The Power of Selection

Effective scaling and root planing is essential to maintaining optimal health of the periodontal tissues. Today, dental hygienists are well equipped to provide therapy with both ultrasonic and hand instrumentation. Each technique requires the use of the most appropriate instrument for the task at hand. In ultrasonic instrumentation, the wide variety of insert and tip designs should be used to the clinician’s advantage. Instrumenting the entire mouth or treating deep pockets with only one ultrasonic insert or tip (UIT) is probably ineffective.

ULTRASONIC INSERT/TIP OPTIONS

Traditional UITs include the beavertail, triple bend, and universal. Although the name “universal” implies that the UIT can be used anywhere, a universal UIT is indicated for supragingival and subgingival applications in probing depths of 4 mm or less depending on the instrument’s angle, length, and diameter. Traditional UITs are used for orthodontic cement (bea vertail), dense or loose supragingival and submarginal deposits (universal regular and thinner diameters), and tenacious (triple bend) or easily removed extrinsic stain. Although these labels describe magnetostrictive inserts, similar designs are available for piezoelectric units.

The wide diameter and long stroke range of traditional UITs provide amplitude or power for the removal of moderate to heavy deposits and tenacious calculus and stain,¹ which is often the first step in oral prophylaxis or initial therapy. Thinner UITs are then used to mechanically remove the bacterial biofilm and lighter deposits. Depending on the situation, such as gingival tissue tone and whether anesthesia is used, a thinner standard universal UIT might adapt more than 4 mm subgingivally.

Thin, precision thin, or ultra-thin UITs are available in varying lengths and diameters. Straight and curved designs (ie, left and right) are purchased as a set to adapt to changing root anatomy. Straight UITs are indicated for simple anatomy, such as facial and lingual surfaces of anterior teeth. Curved UITs are used for complex posterior anatomy, furcations, and proximal areas. Selection of the best UIT for the deposit type and anatomy depends on probing depth; gingival contour and tone (ie, inflammation); furcation grade and access; mobility; and subgingival root topography. Thin UITs can initially create more immediate attachment loss post-therapy in comparison to standard UITs, but long-term healing is similar.² Ultra-thin UITs are indicated for light deposits and biofilm disruption.

Specialty UITs are used for implant debridement, furcations, and finishing of root surfaces. Implant UITs are constructed of specific materials or come with plastic covers. Conventional metal UITs can significantly alter the surface of titanium, type II gold, and cobalt-chromium alloy implants.³ Copper alloy is an alternative for future tip fabrication because it facilitates deposit removal while reducing damage to the implant surface.⁴ Both copper alloy and plastic tips minimally influence the titanium surface, therefore, either is suitable for implant maintenance.⁵ Furcation UITs include thin, very thin, and ball-ended tips. Ball-ended tips (0.8 mm end; left, right, and straight) are used to instrument depressions, concavities, and the roof of furcations. The ball-ended tip is intended to reduce root roughness in complex furcation anatomy.

Diamond-coated UITs are used to finish the root surface, preferably in conjunction with a dental endoscope. Caution must be taken because these tips can inadvertently remove root structure. As such, some manufacturers recommend that diamond-coated tips be used only in surgical procedures.

ASSESSMENT

During therapy, clinicians use the patient’s assessment data to determine UIT selection. The two most influential factors are type of deposit and root anatomy. Gingival inflammation and contour, such as cratering or recession, are also considered. Probing depth is reviewed when selecting the length and diameter of the UIT as well as its shape (curved or straight). Furcations, their topography, and access are also important. Reference to radiographs for root surface anatomy and location of any visible calculus is critical.

The finest ultra-thin diameter UITs can be used to assess the root during therapy, however, an explorer is essential to determine the clinical endpoint. An explorer is also used to determine the therapeutic endpoint at reevaluation of nonsurgical periodontal therapy. At this time, UITs are employed to remove residual calculus, reaccumulated deposits, and biofilm from areas of bleeding on probing.

ADAPTATION

Although all sides of the magnetostrictive insert are active, the lateral sides and back are used. In contrast, the piezoelectric tips are adapted to the tooth on their lateral edges or sides. Some manufacturers of piezoelectric tips recommend adapting other aspects of the tip. Various piezoelectric tips also have blades that make them more like curets.

Even though different aspects of the UIT are adapted based on the ultrasonic device, once the UIT is activated against the tooth, recent research indicates that both magnetostrictive inserts and piezoelectric tips may move in an elliptical motion.^6,7 Both magnetostrictive inserts and piezoelectric tips can damage the root surfaces depending on shape, lateral force, angulation, and power setting.⁶ A recent in vitro study concluded that manual and ultrasonic instruments produce the same roughness, therefore, efficacy should also be similar.⁸

The active part of the UIT—usually the last 2 mm to 4 mm—is adapted to the root contour. ⁹ The active tip area varies by brand and tip design, therefore manufacturer instructions should be consulted. Angulation to the tooth is held constant at 0° to 15° on all surfaces. Adapting the tip more than 15° to the root could cause undesirable striations because the point produces maximum power and can be very thin. A study¹⁰ showed that the force of a magnetostrictive insert was the least powerful at close to 0° and increased to a maximum force when angled at 90°. Flemmig et al¹¹ found that when using a piezoelectric device, forces increased as the angle-to-tooth relationship increased, and peaked when the tip was 45° to the tooth surface.

ACTIVATION

A crosshatch oblique, vertical, and horizontal pattern is used to remove supragingival deposits and fine stain. Subgingival removal of tenacious deposits is approached with tapping motions on the top or side of the dense deposit to fracture its structure. The movement is similar to the motion used with a periodontal probe. Removing deposits from the outside surface to the surface closest to the root structure in a layered approach is more likely to create burnishing or incomplete removal. In other words, with tenacious heavy or moderate deposits, a systematic approach is employed—moving the instrument from the gingival margin to the epithelial attachment. Impenetrable deposits require the use of a periodontal working file to fracture the mass and avoid burnishing. Smaller deposits can also be dense due to formation or burnishing. Removing them requires the use of adequate power and the correct UIT, otherwise burnishing will result.

The UIT must be able to reach the deposit and be indicated for moderate to high power. In this situation, employing a dental endoscope is ideal. In contrast, the removal of light deposits and biofilm occurs from the epithelial attachment to the gingival margin. Light lateral pressure is usually all that is needed for small to moderate deposit removal. More pressure may be required to remove heavy or tenacious deposits. Continuous, overlapping vertical and oblique strokes should cover the root surface, especially for plaque biofilm removal. Stroke activation is slow and methodical while keeping the UIT moving across the tooth anatomy. There has been reference to faster strokes in a “vibrato” motion to finish root surfaces or root plane. However, the literature has not addressed this recommendation.

POWER SETTINGS

UITs should be activated at the ideal power setting to achieve results. Low to medium power is indicated for oral biofilm and definitive periodontal procedures with thin UIT designs. Medium to high power is used for moderate to heavy deposits with traditional UIT designs. New, thin tips that can be used with high power are also available.

WEAR

UITs have a longer life than curets and do not need sharpening. Wear, however, does affect outcomes because it decreases the UIT’s length—reducing the displacement amplitude (ie, power).¹² Prevention of root surface roughness is important in deterring the reestablishment of microbial deposits and wear can significantly increase roughness.¹³ Clinicians should use the tip wear guides provided by manufacturers to determine the need for replacement.

PATIENT PREFERENCES

Patient desires and comfort always need to be considered during UIT selection. Local anesthesia or subgingival application of topical anesthesia can be used to ease patient discomfort. Deposit removal should also be conducted in the most efficient manner possible.

CONCLUSION

Many factors influence UIT selection, including clinician preference and experience, water delivery methods, and the type of ultrasonic unit available in the operatory. Other selection factors include handle diameter, comfort, swiveling and fiber-optic light options, sterilization recommendations, color-coding, and interchangeability with different generators. Limited research is available on UIT design and its relationship to clinical efficacy. Hopefully, future research will adequately address this issue. In vitro research has shown that there is variation in performance of different insert/tip designs as well as generators, but the relevance to clinical outcomes is unknown.¹⁴

Clinicians should review the manufacturer’s recommendations for UIT design, purpose, active tip area, angulation, and power settings to enhance effectiveness and prevent unwanted damage to the root surface. Many manufacturers’ websites contain this information and some provide video instruction on appropriate ultrasonic technique.

References

1. Lea SC, Walmsley AD. Mechano-physical and biophysical properties of power-driven scalers:driving the future of powered instrument design and evaluation. Periodontol 2000. 2009;51:63–78.
2. Casarin RC, Bittencourt S, Ribeiro EP, et al. Influence of immediate attachment loss during instrumentation employing thin ultrasonic tips on clinical response to nonsurgical periodontal therapy. Quintessence Int. 2010;41:249–256.
3. Seol HW, Heo SJ, Koak JY, Kim SK, Baek SH, Lee SY. Surface alterations of several dental materials by a novel ultrasonic scaler tip. Int J Oral Maxillofac Implants. 2012;27:801–810.
4. Otgonbayar U, Jung-Seck L, Jae-Chul C, et al. Comparative evaluation of roughness of titaniumsurfaces treated by different hygiene instruments. J Periodontal Implant Sci. 2012;42:88–94.
5. Baek SH, Shon WJ, Bae KS, Kum KY, Lee WC, Park YS. Evaluation of the safety and efficiency of novel metallic ultrasonic scaler tip on titanium surfaces. Clin Oral Implants Res. 2012;23:1269–1274.
6. Walmsley AD, Lea SC, Felver B, King DC, Price GJ. Mapping cavitation activity around dentalultrasonic tips. Clin Oral Investig. 2012 Aug 15. [Epub ahead of print].
7. Lea SC, Felver B, Landini G, Walmsley AD. Three-dimensional analyses of ultrasonic scaler oscillations. J Clin Periodontol. 2009;36:44–50.
8. Singh S, Uppoor A, Nayak D. A comparative evaluation of the efficacy of manual, magnetostrictive and piezoelectric ultrasonic instruments–an in vitro profilometric and SEM study. J Appl Oral Sci. 2012;20:21–26. 
9. Matsuda, SA. Demystifying piezoelectric ultrasonics. Dimensions of Dental Hygiene. 2006:6:4–11.
10. Flemmig TF, Petersilka GJ, Mehl A, Hickel R, Klaiber B. Working parameters of a magnetostrictive ultrasonic scaler influencing root substance removal in vitro. J Periodontol. 1998;69:547–553.
11. Flemmig TF, Petersilka GJ, Mehl A, Hickel R, Klaiber B. The effect of working parameters on root substance removal using a piezoelectric ultrasonic scaler in vitro. J Clin Periodontol. 1998;25:158–163.
12. Lea SC, Landini G, Walmsley AD. The effect of wear on ultrasonic scaler tip displacement amplitude. J Clin Periodontol. 2006;33:37–41.
13. Arabaci T, Cicek Y, Dilsiz A, Erdogan I, Kose O, Kizilda? A. Influence of tip wear of piezoelectric ultrasonic scalers on root surface roughness at different working parameters. A profilometric and atomic force microscopy study. Int J Dent Hyg. 2012 Oct 4. [Epub ahead of print].
14. Walmsley AD, Lea SC, Landini G, Moses AJ.Advances in power driven pocket/root instrumentation. J Clin Periodontol. 2008;35(Suppl):2–22.

From Dimensions of Dental Hygiene. January 2013; 11(1): 42, 44, 46.