Improving collaboration and clinical outcomes, refinement aligners

Donal Inman, CDT, discusses how to fabricate a single appliance to make simple positioning corrections in a slightly rotated tooth

I am honored to have been asked to write a technical laboratory column for Orthodontic Practice US. I have decided that to best serve the readers, I will gear this feature toward the type of lab work that is often done in-house either by an assistant or a technician. In this article, we will discuss what I call “Refinement Aligners.”

Common appliances we technicians fabricate are clear aligners used to correct minor rotations or lingual labial malpositions of a tooth or teeth. In our lab, we call them Refinement Aligners. They are simple vacuum- or pressure-formed clear retainers made on a model where a tooth or teeth have been sectioned off and placed into a corrected position using wax.

The working model shows a slightly rotated tooth No. 8 (Figure 1). I like to start by marking reference lines on the working cast before sectioning off the tooth (Figure 2). I make both horizontal as well as vertical (long axis) reference marks. We use the horizontal line to set the tooth to the appropriate level and the vertical line to maintain the proper root position. It is important to remember that if we tip the tooth to the lingual, the tooth must be set to a slightly more incisal position. If we tip the tooth toward the facial, it must be placed in a slightly more gingival position. I also suggest that you try to maintain the root apex position and only tip or rotate the tooth or teeth for simple and predictable refinement aligners.

Using a handsaw, section off the tooth or teeth and then taper the stone to allow the tooth to be rotated (Figure 3). Place the tooth or teeth into ideal position using base plate wax (Figure 4).

To be sure the tooth does not move because the wax was softened from the heat from the thermoformed material, either place the model in a refrigerator or use freeze spray before pressing the plastic (Figure 5).

Paint the cast with separator and vacuum or pressure form (Figure 6). Please note: I feel using positive pressure (pressing) is a much better technique compared to vacuum forming. Vacuum forming creates about 15 pounds of suction, whereas pressure forming creates between 45-85 pounds of positive pressure using either a MiniStar® (45 psi) or BioStar® (85 psi), both by Great Lakes Orthodontics. Other choices include the Drufomat (Dentspy) and Erkodent® (Glidewell Dental).

Rough trim the aligner using a separating disk and/or a diamond wheel, and remove the appliance from the cast (Figures 7-9).

Trim the flash using a Dedeco Acrylic Wheel or similar tool, smooth using sandpaper, and polish with a buff wheel (Figures 10-12). The completed appliance can be seen in Figure 13.




Conclusion

This article focuses on simple corrections that can be carried out with one appliance. In more complex cases, you might need incremental tooth movements and a series of clear aligners to complete correction. I feel that sectioning off the tooth or teeth and placing them in the ideal positions on the working cast is better than shaving down and blocking out the tooth or teeth on the cast. In the above situation, one might simply shave down the mesial facial of tooth No.8 on the model and block out the mesial lingual in hopes of correcting the rotation. I think you can achieve a much more intimate fit and better function by physically moving the model tooth or teeth into the ideal position as illustrated in this article.

These types of aligners are simple, and can be very profitable for any practice. They can be fabricated on “doctor’s day off” or on “no patient days,” and require only a small investment in equipment and supplies.

Let us answer your lab questions

In future columns, other lab owners and managers will share more simple ideas to increase your results and profits. If you have suggestions for topics that will address common misconceptions or mistakes, questions about specific techniques, or would like to share with our readers tips on how you improved communication with your lab or situations that have occurred in specific cases, please contact me at 800-289-0118. We hope you enjoy these lab topics and feel they add value to this publication.

Bio

Donal Inman, CDT, began his career in orthodontics in 1976. He became a CDT in 1985. Don is the President of Inman Orthodontic Laboratories, Inc., and also owns and operates Space Maintainers Laboratory of the South East. He developed the Inman Aligner™, the Inman Family of Appliances, and the Inman Power Component. Don was awarded the 2002 and 2004 Harry Hagman Inventor Award from the National Association of Dental Laboratories, and in 2003, he was presented with the Governor’s New Product Award in the small company division from the Florida Engineering Society. His goals are to move dental technology from a trade to a profession through education and attitude. He can be reached by email at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .