Ultrasonics Uncovered

Q. Does the clinician need to actually touch the biofilm or calculus with the ultrasonic insert/tip to accomplish disruption?

A. Sonic and ultrasonic instruments remove calculus layer by layer and not by dislodging calculus through the separation of the calculus-tooth-interface. This is why large chunks of calculus are rarely seen coming out of the pocket following the use of machinedriven instruments. In order to be effective, the sonic or ultrasonic instrument tip has to be in direct contact with the calculus. In removing biofilm, fluid motions are effective in dislodging biofilm only in very close vicinity of the instrument tip. Therefore, the clinician cannot rely on a remote effect for debridement and needs to run the tip over the entire root surface.

BY HAND OR MACHINE DRIVEN?

Q. Is there a need for hand instrumentation to supplement ultrasonic instrumentation in periodontal debridement?

A. Hand instruments are useful in addition to sonic/ultrasonic devices in areas where the tips of oscillating instruments have limited access, eg, the area around the contact point of lower anterior teeth.

In my opinion, if the areas to be scaled are accessible to the tips of an ultrasonic unit and if all calculus and biofilm have been removed using a machine-driven device, following up with a hand instrument is not necessary. A frequently given rationale for following up with hand instruments is that hand instruments plane the root. However, studies that looked at root surface roughness after machine-driven instrumentation or hand instrumentation found comparable levels of roughness following either mode of instrumentation.¹ Therefore, root planing with hand instruments to achieve a smooth surface following machine-driven debridement may not always be necessary.

Q. Are there occasions where ultrasonic instrumentation alone is adequate?

A. Yes, as long as the clinician is able to debride all surfaces sufficiently. Studies that compared ultrasonic or sonic instrumentation alone with hand instrumentation alone have found comparable clinical outcomes.^1,2

AIR POLISHING

Q. Please discuss the use of air polishing devices in instrumentation.

A. Air polishing de vices have experienced a renaissance due to newly developed powders, which consist of small crystals of the amino acid glycine. The first glycine powder* was introduced in Europe. It is approximately 80% less abrasive than conventional sodium bicarbonate powders and can be applied safely to the root surface and gingiva for the removal of supraand subgingival biofilm.^3,4 For subgingival biofilm removal, the water-air-powder jet is aimed directly into the orifice of the periodontal pocket (Figure 1). Glycine powder air polishing (GPAP) is effective in removing biofilm from periodontal pockets with probing depths up to 4 mm.⁵ In patients receiving periodontal maintenance, GPAP results in the significant reduction of subgingival microbial counts in periodontal pockets with probing depths between 3 mm and 5 mm.^6,7

Another glycine powder** is now available in the United States. According to the manufacturer’s information, it is approximately 50% less abrasive as a sodium bicarbonate powder.

Because of its low abrasiveness, GPAP does not remove calculus. In maintenance patients—sonic, ultrasonic, or hand instruments are still needed. As new calculus formation between maintenance visits is usually limited to the supragingival area of the lower anterior and upper posterior teeth, removing supra- and subgingival biofilm using GPAP accomplishes a major portion of the periodontal maintenance procedure and greatly enhances efficiency. Some clinicians start the maintenance therapy with GPAP in order to remove all biofilm first. This makes it easy to visualize any calculus that is then removed in a second step using machine-driven or hand instruments. This reverse order of instrumentation appears counterintuitive at first, but can be efficient in clinical practice.
*Clinpro™ Prophy Powder, 3M ESPE, St Paul, Minn

** Airflow^® Soft Powder, Electro Medical Systems (EMS), Dallas

REFERENCES

1. Tunkel J, Heinecke A, Flemmig TF. A systematic review of efficacy of machine-driven and manual subgingival debridement in the treatment of chronic periodontitis. J Clin Periodontol. 2002; 29(Suppl):72-81.
2. Hallmon WW, Rees TD. Local anti-infective therapy: mechanical and physical approaches. A systematic review. Ann Periodontol. 2003;8:99-114.
3. Petersilka GJ, Bell M, Mehl A, Hickel R, Flemmig TF. In vitro evaluation of novel low abrasive air polishing powders. J Clin Periodontol. 2003;30:9-13.
4. Petersilka G, Faggion CM, Stratmann U, et al. Effect of glycine powder air-polishing on the gingiva. J Clin Periodontol. 2008. In press.
5. Flemmig TF, Hetzel M, Topoll H, Gerss J, Haeber lein I, Petersilka G. Subgingival debridement efficacy of glycine powder air polishing. J Perio dontol. 2007;78:1002-1010.
6. Petersilka GJ, Tunkel J, Barakos K, Heinecke A, Häberlein I, Flemmig TF. Subgingival plaque removal at interdental sites using a low abrasive airpolishing powder. J Periodontol. 2003;4:307-311.
7. Petersilka GJ, Steinmann D, Häberlein I, Heinecke A, Flemmig TF. Subgingival plaque removal in buccal and lingual sites using a novel low abrasive airpolishing powder. J Clin Periodontol. 2003;30:328-333.

From Dimensions of Dental Hygiene. April;6(4): 26, 28.