May’s Tip

IPR in Posterior Sextants-ARS Air-Rotor Slenderizing

By Dr. Adrian J. Palencar, MUDr, MAGD, IBO, FADI, FPFA, FICD

May 2024

IAO Diplomate
68 – Tremont Drive, ST. Catharines
ON L2T 3B2, Canada


Air-Rotor Slenderizing is a protocol for creation of space by removal of precise amount of enamel between the teeth in the posterior sextants.  The crowns of the teeth in posterior region have approximately twice the thickness of the interproximal enamel on the anterior teeth. Thus, we can easily create 4 – 8 mm space per arch in the molar and premolar regions.  Maximum 0.5 mm of interproximal enamel should be removed per tooth.  It means creating total interproximal space not more than 1.0 mm.

The author’s favorite FG burs for ARS/IPR:

  1. Midwest FG 699L – for gross reduction
  2. Midwest FG 7642 – finishing inter-proximal walls and line angles.
  3. Midwest FG 7406 – reforming marginal ridges


ARS/ IPR Protocol:

  1. Sign the Informed consent.
  2. Pumice the teeth and rinse with Peridex.
  3. Do just one interproximal ARS/IPR, per quadrant in one appointment.
  4. Place the separator (leave it for seven days).
  5. Remove the separator apply the topical anesthetic.
  6. Place indicator wire or rigid wedge into the interproximal space.
  7. Reduce the enamel from the lingual side – the bur is in horizontal, sweep from the gingival to occlusal. Just to the middle (horizontally) of the clinical crown.
  8. Reduce the enamel from the buccal side, the same way as from the lingual side.
  9. Smooth down the surfaces, line angles and reform the marginal ridges.
  10. Polish the inter-proximal surfaces.
  11. Measure the created space with the IPR gauge, and record in the “ARS record sheet.”
  12. Apply Topical fluoride and prescribe fluoride rinse at home.
  13. Rx: Acetaminophen 500 mg p.r.n., (not Ibuprofen, as it inhibits the tooth movement)
  14. Give post – IPR instructions.


Air-Rotor Slenderizing was developed and made popular by Dr. Jack Sheridan – Louisiana State University, New Orlans, LA.  It was originally published in 1987 in JCO.  I embraced his technique, expanded on it, and published it in the article in IJO in 2004.  (The link is in References).


  1. Sheridan J.J. Air-Rotor Stripping update, Clin Orthod. 1987, 21:781-788
  2. Sheridan JJ. The updated Air-Rotor Stripping manual, Raintree Essix Inc.
  3. Palencar A. J., Air-Rotor Slenderizing, International Journal of Orthodontics, VOL 15, NO 3, Fall 2004
  4. Palencar A. J., Case Finishing manual, Rondeau Seminars, 340 -349