A lot of people start aligner treatment expecting nothing more than a stack of clear trays, then find their plan lists "attachments" and "IPR" and wonder whether something has gone wrong. It has not. These two steps are routine in aligner treatment, and they help a removable tray move teeth with more control than it would have on its own. Attachments give the tray something to push against, and IPR makes small amounts of room so teeth have space to move into.
A smooth tray can only push on a smooth tooth so far
Plastic sliding over enamel has limited grip. It can tip a tooth, but turning a rounded tooth such as a canine, lifting a tooth down into the bite, or moving a root as well as a crown are harder for a smooth tray to manage.
An attachment helps by giving the tray an edge to engage. It is a small, shaped bump of tooth-coloured composite resin, the same family of material used for white fillings, bonded to the outer surface of selected teeth. Each one is placed in a planned position and shape so that, when the tray snaps over it, the force goes in the intended direction. Some plans use only a few. Others use attachments on most teeth.
How attachments go on and come off
Placing them does not involve drilling or an injection. The tooth surface is cleaned and prepared, then a thin template tray filled with composite is seated over the teeth and the material is set with a curing light. When the template comes out, the bumps stay behind in exactly the planned spots.
They are shade matched to blend with your teeth. Up close they can be seen, particularly in photos with a flash, but they are much less noticeable than brackets. Plaque likes to collect around their edges, so they need a little extra care when brushing.
At the end of treatment the dentist polishes them away and smooths the enamel underneath. They are not permanent.
IPR takes a fraction of a millimetre from between teeth
Interproximal reduction means gently reshaping the sides of teeth where they touch their neighbours. The amount is small, usually measured in tenths of a millimetre per contact, and it is kept within the enamel layer.
Crowded teeth need somewhere to go. Spread across several contacts, those small amounts add up to enough room to straighten mild to moderate crowding, which in some cases avoids the need to remove a whole tooth. IPR is also used to even out teeth that are different widths, and to reshape contact points so gum tissue can fill the space better, which can reduce the small dark gaps known as black triangles.
The work is done with thin abrasive strips or fine discs, guided by the measurements in your plan. Afterwards the surfaces are polished and often a fluoride product is applied. Most people need no anaesthetic and describe it as a vibration or a scratchy feeling rather than pain.
Is removing enamel safe for the teeth?
This is the question we hear most. When IPR is kept within the planned amounts and the surfaces are polished, studies have not found a higher rate of decay or sensitivity in the treated areas. A long-term follow-up by Zachrisson and colleagues (American Journal of Orthodontics and Dentofacial Orthopedics, 2011) examined premolars and molars four to six years after IPR and did not find increased decay on the reduced surfaces.
Enamel removed by IPR does not grow back, which is why planning matters. It is done only where the plan calls for it, in measured steps, and it is checked as treatment goes on. The small gaps it creates close up as teeth move into them.
Why these steps let aligners take on more cases
Earlier generations of aligners were mostly suited to small tipping movements. Attachments, better plastics and digital planning have widened what trays can do, and IPR provides space without fixed appliances. Some bites still respond better to fixed braces, and that is something to weigh at your assessment. Our guides to ways to straighten crooked teeth and lingual braces set out the other options.
Healthy gums matter throughout any tooth movement. If your gums bleed when you brush, our article on bleeding gums explains what helps. And if you are thinking about cosmetic work later, straighter teeth often make it more conservative, a point covered in our smile makeover guide.
What patients ask about attachments and IPR
Can I have aligners without attachments?
Sometimes, if only small tipping movements are needed. For harder movements they are used to give the tray better control, although studies on how much they improve accuracy are mixed. Leaving them off where a plan calls for them can mean a less accurate result or more refinement trays.
Will attachments stain?
Composite can pick up surface staining from coffee, tea and red wine over months. Taking the trays out to drink and cleaning well keeps this to a minimum, and any staining is removed when they are polished off.
What if an attachment falls off?
Keep wearing your trays and contact the practice. A missing attachment can reduce how well that tooth tracks, so it is usually replaced at the next visit.
If you are weighing up aligners, a dentist at Lumi Dental can show you on your own scan where attachments and IPR would fit into your plan. Visit our current deals page or read about care at our Melrose Park practice.
This article is general information and not a substitute for personal orthodontic advice.
