Aligners With Fewer Attachments: How Force Design Makes It Possible

Attachments are small bumps of tooth-coloured filling material bonded to the front of some teeth during clear aligner treatment. They give the aligner something to push against. Many patients can be treated with fewer of them when the tooth movements are planned around the forces the aligner can deliver on its own. At Smile Elements, the plan is designed to avoid attachments, and we add them only where a movement needs the extra grip.

This post explains what attachments do, what the research shows about their benefits and costs, and what to ask at your consultation.

Why aligners use attachments

An aligner is a thin plastic shell. It moves a tooth by pressing on its surface, and a smooth, rounded tooth gives the plastic little to grip. Attachments add an edge for the aligner to push on, especially for turning a tooth or moving its root.

The evidence on how much they help is mixed. A 2022 systematic review in Materials gathered five clinical studies on attachments (Nucera et al.):

• Turning teeth (rotation). Two of the three studies found no significant difference between teeth with and without attachments.
• Settling teeth deeper into the jaw (intrusion). In one trial, every attachment group did better than the group without them.
• Moving back molars (distalization). Accuracy was 88.4% with attachments and 86.9% without, a gap the authors judged clinically unimportant.
• Root control (torque). Up to 50% of the planned torque was commonly lost, and the authors concluded attachments alone may not give adequate root control.

The same review points to something that matters as much as the attachment: how the movement is planned. In one included study, aligners became less effective when a planned rotation exceeded 15 degrees, or when each aligner was asked to turn a tooth more than 1.5 degrees.

What attachments cost you

Attachments are small, but they come with trade-offs worth knowing before treatment starts.

• They show. Aligners are chosen to be discreet, and attachments are visible bumps on the front teeth for the length of treatment.
• They wear and come off. A 2024 clinical study followed 617 attachments in 47 patients for eight months. A typical attachment lost 13.7% of its volume, wear grew steadily with treatment time, and 105 attachments came off during the study (Li and Yang, Progress in Orthodontics). A worn or lost attachment grips less, and a lost one means an extra visit to replace it.
• Removing them touches the enamel. At the end of treatment each attachment is ground off with a bur. In a 2026 laboratory study, none of the 30 teeth tested came through removal with the enamel fully unmarked; the damage was mostly minor and depended on the material used (Nucci et al., APOS Trends in Orthodontics).
• They give plaque another place to sit. Attachments add edges that are harder to keep clean. Researchers at the University of British Columbia are developing attachment materials that resist plaque for this reason (Jiang et al., 2024).

None of this makes attachments wrong. They are a tool with a cost, so each one should earn its place.

Planning the force first

Your result depends on the plan more than on the plastic. The research above shows why: how far each aligner asks a tooth to move, and in what order, shapes the outcome as much as any bump on the tooth.

At Smile Elements, every step of aligner treatment stays with us: the 3D digital plan, the 3D printing and the finished aligners. All of it runs on one platform built on orthodontic biomechanics, the study of how forces move teeth. Dr. Hisham Badawi originated OSIM, a 3D orthodontic force simulator, and earned his PhD at the University of Alberta on that work.

In practice, planning the force first means:

1. Diagnosis before tools. We decide what each tooth needs to do before deciding how to grip it.
2. Steps the aligner can deliver. Each aligner is planned to ask for an amount of movement the plastic can produce without extra grip.
3. Order that helps. Teeth are moved in a sequence where those that have finished moving help steady the ones still moving.
4. Attachments only where earned. Where a movement still needs extra grip, such as some root movements or large rotations, we add an attachment and tell you why.
5. One team from plan to aligner. Because we design and make the aligners here in Calgary, the clinician who plans the movement also checks what is printed.
6. Visits. Many of our aligner patients are seen about every 3 months, which is handy for families who drive in from outside Calgary. Your exam sets your own schedule.

Planning support includes machine-learning clinical decision support, with the clinician in the loop as the sole author of every prescription.

Some cases still need attachments, and some are better treated with braces. The consultation decides which, based on your teeth, not on a product. How We Choose Your Treatment explains how that decision is made.

Questions to ask at any consultation

• How many attachments will I have, and on which teeth?
• What movement is each attachment for?
• Who designs my plan, and who makes my aligners?
• If an attachment comes off, what happens next?
• Would braces suit my case better?

A good answer to each of these tells you how the plan was made. If you would like to hear ours, book a consultation. Your first visit is 60 minutes at our NW Calgary office, where Dr. Badawi examines your teeth and bite and explains your options.

References

1. Nucera R, Dolci C, Bellocchio AM, et al. Effects of composite attachments on orthodontic clear aligners therapy: a systematic review. Materials. 2022;15(2):533.
2. Li Q, Yang K. Surface wear of attachments in patients during clear aligner therapy: a prospective clinical study. Progress in Orthodontics. 2024;25:7.
3. Nucci L, Agostinacchio V, Sassatelli F, et al. Impact of resin composite type on enamel surface damage during rotary instrument removal in aligner therapy: an in vitro study. APOS Trends in Orthodontics. 2026 (article in press).
4. Jiang W, Wang Z, Zhou Y, et al. Bioceramic micro-fillers reinforce antibiofilm and remineralization properties of clear aligner attachment materials. Frontiers in Bioengineering and Biotechnology. 2024;11.

Related: Clear aligners for adults