Is Air Polishing Safe? What the Clinical Evidence Shows

Air polishing is safe when performed with appropriate powder formulations and proper technique. Clinical evidence from published studies shows that modern air-polishing powders—particularly glycine and erythritol—cause minimal enamel abrasion and are safe on soft tissue and implant surfaces. Sodium bicarbonate air polishing, used since the 1980s, is more abrasive and has specific contraindications. All air-polishing methods require screening for respiratory contraindications.

A Brief History: How Air Polishing Evolved

Air polishing as a prophylaxis method was introduced in the 1980s using sodium bicarbonate powder, a powder-abrasive combination that effectively removed stains and plaque but had limitations. The powder was moderately abrasive on tooth structure and could damage soft tissues with improper technique. Recognition of these limitations led to development of low-abrasivity alternatives: glycine powder (introduced around 2004) and erythritol powder (introduced around 2010). These newer formulations are polyols—sugar alcohols with significantly lower Mohs hardness values compared to sodium bicarbonate, reducing abrasion risk while maintaining clinical efficacy.

Safety on Enamel and Dentin: What Published Studies Show

Enamel abrasion is a primary safety concern for any polishing method. Published in vitro and in vivo studies have measured the abrasive potential of different air-polishing powders using standardized metrics including Mohs hardness, scanning electron microscopy, and profilometry measurements.

Glycine powder: Multiple published studies document minimal enamel abrasion with glycine air polishing. Glycine (Mohs hardness ~2) is significantly softer than enamel (hardness ~5), meaning it cannot scratch intact enamel under normal clinical conditions. In vitro studies using scanning electron microscopy have shown that glycine powder produces no visible surface damage to enamel when applied with standard parameters. These findings support glycine's use even on exposed enamel surfaces during supportive periodontal therapy and routine prophylaxis.

Erythritol powder: Erythritol (Mohs hardness ~2.5) similarly shows minimal abrasive potential on enamel. Published comparative studies placing erythritol, glycine, and sodium bicarbonate on the same enamel samples under identical polishing conditions have consistently demonstrated that erythritol produces surface changes significantly less severe than sodium bicarbonate. One published in vitro study found "no significant difference in surface roughness" between unpolished control samples and erythritol-treated enamel, confirming excellent enamel safety.

Sodium bicarbonate powder: In contrast, sodium bicarbonate (Mohs hardness ~3.5) is harder and more abrasive than glycine or erythritol. Published studies show measurable enamel abrasion with sodium bicarbonate under clinical conditions, particularly with extended application time or higher pressure. For this reason, clinical guidelines recommend avoiding sodium bicarbonate air polishing on exposed root surfaces or on tooth-colored restorations (composite, veneers), where enamel is absent or protective anatomy is compromised.

Safety on Soft Tissues and the Emphysema Question

Soft tissue safety is particularly important in subgingival applications and in patients with periodontal disease, where gingival crevices may be deepened and epithelial tissues may be exposed.

Glycine and erythritol safety: Published studies directly examining soft tissue response to glycine and erythritol air polishing have found both to be well-tolerated. Research measuring inflammation markers, clinical attachment gain, and histological response following subgingival air polishing with glycine found "no adverse soft tissue response" and clinical outcomes comparable to ultrasonic debridement. Studies of erythritol similarly document safe use even in deep periodontal pockets, with no increased inflammation or tissue damage.

The emphysema question: A rare but serious complication historically associated with air polishing is air emphysema (subcutaneous air injection). This occurred occasionally in the early sodium bicarbonate era when devices operated at very high pressure and lacked adequate moisture control. Published case reports linking emphysema to air polishing are extremely rare and consistently attributed to improper technique (excessive pressure, inadequate water cooling, directing air subgingivally without safeguards), not to the powder itself. Modern air-polishing devices include pressure regulators, moisture-control systems, and design features that minimize this risk when used according to manufacturer specifications. Risk is further reduced by proper operator training and patient screening for communicable respiratory diseases.

Titanium Implant Surface Safety: A Key Distinction Between Powders

Implant surface maintenance is an increasingly important clinical application for air polishing. The choice of powder significantly affects safety on titanium.

Glycine and erythritol on titanium: Published studies using scanning electron microscopy and profilometry examining glycine and erythritol air polishing on machined and rough titanium surfaces have found no surface damage, no loss of surface texture, and no alteration of titanium oxide layer. Clinical studies of implant maintenance with glycine and erythritol show excellent peri-implant health outcomes without compromise to implant surface integrity. These powders are the preferred choice for implant maintenance applications.

Sodium bicarbonate on titanium: In contrast, published in vitro studies demonstrate that sodium bicarbonate can scratch and damage titanium surfaces. Scanning electron microscopy images from these studies show visible surface scratching and texture loss when sodium bicarbonate is applied to titanium under standard polishing parameters. For this reason, clinical guidelines explicitly contraindicate sodium bicarbonate use on implant surfaces, and manufacturers of implant-specific air-polishing systems use glycine or erythritol exclusively.

Contraindications and Patient Screening

Like all prophylaxis methods, air polishing has specific contraindications that require patient screening before treatment:

• Active respiratory disease or communicable respiratory infections: COVID-19, influenza, tuberculosis, and other respiratory pathogens can be aerosolized during air-polishing procedures. Screening and postponement is indicated for symptomatic patients or those with confirmed active respiratory infections.
• Asthma and COPD: Patients with moderate to severe asthma or COPD may experience bronchospasm triggered by inhalation of fine powder particles. Premedication or postponement may be indicated based on severity and control status. Consultation with the patient's physician is recommended.
• Sodium-restricted diets (sodium bicarbonate only): Patients on strict sodium restriction (severe heart failure, renal disease, hypertension) should not receive sodium bicarbonate air polishing due to systemic absorption risk, though the amount absorbed during a typical prophylaxis appointment is small. Glycine and erythritol are sodium-free alternatives.
• Severe immunocompromise: Patients with severely compromised immune function (active chemotherapy, advanced HIV) may warrant additional precautions, though air polishing itself is not absolutely contraindicated.

Implications for Clinical Practice

The safety data support the following clinical practices:

• Powder selection matters: Choose glycine or erythritol for implant maintenance, subgingival applications, and patients with exposed root surfaces or restorations. Reserve sodium bicarbonate only for supragingival enamel surfaces.
• Patient screening is essential: Respiratory status screening is mandatory before all air-polishing procedures. Documentation of patient tolerance and any adverse reactions guides future appointments.
• Technique and device settings are critical: Air polishing safety depends on proper technique, appropriate pressure settings, adequate water coolant flow, and operator competency. Training and adherence to manufacturer specifications are essential.
• Timing and frequency: Published safety data support routine use for prophylaxis and supportive care. No cumulative toxicity or long-term adverse effects are documented in the literature.

Conclusion

Air polishing is a safe and evidence-supported prophylaxis method when appropriate powders are selected and proper technique is employed. Glycine and erythritol powders demonstrate excellent safety across enamel, soft tissue, and implant applications based on published clinical and laboratory studies. Sodium bicarbonate, while historically important, has specific limitations that restrict its use to supragingival enamel surfaces. All air-polishing methods require respiratory screening and contraindication assessment. The body of published evidence supports air polishing as a clinically safe method that can be integrated into preventive and periodontal treatment protocols with attention to powder selection, patient factors, and proper technique.