Air polishing revisited

Mr. Borneo asks Adam, RDH: "What's that huge monstrosity in the corner of your operatory that looks like a muscular elephant trunk?"

Pennwell web 350 537

Pennwell web 350 537
Author Lynne Slim's hygiene operatory at Legacy Dental Care in Kennesaw, GA.
There's an elephant in the room

by Lynne H. Slim, RDH, MS, and Cher Thomas, RDH

Mr. Borneo asks Adam, RDH: "What's that huge monstrosity in the corner of your operatory that looks like a muscular elephant trunk?" "Oh, that," chuckles Adam, "It's an air cleaning system we use while we're air polishing and performing other dental procedures.

"It looks rather scary, but the truth is it's a flexible suction arm that captures aerosols. Particles are captured by the flexible suction duct before they can spread to other areas of the treatment room and office.

"Of course, I also make sure I wear the appropriate personal protective equipment such as gloves, glasses, and a face mask while treating my patients.

"Pretty nifty, don't you think, Mr. Borneo?"

"Wow! Adam, you guys always have something new. You've come a long way since the day I used to spit in a bowl! Ha ha ha!"

Adam replies, "Only a small handful of patients have medical conditions that make this type of polishing procedure inadvisable. So, before we get started, Mr. Borneo, let's update and review your medical history again. You're really going to love how your teeth feel afterwards and we'll have you out of here in no time."

Many hygienists around the United States are air polishing routinely and many more on a selective basis. Let's look at the science and professional guidelines surrounding this "elephant in the room," because it hasn't been talked about much.

Select the appropriate patient

When reviewing a medical history, we often refer to recommended guidelines and position papers. The American Dental Hygienists' Association 2010 Position on Polishing Procedures lists the following as contraindications for air polishing procedures:1

  • Patients with restricted sodium diets
  • Patients with respiratory, renal, or metabolic disease
  • Patients with infectious disease
  • Children
  • Patients on diuretics or long-term steroid therapy
  • Patients with titanium implants (research is still needed in this area)
  • In its position paper, the ADHA highlights a study by Galloway and Pashley (1986) that demonstrated the air polisher can cause clinically significant loss of tooth structure when used excessively and should, therefore, not be used on exposed cementum or dentin.1 In addition, ADHA cites Woodall's 1993 textbook recommendation that states "air polishers should be avoided around most types of restorative materials due to the possibility of scratching, eroding, pitting, or margin leakage."1

Position papers and treatment guidelines are valuable tools in clinical decision-making, and those of higher quality include unbiased scientific evidence. In addition, it's important that guidelines be updated to keep up with the latest research. They are best used as an instrument to assist and direct us with patient selection and proper patient care. As with all procedures we perform, however, it is imperative that we resist a "cookie cutter" approach to guidelines. For all procedures, patients should be evaluated on a case by case basis.

For example, the ADHA position paper on air polishing lists renal disease as a contraindication. Not all (though many) patients with renal disease would be on sodium restriction. To determine whether a renal patient is a candidate for air polishing, you would have to know the stage of renal disease (there are five stages), the treatment for renal disease (some treatments allow greater flexibility in diet than others), the adherence to treatment and medications, the patient's medical status, comorbidities, etc.

When we find a red flag like this, it doesn't necessarily mean the protocol is wrong. It is a flag that should prompt us to consult with the patient's nephrologists and/or the patient's renal dietitian to determine acceptable sodium exposure. If the patient is stable, adherent to care, and responds well to their medical care, then sodium might not be a huge issue. If the patient is not stable, nonadherent, or unresponsive to medical care, then additional sodium would not likely be recommended. Furthermore, even if we determine a patient is a good candidate for air polishing (from a medical standpoint), we also have to evaluate them from a dental standpoint.

Guidelines are a powerful tool in educating clinicians about medical and dental conditions. It is challenging to read every professional journal and keep up with all of the latest information available. Unquestionably, guidelines are best utilized as a signal and/or a compass for the clinician, indicating when a consultation is warranted. Evidence-based guidelines help us navigate our way to clinical decision-making in a way that determines the proper course of action for individualized care.

After we've taken or updated the medical/dental history, we can determine if a patient is a good candidate for air polishing. Although some procedures can be messier than others, virtually all dental procedures produce aerosols, and the air polisher is no exception. By using high volume evacuation (HVE), an aerosol shield reduction device, or some other air cleaning system or combination of systems, we can protect our patients, our coworkers, and ourselves from contaminated aerosols. To avoid cross-contamination from dental equipment, infection control specialists agree: "The same chemical treatment regimens and technology used in the dental unit should be effective with the ultrasonic and air polishing equipment, which also pose risk of bacterial contamination via biofilm tubing."2

Selective polishing

Routine polishing is still an integral part of today's dental hygiene department even though the concept of polishing "selectively" was first introduced in the early 1980s and reinforced repeatedly by Wilkins and many others over many decades.3 Wilkins indicates that the decision to "polish" should be individualized for each patient and she stresses her main concern about abrasive traditional prophy pastes.4 Wilkins provides an excellent review of selective rubber cup and air polishing in her 10th edition of Clinical Practice of the Dental Hygienist, and it includes contraindications for air polishing. Besides plaque/biofilm and extrinsic stain removal, today's air polishing and rubber cup devices are a way to add medicaments to the tooth, such as desensitizing agents (potassium nitrate and arginine/calcium carbonate) and remineralization agents such as topical fluoride preparations.

Select the optimal polishing powder

Bicarbonate-based air polishing powders have been limited by substantial abrasiveness on composite materials.1 Besides the most common air polishing sodium bicarbonate-based powders, there are some newer air polishing products that are worth mentioning (see "Sources for air polishing powders").

Glycine-based powder is an air polishing powder that is currently being used in Europe as an alternative to sodium bicarbonate-based powders around composites. Glycine-based powder is being promoted as less abrasive than bicarbonate-based powder, and some evidence supports this claim.5 Salerno et al. investigated surface damage of different conditions of air polishing performed in vitro on a recently introduced dental restorative composite. Abrasive powders of sodium bicarbonate and glycine, combined at different treatment times and distances from teeth were tested. The use of glycine in air polishing generated the least surface roughness on the restorative material.6

Of interest in reading this publication were the comments by the authors about surface roughness. Surface roughness is a factor affecting plaque/biofilm adhesion on dental surfaces in vivo. Air polishing dental surfaces removes biofilm but can also damage the tooth/restoration surface by increasing its roughness.6 Calcium carbonate is an active ingredient in one commercial air polishing powder. One in vitro study compared the effect of a calcium carbonate-based powder on dentin bonding to an air polishing powder containing glycine. The authors concluded that calcium carbonate-based air polishing should be avoided when dentin-bonded restorations are applied and that glycine-based powder is an acceptable alternative.7

A recent in vitro study assessed the influence of air polishing devices and various abrasive powders on flat root surfaces. Regardless of the abrasive used, there was some variation in root defects generated by different devices and the glycine-based powder produced the least amount of root damage. Calcium carbonate caused more root substance loss than the glycine-based powder.8

Another new air polishing agent with calcium sodium phosphosilicate claims to desensitize, clean, polish, and regenerate the tooth to create an enamel-like layer in one easy treatment (see "Sources for air polishing powders"). It is a bioactive glass, which is a chemical compound composed of naturally occurring elements (calcium, phosphorus, silica, and sodium) that have been used in medicine for decades to promote bone growth. The trade name for this bioactive glass is NovaMin.

The bioactive glass material reacts with body fluids (saliva) to deposit hydroxycarbonate apatite (HCA), a mineral that is chemically similar to natural tooth minerals. Therefore, it has the potential to facilitate regeneration. In addition, this bioactive glass creates a compact and substantially thicker smear layer that is more resistant to acid attack. The higher acid resistance of the smear layer created by the bioactive glass may also be attributed to a possible remineralization of the smear layer occurring during artificial saliva immersion.9

The sodium phosphosilicate polishing agent has no salty taste, no sodium contraindications, and there isn't any stinging or irritation of soft tissue. The sodium content is less than 500 milligrams which is very little in comparison with 2,000 to 3,000 milligrams in sodium bicarbonate (which is highly soluble and will dissolve quickly). The majority of the sodium is mixed with the particles during the manufacturing process to enhance the calcium phosphate; therefore, the particles dissolve over time, limiting the release of sodium.

Most of the in vitro research on sodium phosphosilicate, to date, has been focused on its ability to form a layer of hydroxycarbonate apatite on tooth dentin and enamel, as well as its effectiveness as a desensitizing and remineralizing agent. The relative abrasiveness of this bioactive glass has not been studied, but studies have been conducted to show the removal of surface stains and hypersensitivity.10,11

Clinicians such as Fay Brown, RDH, from a New York City periodontal practice, have commented (anecdotally) that this particular air polishing agent is a great desensitizer that removes stains quickly. In addition, clinicians have also mentioned that the polishing molecules are so small that very little powder is needed. The bioactive glass polishing agent requires less powder per treatment because it is a dense powder that when applied to the tooth surface stays in place. This results in more powder per tooth surface and less waste in overspray. Current air polishing powders such as sodium bicarbonate or calcium carbonate are composed of lighter molecular structures that easily produce a messy overspray and/or aerosol.

Air polishing and orthodontic patients

Ramaglia et al. compared the efficacy and efficiency of a sodium bicarbonate air polishing and rubber cup (pumice) system in orthodontic patients.12 Sixty-two patients were divided into two groups: one that did not rinse with chlorhexidine and one that did and showed visible extrinsic staining. The air polishing system required less time to remove biofilm and extrinsic stain and was reported to be the most effective method for removal of extrinsic stains.

Air polishing abrasives on sealants

Just as air polishing devices often result in clinically relevant tooth surface damage and restorative material loss, air polishing of sealants always results in substance loss and surface damage, according to Pelka, Altmaier, Petschelt and Lohbauer.13 The authors made plane specimens (N=180) of dental restorative materials and treated the specimens with standardized air polishing for 10 seconds each. Abrasive powders included sodium bicarbonate and glycine-based powder.

The glycine-based powder product produced the smallest defect depth and volume loss. The authors reported that the sealants performed better in terms of abrasion resistance than did the flowable composites tested and recommended the use of low-abrasion powders for frequent cleanings.

To prevent decalcification during orthodontic treatment using fixed appliances, many orthodontists use sealants to protect enamel around brackets.14 Air polishing devices are often used to clean the teeth, and investigators in Germany tested the effects of air polishing on these sealants.14 Three different sealants were applied to the surfaces of 30 extracted human teeth, and the enamel surfaces of 10 teeth were air polished with a sodium bicarbonate based powder for five to 10 seconds or a glycine-based powder for 10 seconds.

Results indicated that sealants had become thinner and revealed minor defects after five seconds of air polishing with the sodium bicarbonate-based powder, practically disappearing after 10 seconds. Use of the glycine-based powder permitted longer air polishing times but the sealant surface also demonstrated minor defects.

Keep in mind that these findings correlated with the type of powder used and air polishing time.

It is important to note that protection against demineralization may be seriously compromised following sealant placement when tooth surfaces are cleaned with air polishing devices.

Novel subgingival biofilm-disruption device

Longitudional studies have demonstrated the efficacy of standard treatment approaches (regular mechanical removal of bacterial biofilm), which consist of meticulous debridement of tooth and root surfaces, consistent self-care measures, and supportive maintenance visits.

Adverse effects of the mechanical approach to plaque/biofilm removal include irreversible hard tissue damage and gingival recession that results from the mechanical scraping of tooth surfaces.15 In addition, loss of hard tissue is a major cause of increased sensitivity of treated teeth to evaporative, tactile, thermal, and osmotic stimuli.15 Well-meaning clinicians sometimes over-instrument during scaling and root planing and adult recare appointments, especially in areas where there is no supra- or subgingival calculus.

It's an exciting time for hygiene instrumentation in many respects, and future dental hygienists may choose to disrupt subgingival plaque/biofilm with a unique device that delivers amino acid glycine powder at limited pressure subgingivally. In vitro and in vivo research studies have begun to test this new device and, to date, no adverse effects on patients have been noted.15-17 This device is not designed for subgingival "polishing" but it could eventually become an alternative (under certain strict conditions including shallow anatomic probing depths and medical clearance) or adjunct to subgingival biofilm disruption with ultrasonics or hand instrumentation.

Before discussing research to date on the use of a pressurized air device subgingivally, it is important to discuss risk for provoking emphysema. Several cases of emphysema have been reported after the use of high-speed dental handpieces, air-water syringes, taking impressions, and cleaning procedures with air polishing devices that used sodium bicarbonate powder.15,18 This condition is reported to resolve rapidly and disappear completely within a few days. No case of emphysema has been reported after instrumentation subgingivally with the device that delivers the glycine-based powder subgingivally.

In 2003, a small (N=23) patient randomized clinical controlled trial was designed to test the efficacy of glycine-based powder air polishing (GPAP) in subgingival plaque/biofilm removal at interdental sites during periodontal maintenance. Using a split mouth design, subgingival plaque/biofilm was removed using the GPAP device or with curettes. Before and immediately after treatment, subgingival plaque/biofilm samples were taken from interdental sites with 3-5 mm probing depths. Anaerobe cultivation was used to assess the mean reduction of total colony-forming units immediately after treatment. GPAP resulted in a significantly greater reduction in subgingival bacterial counts when compared to curettes.16 The authors mentioned that GPAP might save instrumentation time and reported that only 15 minutes was needed to remove plaque-biofilm in the entire dentition. No major gingival damage occurred as a result of this instrumentation.

Flemmig et al. assessed the subgingival efficacy of glycine-based powder air polishing (GPAP) in periodontal pockets of various depths.17 In each of 60 patients with severe periodontitis, one tooth with a probing depth of ≥6 mm was randomly assigned to one of three interventions: no treatment; GPAP performed in previously noninstrumented teeth; and GPAP performed in teeth instrumented three months earlier.

Results showed that GPAP for five seconds per surface was effective in removing most of the subgingival plaque/ biofilm with an anatomic probing depth of 2 mm to 3 mm. The authors mentioned in the discussion section of this study's report that, on average, 66% to 77% percent of subgingival root surfaces were biofilm-free in pockets with probing depths ≥4 mm. No adverse events were reported in this study, and there was minimal gingival irritation.

Lastly, a recent study in 2010 evaluated the safety, patient acceptance, and short-term microbiologic effect of GPAP in periodontal maintenance patients with residual pockets ≥5 mm.15

This randomized, split-mouth clinical trial compared GPAP to conventional curette/ultrasonic debridement in 50 subjects. After removing supragingival deposits, the glycine spray was applied for four to five seconds in all sites ≥5 mm in the test quadrant, whereas curette/ultrasonic debridement was used in the control quadrant. Microbiologic samples were taken and total bacterial counts and counts of six periodontal pathogens were determined by real-time polymerase chain reaction.

GPAP was safe with no adverse events reported, and was perceived to be more acceptable to patients. In addition it was more time efficient but, on a microbiological level, it was not superior to the conventional blended instrumentation approach (curette/ultrasonic instrumentation.)

Air-abrasive powders and dental implants

Most peri-implant lesions (peri-implant mucositis or peri-implantitis) are caused by plaque/biofilm colonization around the implant surface.19 There is a statistically significant higher incidence of peri-implantitis for dental implants placed in patients with a history of chronic periodontitis (28.6%) compared with periodontally healthy individuals (5.8%).20 The correlation between the presence of periodontitis and the development of peri-implantitis has been supported by a recent systemic review.21

Schwarz et al. evaluated the effect of different types of air-abrasive powders in an air-flow system on the removal of nonmineralized plaque/biofilms collected in vivo on rough-

ened titanium implant surfaces, using an intraoral implant system. Cell viability at biologically contaminated specimens was also assessed, which would determine whether or not cells were biologically active.22 Six healthy subjects were included in the study (there were no controls).

After 48 hours, all titanium discs were covered completely in plaque/biofilm. Sodium biocarbonate-based powders did not affect irregular grooves and pits, but sharp-edged elevations were markedly flattened. In contrast, the glycine-based powders did not result in specific surface alterations of the implant. Results indicated that all powders studied were equally effective in removing plaque/biofilms on titanium surfaces. These supragingival plaque biofilms, however, were artificially collected after a period of 48 hours and they are different from subgingival calculus that is permeated with crystals of various calcium phosphates.

Selecting the proper course of action

The phrase "an elephant never forgets" refers to the tenacity of this large mammal to follow the same path, no matter what the circumstance. Dentistry and dental hygiene, on the other hand, change by the minute. As oral health-care providers, we are constantly pushing to keep current with technology and research. Revisiting our polishing options is beneficial to patients and clinicians. Familiarity with aerosol shield reduction devices or the difference between air polishing powders is paramount.

Air polishing is a high quality, efficacious, and efficient service. However, to obtain successful clinical outcomes, we must:

Have the proper protective equipment for our patients and ourselves

Learn to recognize and properly interpret the signals within clinical guidelines that assist us in patient selection

Periodically revisit the assortment of air polishing equipment/powders and apply evidence-based decision-making to clinical decision-making.


Sources for air polishing powders

Sodium bicarbonate powders
3M ESPE's C&P Air Polishing Powder
Biotrol's Perfect Choice Air Polishing Powder
Dentsply's Cavitron Prophy-Jet Powder
Electro Medical Systems' (EMS) Air-Flow Powder Classic
Satelec Acteon Group's Powder Max
Young Dental's Air Polishing Powder

Glycine powders
Electro Medical Systems' (EMS) Air-Flow Powder Perio
Electro Medical Systems' (EMS) Air-Flow Powder Soft

Other powders
Dentsply's Cavitron Jet-Fresh Powder (aluminum trihydroxide)
KaVo's ProphyFlex Powder (calcium carbonate)
OSspray's Sylc (Novamin/calcium sodium phosphosilicate)


Lynne Slim, RDH, BSDH, MSDH, is an award-winning writer who has published extensively in dental/dental hygiene journals. Lynne is the CEO of Perio C Dent, a dental practice management company that specializes in the incorporation of conservative periodontal therapy into the hygiene department of dental practices. Lynne is also the owner and moderator of the periotherapist yahoo group: www.yahoogroups.com/group/periotherapist. Lynne speaks on the topic of conservative periodontal therapy and other dental hygiene-related topics. She can be reached at periocdent@mindspring.com or www.periocdent.com.

Cheryl A. Thomas, RDH, currently resides in Galveston, Texas. She can be contacted at catblue@aol.com, or visit her Web site at dentalinspirations.org.

References

1. ADHA.org, American Dental Hygienists' Association Position Paper on Polishing, webpage updated 2010, http://www.adha.org/profissues/polishingpaper.htm.

2. Bednarsh HS, Eklund KJ, and Mills S. Reprinted from Access Vol. 10, No.9, copyright ©1997 by the American Dental Hygienists' Association, http://www.osap.org/?page=Issues_DUWL_7&hhSearchTerms=polish.

3. Rohleder PV, Slim LH. Alternatives to rubber cup polishing. Dent Hyg 1981: 53(9).

4. Wilkins EM. (9th ed). (2005). Clinical practice of the dental hygienist. Philadelphia, PA: Lippincott Williams & Wilkins: p. 6.

5. Petersilka GJ, Bell M, Haberlein I, Mehl A, Hickel R, Flemmig TF. In vitro evaluation of novel low abrasive air polishing powders. J Clin Periodontol 2003;30:9-13.

6. Salerno M, Giacomelli L, Derchi G, Patra N, Diaspro A. Atomic force microscopy in vitro study of surface roughness and fractal character of a dental restoration composite after air-polishing. Biomed Eng Online. 2010 Oct 12;9(1):59. [Epub ahead of print].

7. Frankenberger R, Lohbauer U, Tay FR, Taschner M, Nikolaenko SA.,J Adhes Dent., The effect of different air-polishing powders on dentin bonding, 2007 Aug; Dental Clinic 1, Operative Dentistry and Periodontology, University of Erlangen-Nuremberg, Erlangen, Germany, 9(4):381-9, frankbg@dent.uni-erlangen.de.

8. Pelka M, Trautmann S, Petschelt A, Lohbauer U. Influence of air-polishing devices and abrasives on root dentin – an in vitro confocal laser scanning microscope study. Quintessence Int. 2010 Jul-Aug; 41 (7): 3 141-8.

9. Burwell, AK, Litkowski LJ, Greenspan DC. Calcium sodium phosphosilicate (NovaMinR): remineralization potential. Advances in Dental Research 2009; 21: 35-9.

10. Narongdej T, Sakoolnamarka, R, Boonroung T. The effectiveness of a calcium sodium phosphosilicate desensitizer in reducing cervical dentin hypersensitivity. A pilot study. JADA 2010; 141(8): 995-999.

11. Salvatore, S, Watson, TF, Thompson, I. Dentine desensitization induced by prophylactic and air-polishing procedures: an in-vitro dentine permeability and confocal microscopy study. Journal of Dentistry 38(2010); 411-422.

12. Ramaglia L, Sbordone L, Ciaglia RN, Barone A, Martina R.A., A clinical comparison of the efficacy and efficiency of two professional prophylaxis procedures in orthodontic patients. Eur J Orthod. 1999 Aug; 21(4): 423-8.

13. Pelka MA, Altmaier K, Petschelt A, Lohbauer U. The effect of air-polishing abrasives on wear of direct restoration materials and sealants. J Am Dent Assoc. 2010 Jan; 141(1): 63-70.

14. Engel S, Jost Brinkmann PG, Spors CK, Mohammadian S, Mûeller-Hartwich R. Abrasive effect of air-powder polishing on smooth surface sealants. J Orofac Orthop. 2009 Sep; 70(5):363-70. Epub 2009 Dec 9.

15. Moëne R, Décaillet F, Anderson E, Mombelli A., Subgingival plaque removal using a new air-polishing device. J Periodontol 2010 Jan; 81: 79-88.

16. Petersilka G et al. Subgingival plaque removal at interdental sites using a low-abrasive air polishing powder. J Periodontol 2003; 74: 307-311.

17. Flemmig TF et al. Subgingival debridement efficacy of glycine powder air polishing. J Periodontol 2007; 78: 1002-1010.

18. Heyman SN, Babayof L., Emphysematous complications in dentistry, 1960-1993: an illustrative case and review of the literature. Quintessence Int. 1995 Aug; 26(8): 535-43.

19. Lindhe L, Meyle J. Peri-implant diseases: consensus report of the sixth European workshop on Periodontology. J Clin Periodontol 2008; 35 (Supp. 8): 282-285.

20. Kotsovili S, Karoussis IK, Trianti M, Fourmousis, I. Therapy of peri-mplantitis: a systemic review. J Clin Periodontol 2008; 35; 621-629.

21. Renvert S. Persson GR. Periodontitis as a potential risk factor for peri-implantitis. J Clin Periodontol 2009; 36 (Suppl. 10): 9-14.

22. Schwarz, F et al. Influence of different air-abrasive powders on cell viability at biologically contaminated titanium dental implant surfaces. J Biomed Mater REs Part B: Appl Biomater 2009; 88B: 83-91.

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