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The “2for2” Technique: A Modified Double-Evacuation Procedure to Minimize Droplet and Aerosol Production






When preparing tooth surfaces by polishing, etching, and scaling for direct or indirect bonding,1 or when removing adhesive for debonding, orthodontists should take strict precautions to prevent COVID-19 transmission by minimizing the production of droplets and aerosols.2,3 A four-handed technique using low- and high-volume saliva evacuators has recently been recommended to control droplets and aerosols,3 but this requires two operators. Here is a “2for2” technique that utilizes a double saliva evacuator and two working hands, thus exposing only one operator to the risk of contagion.


  1. Isolate the dentition to ensure a dry field.**
  2. Connect the low-volume evacuator to the rear connectors.
  3. Tie the high-volume evacuator to the front connector using a 5/16", 2oz orthodontic elastic.
  4. Position the front evacuator at the desired height for the upper or lower arch.
  5. Use a slow-speed handpiece.

Because these materials and equipment are readily available in an orthodontic office, the technique is inexpensive and can be applied immediately. It has the following additional advantages:

  • Droplets and aerosols are controlled in both the anterior and posterior areas of the mouth.
  • The front high-volume evacuator is flexible enough to be used on either side of the upper or lower arch.
  • The technique can be applied in other dental specialties for situations where rubber dams cannot be used.
  • Only one operator needs to be present, reducing the risk of infection to orthodontic staff by 50%.

*Private practice, Città Sant’Angelo, Viale Matrino 124, 65013 Pescara, Italy; e-mail: fabio@studiociuffoloferritto.it.
**NOLA Dry Field System, Great Lakes Dental Technologies, Tonawanda, NY; www.greatlakesdentaltech.com.


1. Ciuffolo, F.; Tenisci, N.; and Pollutri, L.: Modified bonding technique for a standardized and effective indirect bonding procedure, Am. J. Orthod. 141:504-509, 2012.
2. Seto, W.H.; Tsang, D.; Yung, R.W.H.; Ching, T.Y.; Ng, T.K.; Ho, M.; Ho, L.M.; and Peiris, J.S.M.: Effectiveness of precautions against droplets and contact in prevention of nosocomial transmission of severe acute respiratory syndrome (SARS), Lancet 361:1519-1520, 2003.
3. Meng, L.; Hua, F.; and Bian, Z.: Coronavirus disease 2019 (COVID-19): Emerging and future challenges for dental and oral medicine, J. Dent. Res. 99:481-487, 2020.

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