Here’s a case that may stick another tool in your toolbox. As a restorative dentist who treats primarily adults, it’s not uncommon for me to see young adult patients with retained primary molars that weren’t treatment planned comprehensively for the long-term stability of the dentition.

Primary molars maintain a greater mesio-distal width than the adult replacement teeth, and are much shorter than adult premolars. As a result, when retained, they can lead to canting of the adjacent teeth and supereruption of the teeth in the opposing arch.

When we see pediatric patients with retained primary teeth, it is best to treatment plan the case with the adult dentition in mind prior to orthodontics. When we don’t meet the patient until adulthood, what are our options?

Implants are certainly one option, and when the primary teeth are compromised from decay or existing restorations, they can be a good one. However, when the primary molars are intact, or if time, finances, fear, or other barriers to implant treatment make it a subpar solution, what else can we offer our patients?

This patient presented on referral from a periodontist with retained K and T. The patient was opting to maintain the primary teeth, and the periodontist suggested evaluating the occlusal consequences of that decision. In order to avoid canting or supereruption of the surrounding dentition, it was decided that we would wax-up the primary molars to ideal occlusion and use matrices to restore the primary teeth in the mouth with composite. 

retained teeth process

Here are the steps to offer composite “crowns” for primary molars when they are being maintained:

Prep work:

  1. Take impressions of the maxillary and mandibular arches and a bite registration in maximum intercuspation.
  2. Have the lab complete wax-ups of the primary teeth to be restored, instructing the technician to wax the tooth/teeth to the existing occlusal scheme with broad interproximal contacts, and light occlusal contacts. Let them know it is additive to complete chairside with composite without a finish line.
  3. Create a duplicate cast of the wax-up by taking an alginate impression of the waxed-up teeth and pouring it up in stone.
  4. Create a clear suck-down of the duplicate cast (I use 0.8 thickness).
  5. Trim the suck-down to incorporate the tooth in front and the tooth behind for stability.


  1. Isolate the teeth (rubber dam or Isolite)
  2. Air abrade or roughen the surface of the entire tooth; if there is an existing restoration, remove it. For added retention, occlusal potholes may be added. I would recommend this if the occlusal table is eroded and lacking enamel.
  3. Acid etch enamel for at least 15 seconds (be sure not to etch adjacent teeth, or breaking contacts will be difficult).
  4. Copious primer over entire surface to be bonded to and scrubbed for manufacturers recommended time; air dry.
  5. Adhesive over entire surface, air-thinned (again be sure not to coat adjacent teeth for ease of breaking contacts), light cured.
  6. Place composite into the occlusal surface of matrix and seat the matrix. You can add the composite to the matrix at the beginning if you have a light-safe cover. Place pressure on the matrix on the tooth mesial and distal to the one being restored, and light cure.
  7. Hand place and carve composite on the buccal and lingual surfaces.
  8. Finish and polish to remove any flash. Check and adjust occlusion as you usually would
  9. If necessary, break mesial and distal contacts first during the finishing and polishing stage (I use a flame-shaped fine diamond), and then if needed, I use Quikstrips by Kerr.
  10. Floss the contacts and complete final polishing.
quickstrips by kerr use
treatment for retained primary molars
composite crowns for primary molars
primary molar restorations
treatment alternative for retained primary molars
composite crowns for primary molars

This should preserve the position of the surrounding teeth and can be a long term solution to an otherwise compromised situation. 

(Click this link for more dentistry articles by Dr. Courtney Lavigne.)

Courtney Lavigne, D.M.D., Spear Visiting Faculty and Contributing Author -


Commenter's Profile Image James P.
March 8th, 2018
Very nice dentistry, Courtney. It's nice when you have a periodontist who is on the same page as you and refers patients to you for care.
Commenter's Profile Image Ricardo M.
March 9th, 2018
Great job Courtney!!!
Commenter's Profile Image Amir M.
March 9th, 2019
I really enjoyed reading your article. I have a few questions for you. 1- How do you isolate adjacent teeth to prevent etching and bonding? 2- Do you put holes for excess composite to squeeze out? 3- Could you sepcify which Quikstrips do you use (they come in different thickness)? Thank you!
Commenter's Profile Image Courtney L.
March 9th, 2019
Hi Amir! Thanks for the comments. I place Teflon over the adjacent teeth, and use the white Quikstrips, which do not adjust interproximally, they merely have a serrated edge to them. I've tried the matrix both ways: both with a hole for extra to expel and without; Unless you are using a more flowable composite like Sonicfill on placement, the hole only releases a little and you still get extra flash. I don't place the hole, and try to eyeball how much to add before etching and bonding by placing the matrix and visualizing the void I'm filling. I end up with a little extra expressed onto the adjacent teeth but it flicks off easily with a scaler if you haven't bonded those surfaces. I hope that helps!