laboratory findings, we don’t have clinical research to support the cavitation concept. Researchers believe the irrigational effect of both instruments is responsible for the differences between the laboratory and clinical findings. Fluid lavage appears to be more important than a cavitational effect. As long as the bacteria are removed from the pocket, healing can occur.

To determine the best power scaler, researchers will need to utilize the endoscope (Perioscope) to capture subgingival images of instruments at work. This information will provide answers to the question of which power scaler is superior, if one is.

Clinical

You are sure to have your favorite power scaler, based on personal experience. Just as you might prefer Graceys or Universals, depending on your dental hygiene school. Your power scaler preference will be based on experience too. If the unit or handpiece you use in practice is not well maintained and tuned properly; the tips are past their prime; and you don’t understand the specifics about that particular technology or unit, your experience may be negative. Each well maintained power scaler, when used as directed, will effectively remove deposit.

Debate continues on where power scalers fit into the periodontal instrumentation routine. When first introduced, power scalers were used as an adjunct to hand instruments while today, those positions are reversed. Power scalers are used routinely now, as evidenced by just one of many discussions on www.hygienetown.com on this topic. The discussion entitled “Still not using the Cavitron?” has 92 responses discussing the topic and nearly 1,400 people have viewed the discussion. The majority of clinicians are using power scalers more than ever before, and yet some are still reluctant to make that change.

For some clinicians, power scalers have completely replaced hand instruments. For others, the very idea of only using power scalers is blasphemy. For many, hand instruments are still essential for effective treatment. No matter where power scalers fit into your treatment approach, the focus is on oral health outcomes. Establishing and maintaining periodontal health is still the goal of treatment.

As your skills improve with power scalers, your reliance on hand instruments for deposit removal will shift to using a variety of hand instruments for detection. To be effective with hand instruments, you must first find the deposit and then be able to effectively access the deposit, adapt the blade below the deposit and activate the instrument with sufficient lateral pressure to remove it. With a sharp edge and a light touch, various hand instruments can be used to detect deposits.

Effectiveness with power scalers requires superb detection skills, which then allows for proper placement of the power scaler tip on the top edge of the deposit. A light touch is necessary to allow the instrument to effectively vibrate off the deposit. A gentle touch and excellent detection skills are essential. Purposeful, controlled movements with very light pressure, using either a gentle tapping or sweeping stroke are most effective. Knowledge of root anatomy is essential for effective instrumentation.

This is not an overnight transition, but rather a slowly evolving process. I began using power scalers when I worked in Switzerland in 1968 and slowly over the years reversed my primary focus from hand to power scalers. Using power scalers more does not mean giving up your expertise with hand instruments. Instead, it’s a transfer of skills. Your skills with power scalers will continually increase and actually surpass your current expertise with hand instruments for deposit removal. Hand instruments will be used more for detection than deposit removal. Novel curette designs are being introduced to work with power scaling, not as equivalent tools.

Conclusion

Take advantage of this technology and use it to your benefit. Reduce hand, arm, neck, and back pain associated with hand instrumentation and provide better care for your patients. Power scalers contribute to patient oral health while reducing the stress and strain of instrumentation.

Bibliograpy
1. Ewen, S., Glickstein, C.: Ultrasonic Therapy in Periodontics, Charles C. Thomas Publisher, 1968.
2. Badersten, A., Nilveus, R., Egelberg, J.: Effect of Nonsurgical Periodontal Therapy, I. Moderately Advanced Periodontitis. J Clin Perio 8: 57, 1981.
3. O’Leary, T.: Impact of Rough Surfaces Upon Gingival Tissues. J Perio 57: 69, 1986.
4. D’haese, J.: Abstract #217, J Clin Perio, Supplement 4, Vol 30, 2003.
5. Rühling, A., König, J., Rolf, H., Kocher, T., Schwahn, C., Plagmann, H.: Learning Root Debridement with Curettes and Power-Driven Instruments. J Clin Perio 30: 611-615, 2003.
6. Obeid, P., D’Hoore, W., Bercy, P.: Comparative Clinical Responses Related to the Use of Various Periodontal Instrumentation. J Clin Perio 31: 193-199, 2004.
7. Stende, G., Schaffer, E.: Comparison of Ultrasonic and Hand Scaling. J Perio 32: 312-314, 1961.
8. Schwarz, J., Rateitschak-Plüss, E., Guggenheim, R., Düggelin, M., Rateitschak, K. Effectiveness of Open Flap Root Debridement with Rubber Cups, Interdental Plastic Tips and Prophy Paste. J Clin Perio 20: 1-6, 1993.
9. Walmsley, A., Laird, W., Williams, A.: Dental Plaque Removal By Cavitational Activity During Ultrasonic Scaling. J Clin Perio 15:539-543, 1988.
10. Baehni, P., Thilo B., Chapuis, B., Pernet, D.: Effects of Ultrasonic and Sonic Scalers on Dental Plaque Microflora in Vitro and in Vivo. J of Clinical Periodontology 19: 455, 1992.
11. Schenk, G., Flemmig, T., Lob, S., Ruckdeschel, G., Hickel, R.: Lack of Antimicrobial Effect on Periodontopathic Bacteria by Ultrasonic and Sonic Scalers in Vitro. J of Clinical Periodontology 27: 116-119, 2000.